Note: Descriptions are shown in the official language in which they were submitted.
Method and Apparatus for Coolin~ a Hot Particulate-
Laden Process Stream
The present invention relates broadly to cooling
of paTticulate-laden process st~eams and is more
specifically concerned with an integrated method and
means for cooling hot, particulate-laden process streams
and separating the particulate burdens therefrom by
5 cloth filtration.
In many industrial processes products or by-products
are prodllced in suspended par~iculate form, ~hat is to
say, in the form of a solid particulate matteT component
entrained in a hot gas stream component. For instance,
1~ furnace carbon blacks are produced by the thermal decom-
position and/or paTtial combustion of hydrocarbonaceous
feedstocks and are normally initially produced in the form
of an aerosol or suspension of the paTticulate carbon
- black product in hot by-product flue gases. The carbon
15 black process stream is quenched in the carbon black'
forming reactor to terminate the carbon forming reaction,
urther cooled and then treated ~y cloth filtration in
order to collect the carbon black product. Some other
exemplary industrial processes in which a hot, particulate^
2n laden process stream is cooled and then aubj ected to
cloth filtration and to which the present in~ention may
be employed with good efect are: treatment of coal fired
power plant flue gases prior to filtration of the particu-
late burden therefrom, cooling of dry process cemen~ cal-
25 cining streams, cooling of calcined ore or rock dust con-
taining streams and the like.
~"3~
Typically, cloth filtration methods o~ co~erce
in~lve flowing a particulate-laden gaseous s~ream
through one or more pOTOUS cloth or fab~ic fil~ration
elements, said elements having a selected poTosity
or transmissibility which is, at once, sufficient to
allow the gaseous component of the process stream ~o
pass therethrough while being insufficien~ to allow
passage of the particulate component. In consequence,
the par~iculate component is separated from the gaseous
component and is deposited on the upstream or collection
side o-f the cloth fil~ration elemen~s. Means are usually
provided by which to aid removal of the particulate burden
from the filt~ation elements, such as by periodic
repressurization or reversal of the ~as flow therethrough,
mechanical shaking OT vibration thereof and the like.
The thusly separated particulate burden is generally
conducted into a collection hopper and is periodically
removed therefrom for packaging and/or for such further
processing as may be desired or necessary to provide a
finished paTticulate product. In furnace carbon black
processes of commerce, the so-called "fluffy" carbon black
collected from the cloth filtration device may be sub-
jected to such further treatments as: wet pelletizing;
dry pelleti7ing; densing; calcining; surface o~idizing
with ai~, ozone or mineral acids; milling, such as by
pin milling, hammer millin~ OT fluid en~rgy milling;
~reating with surfactants 9 oils or oil emulsions and
~he like.
~a.~
~,J ~ I.J'~
The cloth materials utilized to produce the filtra-
tion elements are usually composed of woven or unwoven
textile fibers such as glass, cotton, wool, polyamide,
pol~ester9 polytetrafluoroethylene or blends thereof.
Said materials are formed or sewn into the geometric
shapes required of the particular cloth filtration
device employed. One commonly employed filtration
devïce is a so-called "bag filter", the cloth filtra-
tion elements of which are of long tubulaT shape.
Other known cloth filtration devices employ cloth
filtration elements in the forms of en~elopes, sheets,
bolts OT disks. Certain other known cloth filtra-
tion de~ices employ cloth filtration elements which
are essentially shapeless, the cloth filtration mater-
ial merely being employed in the form of a stuffing orfiller for a cartridge element through which the parti-
culate-laden process stream is conducted.
Nhatever the particular cloth ~iltration device
used, however, it is essential that the particulate-
laden process stream conducted thereinto have a temp-
erature which is not so high as to bc deletrious to the
cloth filtration elements thereof. Likewise, however,
it is also important that the temperature of the process
stream conducted into the filtration device be sufficiently
high as to maintain the atmosphere within the device at
above the dewpoint of the gaseous component of the process
stream, the~eby to mitigate against condensation
of condensibles therefrom. ~ailure to maintain the former
temperature criterion leads, of course, to excessively
short cloth filtration element life. ~ailu.e to maintain
the latter temperature criterion can lead to collection
of adulterated and/or wetted particulate product and to
~..{.~
blinding of the cloth filtration elements, In the case
of furnace carbon black operations, the collection of
wetted carbon black in the cloth filtration device not
only adversely affects the efficiency of the collection
5 step, but also can adversely affect the efficiency and
quality of downstTeam finishing operations such as
pelletizing, densing OT chemical aftertTeating of the
collected carbon black and the quality and unifoTmity
of the resulting -finished carbon black product.
~ile it is possible to cool a hot, particlllate-
laden process stream to ~ithin the a~oresaid temperature
criteria by means of indirect heat exchangers, the~e a-rises
the pToblem of efficient and economic operations of such
heat exchangers. Normally, the goal temperatures for
15 a particulate-laden process s~ream to ~e treated by cloth
~iltration will range from about 149C to about 371C.
Indirect heat exchange is usually an economically ~us~i-
fiable method of heat extraction only when the temperature
dTop to be achieved is relatiYely great, for instance, on
20 the order of 300C, or more~ and wh~n the hot process
stream to be cooled is at a tempera~ure of substantially
above about 538C. Thus, for example, to cool a 538C
particulate-laden process stream to about 260C by an
indi-rect heat exchange technique geneTally requires
25 substantial and expensive equipment, the process economics
of which are not usually justified even assuming complete
recoupment of the extracted heat energy. Moreover~
indirect heat exchange equipment is usually adapted for
operations under relatively static process conditions and
30 is therefore, usually ill-adapted foT reasona~ly pTeCiSe
contrcl in response to changing process conditions, In
view of these foregoing deficiencies, therefo-re, it is
3t~
conventional prac~ice in chemical plant operations to
first extract and recoup as much heat from the hot pro- ;
cess stream by indirect heat exchange as is economically
feasible and, thereafter, to ~urther quench the pTocess
5 stTeam to suitable cloth filtration temperatures by atom-
izing liquid wa~er thereto.
This quenching of the process stream ~o suitable
cloth filtration temperatures is normally undertaken by
pressure or bi-fluid atomization of the liquid wateT
10 into the process strea~ ~t some point relatively far
upstream of the inlet of the cooled s~ream into the cloth
filtration device. Atomi~ation, as opposed to spraying,
is undertaken in ordeT toperform minute droplets which,
of course, evaporate more quickly than the relatively
15 largeT droplets producible by ordinary spraying techniques.
The lengthy conduit interposed between the point of atom-
ization sf the cooling water into the process stream and
the filtration device is provided or purposes of ensuring
adequate time for the liquid water atomizate to evaporate
20 completely prior to entry of the cooled process stream
into the cloth filtration device. It is obvious, of
course, that failure to completely evaporate the liquid
water in the p~ocess stream can lead to dificulties
similar ~o those which have herein~efore been discussed
25 with respect to condensation of the gaseous component
of the process stream within the cloth filtration device.
The underlying reason for providing a relatively
lengthy Tesidence time after atomizing the liquid coolant
WateT into the process stream ,esides in the fact that,
30 as far as is kno~ to applicant, neither bi-fluid nor
pressuTe atomization techniques currently available in
industrial operations lend themselves to the perfoTmance
3~
,,
of droplets of minu~e size over a sufficien~ly
broad range of process conditions as to gua~antee uniformly
rapid and complete evapDration thereof wi~hin the process
stream. In pressure atomizat-ion water is forced through a
5 nozzle having a restricted orifice and the efficiency at
which the injzcted water is fractured into drople~s and
the average size of the droplets so performed are largely
dependent upon the orifice si;ze of the atomizing
nozzle and the pressure drop achieved across that orifice.
lO In turn, the flow rate of water through an orifice of
- given dimensions is, of course, a function of the pressure
drop, the higher the pressure drop the greater being the
flow rate. Minor variation in any of the foregoing
parameters has a very profound effect upon the uniformity
15 and size of the droplets performed, For most induskrial
chemical plant installations the orifice size of a given
pressure atomizing nozzle may be considered an invarian~
parameter. However, such is not normally the case with
respect to flow rates and pressure drops. In industrial
20 plant operations water line pressure and flow rate and
the temperature and flow rate of the process stream to
be quenched are normally subject to considerable variation.
~'here the hot process stream temperature and/or flow rate
is altered, such as due to changes in reactor conditions
25 in order to alter product properties, it is usually also
necessary to alter the Tate of quench water atomized
in~o the process stream in order to attain the desired
goal temperature preparatory to the cloth filtration
treatment thereof. Thus, considerable variations in the
30 water pressure delivered to the atomizing nozzles may
occur incidentally or by design and can lead to periods
of process operation wherein the pressure atomization
nozzles are not and cannot be operated up to their design
pressure drops and flow rates, Under such conditions,
the droplets produced by pressure ~tomization ~echniques
can be much enlarged and droplet uniformity diminished,
thereby to require substantially increased residence
5 times within the quenched pTocess s~ream so as to ensure
complete evaporation of the water therein. Bi-fluid
atomization nozzles employ motive gas to fracture a water
stream into minute dropiets within the nozzle and to
project said droplets, entrained in the motive gas, into
10 the process gas stream. In order to operate efficiently,
such bi-fluid nozzles generally employ relatively large
volume flow ra~es of the motive gas, which gas is not
normally inherently available at the plant site and which
gas, in any event, represents an added gas burden in the
15 process stream which must ultimately be handled by the
downstream cloth filtration device.
In order to maximize the residence time of the
pressure or bi-fluid atomized quench water in the process
stream the customary approach, as mentioned, has been to
20 interpose a large volume conduit or so-called "riser"
between the point of atomizat on of the quench water into
the process stream and the cloth filtration device. Vnder
thcse conditions wherein the droplet size of the atomized
quench water is relatively large, the evaporation rate
25 thereof can be much reduced within the process stream
flowing through the riser. In furnace carbon black opera-
tions such reduced evaporation Tates can lead to increased
opportunities for wetting and agglomeration of the parti-
culate component of the process stream within the riser
30 and the collection of a carbon black product having sub-
stantial quantities of hard coarse agglomerates therein.
Moreover~ in view of the fact that the process stream can
~ 9~
often be highly corrvsive, the riser conduit is often
also required to be constructed of expensive corrosion
resistant alloys. Neverthe~ess~ the need for avoiding
the presence of liquids within the cloth filtration
5 device has heretofoTe outweighed the considerable eco-
nomic penalties imposed by the construction and operations
of a large volume corrosion resistant alloy riser pre-
ceeding same and the danger of encountering the afore-
mentioned phenomenon of particulate component agglome-
10 ration within the riser and, unti~ the advent of the presentinvention, industry has gTudgingly accepted these defi
ciencies so as to assure complete evaporation of the
quench water introduced in~o the process stream over a
broad range of process conditions.
In accordance with the present invention, many of
the aforemen~ioned difficulties are either completely
resolved or are at least substantially ameliorated.
Objects of the Invention
I~ is a principal object of the invention to pro
vide a novel method for cooling a hot particulate-laden
20 gas stream.
It is another object of the invention to provide
a novel apparatus for cooling a hot, particulate-laden
gas stream.
It is another object of the present invention to
25 provide an improved integrated method for the separa~ion
of the particulate component from a hot, particulate-
laden process stream.
I~ is another object of the pTeSent inven~ion ~o
provide an improved integrated system for the sepa~a-
30 tion of the paTticulate component frcm a hot, particu-
late-laden process stream.
~?~33~
It is still another object of the present iovention
to provide an improved integrated method and system
:For the separation of furnace carbon black from a hot,
furnace carbon black-containing process stream.
Other objects and advantages of the present inven-
tion will in part be obvious and will in part appear
hereinafter.
Summary of the Invention
In accordance with the present invention, a hot,
particulate-laden gas s~ream is conduc~ed ~hrough a
venturi-shaped conduit having a size and geometry adapted
to accelerate the process stream to a Mach number of at
least 0.25. Within the throat portion o~ the venturi-
shaped conduit liquid water is injected substantially
~ransversely into said ~as s~ream through a n~ber of
unrestricted orificesO By reason of the eneTgetic flow
of the process stream at the points of introduction o:E
the liquid water thereinto, the plural streams of water
are rapidly fragmented, disintegrated and sheared into
uniform droplets of relatively minute size9 thereby
extracting heat from the gas stream by rapid evaporation
of the thusly performed water droplets. The thusly cooled
gas OT process stream is conducted through a cloth filtra-
tion device, whereby the particulate component is separated
from the gaseous componen~,
Brief Description of the ~rawing
Figure 1 hereof is a schematic diagrammatic 10w
sheet depicting, in solid lines, a cooling apparatus
in accordance with the invention integrated into a typical
furnace carbon black process line and, in dashed lines,
a rela~ively comparativel~ scaled conventional prior
3~ ar~ cooling apparatus.
Figure 2 hereof is a schematic, diagrammatic
longitudinal sectional view of the embodiment of the
cooling apparatus of the in~ention shown .in Figure 1.
Pigure 3, hereof is an enlarged schematic, diagram-
matic longitudinal sectional YieW of a portion of thesooling apparatus sho~l in Figure 2,
Description of Preferred Embodiments
Referring now to Figure 1 hereof, a conventional
furnace carbon black process line is depicted comprising
major elemen~s 1, 9~ 14 and 15~ A hydrocarbonaceous
feedstock, c~mbustion fuel and a gaseous oxidant (usually
air) are in~roduced into a carbon black reactor 1.
Therein the resulting mixture is ignited and the burning
reaction mixture passed into refractory lined reac~ion
chamber 5 wherein carbon forming conditions are main~ained.
Conventionally, the temperature within reaction chamber 5
is maintained at between about 1315C and about 1760C,
the exact temperature being primarily dependent upon the
desired properties of the carbon blac~ product. Control
of the temperature within reaction chamber 5 is usually
achieved by appropriate proportioning of the oxidant,
fuel and feedstock delivered to ~eac*or 1. Termination
of the carbon forming reaction is initiated by a so-called
'tprimary quench" wherein water is sprayed through no~zle 6
into the reaction mixture as it progresses through the
downstream portion of reaction chamber 5O The rate a~
which the quench water is sprayed into the reaction mix-
~ure is appropriately proportioned 50 as to rapidly reduce
the temperature of the process stream to about 1204C, or
less. Since the thermal energy contained in the reaction
mixture at this point in the process is relatively high,
tD ~L
11
rapid e~aporation of the primary quench water is
inherently assured and the operations of the quench
nozzle 6 are not normally critical.
l'he Tesul~ing process stream, compTising carbon
5 black suspended in process flue gases, is then conducted
from reactor 1 to an indirect heat e~changer 9 wherein
said process stream is fuT~her cooled, usually to a
temperature of between a~out 426C and 648C. Indirect
heat exchange~ 9 îs conventioncllly cooled by the com~
10 bustion oxidant employed in the carbon blac~ orming pro-
~cess, thereby to preheat same prioT to introduction
into reac~oT 1 and thereby to l~ecover subs~antial quanti-
ties of what would otherwise be waste heat and to improve
the thermal efficiency of the overall process.
SeparatioTI of the carbon black from the process
stream is conventionally undertaken in a cloth filtra-
tion device 15, such as a bag filter~ wheTeby the pTO-
cess stream is conducted thTough porous cloth filtTation
elements adapted to retain the carbon black burden on
20 the upstream side thereof while allowing the process
gases to pass therethrough. The carbon black product
separated and collected in cloth filtrat;on device 15
is ~hen packaged or othérwise treated as previously
discussed herein.
In order to preserve the cloth filtration elements
of the cloth filtration device 15, it is first necessary
~o further cool the still Telatively hot process stream
exiting indirect heat exchanger 9~ usually to be~ween
about 149~C and about 371C, the exact ~oal ~empera~ure
30 being dictated largely by the dual considerations of the
J~
12
dewpoint. of the gaseous component of the process stream
and the thermal stahility of the particular cloth fil-
tration elements employed in cloth filtration device 15
The P~ior Art
Conventlonally~ this additional cooling or "second-
ary quenching" of the furnace carbon black process
stream preparatory to cloth filtration thereof is
accomplished by conducting the paTtially ccoled pro-
cess stream from indirect heat exchanger 9 ~hrough a
vertical, lengthy and large ~olume conduit or riser 14
while atomiz;n~ water into the upstream end portion
thereof. For purposes of comparison, said riser 14
may, for example, typically have a length of about
30.48m, a diameter of about 1.524m and will usually
be constructed of an expensive corrosion-resistant alloy~
Stationed at the upstream end portion of riser 14 are
one or more pressure or bi-fluid atomization nozzles 16
through which quench water is atomized into the process
stream at a rate sufficient to cool the process stream
to the selected goal temperature. The extensive portion
of the riser 14 existing downstream from nozzles 16 is
provided largely or purposes of ensuring sufficient
residence time of the quenched process stream therein
as to complete the evaporation of the quench water
atomizate prior to entry of the process stream into
cloth filtration device 15. For whatever reason, should
the atomized water droplets be of a relatively large size
say onthe ~rder of about300 X10 6m or more, the evaporation
rate thereof in the process stream will be relatively
low, theTeby creating significant opportunity for sub-
stantial contact of the suspended particulate componen~
3~
13
carbon black ~ith liquid water during conveyance ofthe process stream through the riser 14, As mentioned
previously, should such wetting of the carbon black
particles occur, the wctted particles can then collide
with one another to fo~n coarse agglomerates. Also,
the wetted caTbon black p'articles can contact the walls
of the riser 14 7 causing accretion and caking of carbon
black thereon.
The Present Invent'ion
In accordance with the present invention, referring
now to the solid line portion of Figure 1 and to Figures
2 and 3~ generally, and in all of which figures like
reference numerals refer to like structures, the rela-
tively hot, particulate-laden process stream exiting
indirect heat exchanger 9 is conducted through a venturi-
shaped conduit 20 having a geometry and shape adaptedto accelerate said stream to a Mach number of at lea~t
about 0.25 within the throat portion 24 thereof. By
"Mach number" is meant the dimensionless numerical
quotient of the actual velocity of the process stream
divided by the local velocity of sound within said
stream. Thus~ the Mach number of the process stream is
both temperature and composition dependent and can be
Teadily determined for any given set of circumstances
by taXing the temperature and composition of the parti-
cular process stream involved into full consideration.Desirably, the size and geometry of the venturi-shaped
conduit 20 will be selected such as to accelerate the
process stream to a Mach numbeT of at least 0.4 within
throat portion 24.
3~
14
The venturi-shaped conduit 20 comprises a rela-
tively rapidly convergent upstream portion 22, a throat
portion 24 and a relatively gen~,ly divergent downstream
portion 26. In the particular embodiment of the inven-
tion shown in the drawing there is centrally locatedalong the longitudinal eenterline of throat portion 24
a supply pipe 25 which ~erminates in an end-cap 27.
Supply pipe 25 is braced in its central position by
means of a strut 28 extending from the wall of conver-
gent portion 22 of the venturi-shaped condui~ 20. End-
cap 27 comprises a plurality of unrestricted orifices
29 which are radially oriented relative ts the longitu-
dinal centerline of the ven~uri-shaped conduit 2,0 and
through which orifices 29 liquid quench wa~er is intro-
duced substantially transversely into the process streamflowin~ throllgh throat portion 24. Control of the quench
water flow rate through orifices 29 may be provided by the
combination of water supply valve 50 and oontToller 51.
Controller -51 receives process st~eam temperature data
from outlet thermocouple To, integrates said data with
respect to a preselected goal OT set point temperature
and responds by adjusting water supply valve 50 as neces-
sary to obtain the set point tempera~ure of the quenched
process stream. Since the present invention depends
primarily on the kinetic energy of the accelerated
process strea~ to fracture the quench water into minute
droplets and to disperse said droplets within said
stream, the diameter(s) of unrestricted orifices 29 and
$he pressuTe (or flow rate) at which the quench water is
supplied therethrough are subject to conside~able vaTia-
tion and are normally non-critical as regaTds the
.f~ t'P~
.performance of minutc, uniform and rapidly evaporable
droplets within the process stream. This beneficial
feature of the pTeSent inventi.on is a marked departure
from the criticalities normally attendant opera~ions
of pressuTe or bi-fluid atomi~ation nozzles of the prior
art. Desirably, the number and diameter(s) of orifices
29 will be selected such that 9 under ~he contemplated
range of quench water rates involved in the particulaT
process under consideration, sufficient pressure will
be developed at each of said orifices 29 as to project
the resulting quench water stream therefrom into the
process stream to at least a small distance from the
surface of end-cap 27 prioT to substantial disin~egra-
tion and breakup of said quench water stream.
The included angle of divergence of the divergent
portion 26 of the venturi-shaped conduit 2G is
generally non-critical. However, it is preferred
that said an~le of divergence reside within the
Tange of between about 6 and about 14 and, even
more preferably, in the range of between about 7
and about 10. By adherence to these preferred
limits said diveTgent por~ion 26 will generally
act as a diffuser, thereby to minimize the pressure
drop geneTated across conduit 20 for a given
acceleration of the process stream and ~o extend the
length over which said process stream maintains high
velocity. In another preferred embodiment of the
invention at least the divergent portion 26 of ven~u~i-
shaped conduit 20 is thermally insulated~ such as by means
of lagging 30. Said insulation 30 serves to reduce the
thermal deposition driving forces of the hot process
stream9 which fOTCe5 might otherwise tend to cause at
least some deposition of the particulate component
thereof on the surfaces immediately downstream of ~hroat
portion 74.
3~
16
In another preferred embodiment of the invention
the u~stream end of conver~ent por~ion 22 of the.ven-
tuTl-shapecl conduit 20 is fed by a sho~t length o~
conduit 18 containing flow-Tectifying means l9 ~h$rein.
The provision of such flow rectifying means immediately
prior to the ~enturi-shaped condui-t 20 minimizes turbu-
lences and eddy currents within the process StTeam as
it approaches said conduit 207 thereby ~o ensure effi-
cient aoceleration therein.
In view of the extremely rapid disintegration and
evapOTation of the quench water introduced into the
process stream in accordance with the invention, both
the venturi-shaped conduit 20 and ~he conduit 31, which
defines the commwlication between the downstream end
of said conduit 20 and the inlet of c:loth filtTation
devicc 15, can be substantially more compact, on an equal
process scale basis, than the riser type secondary
quench;ng systems of the prior art. This represents a
substantial advantage accruing to the practice of the
present invention since, as previously indicated, the
secondary quench TiseT systems of the prior art usually
involve apparatuses of relat;vely very large lengths
and volumes Util.izing the process and apparatus of
the present invention, for example, a furnace carbon
black process stream of the same type contemplated in
the sizing of ~he rise~ 14 previously discussed herein
in the paragraph entitled~ "The Prior Art", can be
effectively cooled to goal tempeTatuTe in a venturi-
conduit 20 of the present invention having inlet and
3D outlet diameters of about 0.~128m, a throat diameter of
about 0.4064m and an overall length of between about
3.6576m to about 4.572m. The length or volume of con-
dui~ 31, moTeoveT~ is dictated substantially only by
17
the need for fluid-~ight communication of the cooled pro-
cess stream into the cloth filtration device lS. Moreover,
the apparatus ~f the in~ention need not be oriented verti-
cally as in the Tisers o:E the prior art, but rather may be
subjected to whate~er orientation thereo may present it-
self as appropriate based on consideTations of available
space and efficient plant layout.
Additionally, the present invention exhibits sub~
stantially less sensi~ivity ~o p~ocess s~ream inlet
temperature variation than does the prior ar~ riser
technique employing pressure atomizing of the quench
water. Utilizing the la~ter pTior ar~ method a decrease
in the inlet tempeTature of the process stream fed to
riser 14 of about 38C, for example, reduces the rate
of water required to be p~essure atomized into the
process stream to attain goal temperature by about 20~.
If the water pressure is reduced 50 as to adjust the
rate of water flow downwardly by 20%,however, the average
droplet size of apressure-atomized spray is maTkedly
inc~eased as is the residence time required to evapoTate
such larger droplets and the Yolume of downstream enclos-
ing conduit ~equired to pTovide such increased resid~nce
time. U ilizing the process and apparatus of the present
invention, howeveT, a similar reduction of inlet temp-
era~uTe of the process stream and a similar reductionof ~he quench wate~ rate Tesults in only a relatively
minor increase in d~oplet size and in only a relatively
minor increase in the residence time ~equired to achieYe
complete evapo~ation of the droplets. Thu~, unlike
prioT art riser systems, little or no additiona~ length
or vol~me of downstream conduit need ordinarily be built
into the apparatus of the present invention simply to
provide an adequate residence time buffer for complete
quench water evapoTation in response to temperature and
flow changes in the p~ocess and quench water s~reams.
Also, while the shearing and disintegration of the quench
water introduced into the p~ocess stream in consequence
of the practice o~ the present invention may be termed
a type cf bi-~luid atomization, the motive gas for ~he
3~
18
atomization of the quench water is not an external
diluent, the process stream and motive gas being one
and the same entity. Thus, the present process and
system avoids further dilu~ion of the process s~ream
and the need for augmentation of the gas handling
capacity of the cloth filtration device 15.
While for purposes of illustration the present
invention has been described hereinbefore in detail
only with respect to a furnace carbon black process
line and only in terms of ultimate sepaTation of the
particulate component by cloth filtration, i~ is obvious
that the present invention can be beneficially applied
to many other chemical process lines wherein it is
Tequired to cool a hot gaseous process stream containing
particulate solids suspended therein.
Also, while the present invention has been described
hereinbefore with respect to certain preferred embodi-
ments thereof, it it to be noted that the Eoregoing
descTiption is intended to be illustrative in natu~e
and not as being limiting of the invention. For instance,
while the specific apparatus shown and described com-
prises a centrally located end-cap 27 within the throat
portion 24 of venturi-shaped conduit 207 which end-cap
27 serves as the final element for the introdu~tion
Z5 of the quench wate~ into the process stream, it is
obvious that other functional equivalents of this arrange-
ment can be achieved. For instance 9 the means to in~ro-
duce the quench water can also take the form of a plurali~y
of radial quench water orifices penetrating through the
enclosing wall and positioned about t}le peTiphery~of
throat portion 24 of venturi-shaped conduit 20. Said
orifices may then be enclosed by a common manifold equip-
ped with a water supply line thereto.
3~
19
Obviously, many other suitable alternative and
equi~alent constTuctionS of the apparatus and method
of the invention will suggest themselves to those of
sXill in the art and it should be understood that all
S such chan~es, alterations, modifications and the like
are intended to fall within ~he essential spirit and
scope of the invention as defined in ~he appended claims.
