Note: Descriptions are shown in the official language in which they were submitted.
1~7~0~4
PARTIAL OXIDATION PROCESS
This invention relates to the manufacture of gaseous
mixtures comprising H2 and CO, e.g., synthesis gas, fuel gas,
and reducing gas by the partial oxidation of pumpable slurries
of solid carbonaceous fuels in a liquid carrier and/or liquid
or gaseous hydrocarbon fuels. In one o~ ~ts more specific
aspects, the present invention pertains to switching from
one type of fuel to another without interruption of the
process.
In the operation of a partial oxidation synthesis gas
generator when the principal fuel becomes unavailable or
in short supply and it is desired to operate the gas
generator with a substitute or stand-by fuel, then previously
it was necessary to depressurize the system and shut down the
gas generator while the burner is changed and other adjust-
ments are made to the system to provide for the new fuel.
By the subject process, such costly down-time is avoided.
Annulus-type burners have been employed for introducing
liquid hydrocarbonaceous fuels into a partial oxidation gas
generator. For example, U.S. Patent 3,528,930 shows a single
annulus burner, and U.S. Patents 3,758,037 and 3,847,564 show
double annulus burners. To obtain proper mixing, atomization,
and stability of operation a burner is sized for a
specific throughput. Should the type of fuel feedstream or re~uired
out~ut of~roduct gas change ~bstantially, ord~rily shut-~.n of the
system is required to replace one ~urner with ar.other. ~uch costly shut-downs
are avoided by the subject process and control system. The
more complex process for preheating a gas generator by means
of a preheat burner, removing the preheat burner from the
gasifier, and inserting a separate production burner is
described in U.S. Patent No. 4,113,445.
A partial oxidation process and control system for
continuously producing synthesis gas, fuel gas or reducing
gas while changing from one type of fuel to another without
shutting down or depressurizing the gas generator is described.
This multifuel process is not tied to one particular fuel and
reacts slurries of solid carbonaceous fuel and/or liquid or
117~0~4
gaseous hydrocarbonaceous fuels. Problems of fuel availability are
reduced due to the wide selection of fuels that are suitable for
the subject process. By the subject process the total output from
the partial oxidation gas generator may be maintained substantially
constant while the feed is changed from one fuel to another.
According to one aspect of the present invention there
is provided a process for producing gaseous mixtures comprising
H2, CO, CO2, entrained particulate carbon, and at least one material
from the group consisting of H2O, N2, H2S, CoS, CH4, Ar, and ash
in a free-flow non-catalytic partial oxidation gas generator,
including employing a one or two-section burner having at least one
first fluid conduit or group of conduits to provide a first fluid
passage or passages, and at least one related radially spaced
second fluid conduit surrounding said first fluid conduit or group
of conduits to provide at least one annular second fluid passage
therebetween and having either a central or a central and annular
exit orifice at the tip of the burner, and changing from one
reactant feedstream to another without shutting down or depressuriz-
ing the system, the process comprising the combination of the
steps of:
(1) passing a first reactant stream of first solid
carbonaceous fuel slurry or hydrocarbonaceous fuel with or without
mixture with a temperature moderator through either at least one of
said first or second fluid passages;
(2) simultaneously passing a separate reactant stream of
free-oxygen containing gas with or without mixture with a
temperature moderating gas through the unused passage or passages
in said burner which are related to a passage through which said
L~ ~
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1172Q~4
first reactant stream in (1) is flowing;
(3) mixing together said reactant streams from (1) and (2)
to produce a well-distributed blend, and reacting said mixture by
partial oxidation in the reaction zone of said gas generator at an
autogenous temperature in the range of about 1700 to 3500F.,
a pressure in the range of about 1 to 300 atmospheres, an atomic
ratio of oxygen/carbon in the range of about 0.5 to 1.7, and a
weight ratio H20/fuel in the range of about 0 to 5.0;
(4) phasing out of the fluid passage or passages in which
it is flowing in said burner said stream of first solid
carbonaceous fuel slurry or hydrocarbonaceous fuel with or without
mixture with a temperature moderator, said phasing out being with
a uniformly decreasing rate of flow that varies from maximum to
0 over a period of time in the range of about 1-3600 seconds; and
simultaneously phasing said stream of second solid carbonaceous
fuel slurry or hydrocarbonaceous fuel with or without mixture with
temperature moderator into the same fluid passage in said burner
at a uniformly increasing rate of flow that varies from 0 to
maximum rate over the same period of time, and mixing the phased-in
20 stream with the remaining portion of said stream of first solid
carbonaceous fuel slurry or hydrocarbonaceous fuel with or without
mixture with a temperature moderator flowing therein; and
(5) adjusting the flow rate of the reactant stream of
free-oxygen containing gas with or without mixture with a
` temperature moderator passing through the burner and if necessary
introducing supplemental H2O into the reaction zone, so as to adjust
the free oxygen/carbon atomic ratio and the weight ratio H2O/fuel
in the reaction zone to design conditions for the partial
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:
~172{~
oxidation reaction.
Aceording to another aspect of the present invention
there is provided a system for controlling the introduction of a
plurality of reactant streams into the reaetion zone of a partial
oxidation gas generator comprising: a burner comprising at least
one first fluid conduit or group of conduits to provide a first
fluid passage or passages and a second fluid eonduit surrounding
each of said first fluid conduit or group of conduits to define a
second fluid passage therebetween; two separate burner inlet lines
eonneeted to each of said first fluid eonduit or conduits and to
each of said seeond fluid eonduit, respeetively; eonduit means
ineluding four feed lines for eonnecting four different material
feedstreams to said two burner inlet lines for introdueing said
feedstreams into the burner, one respective pair of said feed lines
being assoeiated with eaeh burner inlet lines, said burner
diseharging said feedstreams or mixtures thereof into said reaetion
zone; a separate flow rate sensing means and a separate flow rate
controller in each of said feed lines for independently sensing
the flow rate for each material flowing through a particular feed
line and providing a signal corresponding-to the actual flow
rate for that feedstream; and a control means for reeeiving said
signals from said flow rate sensing means and for comparing each
aetual flow rate signal with a manual or automatieally eomputed
and inserted input signal representing the desired flow rate or
set point at that moment for each feedstream and providing a
corresponding adjustment signal for separately operating the flow
rate controller in that particular feed line, and for independently
controlling the flow rate for each feedstream entering the
~,
3a-
117Z~4
burner at that moment such that one feedstream in each pair of
feedstreams is phased out with a uniformly decreasing rate of
flow that varies from maximum to 0 over a period of time in the
range of about -13600 seconds; and simultaneously a different
feedstream is phased into the same feed line with a uniformly
increasing rate of flow that varies from 0 to maximum rate over
the same period of time.
A particular embodiment of the above control system is
one wherein the first feedstream comprises steam, the second
feedstream comprises a liquid or gaseous hydrocarbonaceous fuel,
the third feedstream comprises a pumpable solid carbonaceous
fuel slurry, and the fourth feedstream comprises a free-oxygen
containing gas, and each flow rate controller for independently
controlling the rate of flow of the first, second, and fourth
feedstreams is a flow control valve, and the flow rate controller
for independently controlling the rate of flow of the third
feedstream is a speed controlled pump.
According to a further aspect of the present invention
there is provided a process for producing gaseous mixtures
comprising H2, CO, CO2, entrained particulate carbon, and at least
one material from the group consisting of H2O, N2, H2S, COS, CH4,
Ar, and ash in the free-flow non-catalytic partial oxidation gas
generator, wherein, for starting up and operating the gas generator
by employing a two-section burner having a central section and an
annular section with two separate fluid passage means in each
section, and changing from one reactant feedstream to another
without shutting down or depressuriæing the system, the process
comprises the steps of:
;~. -3b-
, . . .
-
117Z044
(1) passing a first reactant stream of gaseous or liquid
hydrocarbonaceous fuel with or without mixture with H2O through
either the first or second fluid passage means in the central
section of said burner, and/or simultaneously passing a second
reactant stream of gaseous or liquid hydrocarbonaceous fuel with
or without mixture with H2O through either the third or fourth
fluid passage means in the annular section of said burner;
(2) simultaneously passing a separate reactant stream of
air with or without mixture with H2O through the unoccupied fluid
passage means in each of the central and/or annular sections of
said burner which are associated with said fluid passage means
through which said stream(s) of first gaseous or liquid hydro-
carbonaceous fuel with or without mixture with H2O are passing;
(3) mixing together said reactant streams from (1) to (2)
to produce a well-distributed blend, and burning said mixtures
by substantially complete combustion in the reaction zone of said
gas generator at a temperature in the range of about 2000 to
4500F. and a pressure in the range of about 0.5 to 300 atmospheres;
(4) phasing out of the fluid passage means in which it is
flowing in said central and/or annular section(s) said stream(s)
of first gaseous or liquid hydrocarbonaceous fuel with or without
mixture with H2O, said phasing out being with a uniformly
decreasing rate of flow that varies from maximum to 0 over a
period of time in range of about 1-3600 seconds; simultaneously
phasing said stream(s) of principal solid carbonaceous fuel
slurry or hydrocarbonaceous fuel with or without mixtures with
H2O into the same fluid passage means at a uniformly increasing
rate of flow that varies from 0 to maximum rate over the same
-3c-
1~20~4
period of time and mixing with the remaining portion of and
replacing the phased out portion of said stream of first solid
carbonaceous fuel slurry or hydrocarbonaceous fuel with or
without mixture with H2O flowing therein; simultaneously phasing
out of the fluid passage means in which it is flowing in said
central and/or annular section(s) said stream(s) of air with or
without mixture with H2O, said phasing out being with a uniformly
decreasing rate of flow that varies from maximum to 0 over a
period of time in the range of about 1-3600 second; and simultane-
ously phasing a replacement stream(s) of free-oxygen containing gas
with or without mixture with H2O into the same fluid passage means
at a uniformly increasing rate of flow that varies from 0 to
maximum rate over the same period of time and mixing with the
remaining portion of and replacing the phased out portion of said
stream of air with or without mixture with H2O flowing therein; and
(5) adjusting the flow rate(s) of the reactant stream(s~ of
free-oxygen containing gas with or without mixture with H2O
passing through the burner, and if necessary introducing
supplemental H2O into the reaction zone so as to adjust the free
oxygen/carbon atomic ratio and the weight ratio H2O/fuel in the
reaction zone at design conditions for partial oxidation.
Manual or automatic control means are included for
switching and controlling the fuel, oxidant, and steam streams.
By this means, the principal and stand-by fuels may be switched
and the stream of free-oxygen containing gas and/or temperature
moderator may be controlled up or down - to maintain the
gasifier output while retaining efficiency and stability.
In order to illustrate the invention in greater detail,
` ~A` ' -3d-
117Z0~4
reference is made to several embodiments as shown in the figures
of the drawing wherein:
Fig. 1 is a schematic representation of one embodiment
of the invention showing control means for replacing one fuel
with another while maintaining continuous operation;
Figs. 2 and 3 are vertical longitudinal schematic
representations of two preferred burners for use in the subject
process;
'.' ~ '
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~17Z04~
-- 4
Fig. ~ i5 a schematic represe~tation of another
embodiment of the invention; and
Fig. 5 is a vertical, longitudinal schematie representation
of a two seetion burner suitable for the subjeet proeess.
The present invention pertains to a continuous
process for the manufacture of gas mixtures comprising H2,
CO, C~2, particulate carbon and at least one material
selected from the group consisting of H2O, N2, Ar CH4, H2S,
CoS, and ash such as synthesis gas, fuel aas, cnd reducina
gas, by the partial oxidation of one reactant strezm of ~uel
which is then replaced by a different reactant stream of
fuel without shutting do~7n or depressurizing the C2S g2nerator.
Further, there may be subs.antially no change in the amount
of sas produced. This multifuel process is not restricted to
one particul2r fuel. Problems of fuel availability are
reduced. The two reactant fuel streams may be selected from
the group consisting of a pumpable slurry of solid carbonaceous
fuel in a liquid carrier, liquid or gaseous hydrocarbonaceous
fuel, and muxtures thereof with or without admixture with a
temperature moderator. The fuels are reacted by partial
oxi~ation with a reactant stream of free-oxygen containing
gas with or without admixture with a temperature moâerator.
~he product gas mixture is produced in the reaction zone of
a noncatalytic, refractory-lined, free-flo~ partial oxidation
aas generator, such as described in coassigned U. S. Patent
No. 2,809,104 issued to Dale M. Strasser et al at a temperature
in the range of about 1700 to 3500F. and a pressure in the
range of about 1 to 300 atmospheres, such as about 5 to 250
atmospheres, say about 10 to 100 atmospheres.
During operation of the partial oxidation gas
seneratorf it may be necessary to change from one fuel
" 1~7~)44
-- 5 --
to another without replacing t~e burner and without
sacrificing stable operation and efficiency. Changing
the burner re~uires a costly shut-down period with
resultant delay. Further, the burner should operate with
a variety of liquid, solid, and gaseous fuels, and mixtures
I thereof. Combustion in~tability and poor efficiency can be
¦ encountered when certain prior art burners are used for the
gasification of liquid phase slurries of solid carbonaceous
fuels. Further, feedstreams may be poorly mixed and solid
fuel particles may pass through the gasifier without
contacting significant amounts of oxygen. Unreacted oxygen
in the reaction zone may then react with the product gas.
A novel burner that may be employed in the
sub~ect process is shown in Fig. 2 of the drawing and
comprises: a retracted central conduit means coaxial with
the central longitudinal axis of the burner and having an
upstream inlet through which a first feedstream may be
separately introduced and a downstream discharge outlet
means; an outer coaxial conduit concentric with said
central conduit and having an upstream inlet through
which a second feedstream may be separately introduced,
J and a converging at least partially frusto-conical shaped
~ exit noz71e terminating said outer conduit at the downstream
j tip of the burner; wherein said central conduit downstream
discharge outlet means is retracted upstream from the
downstream face of the burner a distance of two or more
times say 3 to 10 times the minimum diameter of said
outer conduit downstream exit nozzle to provide a pre-mix
¦ zone; and means for radially spacing said central and ou~er
30 condultE from eEch other ~o provlde a coaxial annular
li7Z~44
-- 6 --
passage through which said second feedstream may separately
pass concurrently with said first feedstream into said pre-
mix zone where a multiphase mixture is produced prior to
being discharged through said outer conduit exit nozzle.
Another novel burner that may be employed in the
subject process is shown in Fig. 3 of the drawing and com-
prises: a central conduit coaxial with the central longi-
tudinal axis of the burner and having an upstream inlet
through which a first feedstream may be introduced and a
circular downstream discharge outlet, and said central
conduit discharge outlet is retracted upstream from the
downstream face of the burner a distance of 3 to 10 times
the minimum diameter of an outer conduit downstream exit
nozzle to be further described so as to provide a pre-mix
zone comprising 2 to 5 cylindrically shaped pre-mix cham-
bers in series and coaxial with the central longitudinal
axis of said burner; an intermediate coaxial conduit con-
centric with said central conduit and having an upstream
inlet through which a second feedstream may be introduced,
and a converging at least partially frusto-conical shaped
downstream exit nozzle terminating said intermediate con-
duit, and the tip of said intermediate exit nozzle is re-
tracted upstream from the downstream face of the burner a
distance of 1 to 5 times the minimum diameter of said
outer conduit downstream exit nozzle; an outer coaxial
conduit concentric with said central and intermediate
conduits and having an upstream inlet through which a
third feedstream may be introduced, and a converging down-
stream exit nozzle terminating said outer conduit and com-
prising a frusto-conical shaped rear portion and a right
cylindrical shaped front portion at the downstream
~., ~ ,
~1~2044
~ 7
tip of the burner; and means for radially spacing said
central, intermediate, and outer conduits with respect
to each other to provide intermediate and outer coaxial
annular passages, and said intermediate annular passage is
situated between the outside diameter of the central conduit
and the inside diameter of the intermediate conduit and is
the passage through which said second feedstream may
separately pass concurrently with said first feèdstream
into a pre-mix zone where a multiphase mixture of said
first and second feedstreams is produced, and said outer
annular passage is situated between the outside diameter
of said intermediate conduit and the inside diameter of
said outer conduit and is the passage through which said
third feedstream may separately pass concurrently with said
first and second feedstreams and then mix with said
multiphase mixture of said first and second feedstreams
upstream from the downstream face of the burner. Optionally,
the walls of said intermediate conduit may contain a
plurality of small diameter holes or passages in a
plurality of circumferential rings along its length to
permit at least a portlon of said third feedstream flowing
in said outer annular conduit to pass through and mix
with one or more of the other materials simultaneously
flowing at a lower pressure through the other passages or
pre-mix zone of the burner. Optionally, blocking means may
be provided at the downstream outlet of said outer annular
passage for completely or partially closing the downstream
outlet of said outer annular p2ssage. The blocking means
may comprise an annular plate disposed perpendicular to
the central longitudinal axis of the burner with or
I
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117~044
without a plurality of small diameter holes. Said third
~eedstream may be a temperature moderator selected from
the group consisting of H20, C02, N2 and mixtures thereof.
Alternatively, a recycle portion of cooled and cleaned
product gas or a stream of free-oxygen containing gas may
comprise the third feedstream.
Thus, in this embodiment of the burner, as shown
in Fig. 3, a plurality of high pressure high velocity ~et
streams of said third feedstream may be passed through the
walls of the intermediate conduit and into the annular
passage and pre-mix chambers at various locations along
their length. By this means atomizing of the fuel feedstream
and, optionally, mixing it with the oxidant stream may be
facilitated. For example, the third feedstream may be
passed through a plurallty of small diameter passages or
holes i.e. about .032 to 0.50 diameter that lead into
said annular passage and pre-mix chambers.
- In other embodiments an annular-type burner such
as shown and described in coassigned U. S. Patent 3,874,592
was employed. Further, the central and/or annular conduit
means may lnclude a plurality of parallel or helical tubes.
Alignment pins, fins, centering vanes, spacers
and other conventional means are used to symmetrically
space the burner conduits with respect to each other and
to hold same in stable alignment without obstructing the
free-flow of the feedstreams in the central conduit means
and annular passage means.
The outer and/or intermediate conduit exit nozzle
may comprise a frusto-conical rear portion having a
converging angle in the range of about 15 to 90 from tne
` " l~Z~ 4
g
central longitudinal axis of the burner. The rear portion
may develop into a normal cylindrical front portion which
terminates at the downstream face of the burner. The
cylindrical front portion may have a height in the range of
about 0 to 1.5 times its own diameter. In one embodiment,
the outer conduit exit orifice is in the shape of or is
generated by an American Society of Mechanical Engineer'~
standard long-radius nozzle. A further description of said
nozzle may be found in "Thermodynamics Fluid Flow and Heat
Transmission" by Huber 0. Croft, page 155, First Edition,
1938 McGraw-Hill Book Company.
The burner may be cooled on the outside by means
of cooling coils that encircle the outside barrel of the
burner along its length. The downstream end of the burner
may be provided with a cored face plate through which a
coolant is circulated. For example, an annular cool~ng
chamber may encircle the outer conduit downstream exit
nozzle. The cooling chamber and the outer conduit exit
nozzle may constitute a single piece of thermal and wear
resistant material such as tungsten carbide or silicon
carbide. Any suitable coolant may be employed e.g. water.
Preferably, the downstream end of the central conduit means
may be retracted upstream from the entrance to the first
pre-mix chamber in the line. For example, the set back of
the end of the central conduit means from the entrance to
the first pre-mix chamber may be in the range of about
0.1-2.0 times the diameter of the first pre-mix chamber.
In one embodiment, each of the pre-mix chambers
in the central conduit except the first are cylindrical
11721g4~ .
shaped and comprises a coaxial cylindrical body portion
followed by a coaxial at least partially converging outlet
portion. The first cylindrical-shaped pre-mix chamber in
the central conduit comprises a normal coaxial cylindrical
body portion that discharges directly into the next in line
coaxial cylindrical shaped pre-mix chamber. The converging
outlet portions of said pre-mix chambers may be made from
tungsten carbide or silicon carbide for increased wear
resistance.
The size relationship between successive pre-mix
~ chambers in the sub~ect burners may be expressed in the
f following manner: For burners in which the pre-mix chambers
! in the central conduit means are successively numbered 1 to
5 , then the ratio of the diameter of any one of said
central chambers to the diameter of the next central
chamber in the line i-e- Dl:D2; D2 D3; D3:D4; or D4 D5 y
be in the range of about 0.2-1.2. The ratio of the length
of any one central pre-mix chamber in said central conduit
means to the length of the next central pre-mix chamber in
20 the line i-e- Ll L2; L2 L3; L3:L4, or L4:L5 may be in the
range of about 0.1-1Ø
In the operation of the embodiment of the burner
employing pre-mix chambers flow control means may be used
to control the flow of the feedstreams to the passages
in the burner in the same manner as described previously.
The feedstreams entering the burner and simultaneously ~nd
concurrently passin~ through at different velocities
impinge and mix with each other in the first pre-mix
chambers. The impingement of one reactant stream, such
¦ 30 as the 11quld slurry o~ s~lld carbonaceous ~uel 1~ a
117~1044
liquid medium optionally in admixture with a temperature
moderator, with another reactant stream, such as a gaseous
stream of free-oxygen containing gas optionally in admixture
with a temperature moderator at a higher velocity, causes
the liquid slurry to break up into a fine spray. The
multiphase mixture produced then successively passes through
any remaining pre-mix chambers where additional mixing takes
place. As the mixture passes freely through the sub~ect
unobstructed burner its velocity changes many times. For
example, at various points in the burner the velocity of
the mixture may range from about 20 to 600 ft. per sec.
As the mixture flows from one pre-mix chamber to the next,
the velocity changes are mainly the result of changes in the
diameter of the flow path and the temperature of the
mixture. This promotes a thorough mixing of the components.
By operating in the region of turbulent flow, mixing may be
maximized. Further, direct heat exchange between the
materials takes place within the burner. From 0-100 vol. ~,
say about 5-25 vol. % of the liquids in the feedstreams
may be vaporized before the feedstreams leave the burner.
By means of converging exit orifices, the feedstreams may
be accelerated directly into the reaction zone of the
partial oxidation gasifier.
Burning of the combustible materials while passing
through the pre-mix zone of the burner may be prevented by
discharging the multiphase mixtures at the outer conduit
exit nozzle at the tip of the burner with a discharge
velocity which is greater than the flame propagation
velocity. Flame speeds are a function of such factors as
; 30 composition of the mixture, temperature and pressure. They
may bs calculated by con/ent~onal methods or detsrD~ned
-
~1172044
experimentally. Advantageously, by means of the sub~ect
burner, the exothermic partial oxidation reactions take place
, a sufficient distance downstream from the burner face so
¦ as to protect the burner from thermal damage.
Depending on such factors as the temperature,
velocity, dwell time and composition of the feedstreams;
the desired amount of vaporization of liquid carrier, the
temperature and amount of recycle gases in the generator
and the desired life of the burner, cooling coils may or
may not encircle the outside barrel of the burner along its
length. For similar reasons, the burner may or may not be
provided with an annular shaped cooling chamber at the
downstream end.
Liquid hydrocarbon fuels and/or pumpable slurries
of solid carbonaceous fuels having a dry solids content in
the range of about 30 to 75 wt. %, say about 40 to 70 wt. %
may be passed through the inlet passages of the sub~ect
burner. For example, the fuel streams with or without
mixture with the temperature moderator i.e. H20 may be
passed through the central conduit means or through the
annular passage means. The inlet temperature of the liquid
hydrocarbon fuel or the slurry is in the range of about
ambient to 500F., but preferably below the vaporization
temperature of the liquid hydrocarbon at the given inlet
pressure in the range of about 1 to 300 atmospheres, such
as 5 to 250 atmospheres, say about 10 to 100 atmospheres.
Simultaneously the free-oxygen containing gas with or without
mixture with the temperature moderator is passed through
the corresponding unoccupied passage in the burner.
Thus, if the principal or first fuel flowing
through a central conduit means of the burner or through
~72044
the coaxial annular passage means of the burner becomes
unavailable and it is desired to switch to a stand-by
or second ~uel, or for any reason whatsoever lt is desired
to switch from a first solid carbonaceous ~uel slurry or
hydrocarbonaceous fuel to a second solid carbonaceous fuel
slurry or hydrocarbonaceous fuel without shutting down or
depressurizing the system, one may proceed as follows:
(1) separately sensing the flow rates of four
feedstreams 1-4 respectively consisting of steam, stand-by
fuel, principal fuel, and free-oxygen containing gas, and
providing signals s, m, a, and b corresponding respectively
to the actual flow rates of feedstreams 1-4 to a control unit,
(2) comparing said actual flow rate signals s, m,
a, and b respectively with manual or automatically computed
and inserted input signals representing the desired flow
rate or set point for that moment for each of the four
feedstreams, and providing a corresponding ad~ustment signal
to a flow rate control means for controlling the flow rate
of each feedstream 1-4 in accordance with the respective
set point of each;
(3) passing a feedstream of said principal fuel into
the reaction zone of a free-flow noncatalytic partial
oxidation gas generator~ by way of a burner comprising a
central conduit means radially spaced from a concentric
coaxial outer conduit means having a downstream exit nozzle
and providing a coaxial annular passage means therebetween
and wherein said feedstream of principal fuel is passed
through either the central conduit means of the burner or
through the coaxial annular passage means;
(4) simultaneously passing _ separate feedstream
of free-oxygen containing gas with or without mixture with
`13-
~1720~4
, 14 -
a separate feedstream of steam through the unoccupied fluiQ
passage means in said burner;
(5~ mixing together said reactant streams from (31
and (41 to produce a well-distributed blend, and reactlng
said mixtures by partial oxidation in the reaction zone of
said gas generator at an autogenous temperature in the
range Or about 1700 to 3500F., a pressure in the range
of about l to 300 atmospheres, an atomic ratio of oxygen/
carbon in the range of about 0.5 to 1.7, and a weight ratio
H20/fuel in the range of about 0 to 5.0, such as about 0.1
to 3.0;
(6) replacing in said central conduit means or
annular passage means said feedstream of principal fuel
with a replacement feedstream of stand-by fuel by phasing
out of the fluid passage means in which it is flowing said
stream of principal fuel comprising first solid carbonaceous
fuel slurry or hydrocarbonaceous fuel, said phasing out
being with a uniformly decreasing rate of flow that varies
from maximum to 0 over a period of time ln the range of
about 1-3600 seconds, and simultaneously phasing sald
stream of stand-by fuel comprising second solid carbonaceous
fuel slurry or hydrocarbonaceous fuel into the same fluid
passage,means at a uniformly increasing rate of flow that
varies from 0 to maximum rate over the same period of time
and mixing with the remaining portion of and replacing the
phased out portion of said stream of first solid carbonaceous
fuel slurry or hydrocarbonaceous fuel; and simultaneously
with or after the completion of said replacement of
feedstreams; and simultaneously with or following C6~;
~1~2044
(7) ad~usting the flow rate of the feedstream of
free-oxygen containing gas passing through the burner, and
necessary introducing supplemental H20 into the reaction
zone so as to ad~ust the free oxygen/carbon atomic ratio
and the weight ratio H20/fuel in the reaction zone at design
conditions-~artial oxida~ion reaction.
By means of the sub;ect process the temperature
in the reaction zone may be maintained substantially
constant i.e. a variation of less than - 100F., and the
weight ratio H20/fuel may be maintained in the range of
about 0.1 to 3Ø
In the sub~ect flow control means a manual or
automatically controlled flow recorder-controller with
transmitter is employed to provide signals to a flow rate
controller located in each feed line. For slurry fuel
feed lines, a signal from the flow recorder-controller is
provided to a speed control for a positive displacement
pump. For liquld or gaseous hydrocarbon fuel feed lines
and for oxidant feed lines, the signal from the flow
recorder-controller is provided to a flow control valve.
Responsive to said signal(s), the speed of said pump(s)
is varied, or alternatively the opening in said flow control
valve(s) is changed. By this means, the flow rate for each
stream of fuel passing through the burner may be ad~usted
up or down depending on whether lt is being phased in or
out.
The velocit~ of the reactant stream through the
central conduit means or annular passage means is in the
range of about 0.5-100, such as 10-50 feet per second,
say 2-20 ft. per sec. at the face of the burner when S2id
11;7Z044
reactant stream ~s a liquid hydrocarbon fuel or liquid
slurry of solid carbonaceous fuel, or m~xtures thereof, and
in the range of about 85 feet per second to sonic velocity,
say 100-600 feet per second when said reactant stream is a
gaseous hydrocarbon fuel or a free-oxygen containing gas
with or without admixture with a temperature moderator or
a temperature moderating gas. The velocity of a stream of
reactant fuel or a stream of a mixture of reactant fuels
exceeds the flame propagation velocity for that fuel or
fuel mixture.
The term solid carbonaceous fuels, as used herein
to describe suitable solid carbonaceous feedstocks, is
intended to include various materials and mixtures thereof
from the group consisting of coal, coke from coal, char
from coal, coal liauefaction residues, petroleum coke,
particulate carbon soot, and solids derived from oil sha]e,
tar sands, and pitch. All types of coal may be used
including anthracite~ bituminous, sub-bituminous, and lignite.
The particulate carbon may be that which is obtained as a
by-product of the sub~ect partial oxidation process, or
that which is obtained by burning fossil fuels. The term
solid carbonaceous fuel also includes by definition bits of
garbage, dewatered sanitary sewage sludge, and semi-solid
organic materials such as asphalt, rubber and rubber-like
materials including rubber automobile tires which may be
ground or pulverized to the proper particle size. Any
suitable grinding system may be used to convert the solid
carbonaceous fuels or mixtures thereof to the proper size.
The solid carbonaceous fuels are preferably
ground to a particle size so that 100% of the materi21
passes through an ASTM E 11-70 Sieve 3esignation Stand2rd
117Z~44
- 17 -
1.4 mm (Alternative No. 14) and at least 80% passes through
an ASTM E 11-70 Sieve Designation Standard 425 ~ m (Alternative
No. 40)-
The moisture content of the solid carbonaceousfuel particles is in the range of about 0 to 40 wt. %, such
as 2 to 20 wt. %.
The term liquid carrier, as used herein as the
suspending medium to produce pumpable slurries of solid
carbonaceous fuels is intended to include various materials
from the group consisting of water, liquid hydrocarbonaceous
material, and mixtures thereof. However, water is the
preferred carrier for the particles of solid carbonaceous
fuel. In one embodiment, the liquid carrier is liquid
carbon dioxide. In such case, the liquid slurry may
comprise 40-70 wt. % of solid carbonaceous fuel and the
remainder is liquid C02. ~he C02-solid fuel slurry may be
introduced into the burner at a temperature in the range of
about -67F to 100F depending on the pressure.
The term liquid hydrocarbonaceous material as used
herein to describe suitable liquid carriers and fuels is
intended to include various liquid hydrocarbon materials,
such as those selected from the group consisting of
liquefied petroleum gas, petroleum distillates and residues,
gasoline, naphtha, kerosine, crude petroleum, asphalt, gas
oil, residual oil, tar sand oil and shale oil, coal derived
oil, aromatic hydrocarbons (such 2S benzene, toluene,
xylene fractions), coal tar, cycle gas oil from fluid-
catalytic-cracking operation, furfural extract of coker ~as
oil and mixtures thereof.
117~044
The term liquid hydrocarbonaceous material as
used herein to describe suitable liquid fuels is also
intended to include various oxygen containing liquid
hydrocarbonaceous organic ma~erials, such as those selected
from the group consisting of carbohydrates, cellulosic
materials, aldehydes, organic acids, alcohols, ketones,
oxygenated fuel oil, waste liquids and by-products from
chemical processes for producing oxygenated hydrocarbonaceous
organic materials, and mixtures thereof.
For example in one embodiment, the feedstream
comprises a slurry of liquid hydrocarbonaceous material
and solid carbonaceous fuel. H20 in liquid phase may be
mixed with the liquid hydrocarbonaceous carrier, for example
as an emulsion. A portion of the H20 i.e., about 0 to 25
weight % of the tota~ amount of H20 present may be
introduced as steam in admixture with the free-oxygen
containing gas. The weight ratio of H20/fuel may be in
the range of about 0 to 5~ say about 0.1 to 3.
The term gaseous hydrocarbonaceous material as
used herein to describe suitable gaseous hydrocarbonaceous
fuels is intended to include ~ gaseous feedstock from the
group consisting of ethane, propane, butane, pentane,
methane, natural gas, coke-oven gas, refinery gas,
acetylene tail gas, ethylene off-gas, and mixtures thereof.
Simultaneously with the fuel stream(s), a
free-oxygen containing gas stream is supplied by way of a
free passage(s) in the burner. The free-oxygen containing
gas may be passed through the central and/or annular condults
at a temperature in the range of about ambient to 1500F.,
1172V4~
-- 19 --
and preferably in the range of ~bout ambient to 300~F.,
for oxygen-enriched air, anà about 500 to 1200F., for air,
and a pressure in the range of above about 1 to 300
atmospheres, such as 5 to 250 atmospheres, say 10 to 100
atmospheres. The atoms of free-oxygen plus atoms of
organically comb~ned oxygen in the solid carbonaceous fuel
per atom of carbon in the solid carbonaceous fuel (0/C atomic
ratio) may be in the range of 0.5 to 1.95. With free-oxygen
containing gas in the reaction 30ne the broad range of
said 0/C atomic ratio may be about 0.5 to 1.7, such as about
0.7 to 1.4. More specifically, with air feed to the
reaction zone, said 0/C atomic ratio may be about 0.7 to
1.6, such as about 0.9 to 1.4.
The term free-oxygen containing gas, as used
herein is intended to include air, oxygen-enriched air,
i.e., greater than 21 mole % oxygen, and substantially pure
oxygen, i.e., greater than 95 mole ~ oxygen, (the remainder
comprising N2 and rare gases).
The free-oxygen containing gas may be supplied
with or without mixture with a temperature moderating gas.
The term temperature moderator or temperature moderating
` gas as employed herein is intended to include by definition
a member of the group consisting of ~2~ C02, N2, a recycle
portion of the cooled and cleaned effluent gas stream from
the gas generator, and mixtures thereof. When supplemental
steam is employed as a temperature moderator, all of the
steam may be passed through one passageway. Alternatively,
about 0 to 25 volume percent of the steam may be mixed
with the stream of free-oxygen containing gas and passed
through one passageway, and the remainder of the steam may
be passed ~hrough the remaining passageway.
117Z044
- 20 -
The subject single and multi-annulus pre-mix
burners may be operated with the feedstreams passing through
alternate passages in the burner. Typical modes of
operation are summarized in Tables I to III below.
Table I lists the materials being introduced into
the gasifier by way of the burner and their corresponding
symbol. The solid carbonaceous fuel (B), water (C)~ and
liquid hydrocarbonaceous material (E) may be mixed together
in various combinations upstream from the burner inlet to
produce a pumpable slurry which may be introduced into the
burner and then passed through one of the several free-flow
passages of the burner as shown in Table II for the single
annulus pre-mix burner (see Figures 1 and 2); and as shown
in Table III for the double annulus pre-mix burner (see
Figure 3). For example, the first entry in Table II shows
that a pumpable slurry stream comprlsing solid carbonaceous
fuel tB) in admixture with water (C) may be passed through
the retracted central conduit 15 of a single annulus pre-mix
burner i.e. Fig. 1 and 2 while simultaneously a stream of
free-oxygen containing gas may be passed through annular
passage 17.
Other modes of operation of the sub~ect invention
are possible in additlon to those shown in Tables II and
III.
With respect to the operation of a double annulus
embodiment of the burner shown in Fig. 3, the second entry
of Table III shows that free-oxygen containing gas (A)
may be passed through both annular passages. In such case,
any member of the ~ollowing group may be simultaneously
passed through one or ~oth anrular passaees 17 and 51:
.
17Z044
- 21 -
air, oxygen-enriched air, and substantially pure oxygen.
Also, as shown in the seventh entry in Table III, free-oxygen
containing gas (A) in admixture with steam (D) (say up to
25 vol. % of t~,e total amount o~ H20) may be passed through
the central conduit 15 and the remainder of the H20 as
water (C) may be passed through the intermediate annulus 17
as part of the liquid carrier for the slurry.
When the liquid carrier for the slurry of solid
carbonaceous fuel is a liquid hydrocarbonaceous material
premature combustion within the burner may be avoided by
one or more of the following:
(1) keeping the fuel below its autoignition temperature,
(2) ~ncluding water in the solid fuel slurry,
(3) using air or air enriched with oxygen i.e. up to about
40 vol. % 2'
(4) mixing steam with the air,
(5) employing a double annulus pre-mix burner (Fig. 3) in
which the tip of the intermediate exit nozzle has about
0 retraction from the face of the burner. In such
case, the ~ree-oxygen containing gas such as substan-
tially pure oxygen may be separately passed through the
outer annular passage of the burner and into the
reaction zone of the gas generator where it reacts by
partial oxidation with the multiphase mixture dis-
charged from the pre-mix zone of the burner, and
(6) discharging the multiphase mixture at the exit orifice
at the tip of the burner with a disch2rge velocity
which is greater than the fl2me propagation velocity.
117Z044
- 22 -
TABLE I
Material Sym~ol
Free-Oxygen Containing Gas A
Solid Carbonaceous Fuel B
Water C
Steam D
Liquid Hydrocarbonaceous Material E
Temperature Moderating Gas F
. - 10 TABLE II
SINGLE ANNULUS PRE-MIX BURNER (See Figures 1 and 2)
Central Conduit Means 15 Annular Passa~e Means 17
B + C A
B + C + E A
B + C A + D
A ! B + C
A B + C + E
A + D B + E
TABLE III
DOUBLE ANNULUS PRE-MIX BURNER (See Fi~ure 3)
Intermediate Outer
Central Conduit 15 Annulus 17 Annulus 51
A B + C A
B + C A A
B + C A F
A B + C + E A
A B + C + E A + D
D B + C + E A
30 A + D B + C + E A
B + C + E A A
B + C + E D A
B + C + E A D
A B + E A + D
A + D B + E A
A + D B + E A + D
D B + E A
A B + E D
B + E A + D A + D
. 40 B + E A A + D
: B + E D A
B + E A D
A B ~ E F
~ F B + C A
: ~ A B ~ C F
E B + C A
El + C E A
~,
., ~ .
- 23 -
~ he subject burner assembly is inserted downwardthrough a top inlet port of a compact unpacked free-flow
noncatalytic refractory lined synthesis gas generator, for
example as shown in Figure l. The burner extends along the
central longitudinal axis of the gas generator with the
downstream end discharging a multiphase mixture of fuel,
free-oxygen containing gas, and temperature moderator
directly into the reaction zone.
The relative proportions of solid or solid and
liquid fuel, water and oxygen in the feedstream to the gas
generator are carefully regulated to convert a substantial
portion of the carbon in the fuel e.g., up to about 906 or
more by weight, to carbon oxides; and to maintain an auto-
genous reaction zone temperature in the range of about 1700
to 3500F., preferably in the range of 2000 to 2800F.
The dwell time in the reaction zone is in the
range of about l to 10 seconds, and preferably in the range
of about 2 to 8. With substantially pure oxygen feed to the
gas generator, the composition of the effluent gas from the
gas generator in mole % dry basis may be as follows: H~ 10
to 60, CO 20 to 60, CO2 5 to 40, C~4 0.01 to 5, H2S+COS 0 to
5, N2 nil to S, and Ar nil to l.S. With air feed to the gas
generator, the composition of the generator effluent gas in
mole % dry basis may be about as follows: H2 2 to 20, CO 5
to 35, CO2 S to 25, CH4 0 to 2, H2s+cos 0 to 3, N2 45 to 80~
and Ar 0-5 to l.S. Unconverted carbon and ash are contained
in the effluent gas stream.
117~40~4
The hot gaseous effluent stream from the reaction
zone of the synthesis gas generator is quickly cooled below
the reaction temperature to a temperature in the range of
about 250 to 700F. by direct ~uenching in water, or by
indirect heat exchange for example ~ith water to produce
steam in a gas cooler.~ The gas stream may be cleaned and
purified by conventional methods.
A more complete understanding of the invention may
be had by reference to the accompanying schematic drawing
which shows the sub~ect invention in detail. Although the
drawing illustra~es preferred embodiments of the invention,
it is not intended to limit the subject invention to the
particular apparatus or materials described.
Referring to the figures in the drawing, FIG. 1
is a schematiG representation of one embodiment of the
invention showing control means for the continuous operation
of a synthesis gas generator while phasing out one fuel and
simultaneously phasing in another without depressurizing
the gas generator. Further, the control means may be used
for rapidly changing throughput levels - up or down over
the flow range for which the bu~ner shown is designed.
By this means ad~ustments may be made to control the amount
of raw effluent gas produced, and to provide for a change
in demand for the product gas. Further, another use for
the control system is to maintain the desired composition
of the product gas when po~sible to do so by ad~ustments
to the flow rates of one or more of the reactant streams.
Thus, by the sub~ect flow control system, the flow r~tes
for all of the reactant streams are separately and
-" 117Z044
- - 25 -
independently controlled so that the temperature and weight
ratio of H20 to fuel in the reaction zone are maintained at
design conditions and within desired operating ranges for
the fuel being reacted. If necessary the atomic ratio of
free-oxygen to carbon in the fuel in the reaction zone may
also be co7trolled within design conditions.
While the control system shown in Figure l is
specifically designed for the combination of feedstocks
comprlsing a solid carbonaceous fuel slurry and a liquid
hydrocarbonaceous fuel, by simple modifications to the
means for changing the flow rate of the fuel stream as
described below, the system may be used to control other
combinations of solid carbonaceous fuel slurries, and
liquid, or gaseous hydrocarbonaceous fuels.
In Figure l, burner l is mounted in central
flanged inlet 30 which is located in the upper head of
conventional refractory lined free-flow synthesis gas
generator 41 along the central longitudinal axis. The
reactant streams enter through the upstream end of burner l,
pass downward therethrough, and are discharged through
downstream end 42. Burner 1 is designed so that the
required system output for steady-state operation may be
achieved or even exceeded by a specified amount when the
flow rate through all passages is a maximum. The control
system can independently change the flow rate of any one
or more of the feedstreams in lines 181, 161, 43 and 63.
By this means the temperature in the reaction zone 31 is
1~7209~4
- 26 -
mainta~ed at the desired operating temperature. Further,
the W2~ ght ratio H~O to ~uel, and if necessary the atomic
ratio of free-oxygen to carbon in the fuel in the reaction
zone may be maintained at design conditions.
Operation o~ the process and control system
shown in Figure 1 follows. For purpsses of illustration,
the principal fuel may be for example a solid carbonaceous
fuel slurry i.e. coal-water or coal-oil slurry in line 43.
The stand-by fuel is a liquid hydrocarbonaceous fuel
i.e. residual oil in line 161. Of course, the principal
fuel may have been chosen to be any liquid or gaseous
hydrocarbonaceous fuel.
In the sub;ect process, the remaining portions of
the princlpal fuel stream being phased out of line 50
is mixed in line 14 with the stand-by fuel stream belng
phased into line 167. H2O may be in admixture with the
fuels in lines 161 and 43 or the free-oxygen containing gas
in line 63. Alternatlvely, as shown in Flg. 1, at least
a portion i.e. 10-100 vol. % of the H2O may be provided
as the temperature moderator, for example steam. Thus,
as shown in Fig. 1, steam in line 187 preferably may be
mixed in line 18 with the free-oxygen containing gas flowing
in line 70. By this scheme, controlled amounts of steam
may be introduced into and mixed with the stream of
free-oxygen containing gas and/or fuel upstream from the
burner.
Valves 183, 163, 77, and 65 may be manually or
1172044
- 27 -
automatlcally operated to obtain a wide open position to
a completely closed position. The rates that each valve
may be opened and closed is also controllable. The slurry
feedstream in line 43 is pumped into the reaction zone 31 of
synthesis gas generator 41 by way of positive displacement
pump 45 equipped with speed control 46, line 47, flow
measurer and transmitter 48, line 49, valve 77, lines 50
and 14, and inlet 8 of burner 1. The slurry flow rate
through line 43 is controlled by the speed of positive
displacement pump 45. In order to phase out the slurry
flowing through line 43, this speed is continuously decreased
from maximum to zero over a period in the range of about 1
to 3600 seconds, such as about 60 to 1800 seconds, say
about 300 to 1000 seconds. Flow recorder-controller with
transmitter 51 includes a microcomputer means which is
programmed with the desired time vs. decreasing flow rate
curve. The rate of slurry flow in line 47 is measured and
a signal a is provided by flow transmitter 48 corresponding
to the flow rate of the slurry in line 43. Flow recorder-
controller 51 receives signal a, compares it with a signalrepresenting the desired flow rate for that moment, and
provides a corresponding ad~ustment signal to speed control
46 to adjust the speed of pump 45 downward so that the
charge slurry flowing in line 49 assumes a given decreased
flow rate for that moment in the phase-out period. The
11722044
new slurry rate is measured and the cycle is repeated. By
this means, repeated ~djustments to the rate of flow are
made and the slurry flowing in line 50 is phased out.
Simultaneously with the phasing out of the principal
slurry fuel flowing in line 43, the stand-by liquid
hydrocarbonaceous fuel flowing in line 161 is phased in over
the same period of time. Flow recorder-controller with
transmitter 171 includes a microcomputer means which is
programmed with the desired time vs. increasing flow rate
10 curve. The rate of oil flow in line 161 is measured and a
signal m is provided by flow transmitter 165 corresponding
to the flow rate of the oil in line 161. Flow recorder-
controller 171 receives signal m, compares it with a signal
representing the deslred flow rate for that moment and
j provides a corresponding adjustment signal to valve 163 to
open wider so that the charge oil in line 166 assumes a !i given increased flow rate for that moment in the phase-in J
period. The new oil rate is measured and the cycle is
repeated. By this means, repeated adjustments to the rates
20 Of flow of the principal and stand-by fuels may be made so
that the oil flowing in line 167 may be phased into line 14
¦ in an amount that compensates for the reduced amount of
solid carbonaceous fuel slurry flowing in line 50.
During or following the period that the portion of
principal solid carbonaceous slurry fuel from line 43 is
phased out and the portion of stand-by liquid hydrocarbon
fuel from line 161 is phased in, the weight ratio of H2O to
fuel in the reaction zone may be controlled at design
conditions or maintained substantially constant i.e. less
30 than +10% variation, by increasing or decreasing the flow
rate of the temperature moderator. Accordingly
- 1172044
- 29 -
in the subject example, simultaneously with the phase-out of
the coal-water slurry a supplemental amount of H20 from an
external source may be phased in over the same period of
time. Thus, in Fig. 1, a portion of the steam in line 181
is passed through line 187 and phased into line 18 where it
mixes with the free-oxygen containing gas from line 70. Flow
recorder-controller with transmitter 191 includes a microcomputer
means which is programmed with the desired time vs. increasing
flow rate curve.
The rate of steam flow in line 181 is measured and
a signal s is provided by flow transmitter 185 corresponding
to the flow rate of the steam in line 181. Flow recorder-
controller 191 receives signal s, compares it with a signal
representing the desired flow rate for that moment and
provides a corresponding adjustment signal to valve 183 to
open wider so that the charge steam in line 186 assumes a
given increased flow rate for that moment in the phase-in
period. The new steam rate is measured and the cycle is
repeated. By this means, repeated adjustments to the rate
of steam flow are made and the steam flowing in line 187 is
phased into line 18 in an amount that will maintain the
weight ratio of H20 to fuel in the reaction zone at design
conditions, for example substantially constant. In another
embodiment the weight ratio H2O/fuel in the reaction zone is
adjusted up or down by controlling the steam rate as described
previously in order to obtain a desired temperature in the
reaction zone and composition of the product gas.
Simultaneously with or after the phasing out of
the principal fuel, the phasing in of the stand-by fuel, and
optionaly with or without the phasing in or out of the steam
depending on the nature of the uels, the free-oxygen
--` 1172044
containing gas may be adjusted up or down. By this means
the temperature in the reaction zone may be controlled at
design conditions, or maintained substantially constant i.e.
less than +200F. variation. Thus, in the present example
in Fig. 1, a portion of the free-oxygen containing gas in
line 63 is passed through line 70 and phased into line 18
where it mixes with the steam, if any, from line 187 as
previously described. Flow controller 74 is programmed with
the desired time vs. flow rate curve. The period of adjustment
is the same as that for the fuel and steam streams. The
adjustment to the oxygen flow rate may be up or down depending
on the nature of the fuel streams and the addition of steam,
if any. In the subject example, the oxygen flow rate will
be increased to satisfy the additional requirements for the
partial oxidation of a liquid hydrocarbon in comparison with
a solid carbonaceous fuel.
The rate of free-oxygen containing gas in line 63
is measured and a signal b is provided by flow transmitter
67 corresponding to the flow rate of the free-oxygen containing
gas in line 63. Flow recorder-controller with transmitter
74 includes a microcomputer means which receives signal b,
compares it with a signal representing the desired flow rate
for that moment, and provides a corresponding adjustment
signal to valve 65 to open wider so that the charge free-
oxygen containing gas in line 68 assumes a given increased
flow rate for that moment in the phase-in period. The new
free-oxygen containing gas rate is measured and the cycle is
repeated. By this means repeated adjustments to the rate of
oxygen flow are made and the free-oxygen containing gas
flowing in line 70 is phased into line 18 in an amount that
--30--
i~ .
2044
- 31 -
will maintain the temperature in the reaction zone at design
conditions or substantially constant. In one embodiment in
which the burner shown in Figure 3 is employed, a portion of
the temperature moderator, fox example steam in line 187, is
passed through inlet 13 of the burner.
In another embodiment, the free-oxygen containing
gas rate is adjusted up or down to obtain a desired temperature
in the reaction zone and composition of the product gas.
Alternatively, by the previously described means, the atomic
ratio of oxygen to carbon in the reaction zone may be controlled
at design conditions i.e. in the range of about 0.5 to 1.7.
The previously mentioned time vs. flow rate
curves for programming conventional flow recorder-controllers
191, 171, 51, and 74 may be determined by conventional
calculations based on heat and weight balances for the
entire system.
In another embodiment, the parameters for said
calculations and any others may be measured by conventional
detectors and the signals responsive thereto may be fed to
an overall control system means 40. The input to system
control means 40 may be manual or a signal from a computer,
analyzer, or sensor. Control means 40 comprises conventional
circuits and components for providing or converting signals
i.e. pneumatic or electronic to operate said speed controls
and valves.
-~ 1172()44
- 32 -
In control means 40, the computer calculated
values or the manually inserted set points for the desired
rates of flow at specific moments for the various streams
are compared respectively with the signals a, m, s and b.
For example, responsive to signal a, control means 40 may
automatically control pump speed control 46 by sending
signal c to flow-recorder-controller 51. Alternatively,
signal c may be fed directly to speed control 46. In another
embodiment, for example flow recorder-controller 51 may
receive signal a from flow transmitter 48 and signal c from
control means 40 and compute the speed adjustment signal for
the operation of speed control 46. In still another embodiment,
the flow of the feedstream may be stopped by a signal i from
control means 40 to valve 77.
Similarly, responsive to signal m, control means
40 may automatically control liquid hydrocarbonaceous fuel
valve 163 by sending signal w to flow-recorder-controller
171.
In a similar manner, responsive to signal s,
control means 40 may automatically control steam valve 183
by sending signal u to flow-recorder-controller 191.
Also, similarly, responsive to signal b, control
means 40 may automatically control free-oxygen containing
gas valve 65 by sending signal j to flow-recorder-controller
74.
117~44
- 33 -
Two suitable burners for use in the sub~ect
process and control system are shown in Fi~ures 1-3.
Corresponding parts of the burner shown in Figures 1 and 2
have the same reference number.
Burner 1 is shown in greater detail in Fig. 2
and substantially comprises unobstructed inner coaxial
retracted central conduit means 15 and outer concentric
coaxial conduit 16 which is disposed longitudinally about
inner central conduit means 15. Disc flange 10 is attached
to the outside circumference of outer coaxial conduit 16
and supports burner 1 in a vertical longitudinal direction.
The central longitudinal axes of burner 1 and gasifier 41
are coaxial. Spacing means 18 provide a free-flow annular
passage means 17 between the outside diameter of central
cylindrical conduit means 15 and the inside diameter of
outer cylindrical conduit 16. Exit orifice 20 at the
downstream tlp of central conduit 15, is preferably straight,
circular in cross-section, and perpendicular to the
longitudinal axis of the burner. Alternatively, exit
orifice 20 may be converging or diverging. Outer conduit 16
terminates at the downstream end of the burner with
converging nozzle 21. A vertical cross-section of exit
orifice 21 may be frusto-conically shaped, which may or
may not merge into a right cylinder. Preferably for wear
resistance, as shown in Fig. 2, nozzle 21 comprises a
frusto-conical rear portion 22 that develops into a right
cylindrical front portion 23 which terminates at the
downstream face ~ of the burner. The cylindrical exit
s=ctlon w111 permlt: (1) addltlonal burner 11fe because of
.
.,
--; 117~ 4
- 34 -
increased surface available for abrasion, and (2) fab-
rication of a ceramic or refractory insert or an entire
cooling chamber ~rom a thermal and abrasion resistant materi~l
i.e., tungsten or silicon car~ide in order to reduce damage
and to extend burner life.
The height of the front cylindrical portion 23 of
exit nozzle 21 is in the range of about O to 1.5, say about
0.1 to 1.0 times, its own diameter i.e. the minimum diameter
of converging nozzle 21. The diameter of exit orifice 20 of
central conduit 15 is in the range of about 0.2 to 1.5, say
about 0.5 to o.8 times the minimum diameter of converging
nozzle 21.
The downstream end of the burner may or may not be
cooled. Preferably, as shown in Fig. 2, coaxial annular
shaped cooling chamber 2 surrounds exit orifice 21 at the
burner tlp. By passing water through cored section 24 of
cooling chamber 2, the tip of burner 1 may be prevented from
overheating. Optionally for similar reasons, outer conduit
16 may be kept cool by passing water through coils 4 which
encircle the outside surface of outer conduit 16 along its
length. Suitable converging angles for orifice 21 are in
the range from about 15 to 90 from the central longitudin-
al axls of the burner. The downstream tip of exit orifice
20 of central conduit means 15 is severely retracted upstream
from face 6 of burner 1 a distance of two or more times the
minimum diameter of converging exit nozzle 21. For example,
the setback of tip 20 of central conduit 15 from burner face
6 may be in the range of about 3 to 10 times the minimum
d,ameter of converging exit nozzle 21. The space between
11720~
- 3S -
tip 20 of central conduit 15 and burner face 6 constitutes
the unobstructed pre-mix zone.
In the operation of burner 1, either reactant
stream i.e. see Table II supra, may enter burner 1 by way o~
inlet 9 of Fig. 1 and pass directly from the upstream
portion down through free-flow central conduit 15, through
exit oriflce 20, and into pre-mix zone 25, as shown in
Fig. 2. Cover plate 11 seals off the upper end of annular
passage means 17. The upstream inlet end 9 of central
conduit 15 is coupled to a feed line and the downstream end
passes through cover plate 11 and is sealed thereto.
Simultaneously, the.other reactant stream may enter burner 1
by way of inlet 8 and pass directly from the upstream portion
30 of outer conduit 16 down through free-flow annular
passage 17 and into pre-mix zone 25 where intimate mixing of
the two reactant streams takes place. Inlet 8.may or may not
be tangential to outer conduit 16. Further, direct heat
exchange between the two reactant streams takes place in
pre-mix zone 25. The temperature in the pre-mix zone is
controlled so that a controlled amount of the liquid carrier
may be vaporized without burning i.e. from 0 to 100 vol. %
say about 2 to 80 vol. %. Temperature control in the pre-m.x
zone may be effected by controlling such factors as dwell
time and heat content o~ the entering streams~ and amount
of external cooling such as by coils 4, if any. Pre-mix
zone 25 is substantially free from any obstruction to the
free-flow of the materials passing therethrough.
117~()44
- 36 -
In the burner shown in Figs. 1 and 2, streams of
different materials flowing down through coaxial retracted
central conduit 15 and simultaneously down through annular
passage 17 are successively mixed together in tandem pre-mix
chambers 25 and 40'. While the pre-mix zone in this embodiment
is shown as comprising two separate coaxial pre-mix chambers
25 and 40' in series, the pre-mix zone for other embodiments
of the subject invention may actually comprise one or more,
such as 2 to 5 coaxial pre-mix chambers. For example, three
pre-mix chambers 25, 40', and 41 are included in the embodiment
of the burner shown in Fig. 3. Each pre-mix chamber in
Figures 1, 2 and 31 except for the first chamber in the
line, comprises a coaxial cylindrical body portion 45 followed
by a coaxial at least partially converging outlet portion 22
or 46 in Fig. 3 that may optionally develop into a straight
cylindrical portion 23 or 49, respectively. Optionally,
such outlets may be made from a thermal and wear resistant
material i.e. silicon or tungsten carbide, such as previously
described. In embodiments having a plurality of pre-mix
chambers, the first pre-mix chamber in the line may have a
straight coaxial cylindrical body portion 47, that discharges
through circular orifice 39 directly into the next in line
coaxial pre-mix chamber 40'. Alternatively, one or more of
the pre-mix chambers may be a converging frusto-conical
shaped section. Preferably, the mixture leaving one pre-mix
chamber expands into the next successive pre-mix chamber.
When the mixture is accelerated and expanded through a final
i exit nozzle at the tip of the burner into the combustion
! chamber, a more stable and efficient combustion pattern
results. The temperature, pressure and velocity ranges for
i
117210~4
- 37 -
the streams of materials passing through the various passages
o~ the burner are substantially the same as those discussed
previously. The inlet to the first pre-mix chamber 25 may
have a converging inlet 48 as shown in Figures 1, 2 and 3.
FIG. 3 is a vertical sectional view of an embodiment
of the retracted central conduit 15 pre-mix burner similar
to burner 1, as shown in Fig. 2, but modified to provide two
coaxial annular passages i.e. intermediate annular passage
17 and outer annular passage 51. Further, the pre-mix zone
comprises three successive free-flow coaxial pre-mix chambers
25, 40', and 41. By spacing means 18, concentric coaxial
outer conduit 52, retracted coaxial intermediate conduit 53,
and retracted coaxial central conduit 15 may be radially
spaced from each other to provide said separate annular
passages and pre-mix chambers with substantially no obstruction
to the free-flow of materials therethrough. The downstream
tip 20 of central conduit 15 is retracted upstream from face
6 of the burner a distance in the range of 2 or more, say 3
to 10 times the minimum diameter of converging exit orifice
21. The downstream tip 54 of intermediate conduit 53 is
retracted upstream from face 6 of the burner a distance in
the range of 0 to 12, say 1 to 5 times the minimum diameter
of converging exit orifice 21.
Central conduit 15, and annular passages 17 and 51
of the burner in Fig. 3 are respectively connected upstream
to separate inlets in a manner similar to that shown in Fig.
2. Thus, the upstream inlet end 9 of inlet pipe 9 of
117Z~4
- 38 -
central conduit 15 is coupled to a feed line and the ~own-
stream end passes through cover plate 12 and is sealed
thereto. Cover plate 12 seals off the upper ends of annular
passages 51 and 17. Simultaneously, the other feedstreams
may enter burner 1 by way of upstream inlet 8 that leads
into annular passage 17, and upstream inlet 13 which leads
into annular passage 51. Optionally, annular disc 56, with
or without a plurality of small diameter holes 57, may close
off the downstream end of annular passage 51. Inlets 8 and
13 may or may not be tangential to coaxial intermediate
conduit 53 and outer conduit 5~, respectively. The burner
tip may be cooled by passing water through cored section 24
of annular cooling chamber 2 which is coaxial with the
central longitudinal axis of th~ burner at the downstream
end in the manner shown. Alternatively, cooling chamber 2
may be eliminated. Cooling coils 4 may encircle the burner
along its length.
In the operation of the embodiment of the burner
shown in Figure 3, the feedstreams simultaneously passing
down through central conduit 15 and intermediate annular
passage 17 at different velocities impinge and mix with each
other in the first pre-mix chamber 25. The impingement of
one reactant stream, such as the liquid slurry of solid
carbonaceous fuel in a liquid medium with another reactant
stream, such as a gaseous stream of free-oxygen containing
gas, steam, or temperature moderator at a higher velocity
causes the liquid slurry to break up into a fine spray. The
multiphase mixture then passes into the second pre-mix
chamber 40' for additional mixing. Leaving chamber 40' by
way of converging exit nozzle 46 and oircular ori~ice 54 at
'
~ - - . , '
. .
~172044
- 39 -
~the downstream tip of chamber 40', the multiphase mixture
passes into the third pre-mix chamber 41. The third feed-
stream enters the burner upstream through a separate inlet
13, and passes down outer annular passage 51. Optionally,
at least a portion of the third feedstream in annular passage
51 may be mixed with the other feedstreams in annular passage
17 and pre-mix chamber 25, 40', and 41 by beina passed
through a plurality of rings of small diameter passages or
holes 60, 61, 62 and 57 located in the wall of intermediate
conduit 53 and annular disc 56. When the set back of orifice
54 at the tip of intermediate conduit 53 from face 6 of the
burner is greater than 0, say in the range of about 1.0 to 5
times the minimum diameter of exit orifice 21, then the
third feedstream may mix with the first and second feed-
streams in pre-mix chamber 41 to produce a multiphase mix-
ture. Further, in such embodiment, there may be 2 or more
say 2 to 5 cylindrical coaxial pre-mix chambers in series.
The multiphase mixture passes through converging nozzle 21
at the downstream tip of the burner into the reaction zone
of the gas generator.
In the embodiment of the burner shown in Fig. 3
with a set back of orifice 54 of about 0, the third feedstream
passing through outer annular passage 51 will contact and
mix with the multiphase mixture of the other two feedstreams
from the pre-mix zone downstream from face 6 of the burner,
say about 1 to 24 inches. Further, in such embodiment,
there may be one or more say 2 to 5 cylindrical coaxial pre-
mix chambers in series. For example, the stream of free-
oxygen containing gas may be passed through either central
conduit 15 or intermediate passage 17 and the fuel feedstream
may be passed through the other passa~e i.e. the ce~tral
117204~
40 -
conduit or intermediate passage whichever is free. Simultan-
eously, a stream of temperature moderator may be passed
through the outer annulus passage 51.
Reference will now be made to Figures 4 and 5 of the
drawings. During operation of the partial oxidation gas
generator, it may be necessary to rapidly turndown the
production of the effluent gas to about 1/8 to 3/4 of the
plant-design output, without replacing the burner~ Changing
the burner requires a costly shut-down period with resultant
delay. Thus, in combined cycle operation for power
generation a durable burner is required which offers minimum
pressure drop and with which throughput levels may be
rapidly changed - up and down - without sacrificing stable
operation and efficiency. Further, the burner should
operate with a variety of liquid, solid, and gaseous fuels,
and mixtures thereof. Combustion instability and poor
efficiency can be encountered when prior art burners are
117Z044
- 41 -
used for the gasification of ]iquid phase slurries of solid
carbonaceous fuels. Further, feedstreams may be poorly
mixed and solid fuel particles may pass through the gasifier
without contacting significant amounts of oxygen. Wnreacted
oxygen in the reaction zone may then react with the product
gas.
These problems and others are avoided by a novel
two-section burner employed in the subject process
comprising: a central conduit, said central conduit being
closed at the upstream end and having a downstream circular
exit orifice at the tip of the burner; an outer conduit
coaxial and concentric with said central conduit and forming
an annular passage therebetween, said outer conduit and
annular passage being closed at the upstream end and having
a downstream annular exit orifice at the tip of the burner;
a central bundle of open-ended parallel or helical tubes
passing through the closed end of said central conduit and
making a gas tight seal therewith; means for supporting
said central bundle of parallel or helical tubes so that
the external surfaces of said central bundle of parallel
or helical tubes forms a plurality of passages within said
central conduit; upstream inlet means including a manifold
for splitting and introducing a first reactant feedstream
into the upstream ends of said central bundle of parallel
or helical tubes; and wherein the downstream ends through
which said first feedstream is discharged are retracted
upstream from the burner face a distance of 0 to 12 say
about 3 to 10 times the minimum diameter of the central
conduit exit orifice at the tip of the burner; upstream
inlet means for introducing a second reactant feedstream
1172044
- 42 ~-
lnto said central condui~ and do~n through said plurallty
of passages within said centrzl condu~t; an annular bundle
of open-ended parallel or helical tubes passing through the
closed end of said annular passage 2nd making a gas tight
seal therewith, so that ~he external surfaces of said annular
bundle of parallel or helical tubes forms a plurality of
passages within said annular passage; upstream inlet means
including a manifold for splitting and introducing a third
reactant feedstream into the upstream ends of said annular
bundle of parallel or helical tubes, and wherein the
downstream tube ends through which said third reactant
feedstream is discharged are retracted upstream from the burner
face a distance of 0 to 12 say about 3 to 10 times the minimum
width of the annular exit nozzle at the tip of the burner;
means for supporting said annular bundle of parallel or
helical tubes with respect to the inside wall of said annular
passage and to each other so that the external surfaces of said
annular bundle of parallel or helical tubes forms a plurality
of passages within said annular passage; and upstream inlet
means for introducing a fourth reactant feedstream into
said annular passage and down through said plurality of
passages within said annular passage.
Advantageously, by means of the subject burner,
three ranges of flow through the burner may be obtained by
using one or both bunches of tubes and their surrounding
conduits. Throughput levels may be rapidly changed -
up and down - without sacrificing stable operation.
In one embodiment of the aforesaid burner in
which the downstream ends of the central and/or annular
3o bundles of parallel or helical tubes are retracted upstream
ll~Z3044
from the ~urner ~ace, addi~l~nal mixing of the feedstre2r.s
may be obtained by providing at least one coaxial cyl ndric~'
shaped pre-mix chambers in series in said central conduit in
which said firsi and second feedstreams are mixed, and/or
at least one coaxial annular shaped pre-mix chambers in
series in said annular passage in which said third and fourth
feedstreams are mixed.
; The burner may be provided with a plurality of
longitudinal gas conduits parallel tO the burner axis and
; 10 radially spaced between said central conduit and said
annular passage. Said gas conduits are closed at the
downstream end near the burner tip and are connected to a
gaseous feedstream at the upstream end. A plurality of
feeder lines connect said gas conduits to said pre-mix
chambers in said central conduit and/or to said annular
passage. A gaseous feedstream selected from the group
consisting of steam, free-oxygen containing gas, C02,
N2, fuel gas, a recycle portion of the product gas, and
mixtures thereof may be thereby passed through said
longitudinal gas conduit and feeder lines and into said
pre-mix chambers to impro~e mixing, break-up packed passages,
or to introduce a gaseous constituent which will influence
the reaction going on in the gasifier.
The fuel may be passed through either the central
I and/or annular bundle(s) of tubes, or alternatively throug:~
¦ the conduit(s) surrounding the tubes in the central and/or
annular sections of the burner. Si~ultaneously the
free-oxygen containing gas is passed through the correspGndlng
unoccupied passageCs~ in the central 2nd/or annular secticns
the burner. In one embod1~ent, one type Or r~el ts
.
,.
`` 11'72~
- 44 -
passed through one sect~on o~ the burner i.e. cenvral or
2nnular section, while a second type cr fuel is passed
through the remalning section of the burner.
Preferably~ in the subject two-section burner
said first and thi-d reactant feedstreams and said second
and fourth reactant feedstreams are respectively made up
of split streams from the fuel stream(s2, and the gaseous
oxidant stream. By this means, fuel is passed through the
central and annular bundles of tubes, while simultaneously
free-oxygen containing gas is passed through the corresponding
central and annular conduits. In one embodiment J however,
the first and fourth feedstreams, and the second and third
feedstreams are respectively made up of split streams
from the fuel stream~s), and the stream of gaseous oxidant.
By this means, fuel is passed through the central bundle of
tubes and the annular conduit, while simultaneously
free-oxygen containing gas is passed through the corresponding
central conduit and annular bundle of tubes.
Flow control means are provided in the sub~ect
process for controlling the introduction of said reactant
feedstreams into the burner. Further, means are provided
for changing fuels without shutting down or depressurizing
the gas generator.
When the principal fuel is flowing through the
tubes or surrounding passages in the central and/or annular
sections of the burner, some preferred embodiments of the
sub~ect process for replacing ~he principal fuel with the
stand-by fuel follow:
Cl~ the replacement of the princip~l fuel with the
stand-by fuel may take place simultaneously in the central
117~144
~ 45 -
'anà/or annular sections of the burner.
(2) alter~atively, the replacement of ~,he principal
fuel with the stænd-by fuel may take place sequentially, and
first in either one of the sections of the burner. This is
then followed by the substitution of the ~uels in the
remaining section of the burner.
When a stream of the principal fuel is flowing
through only one section of the burner and the other section
is unused~ then first a stream of the stand-by fuel may be
introduced into the unused section of the burner. The
principal fuel may be stopped in the section in which it is
flowing along with the related stream of free-oxygen
containing gas with or without mixture with a temperature
moderating gas. The principal fuel stream may be stopped
simultaneously with or after the introduction of the
stand-by fuel stream. In such case, after the stand-by
fuel replaces the principal fuel only one section of the
two-sectlon burner is in use. Alternatively, the principal
fuel may be also replaced in the section in which it was
originally flowing by a stream of said second solid
carbonaceous fuel slurry or hydrocarbonaceous fuel. In
such case, after the stand-by fuel replaces the principal
fuel both sections of the burner are in use.
In the above schemes, the principal and/or
stand-by fuels may or may not be in admixture with H20.
Ad~ustments are made to the free-oxygen containing gas
stream with or without mixture with a temperature moderatin~
gas flowing in the tubes or surrounding passages that are
related to the corresponding surrounding passages or tubes
in which the fuel stream is flowing and if necessary
`" 1172044
. - 46 -
supplemental H20 is introduced into the reaction zone so
as to maintain the weight ratio of the H2O to fuel and the
temperature in ~he reaction zone at design conditions.
For example, the temperature in the reaction zone may be
maintained substantially constant i.e. less than + 200F.
variation, and, the weight ratio H2O/fuel in the reaction
zone may be maintained in the range of about 0.2-3Ø
Thus, if the principal or first fuel flowing
through a first or second fluid passage in the central or
first section of the burner and/or through the third or fourth
fluid passage in the annular or second section of the burner
becomes unavailable and it is desired to switch to a stand-by
or second fuel, or for any reason whatsoever it is desired
to switch from a first solid carbonaceous fuel slurry or
hydrocarbonaceous fuel to a second solid carbonaceous fuel
slurry or hydrocarbonaceous fuel, one may proceed as follows:
i(1) passing a first reactant stream of first solid
carbonaceous fuel slurry or hydrocarbonaceous fuel with or
without mlxture with H20 through either the first or second
fluid passage means in the central or first section of said
burner, and/or simultaneously passing a second reactant stream
of said first solid carbonaceous fuel slurry or hYdrocarbon-
aceous fuel with or without mixture with H2O through either
the third or fourth fluid passage means in the annular or
second section of said burner;
`(2~ simultaneously passing a separate reactant stream
of free-oxygen containing gas with or without mixture with
a temperature moderating gas through the unused fluid
passage means in each of the central and~or annular sectior.s
3Q of said burner which are related to said fluid passage
` 117Z044
- 47 -
means through which said stream(s) of first solid carbonace~us
fuel slurry or hydrocarbonaceous fuel with or without mixture
with H20 are passing;
(3) mixing together said reactant streams from (l) ~nd
(2) to produce a well-distributed blend, and reacting said
mixtures by partial oxidation in the reaction zone of said
gas generator at an autogenous temperature in the range of
about 1700 to 3500F., a pressure in the range of about
l to 300 atmospheres, an atomic ratio of oxygen/carbon in
the range of about 0.5 to 1.7, and a weight ratio H20/fuel
in the range of about 0 to 5.0;
(4) phasing out of the fluid passage means in which it
is flowing in said central and/or annular section(s) said
stream(s) of first solid carbonaceous fuel slurry or hydro-
carbonaceous fuel with or without mixture with H20, saidphasing out being with a uniformly decreasing rate of flow
that varies from maximum to 0 over a period of time in the
range of about l - 3600 seconds; and simultaneously phasing
said stream(s) of second solid carbonaceous fuel slurry or
hydrocarbonaceous fuel with or without mixture with H20 into
the same fluid passage means at a uniformly increasing rate
of flow that varies from 0 to maximum rate over the same
period of time and mixing with the remaining portion of and
replacing the phased out portion of said stream of first
solid carbonaceous fuel slurry or hydrocarbonaceous fuel with
or without mixture with H20 flowing therein, and
(5) controlling the temperature and weight ratio H20/fuel
in the reaction zone at design conditions by adjusting the
flow rate(s) of the reactant stream(s) of free-oxygen
containing gas with or without mixture with a temperature
moderating gas passing through the burner, and if necessary
introduclng supplemental H20 into the reaction zone.
For example, by means of the subject process the tempera-
ture in the reaction zone may be maintained substantially
constant i.e. a variation of less than - 200F., and the
weight ratio H20/fuel may be maintained in the range of about
0,2 to 3Ø
'7Z044
- 48 -
~ n the subject flow control means a manual or
automatically controlled fluid-controller is placed in
each feed line. For slurry fuel feed lines, a signal
from the controller is transmitted to a speed control for
a positive displacement pump. For liquid or gaseous hydro-
carbon fuel feed lines and for oxidant feed lines, the signal
from the controller is transmitted to a flow control valve.
Responsive to said signal(s3, the speed of said pump(s) is
varied, or alternatively the opening in said flow control
valve(s) is changed. By this means, the flow rate for the
streams of fuel and/or oxidant passing through the burner may
be
74290 ~ ~
adjusted up or down, say up to about 50% of the Des~gn
Conditions Al~ernatively, a flow control vaive ma~ be
inserted in each of the feedstreams to start or stop the
flow of the feedstreams to the central conduit and/or the
annular passage and to their respective bundles of tubes.
By this means, three ranges of flow through the burner may
be obtained. Further, both of these flow control schemes
may be combined.
By means of the subject burner a large volume of
the first reactant stream is split into a plurality of
separate streams of reactant fluid flowing through the
central bunch of helical or parallel tubes. This permits
the introduction of the second stream of reactants passing
concurrently through the central conduit into the interstices
- and/or passages surrounding the central bunch of helical or
parallel tubes. Similarly, a large volume of the third
reactant stream is split into a plurality of separate streams
of reactant fluid flowing through the annular bunch o~
helical or parallel tubes. The fourth stream of reactants
passing concurrently through the annular passage is
introduced into the interstices and/or passages surrounding
the annular bunch of helical or parallel tubes. The greater
the number of tubes in a bunch, the better the distribution
of one reactant within the other reactant. The mixing of
the reactant streams which takes place downstream of the ends
of the tubes is facilitated by this improved distribution.
Such efficient mixing of the feedstreams facilitates a
more uniform partial oxidation of the fuel to produce ~2 and
C0. The combustion efficiency of the process is thus increased.
By means of the sub~ect invention, reactions are
made to proceed in local regions where there is less
117;5~44
opportunity for overneating the fuel with an insu~ficient
supply o~ oxygen to resu't in the formation of soot. Thus,
the amount of unconverted particulate carbon Produced for a
given oxygen to carbon atomic ratio in the feed may be
substantially reduced. Further, I'overburning'' of the fuel
to produce carbon dioxide is substantiallY reduced. The
sub~ect burner is preferably made from heat and corrosion-
resistant metal alloys.
The velocity of the reactant stream through the
central and annular bunches of tubes, or alternatively
through the central conduit or annular passage surrounding
said tubes is in the range of about 5-100, say 10-50 feet
per second at the face of the burner when said reactant
stream is a liquid hydrocarbon fuel or liquid slurry of
solid carbonaceous fuel, or mixtures thereof, and in the
range of about 150 feet per second to sonic Yelocity, say
200-500 feet per second when said reactant stream is a
gaseous hydrocarbon fuel or a free-oxygen containing gas
with or without admixture with a temperature moderator.
The velocity of a stream of reactant fuel or a stream of
a mixture of reactant fuels exceeds the flame propagation
velocity for that fuel or fuel mixture.
The central bunch of tubes may number in the range
of about 1-200 or more, such as about 2-180 say about 4-48.
The annular bunch of tubes may number in the range of about
1-600, or more, such as about 2-580, say about 8-108.
There may be 1 to 7'or more concentric rings of tubes in
the central and/or annular bundles.
The ratio of the total tube cross-sectional zreâ
(basis inside diameter) for the annular bunch of tubes (TA)
117Z0'~4
to the total tube cross-sectional area (basis inside diamet r)
for the central bunch of tubes (T ) may be in the ran~e of
about 2-8. Similarly, the rat~o of the annular intersti~ial
cross-sectional area ~I ) surrounding the annular bunch of
tubes to the central interstitial cross-sectional area (Ic)
surrounding the central bunch of tubes may be in the range of
about 2-8.
The inside diameter of the tubes in either bunch
may range from about 1/16 to 2 inches in diameter. The
length of the tubes in the central and annular bunches and
their spacing are such as to permlt the external reactant
stream to flow evenly into the interstices between the
tubes. For example, the length of the tubes or the height
of the coils in either tube bundle may range from about 1/2
to 36 inches or longer and preferably from about 4 to 12
inches, with greater lengths required as the number of tubes
and the total size of the burner increases. Preferably,
the ratio of the length to lnside diameter of the tubes
should be at least 8. Preferably, the inside diameter and
the length of each tube should be the same for all tubes
in the central bunch or the annular bunch. By this means
equal flow may be obtalned through all of the tubes.
Alignment plns, fins, centering vanes, spacers and
other conventional means are used to symmetrically space the
tubes and conduits with respect to each other and to hold
same in stable alignment without obstructing the free-flow
of the feedstreams in the central and annular interstitial
zones.
The downstream exit ends of the plurality of
arnular and central bunches of parallel tubes terminate
- 117~0~4
- 52 -
in the same ~lane perpendicular to the longitudinal cent~a
axis o~ the burner. In one embodiment employing pre-mix
chambers~ to be further described, the ends of the centrai
and/or annular bunch of tubes are retracted upstream from
the burner face to provide substantial mixing of the
reactants and volatili~ation of the slurry medium prior to
discharge.
The central conduit exit orifice and/or the
annular exit orifice may have converging sections. For
example~ the central condult exit orifice may comprise a
frusto-conical rear ~ortion having a converging angle in the
range of about 15 to 90 from the central longitudinal axis
of the burner. The rear portion may develop into a normal
cylindrical front portion which terminates at the downstream
face of the burner. The cylindrical front portion may have
a height in the range of about 0 to 1.5 times its own diameter.
In one embodiment the first conduit downstream
outlet comprises a converging frusto-conical rear portion
that develops lnto a diverging frusto-conical front portion
that terminates at the downstream tip of the burner. The
converging and diverging angles are in the range of about
15 to 90 with the central longitudinal axis of the burner.
Similarly, said annular exit orifice may comprise
a generated converging frusto-conical shaped annular rear
portion having a converging angle in the range of about 15
to 90 from the central axis of the frusto-conical section,
said central axis being parallel to the central longitudinal
axis of the burner. The rear portion may develop into a
generated normal cylindrical annular front portion which
terminates at the downstream face of the burner. The
1~72044
cylindrical front portion may have a height in the range of
about 0 to 1.5 times ~ts own width.
In one embodiment, the central conduit exit orifice
and/or the annular exit orifice are in the shape of or is
I generated by an American Society of Mechanical Engineer's
i standard long-radius nozzle. A further description of said
nozzle may be ~ound in "Thermodynamics Fluid Flow and Heat
Transmission" by Huber 0. Croft, page 155, First Edition,
1938 McGraw-Hill Book Company.
The burner may be cooled on the outside by means
of coollng coiis that encircle the outside barrel of the
burner along its length. The downstream end of the burner
may be provided with a cored face plate through which a
coolant is circulated. For example, an annular cooling
chamber may encircle the annular exit orifice and/or the
central conduit exit orifice. The cooling chamber, central
conduit exit orifice and/or the annular exit orifice may
constitute a single piece of thermal and wear resistant
material such as tungsten carbide or silicon carbide. Any
suitable coolant may be employed e.g. water.
In one embodiment of the sub~ect burner, a
plurality of high pressure high velocity ~et streams of a
~aseous material is passed into the central conduit and/or
annular passage at various locations along their length.
By this means atomizing of the fuel feedstream and, optionally,
mixing it with the oxidant stream may be facilitated. For
example~ the gaseous material may be passed through a
plurality of small diameter passages or holes i.e. about
.032 to 0.5Q diameter that lead into said central conduit
3o and~or annular passage.
--~3 -
11720~4
I - 54 -
i ~he gaseous material may be selected from the
group consisting of steam, free-oxygen containlng gas, C02,
N2, fuel gas, a recycle portion of the product gas, and
mixtures thereof. The gaseous material may be introduced
into the burner at a temperature in the range of about
ambient to 1500F. and a velocity in the ran~e of about
100 feet per second to sonic velocity. The pressure of the
gaseous material may be in the range of about 76 to 4500
psia and is greater than the pressure of the other feedstreams
passing through the burner.
The discharge velocity for the material leaving
through the central exit orifice is in the range of about
0.5 to 1.5 times, and preferably the same as, the discharge
velocity of the material leaving through the annular exit
orifice. ~he streams leaving the two exit orifices mix
together and atomization may take place immediately downstream
from the face of the burner.
In another embodiment of the invention, additional
mixin~ of the reactant streams is effected in at least one~
say 2 to 5 coaxial cylindrical shaped pre-mix chambers in
series in the central condult and/or at least one, say 2 to
¦ 5 annular shaped pre-mix chambers in series in the annular
! passage. In such case, the downstream ends of the central
¦ bunch of helical or parallel tubes are retracted upstream
from the face of the burner a distance of 0 to 12, such as
about 2 or more, say about 3 to 10 times the minimum diameter
of the circular exit orifice and/or the downstream ends of
the annular bunch of helical or parallel tubes are retracted
upstream from the face of the burner a distance of 0 to 12,
such as about 2 or more, say about 3 to 10 t~.es the m~nimum
., ,
117~2044
- . - 5~ -
width of the annular exit or~fice. Preferably, the downstream
ends of the central and annular bunches of helical or parallel
tubes are retracted upstream from the entrance to the first
pre-mix chamber in the line. For example, the set back of
the ends of the tubes from the entrance to the first pre-mi~
chamber may be in the range of about 0.1-2.0 times the
diameter of the first pre-mix chamber.
In one embodiment, each of the pre-mix chambers in
the central conduit except the first are cylindrlcal shaped
and comprises a coaxial cylindrical body portion followed by
a coaxial at least partially converging outlet portion. The
first cylindrical-shaped pre-mix chamber in the central
conduit comprises a normal coaxial cylindrical body portion
that discharges directlY into the next in line coaxial
cylindrical shaped pre-mix chamber. Each pre-mix chamber in
the annular conduit except the first is annular shaped and
comprises a coaxial generated normal cylindrical annular
body portion followed by a coaxial generated converging
frusto-conical shaped annular outlet portion. The first
annular shaped pre-mix chamber comprises a coaxial generated
normal cylindrical annular body portion that discharges
; directly into the next in line coaxial annular shaped
pre-mix chamber. The converging outlet Portions of said
pre-mix chambers may be made from tungsten carbide or silicon
carbide for increased wear resistance.
The size relationship between successive pre-mi~
chambers in the sub~ect burners may be expressed in the
following manner: For burners in which the pre-mix chambers
in the central conduit are successively nu~hered 1 to 5
and/or the pre-mix chambers in the annular passage are
~1"7~044
numbered 6,10, then the ratio of the diameter of zny one cf
said central chambers to the diameter of the next central
chamber ~n the line i.e. D :D ; D :D ; D3:D4i or D4:D5 may
be in the range of about 0.2-1.2. ~he ratio of the length
of any one central pre-mix chamber in said central conduit
to the length of the next central pre-mix chamber in the
li 1 2 2 3 3 4 4 5
of about 0.1-1Ø The ratio of the annular width of any one
of said annular pre-mix chambers to the width of the next
annular chamber in the line i.e. W6:W7; W7:W8; W8:Wg; or
Wg:W10 may be in the range of about 0.1-1.2. The ratio of
the lengtn of any one annular pre-mix chamber in said annular
passage to the length of the next annular pre-mix chamber in
6 7; L7:L8; L8:Lg; or L :L may be in the
range of about 0.1-1Ø
In most other respects the design of this pre-mix
embodiment of the burner, including the tubes, passages,
orifices, water-cooled face-plate and cooling coils, high
pressure high velocity ~ets of a gaseous material entering
said central and/or annular pre-mix chambers, and flow
control means are substantially the same as previously
described. Further, the temperature, pressure and velocity
ranges for the streams of materials Passing through the
various passages of the burner are substantially the same
as those discussed previously.
In the operation of the embodiment of the burner
employing pre-mix chambers flow control means may be used to
control the flow of the four feedstreams to the tubes and
passages in the burner in the same manner as described
previously. The feedstreams entering the burner and
- 5l-
~17Z~44
- 57
simultaneously and concurrently passing through at dif~erent
velocities impinge and mix with each other in the first
pre-mix chambers. The impingement of one reactant stream,
such as the liquid slurry of solid carbonaceous fuel in a
liquid medium optionally in admixture with a temperature
moderator, with anotr.er reactant stream, such as a gaseous
stream of free-oxygen containing gas optionally in admixture
with a temperature moderator at a higher velocity, causes
the liquid slurry to break up into a fine spray. The
multiphase mixture produced then successively passes through
any remaining pre-mix chambers where additional mixing takes
place. As the mixture passes freely through the sub~ect
unobstructed burner its velocity changes many times. For
example, at various points in the burner the velocity of
the mixture may range from about 20 to 600 ft. per sec.
As the mixture flows from one pre-mix chamber to the next,
the velocity changes are mainly the result of cnanges in the
diameter of the flow path and tne quantity and temperature
of the mixture. This promotes a thorough mixing of the
components. By oPerating in the region of turbulent flow,
mixlng may be maximized. Further, direct heat exchange
between the materials takes place within the burner. From
0-100 vol. %, say about 5-25 vol. % of the liquids in the
feedstreams may be vaporized before the feedstreams lea~e
the burner. By means of converging exit orifices, the
feedstreams may be accelerated directly into the reaction
zone of the partial oxidation gasifier.
Burning of the combustible materizls while passing
through the pre-mix zone of the b-urner may be prevented by
discharging the multiphase mixtures at the central and
117~ 44
- 58 -
annular exit orifices at the tip of the burner with a
discharge velocity which is ~reater than the flame propa~at'on
velocity. Flame speeds are a function of such factors as
composit~on of the mixture, temperature and pressure. They
may be calculated by conventional methods or determined
experimentally. The ratio of the discharoee ~elocity for the
multiphase mixture being discharged through the central exit
orifice to the multiphase mixture being discharged through
the annular exit orifice may be in the range of about 0.5 to
1.5, such as 1Ø
Depending on such factors as the temperature,
velocity, dwell time and composition of the feedstreams, the
desired amount of vaporization of liquid carrier; the
temperature and amount of recycle gases in the generator;
and the desired life of the burner; cooling coils may or may
not encircle the outside barrel of the burner along its length.
For similar reasons, the burner may or may not be Provided
with an annular shaped cooling chamber at the downstream
end.
The multiphase mixtures simultaneously departing
from the central orifice and/or the annular orifice at the
downstream tip of the burner mix together-downstream from
the face of the burner.
Advantageously, by means of the subject burner,
the exothermic partial oxidation reactions take place a
sufficient distance downstream from the burner face so as to
protect the burner from thermal damage.
Liquid hydrocarbon fuels and~or pum?able slurries
of solid carbonaceous fuels having a dry solids content in
3o the range of about 30 to 75 wt. ~, say about 40 to 70 wt. p
117Z~44
- 59 -
may be passed through the ~nlet passages of the sub~ect
burner. For example, the fuel streams may be passed through
the central and/or annular bunch Or tubes. The inlet
temperature of the liquid hydrocarbon fuel or the slurry
is in the range of about ambient to 500F., but preferably
below the vaporization temperature of the liquid hydrocarbon
at the given inlei pressure in the range of about 1 to 300
atmospheres, such as 5 to 250 atmospheres, say about 10 to
100 atmospheres.
The term solid carbonaceous fuels, as used herein
to describe sultable solid czrbonaceous feedstocks, is
intended to include various materials and mixtures thereof
from the group consisting of coal, coke from coal, char from
coal, coal liquefaction residues, petroleum coke, particulate
carbon soot, and solids derived from oil shale, tar sands,
and pitch. All types of coal may be used including
anthracite, bituminous, sub-bituminous, and lignite. The
particulate czrbon may be that which is obtained as a
by-product of the sub~ect partial oxidation process, or that
which is obtained by burning fossil fuels. The term solid
carbonaceous fuel also includes by definition bits of
garbage, dewatered sanltary sewage sludge, and semi-solid
organic materials such as asphalt, rubber and rubber-like
materials including rubber automobile tires whi~h may be
ground or pulverized to the proper particle size. Any
suitable grindlng system may be used to convert the solid
carbonaceous fuels or mixtures thereof to the proper size.
The solid carbonaceous fuels are preferably ground
to a particle size so thzt lOOp of the material passes
3o through an ASTM E 11-70 Sieve Designation Standard 1.~ m~
117~
- 60 -
(Alternative No. 14l and at least 80~o passes through an ASTM
E 11-70 Sieve Designation Standard 425,~m (Alternative No.
40).
The moisture content of the solid carbonaceous
~uel particles is in the range of about 0 to 40 wt. ~, such
as 2 to 2~ wt. %.
! The term liquid carrier, as used herein as the
suspending medium to produce pumpable slurries of solid
carbonaceous fuels is intended to lnclude various materials
from the group consisting of water, liquid hydrocarbonaceous
material, and mixtures thereof. However, water is the
preferred carrier for the particles of solid carbonaceous
fuel. In one embodiment, the liquid carrier is liquid
carbon dioxide. In such case, the liquid slurry may
comprise 40-70 wt. % of solid carbonaceous fuel and the
remainder ls liquid C02. The C02-solid fuel slurry may be
introduced into tne burner at a temperature in the range of
about -67F to 100F depending on the pressure.
The term liquid hydrocarbonaceous material as used
herein to describe suitable liquid carriers and fuels is
intended to include various liquid hydrocarbon materials,
such as those selected from the group consisting of
liquefied petroleum gas, petroleum distillates and residues,
gasoline, naphtha, kerosine, crude petroleum, asphalt, gas
oil, residual oil, tar sand oil and shale oil, coal derived
oil, aromatic hydrocarbons Csuch as benzene, toluene,
xylene fractions~, coal tar, cycle gas oil from fluid-
catalytic-cracking operation, furfural extract of coker gas
oil and mixtures thereof.
117~044
-- 61 --
The term liquld hydro~arbonaceOUS material as
usea herein to describe suitable liquid ~uels is also
intended to include various oxygen containing liquid
hydrocarbonaceous organic materials, such as those selected
from the group consisting of carbohydrates, cellulosic
materials, aldehydes, organic acids, alcohols, ketones,
oxygenated fuel oil, waste liquids and by-products from
chemical processes for producing oxygenated hydrocarbonaceous
organic materials, and mixtures thereof.
For example in one embodiment, the feedstream
comprises a slurry of liquid hydrocarbonaceous material
and solid carbonaceous fuel. H20 in liquid phase may be
mixed with the liquid hydrocarbonaceous carrier, for example
as an emulsion. A portion o~ the H2O i.e., about 0 to 25
weight % of the total amount of H20 present may be
introduced as steam in admixture with the free-oxygen
containing gas. The weight ratio of H20/fuel may be in
the range of about 0 to 5, say about 0.1 to 3.
The term gaseous hydrocarbonaceous material as
used herein to describe suitable gaseous hydrocarbonaceous
-~ fuels is intended to include a gaseous feedstock from the
group consisting o~ ethane, propane, butane, pentane,
methane, natural gas, coke-oven gas, refinery gas,
acetylene tail gas, ethylene off-gas, and mixtures thereof.
Simultaneously with the fuel stream(s~, one or more
free-oxygen containing gas stream~s) is supplied by way of
a free passageCs~ in the burner. The free-oxygen containi~g
gas may be passed through the central and/or annular sections
at a temperature in the range of about ambient to 15Q0F.,
~17Z0~4
- 62 -
and preferably in the rang~ Or about ambient to 300F.,
for oxygen-enriched air, and about 500 to 1200F., for air,
- and a pressure in the range of above about 1 to 300
atmospheres, such as about 5 to 250 atmospheres, say about
10 to 100 atmospheres. The atoms of free-oxygen plus atoms
of organically combined oxygen in the solid carbonaceous
fuel per atom of carbon in the solid carbonaceous fuel
(O/C atomic ratio) may be in the range of 0.5 to 1.95. With
free-oxygen containing gas in the reaction zone the broad
10 range of said 0/C atomic ratio may be about 0.5 to 1.7, such
as about 0.7 to 1.4. More specifically, with air feed to
the reaction zone, said 0/C atomic ratio may be about 0.7 to
1.6, such as about 0.9 to 1.4.
The term free-oxygen containing gas, as used
herein is intended to include air, oxygen-enriched air,
i.e., greater than 21 mole % oxygen, and substantially pure
oxygen, i.e., greater than 95 mole % oxygen, (the remainder
comprising N2 and rare gases).
The free-oxygen containing gas may be supplied
with or without mixture with a temperature moderating gas.
The term temperature moderating gas as employed herein
is intended to include by definition a member of the group
consisting of steam, CO2, N2, a recycle portion of the
cooled and cleaned effluent gas stream from the gas
generator, and mixtures thereof.
The sub~ect burners as shown in Figures 3-4 may be
operated with the feedstreams passing through alternati~e
passages in the burner. Typical modes of operation before
or after replacement of fuels are summarized in Tables I
~ 3o and II below.
.:
117~044
- 63 -
~ able I lists the materials being introduced in c
the gasifier by way of ~he burner and their correspondin~
symbol. The solid carbonaceous fuel (B~, water (5), and
liquid hydrocarbonaceous material (E~ may be mixed together
in various combinations upstream from the burner inlet to
produce a pumpable slurry which may be introduced into the
burner and then passed through one of the several free-flow
passages of the burner as shown in Table II. For example,
the first entry in ~able II shows that a pumpable slurry
stream comprising solid carbonaceous fuel (B) in admixture
with water (C) may be passed through the central and/or
annular bunch of tubes in the burner i.e. Fig. 1 or 2.
Whenever a fuel stream is introduced into the burner by way
of the central and/or bundles of tubes, a corresponding
stream of free-oxygen containing gas is simultaneously
passed through the related central conduit and/or annular
passage. Some addltional examples follow:
(1) separate streams of free-oxygen containing gas
may be passed through said central and/or annular bunches
of tubes; and simultaneously separate corresponding streams
of a pumpable slurry of solid carbonaceous fuel in a liquid
carrier or a hydrocarbonaceous fuel may be passed through
the related central conduit and/or annular passage.
(2) separate streams of free-oxygen containing gas
may be passed through sa~d central conduit and said annular
passage, while simultaneously a corresponding stream of
liquid hydrocarbonaceous material is passed through the
related central and~or annular bunches of tubes; and
simultaneously a pumpable slurry of solid carbonaceous fuel
~17Z044
- - 64 -
in a liquid carrier may be passed throu~h the unoccupled
bunch of said tubes, if any.
(3) separate streams of free-oxygen containing gas
may be passed through said central and/or annular bunches
of tubes; while simultaneously a corresponding stream of
liquid hydrocarbonaceous material is passed through the
related central conduit and/or annular passage; and
simultaneously a pumpable slurry of solid carbonaceous fuel
in a liquid carrier may be passed through the unoccupied
passage, if any.
TABLE I
Material Symbol
Free-oxygen Containing Gas A
Solid Carbonaceous Fuel B
Water C
Steam D
Liquid Hydrocarbonaceous Material E
Temperature Moderating Gas F
Gaseous Hydrocarbon Fuel G
TABLE II
Central Central Annular Annular
Conduit Bunch of Tubes Passa~e Bunch of Tubes
A B+C A B+C
A+D B+C A+D B+C
B+C A B+C A
A B+C B+C ~ A
B+C A A B+C
A B+C+E A B+C+E
: B+C+E A+D B+C+E A+D
3 A E A E
A+D B+E A+D B+E
B+E A+D B+E A+D
A+D E A B+C
E A E A
B+C A E A
E A B+C A
A G A B+C
A G A+D E
A E+F A E~F
40 E+F A+D , E+F A+D
Other modes of operation of the sub~ect invention
are possible in addition to those shown ln Table II.
1172~)44
- 65 -
~ For example, ~et streams of a gaseous material
may be simultaneously introduced into the central conduit
and/or annular passage, as previously described.
When one of the fuel streams is a liquid hydrocarbon
or the liquid carrier for the slurry of solid carbonaceous
fuel is a liquid hydrocarbonaceous material premature
combustion within the burner may be avoided by one or more
of the following:
(1) keeping the fuel below its autoignition temperature, -
~2) including water in the solid fuel slurry,
(3) using air or air enriched with oxygen i.e. up to about
40 vol- % 2~
(4) mixing steam with the air,
(5) employing about 0 retraction of the ends of the central
and annular bunches of tubes from the face of the
burner. In such case, the free-oxygen containing gas
such as substantially Pure oxygen may be separately
discharged from the burner without first contacting the
fuel stream.
(6) discharging the multiphase mixture at the central and
- annular exit orifices at the tip of the burner with
- discharge velocities that exceed the t'lame propagation
velocity.
The subject burner assembly is inserted downward
through a top inlet port of a compact unpacked free-flow
noncatalytic refractory lined synthesis gas generator, for
example as shown in coassigned U. S. Patent No. 3,5~4,291.
The burner extends along the central longitudinal axis of
the gas generator with the downstream end discharging
directly into the reaction zone.
The relative proportions of the reactant feedstreams
and optionally temperature moderator that are introduced
into the gas generator are carefully regulated to convert
a substantial portion of the carbon in the fuel e~g., u~
to about ~0% or more by weight~ to carbon oxides, and to
ma~ntain an autogenous reaot~on zone temperature ~n the
1~7Z~)44
- 66
range of about 1700 to 3500F., preferably in the range
of 2000 to 2800F.
The dwell time in the reaction zone is in th~
range of about 1 to 10 seconds, and preferably in the range
of about 2 to 8. With substantially pure oxygen feed to the
gas generator, the composition of the effluent gas from the
gas generator in mole ~ dry basis may be as follows:
H2 10 to 60, C0 20 to 60, C02 5 to 40, CH4 0.01 to 5,
H2S+COS nil to 5, N2 nil to 5, and Ar nil to 1.5. With air
feed to the gas generator, the composition of the generator
effluent gas in mole % dry basis may be about as follows:
H2 2 to 30, C0 5 to 35, C02 5 to 25, CH4 nil to 2,
H2S+COS nil to 3, N2 45 to 80, and Ar 5 to 1.5. Unconverted
carbon and ash are contained in the effluent gas stream.
The hot gaseous effluent stream from the reaction
zone of the synthesis gas generator is quickly cooled below
the reaction temperature to a temperature in the range of
about 250 to 700F. by direct quenching in water, or by
indirect heat exchange for example with water to produce
stea~ in a gas cooler.
Advantageously, in another embodiment of the
sub~ect invention the sub~ect two-section burner may be used
as the preheat burner during start-up of the gasifier, as
well as the production burner. Start-up procedures are
- thereby simplified. Previously, time was lost when the g2S
preheat burner was replaced by the production burner, and the
; gasifier cooled down. Now the gasifier may be brought up to
operating temperature and held there by simultaneously
passing a gaseous or liquid hydrocarbonaceous fuel i.e. fuel
gas, with or without mixture with H20, through the central
117~44
- 67
and/or annular bund e(s) of tubes and a ~ree-oxygen
containin~ gas~ p~e~erably a~r, with or without mixture with
H 0 through the associated central conauit and/or annular
passage. Alternately, the gaseous or liquid hydroc2rbonaceous
fuel i.e. fuel gas with or without mixture with H20 may be
passed through the central conduit and/or annular passage in
the burner and the air with or without mixture with H 0
may be passed through the associated central and/or annular
bundle~s) of tubes. The fuel gas and air are mixed together
to produce a well-distributed blend. Burning of the mixture
by substantially complete combustion then takes place in the
reaction zone of the gas generator at a temperature in the
range of about 2000 to 4500F., such as about 2000 to 3000F.
and at an absolute pressure in the range of about 0.56 to
300 atmospheres, and preferably at 1 atmosphere. The products
of the complete combustion are removed from the reaction zone.
For example, they may be vented to the atmosphere.
By this means, the reaction zone is heated to the
temperature required for ignition of the autothermal partial
oxidation reaction of the principal fuel selected from the
group consisting of a pumpable slurry of solid carbonaceous
fuel, liquid or gaseous hydrocarbon fuel, and mixtures
thereof with a free-oxygen containing gas and with or
without a temperature moderator. For example, the auto-
ignition temperature may be in the range of about 2000 to
2700F. At this point, the fuel gas, with or without
mixture X 0, is phased out of the tubes or conduits in
which it is flowing in the central and~or annular section
(52 of said two-section burner with a uniformly decreasing
rate of flow that varies from maximum rate to 0 over a
period in the range of about 1-3600 seconds, say about
117~(~44
- 68 -
60-1800 seconds. Simultaneously, the principal solid
carbonaceous ~uel slurry or liquid hydrocarbonaceous fuel,
with or without mixture with H2O, ls phased into the
remaining portion of sald fuel gas and replaces tne
phased-~ut portion of the fuel gas with a uniformly increasing
rate of flow that varies from 0 to maximum over the same
period of time.
Simultaneously with the replacement of the fuel,
or alternatively when the fuel gas has been completely
replaced in the burner by the principal fuel, the free-oxygen
containing gas i.e. air, with or without mixture with H2O,
is phased out with a uniformly decreasing rate of flow that
varies from maximum to 0 over a period in the range of
1-3600 seconds, say about 60-1800 seconds. Simultaneously,
another free-oxygen containing gas i.e. oxygen-rich gas or
substantiall~ pure oxygen for the production of syngas is
phased into the same line to replace the air at a uniformly
,increasing rate of flow that varies from 0 to maximum over
the same period of time. Further, the rates of flow of the
free-oxygen containing gas with or without mixture with
H2O and lf necessary the weight ratio H2O/fuel in the
reaction zone are ad~usted so as to continuously maintain
the temperature and the weight ratio H2O/fuel in the
reaction zone at design conditions for the partial oxidation
of said principal fuel.
Partial oxidation of the principal fuel takes
place downstream in the reaction zone of the free-flow
noncatalytic gas generator at design conditions which include
an autogenous temperature in the range of about 1700 to 3500F.,
a pressure in the range of about 1 to 300 atmospheres, an
1172044
- 69 -
atomic ratio of oxygen to carbon in ~he range of about
0.5 to 1,7, say to 0.8 to 1.2, and an H20/fuel weight ratio
in the range of about 0 to 5.0, such as 0.1 to 3.
The hot gaseous effluent stream from the reaction zone
of the synthesis gas generator is quickly cooled below
the reaction temperature to a temperature in the range of
about 250 to 700F. by direct quenching in water, or by
indirect heat exchange for example with water to produce
steam in a gas cooler. The gas stream may be cleaned and
purified by conventional methods.
A more complete understanding of the invention may be
had by reference to Figures 4 and 5 of the drawings which
show the subject invention in detail. Although the drawing
illustrates preferred embodiments of the invention, it is
not intended to limit the subject invention to the particular
apparatus or materials described. Like parts in the
embodiments of Figures 1 to 5 are given like reference
numerals.
Referring to Fig!s. 4 and 5, Fig. 4 is a schematic
representation of one embodiment of the invention showing
control means for the continuous operation of a synthesis
gas generator while phasing out one fuel and simultaneously
phasing in another without depressurizing. Further, the
control means may be used for rapidly changing throughput
levels - up or down over the flow range for which the two-
section burner shown in designed. By this means adjustments
may be made to control the amount of raw effluent gas
produced, and to provide for a change in demand for the
product gas. Further, another use for the control system
is to maintain the desired composition of the product gas
when possible to do so by adjustments to the flow rates
of one or more of the reactant streams. Thus, by the subject
11~2044
- 70 -
flow ~on~rol system, the flow rates for all of the reactant
streams are separately anà independently controlled so
that the temperature and wei~ht ratio of H20 to fuel in the
reaction zone are maintained at design conditions and
within desired operating ranges for the fuel being reacted
If necessary the atomic ratio of free-oxygen to carbon in
the fuel in the reaction zone may also be controlled within
design conditions.
While the control system shown in Figure 4 is
specifically deslgned for the combination of feedstocks
comprising a solid carbonaceous fuel slurry and a liquid
hydrocarbonaceous fuel, by simple modifications to the
means for changing the flow rate of the streams up or down
in a manner similar to that as described below, the system
may be used to control other combinations of solid carbonaceous
fuel slurries, and liquid, or gaseous hydrocarbon fuels.
Two-section burner 1 is mounted in central
flanged inlet 30 located in the upper head of conventional
refractory lined free-flow synthesis gas generator 41 along
the central longitudinal axis. The reactant streams enter
through the upstream end of burner 1, pass downward
therethrough, and are discharged through the downstream
end. Burner 1 is designed so that the required system
output for steady-state operation may be achieved or even
exceeded by a specified amount when the flow rate through
all passages in ~oth sections of the two-section burner is
a maximum. The con$rol system can independently change up or
down the flow rate of any one or more of the reactant s'reams
in lines 187, 1~0, 167, 170, 50, 60, 70 and 73. By this
means the temperature in t~e reaction zone 31 is maintained
at the desired operating temperature. Further, the weight
1172~4
- 71 -
ratio H20 ~o ~uel, and if necessary the atomic r-~io of
free oxygen to carbon in the fuel in the reacti~n zone may
be maintained at design conditions whether one or both
sections of the burner are employed to step-up or step-down
production of product gas.
~ wo-section burner 1 comprises a central section
and a concentric annular section. The central section
substantially comprises: central cylindrical conduit 2
having a closed upstream end and an open downstream end,
central bunch of parallel tubes 3 supported longitudinally
in central passage 4 of central conduit 2 and having open
upstream ends that pass through and are sealed in the
closed upstream end of central conduit 2 and are in
- communication with central cylindrical shaped manifold 19,
inlet feed pipe 20 connected to and in communication with
central manlfold 19, and inlet feed pipe 25 connected to
and in communication with the closed upstream end of
central conduit 2. The annular section comprises: outer
cylindrical concentric conduit 5 which is closed at the
upstream end and open at the downstream end, annular
passage 6 between the outside diameter of central conduit 2
and the inside diameter of outer conduit 5 along its length,
annular bunch of parallel tubes 7 supported longitudinally
in said annular passage 6 and having open upstream ends
that pass through and are sealed in the closed upstream
annular end of outer conduit 5 and are in communication with
annular manifold 28, inlet feed pipe 2~ connected to and
in communication with annular manifold 28, and inlet feed
pipe 35 connected to and in communication with the upstream
closed end of outer conduit 5.
1172044
, - 72 -
While the downstream tips of central bunch of
tubes 3 and annular bunch of tubes 7 are shown in Fig. 4
as being flush with ~he face of burner 1, in other embodimenvs
of the two-section burner the downstream tips of the central
and/or annular bunch(es) of tubes may be retracted upstream
to provide at least one premix zone as shown in Fig. 5
Although central bunch of tubes 3 and annular
bunch Or tubes 7 are shown in Fig.4 as being parallel to
each other and to the burner axis, in another embodiment of
the two-compartment burner which is shown and descrlbed
in coassigned U. S.,Patent Application S.N. 212,054 i.e.
Fig. 5 thereof,
the central and/or annular bunches of tubes may
be helical-shaped. By this means the swirling reactant
streams passing down through the central and/or annular
bundles of helical tubes; and separately down through the
helical passages on the outside of the helical bundles of
tubes may impinge together either in the premix zones or
downstream in the reaction zone and may be thereby intimately
mixed together. Combustion efficiency of the burner is
thereby improved.
In Fig. 4 for purposes of illustration, the
principal fuel may be for example a solid carbonaceous fuel
slurry i.e. coal-water slurry in line 42. The stand-by fuel
is a liquid hydrocarbonaceous fuel i.e. residual oil in line
160. Of course, the principal fuel may have been chosen to be
any liquid or ~aseous hydrocarbonaceous fuel or a coal-oil
slurr,y. The metered feed~tream of solid carbonaceous fuel
slurry in line 42 is split into two fuel feedstreams 43 and
44 by separate flow control means in each line. Similarly,
1172044
~ 73 -
the metered feedstream of llquid hydrocarbonaceous fuei
in l~ne 160 ls split into two fuel feedstreams 161 and 162
bY separate flow ~ontrol means in each line. In the subject
process, the remaining portions of the principal fuel stream(s)
being phased out of line 50 and/or line 60 are respectively
mixed in lines 15 and/or 16 w~th the stand-by fuel stream(s)
being phased into line 167 and/or line 170.
In a similar manner, the metered feeds~ream of
free-oxygen containing gas in line 62 is split into two
feedstreams 63 and 64 by separate flow control means in each
line.
H20 may be in admixture with the fuels,in lines
160 and 42 or the free-oxygen containing gas in line 62.
Alternatively, as shown in Fig. 1, at least a portion i.e.
10-100 vol. % of the H20 may be provided as steam. Thus,
steam in line 180 ls split into two feedstreams 181 and 182
by separate flow control means in each line. By this means
as shown in Fig. 4, steam in line~s) 187 and/or 190 preferably
may be mixed respectively in line(s) 18 and/or 17 wlth the
free-oxygen containing gas flowing into one or both sections
of the burner. In a similar manner (not shown) steam from
line(s) 187 and/or 190 may be respectively supplied to the
fuel in line(s) 15 and/or 16. By this scheme, controlled
amounts of steam may be introduced lnto and mixed with the
streamCs~ of free-oxygen containing gas and/or fuel upstream
from the burner.
The weight or volumetric rate of flow for that
portion of the feed flowing through each of the feedlines
to the burner is a function of the burner design. For
example, the burner passages may be sized so that one-third
117204~
- 74 -
of the t~tal quantity of the solid carbonaceous fuel slurry
flowing through line 42 plus tne liquid hydrocarbonaceous
fuel flowing through line 160 may be discharged through
central bunch of tubes 3 at a specified velocity range.
Simultaneously, the remaining two-thirds of the total
quantity of solid carbonaceous fuel slurry plus liquid
hydrocarbonaceous fuel may be discharged throu~h annular
bunch of tubes 7 at a specified velocity range.
Valves 183, 184, 163, 164, 77, 76, 65 and 66
may be manually or automatically operated to obtain a wide
open position to a completely closed position. The rates
that each valve may be opened and closed is also controllable.
In one embodiment to be further described, by closing
specific valves one may turndown or sectionalize the burner.
The burner may be thereby operated either in the central
section i.e. central tubes 3 and annular passage 4, or in
the outer annular section i.e. annular tubes 7 and annular
passage 6, or with both the central and annular sections
of the burner in simultaneous operation.
Operation of the system while employing only
the central section of the burner will be described first.
The portion of the slurry feedstream in line 43 is pumped
into the reaction zone 31 of synthesis gas generator 41
by way of positive displacement pump 45 e~uipped with speed
control 46, line 47, flow measurer and transmit~er 48, line 49,
valve 77, lines 50 and 15, inlet 20 of burner 1, central
manifold 1~, and central bunch of tubes 3.
The slurry flow rate through line 43 is controlled
by the speed of positive displacement pump 45. In order
to phase out the slurry flowinc through line 43, this speed
117~0~4
75 -
is continuou~ly decreased from maximum to zero over a pericd
in the range of about 1 to 3600 seconds, such as about 60
to 1800 seconds, say about 300 to 1000 seconds. Flow
recorder-controller with transmitter 51 comprises a
microcomputer means which is programmed with the desired
time vs. decreasing flow rate curve. The rate of slurry flow
in line 47 is measured and a signal a is provided by flow
transmitter 48 corresponding to the flow rate of the slurry
in line 43. Flow recorder-controller 51 receives signal a,
compares it with a signal representing the desired flow rate
for that moment, and provides a correspondin~ ad~ustment
signal to speed control 46 to adjust the speed of pump 45
downward so that the charge slurry flowing in line 49 assumes
a given decreased flow rate for that moment in the phase-out
period. The new slurry rate is measured and the cycle is
repeated. By this means, repeated adjustments to the rate
of flow are made and the slurry flowing in line 50 is phased
out.
Simultaneously with the phasing out of the portion
o~ principal slurry fuel flowing in line 43, the portion of
stand-by liquid hydrocarbonaceous fuel flowlng in line 161
is phased in over the same period of time. Flow recorder-
controller with transmitter 171 comprises a microcomputer
means which is programmed with the desired time vs~ increasing
~low rate curve. The rate of oil flow in line 161 is measured
and a signal m is provided by flow transmitter 165
corresponding to the flow rate of the oil in line 161.
Flow recorder-controller 171 receives signal m, compares it
with a signal representing the desired flow rate for that
3o moment and provides a corresponding ad~ustment signal to
va ve 1~3 to open wlder so that the c~2rge oll ln 11ne 166
" - 76 - 1 1 7 2 O 4 4
assumes a given increased flow rate for that ~oment in
the phase-in period. The new oil rate is measured and the
cycle is repeated. By this means, repeated adjustments to
the rates o~ flow of the principal and stand-by fuels may
be made so that the oil flowing in line 167 may be phased
in~o line 15 in an amount that compensates for the reduced
amount of solid carbonaceous fuel slurry flowing in line 5Q.
~ uring or after the period that the portion of
principal solid carbonaceous slurry fuel from line 43 is
phased out and the portion of stand-by liquid hydrocarbon fuel
from line 161 is phased in, the weight ratio of temperature
moderator to fuel in the reaction zone may be controlled
for example at design conditions, or substantially constant
i.e. less than + 10% variation, by increasing or decreasing
the flow rate of the temperature moderator. Accordingly
in the subject example, simultaneously with the phase-out
of the coal-water slurry a supplemental amount of H20 from
an external source may be phased in over the same period of
time. Thus, in Fig. 4, a portion of the steam in line 180
is passed through line 181 and is phased into line 18 where it
mixes with the free-oxygen containing gas from line 70. Flow
recorder-controller with transmitter 191 comprises a micro-
computer which is programmed with the desired time vs.
increasing flow rate curve.
- The rate of steam flow in line 181 is measured
and a signal s is provided by flow transmitter 185
corresponding to the flow rate of the steam in line 181.
Flow recorder-controller 191 receives signal s, compares it
with a signal representing the desired flow rate for that
moment and provides a corresponding adjustment signal to valve
183 to open wider so that the charge steam in line 186 assumes
3~17~44
- 77 -
a given increased ~low rate for that moment in the phase-in
period. The new steam rate is measured and the cycle is
repeated. By this means, repeated adjustments to the rate
of steam flow are made and the steam flowing in line 187 is
phased into line 18 in an amount that will maintain the
weight ratio of H20 to fuel in the reaction zone at design
conditions.
In another embodiment the weight ratio H20/fuel in
the reaction zone is ad~usted up or down by controlling the
steam rate as described previously in order to obtain a
desired temperature in the reaction zone and composition of
the product gas.
Simultaneously with or after the phasing out of
the principal fuel, the phasing in of the stand-by fuel, and
optionally with or without the phasing in or out of the
steam depending on the nature of the fuels, the free-oxygen
containing gas may be adjusted up or down so as to control
the temperature in the reaction zone for example at design
conditions, or substantially constant i.e. less than -
200F.-variation. Thus, in the present example in Fig. 1, a
portion of the free-oxygen containing gas in line 62 is
passed through line 63 and is phased into line 18 where it
mixes with the steam, if any, from line 187 as previously
described. Flow controller 74 is programmed with the desired
time vs. flow rate curve. The period of ad~ustment is the
same as that for the fuel and steam streams. The adjust-
ment to the oxygen flow rate may be up or down depending on
the nature of the fuel streams and the addition of steam, if
any. In the sub~ect example, the oxygen flow rate will be
increased to satlsfy the additional requirements for the
partial oxidation of a liquid hydrocarbon in compar son with
a solid carbonaceous fuel.
117Z044
- 78 -
The rate of free-oxygen containing gas in line 63
is measured and a signal b is provided by flow transmltter
67 corresponding to the flow rate of the free-oxygen
containing gas in line 63. Flow recorder-controller with
transmitter 74 comprises a microcomputer means which receives
' signal b, compares it with a signal representing the desired
i flow rate for that moment~ and provides a corresponding
¦ adjustment signal to valve 65 to open wider so that the
¦ charge free-oxygen containing gas in line 68 assumes a given
increased flow rate for that moment in the phase-in period.
The new free-oxygen containing gas rate is measured and the
cycle is repeated. By this means repeated ad~ustments to the
rate of oxygen flow are made and the free-oxygen containing
gas flowing in line 70 is phased into line 18 in an amount
that will maintain the temperature in the reaction zone
substantially constant.
In another embodiment, the free-oxygen containing
gas rate is ad~usted up or down to obtain a desired
temperature in the reaction zone and composition of the
product gas. Alternatively, by the previously described
means, the atomic ratio o~ oxygen to carbon in the reaction
zone may be controlled at design conditions i.e. in the
range of about 0.5 to 1.7.
Operation of the system while employing only
the annular section of the burner is similar to that
described previously in connection with the central section
of the burner. The portion of the slurry feedstream in
line 44 is pumped into the reaction zone 31 of synthesis
gas generator 41 by way of positive displ~cement pump 55
equlpped w1th apeed control 56, 11ne 57, flow me3aurer and
'
.
~17~044
- 79 -
transmltter 58~ line ~9, valve 76, lines 60 and 16, inlet 2a
of burner l, annular manifold 28, 2nd annular bunch of
tubes 7.
The slurry flow rate through line 44 is controlled
by the speed of positive displacement pump 55. In order
to phase out the slurry flowing through line 44, this speed
ls continuously decreased from maximum to zero over a period
in the range of about l to 3600 seconds, such as about 60
to 1800 seconds, say about 300 to lO00 seconds. Flow
recorder-controller with transmitter 61 comprises a
mic~ocomputer which is programmed with the desired time vs.
decreasing flow rate curve. The rate of slurry flow in
line 57 is measured and a signal d is provided by flow
transmitter 58 corresponding to the flow rate of the slurry
in line 44. Flow recorder-controller 61 receives signal d,
compares it with a signal representing the desired speed at
that moment, and provides a corresponding ad~ustment.signal
to speed control 56 to ad~ust the speed of pump 55 downward
so that the charge slurry flowing in line 59 assumes a given
decreased flow rate for that moment in the phase-out period.
The new slurry rate is measured and the cycle is repeated.
By this means, repeated ad~ustments to the rate of flow are
¦ made and the slurry flowing in line 60 is phased out.
Simultaneously with the phasing out of the portion
of principal slurry fuel flowing in line 44, the portion of
stand-by liquid hydrocarbonaceous fuel flowing in line 162
is phased in over the same period of time. Flow recorder-
controller with transmitter 172 comprises a microcomputer
means which is programmed with the desired time vs. increasing
flow rate curve. The rate of oil flow in line 162 is
llt~Z044
- 80 -
measured and a signal q is provided by flow transmitter 168corresponding to the flow rate of the oil in line 162. Flow
recorder-controller 172 receives signal q, compares it with
a signal representing the desired flow rate at that moment,
and provides a corresponding ad~ustment signal to valve 164
to open wider so that the charge oil in line 169 assumes a
given increased flow rate for that moment in the phase-in
period. The new oil rate is measured and the cycle is
repeated. By this means, repeated adjustments to the rates
of flow of the principal and stand-by fuels may be made so
that the oil flowing in line 170 may be phased into line 16
in an amount that compensates for the reduced amount of
solid carbonaceous fuel slurry flowing in line 60.
During or after the period that the portion of
principal solid carbonaceous slurry fuel from line 44 is
phased out and the portion of stand-by liquid hydrocarbon
fuel from line 162 is phased in the weight ratio of temp-
erature moderator to fuel in the reaction zone may be con-
trolled for example at design conditions, or substantially
constant i.e. less than - 10% variation by increasing or
decreasing the flow rate of the temperature moderator.
Accordingly, in the subject example, simultaneously with the
phase-out of the coal-water slurry a supplemental amount of
H20 from an external source may be phased in over the same
period of time. Thus, in Fig. 4, a portion of the steam in
line 180 is passed through line 182 and is phased into line
17 where it mixes with the free-oxygen contalning gas from
line 73. Flow recorder-controller with transmitter 192
comprises a microcomputer means which is programmed with the
desired time vs. increasing flow rate curve.
.
44
- 81 -
The rate o~ steam flow in line 182 is measured and
a signal t is provided by ~low transmitter 188 corresponding
to the flow rate of the steam in line 182. Flow recorder-
controller 192 receives signal t, compares it with a signal
representing the desired flow rate at that moment, and
provides a corresponding adjustment signal to valve 184 to
open wider so that the charge steam in line 189 assumes a
given increased flow rate for that moment in the phase-in
period. The new steam rate is measured and the cycle is
repeated. By this means, repeated adjustments to the rate
of steam flow are made and the steam flowing in line 190 is
phased into line 17 in an amount that will maintain the
weight ratio of H20 to fuel in the reaction zone at design
conditions.
In another embodiment the weight ration H20~fuel
in the reaction zone is adjusted up or down by controlling
the steam rate as described in the manner described pre-
viously in order to obtain a desired temperature in the
reaction zone and composition of the product gas.
Simultaneously with or after the phasing out of the
principal fuel, the phasing in of the stand-by fuel, and
optionally with or without the phasing in or out of the
steam depending on the nature of the fuels, the free~oxygen
containing gas may be ad~usted up or down so as to control
the temperature in the reaction zone for example at design
conditions, or substantially constant i.e. less than - 200F.
variation. Thus in the present example, in F~g. 1, a portion
of the free-oxygen containing gas in line 62 is passed
through line 64 and is phased into line 17 where it mixes
with the steam, if any, from line 190 as previously described.
~17Z04~
Flow recorder-controller with transmitter 75 comprises a
microcomputer means which is progr~mmed with the desired
time vs. flow rate curve. The perlod of adjustment is
the same as that for the fuel and steam streams. The
ad~ustment to the oxygen flow rate may be up or down
depending on the nature of the fuel streams and the
addition of steam, if any. In the subject example, the
oxygen flow rate will be increased to satisfy the additional
requirements for the partial oxidation of a liquid hydro-
carbon in comparison with a solid carbonaceous fuel.
The rate of free-oxygen containing gas in line 64
is measured and a signal e is provided by flow transmitter
71 corresponding to the flow rate of the free-oxygen
containing gas in line 64. Flow recorder-controller 75
receives signal e, compares it with a signal representing the
desired flow-rate for that moment, and provides a corresponding
ad~ustment signal to valve 66 to open wider so that the
charge free-~xy~en containing gas in llne 72 assumes a
given increased flow rate for that moment in the phase-in
period. The new free-oxygen containing gas rate is measured
and the cycle is repeated. By this means repeated ad~ustments
to the rate of oxygen flow are made and the free-oxygen
containing gas flowing in line 73 is phased into line 17 in
an amount that will maintain the temperature in the reaction
zone substantially constant.
In another embodiment, the free-oxygen containing
gas rate is adjusted up or down to obtain a desired
temperature in the reaction zone and composition of the
product gas. Alternatively, by the previously described
means, the atomic ratio of oxygen to carbon in the reaction
zone may be controlled at design conditions i.e. in the
1~7204* 83 -
range of about 0.5 to 1.7.
The previously mentioned time vs. flow rate curves
for programming flow controllers 191, 192, 171, 172, 51, 61,
74 and 75 may be determined by conventional calculations
based on heat and weight balances for the entire system.
In another embodiment, the parameters for said
calculations and any others may be measured by conventional
detectors and the signals responsive thereto may be fed to
an overall control means or computer 40. The input to flow
control means 40 may be manual or a signal from a computer,
analyzer, or sensor. Control means 40 comprises conventional
circuits and components for providing signals i.e. pneumatic
or electronic to operate said speed controls and valves.
In control means 40, the computer calculated
values or the manually inserted set points for the desired
rates of flow at specific moments for the various streams
are compared respectively with the signals a, d; s, t; m, q;
and b, e. For example, responsive to signal(s) a and/or d,
control means 40 may automatically control pump speed control(s)
46 and/or 56 by sending signal~s) c and/or f respectively to
flow-recorder-controller(s) 51 and/or 61. Alternatively,
signal(s) c and/or f may be fed directly to speed control(s)
46 and/or 56 respectively. Signals 1 and/or g from control
means 40 may be employed to close respectively solid car-
bonaceous fuel slurry valves 77 and/or 76. In another
embodiment, for example flow recorder-controller 51 may
receive signal a from flow transmitter 48 and signal c from
control means 40 and compute the speed ad~ustment signal for
the operation of speed control 46.
In a similar manner9 responsive to signal~s) s
an~/or t, control means 40 may automatically control steam
~ 0~4 84 -
valve(s) 183 and/or 184 by sending si~nal(s) u and/or r
respe~tively to flow-recorder-controller(s) 191 and/or 1~2.
Similarly, responsive to signal~s) m and/or q,
control means 40 may automatically control liquid hydrocarbon-
aceous fuel valveCs~ 163 and/or 164 by sending signal(s)
w and/or x respectively to flow-recorder-controller(s~ 171
and/or 172.
Also, similarly, responsive to signal(s) b
and/or e, control means 40 may automatically control
free-oxygen containing gas valve(s~ 65 and/or 66 by sending
signal(s) J and/or h respectively to flow-recorder-
controller(s) 74 and/or 75.
FIG. 5 is a vertical longitudinal schematic
representation of another embodiment of the subject two-section
burner. Two pre-mix chambers in series are located in the
central conduit in the central section and also in the annular
passage in the annular section. The ends of the central
bundle of tubes in the central section and the annular bundle
of tubes in the annular section are retracted upstream from
the face of the burner. In FIG. 5, burner 80 comprises
central conduit 81 which in part constitutes the wall 82
between central passage 83 and coaxial radially spaced
annular passage 84, two rows of a central bundle of parallel
tubes 85 that pass longitudinally through the upper portion
of central passage 83 and having upstream ends 86 that pass
through tube sheet 87 making a gastight hermetic seal there-
with, and downstream ends 88 which are retracted upstream
from face 8~ at the downstream end of burner 80, coaxial
concentric radially spaced outer conduit ~0 surrounding said
3o annular passage 84 along its length, two rows of an annular
bundle of parallel tubes 95 that pass longitudin211y througn
~17~044
- 85 -
annular passage 84 with upstream ends 96 passlng through
tube sheet 97 and making a gastight seal therewith and
having downstream ends 98 retracted upstream from face 89,
annular manifold 100 in communication with the upstream ends
96 of said annular bundle of tubes 95, manifold 101 which may
be cylindrical-shaped in communication with the upper ends
86 of said central bundle of tubes 85, inlet means 102 for
introducing a first feedstream into said central manifold
101, inlet means 103 for introducing a second feedstream
into said centra~ passage 83 and in the interstices surrounding
said central bundle of tubes 85, inlet means 104 for
introducing a third feedstream into said annular manifold 100,
inlet means 105 for introducing a fourth feedstream into
said annular passage 84 and into the interstices surrounding
the annular bundle of tubes ~5, cooling coils 106 which
encircle the outside diameter of outer conduit 80 along its
length, and cored cooling chamber 107 at the downstream tip
of the burner.
Disc shaped central tube sheet 87 closes off
central passage 83 below lts upstream end. Similarly,
annular shaped tube sheet 97 closes off annular passage 84
below its upper end. Conventional means i.e. welding,
turning, crimping, threading, rolling may be employed to
provide a pressure and gastight hermetic seal or ~oint
where the central and annular bunches of tubes penetrate the
respective tube sheets. Mechanical pressure fittings and
coupling devices may be also employed.
Plate 108 which may be disc-shaped seals off the
upper end of central conduit 81. The space between plate
108 and tube sheet 87 constitutes said central manifold 101.
By this means, for example, a portion of a first reactant
' .
- ~172044 86 -
feedstream in feed pipe 102 may be introduced into central
manifold 101 and then split into a plural~ty of streams
whlch pass through tube sheet 87 and the individual tubes
in central bundle 85. Annular shaped disc 109 seals off
the upper end of annular passage 84. ~he space between
annular disc 109 and annular tube sheet 97 constitutes
annular manifold 100. Simultaneously and concurrently
with the introduction of the first react.ant ~eedstream,
the third reactant feedstream in feed pipe 104 may be
introduced into annular manifold 100, split into a plurality
of streams which pass through tube sheet 97 and the
individual tubes in annular bundle 95.
Wall brackets or tube spacers 115 hold the
individual tubes in annular tube bundle 95 in a fixed
parallel nontouching relationship with respect to each other,
the inside of outer conduit 90, and the outside diameter of
central conduit 81. Similarly, wall brackets or tube
spacers 116 hold the individual tubes in central tube
bundle 85 in a fixed parallel nontouching relationship with
respect to each other and the inside diameter of central
i conduit 81.
While the pre-mix zones in the embodiment in
FIG. 5 are shown as comprising two separate coaxial central
pre-mix chambers 117 and 118 in series in central conduit 83,
and two separate coaxial annular pre-mix chambers 119 and
120 in series in annular passage 84, the pre-mix zone of
other embodiments of the sub~ect invention may actually
comprise one or more, such as 2 to 5 coaxial central and/or
annular pre-mix chambers. Each central pre-mix chamber,
except for the first chamber in the line, com?r~ses a coaxial
; cylindrical body portion 121 followed by ~ c02x121 at least
11'7~ 4
- 87 -
partlally convergin~ frusto-conical outlet portion 122 tha~
may optionally develop into a normal cylindrical portion
123. This outlet portion is shown in FIG.5 as a converging
central nozzle 124 which terminates at the downstream face
of the burner. Optionally, nozzles 124 and 133 to be further
described may be made from a thermal and wear resistant
material i.e. silicon carbide or tungsten carbide.
The first central pre-mix chamber in the line may
have a straight coaxial cylindrical body portion 125, that
discharges through circular orifice 126 directly into the
next in line central coaxial pre-mix chamber 118. Preferably,
the inlet to the first central pre-mix chamber 117 is a
portion of a converging frusto-conical shaped section 127.
Each of the coaxial annular shaped pre-mix chambers
120 except the first annular shaped chamber 119 comprises a
coaxial generated normal cylindrical annular body portion
130 followed by a coaxial generated at least partially
converging frusto-conical shaped annular outlet portion 131
that may optionally develop lnto a coaxial generated normal
cylindrical annular portion 132. This outlet portion is
shown in FIG. 5 as a converging annular exit nozzle 133
which terminates at the downstream face of the burner. The
first coaxial annular shaped pre-mix chamber 119 comprises a
coaxial generated normal cylindrical annular body portion
134 that discharges through annular orifice 135 into the
next in line coaxial annular shaped pre-mix chamber 120.
Preferably, the inlet to the first annular shaped pre-mix
chamber 119 comprises a portion of a coaxial generated
converg~ng frusto-conical shaped section 136.
Cored faceplate 107 comprises a front portion 137
at the extreme tip of the burner, which may be flat or
curved, and which contains a coaxial central annular shaped
:117;~044
-- 88 --
cooling chamber 138 surrounding the central conduit exit
nozzle 124 and/or a coaxial radially spaced annular shaped
cooling chamber 139 surrounding said annular exit nozzle 133
at the tip of the burner. The cooling chamber may be ~oined
to the otherwise flat burner tip such as shown in FIG. 4, or
lt may be an extension of the central and outer conduits.
Cold cooling water in line 140 enters annular shaped cooling
chamber 139, splits by means of baffles and flows about
180~, and leaves by way of an opposite outlet which is
connected to outer coils 106. Cooling water is introduced
into central annular cooling chamber 138 by way of line 145
which is connected to passage 146 that passes longitudinally
down through wall 82 in central conduit 81. ~he cool water
splits by means of baffles, flows about 180 around central
cooling channel 138, and leaves by way of an opposite coaxial
longitudinal passage (not shown) similar to passage 146 but
in another location in wall 82.
Optionally, a gaseous feedstream selected from the
group consisting of steam, free-oxygen containing gas, CO2,
N2, fuel gas, recycle portion of the product gas, and
mixtures thereof may be introduced into at least one of the
central and/or annular pre-mix chambers by way of at least
one inlet pipe 149 which is connected to at least one
longitudinal passage 147 in wall 82 of central conduit 81,
and at least one branch passage 148 connecting longitudinal
passage 147 with said pre-mix chambers.
While the central bundle of tubes 85 and the
annular bundle of tubes 95 are shown in Figure 5 as
comprising a plurality of parallel tubes, in another
embodiment of the burner depicted in Figure 5 of coassigned
patent application Serial No. 212,054 iled in the U. S.
- 117~044
- 89 -
Patent and Trademark Office on December 3, 1980 and Figure
13 of our published French Patent Applicat10n No. $027516,
and which are incorporated herein by reference, the central
and annular bundles of tubes may be helical shaped.
Although modifications and variations of the invention
may be made without departing from the spirit and scope
thereof, only such limitations should be imposed as are
indicated in the appended claims.
