Note: Descriptions are shown in the official language in which they were submitted.
78~
BACKGROUND OF THE INVENTION
Field of the Invention
Thi~ invention relates ~o nonrecovery coke oven
apparatus and method of operating such apparatus, and more
particularly to apparatus for and method of incineratin~
particulate and gaseous emissions produced during the
production of coke in and the pushing of coke from non-
recovery coal coking ovens.
Description of the Prior Art
In the operation of nonrecovery coke ovens,
distillation products liberated from coal being coked are
partially burned in the coking chamber to supply necessary
heat to the top oE the coal charge to continue the coking
process. In sole flue ovens, the partially burned distilla-
tion products are led from the top portion or crown of the
coking chamber through channels or downcomers to a series
of sole flues extending beneath the chamber for further
burning to supply heat to the bottom of the oven before
bein~ exhausted into a stack for discharge into the atmos
phere. Under ideal conditions, the sole flue exhaust is
so completely incinerated when discharged from the stack
as not to present a serious pollution problem. Such ideal
--2--
97804
conditions were seldom achieved in operation of the prio~
art sole flue ovens however, particularly during the early
stages of the coking cycle. Canadian Patent 1,139,707 issued
January 18, 1983 does, however, disclose a way to assure
substantially complete incineration of the particulate and
gaseous combustible effluent from such ovens during the
charging and coking operations.
In nonrecovery ovens which do not employ sole
flues, the partially burned distillation products are exhaust-
ed directly from the crown of the ovens, through suitableconduits, to a stack for release into the atmosphere. In
either type o oven, the stack maintains sufficient draft to
withdraw particulate and gaseous efluent from the oven
chamber during coking. A controlled amount of combustion
air is admitted into the oven crown, under influence of the
stack draft, for controlled partial burning of the distilla-
tion products in the oven crown above the coal charge to
supply heat for the coking process without excessive con-
sumption of the charge. Additional combustion air may be
supplied to the effluent after it leaves the co~ing chamber
to further incinerate the effluent before it is admitted to
the atmosphere.
In recent years, increasingly stringent regula-
tions for the operation of coke ovens have resulted in various
attempts to reduce or eliminate gaseous and particulate
combustible emissions from such coking processes. For
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example, liquid scrubbers have been installed in ~he oven
stacks, and afterburners employing liquid hydrocarbon fuels
and checkerbrick filled ignition chambers have been proposed
to ~urther incinerate the coke oven effluent before it is
admitted to the atmosphere. These attempts have not been
entirely satisfactory, however, for various reasons. For
example, stack gas scrubbers and checker-filled ignition
chambers greatly reduce the stack draft and frequently result
in the requirement of an exhaust fan operatin~ in the hot,
corrosive atmosphere of the stack gases to maintain a draft,
or negative pressure in the oven chamber. Further, the use
of oil burners to incinerate the combustible ef1uent
substantially increases the cost of operation and requires
substantial quantities of scarce uel oil~ Complete
incineration o~ the liberated distillation products has been
particularly difficult during the early portion of the cokin~
cycle when temperatures in the coking chan~er are relatively
low and substantial quantities of unburned particulate
material and smoke are entrained in the ~aseous effluent.
An improved method and apparatus for the high
speed smokeless operation of a nonrecovery coke oven
battery which overcomes tne foregoing and other defects
of the prior art is disclosed in the above-identified
n~l;n~p~llr~n ~ n and wherein the partially burned
distillation products rom a plurality of adjacent ovens
in a battery are discharged into a common waste heat tunnel
--4--
leading to a stack. The elongated waste heat tunnel
increases the retention time to provide greater opportunity
for complete incineration. Also, the intermixing of the hot
efEluent from a plurality of ovens creates turbulence and
maintains a uniformly high temperature to promote combustion
in the tunnel and stack. This system has proven to be
highly effective in incinerating the increased particulate
material from an oven during and immediately after charging.
A ~urther air pollution problem encountered in the
operation of coal coking ovens, whether of the recovery or
nonrecovery type, is the gaseous and particula~e effluent
(pushing emissions) released into the atmosphere during
pushing of the.incandescent coke from the oven chamber and
transportation of such hot coke from the coke side of the
lS oven battery to the quenching station. Numerous attempts
have been made to capture such pushing emissions to prevent
them from polluting the atmosphere. For example, it has
been proposed to employ an enclosed coke guide and hood
structure for receiving and guiding coke pushed from an
oven into a covered quench car, with powerful cyclone
cleaning apparatus carried on an adjacent car withdrawing
the pushing emissions from beneath the quench car cover and
removing particulate matter before releasing the cleaned
emissions to the atmosphere, one such apparatus being
disclosed in U. S~ Patent No. 4,113,572.
--5~
It has also been proposed to construct a quench-
ing track hall, or shed alon~ the coke side of a battery
of ovens to enclose the guide car and quench car tracks and
capture pushing emissions. The captured emissions are
removed from the top portions of the shed through a suitable
conduit for processing to remove polluting particulate mate-
rial, one such apparatus being shown, for example, in U. S.
Patent No. 3,844,901. In this prior art patent, coke is
pushed from an oven through the guide car into a quench car
supported on tracks adjacent the coke side of the battery,
then transferxed to a quenching tower located at one end
of the shed. An exhaust fan withdraws the pushing emissions
from the shed for cleaning by a suitable scrubbing device
at a remote l~cation~ In order to reduce the volume of gas
removed, and the power requirements for the apparatus, the
volume of the coke side shed is maintained at a minimum,
with the vertical sidewall of the shed extending in close
proximity to the side of the quench car.
It has also been proposed to quench hot coke with
water either on a quenching whar~ or in a quench car as the
coke is pushed from the oven, or immediately thereafter,
and to employ a coke side shed structure to capture the
combined pushing and quenching emissions, examples of such
apparatus being disclosed, for example, in U. S. Patent
Nos. 3,630,852, 4,050,992, and 4,~11,757. In the apparatus
of Patent No. 3,630,852 and 4,050,992, the combined pushing
--6--
and quenching emissions are withdrawn from the coke side
shed for processing at a remote location by suitable
scrubbing or cyclone cleaning apparatus. In Patent No.
4,111,757, the combined pushing and quenching emissions are
incinerated in a checker-filled ignition chamber. Oil burners
are employed to supplement heat scavenged from the sole flue
exhaust to supply the necessary heat to the checker-fillèd
ignition chamber to incinerate the combined emissions.
Summary of the.Invention
It is a primary object of the present invention
to provide an improved coke oven emission control method
and apparatus effective in controlling both coking and
pushing emissions.
It is another object of the present invention
to provide such an improved coke oven emission control
method and apparatus in which polluting elements of the
coking and pushing emissions are incinerated be~ore being
admitted to the atmosphere and in which no external source
of energy is re~uired for the handling and/or incineration
of such emissions.
Another object of the invention is to provide
an improved nonrecovery coke oven battery in which the
partially burned distillation products from a plurality
of adjacent ovens in the battery are collected and inter-
mixed in an elongated common waste heat tunnel connectedto a stack to increase the retention time and provide more
--7--
:
~7B04
complete incineration of the mixed effluent before it is
discharged from the stack, and in which pushing emissions
are captured and admitted into the waste heat tunnel during
the pushing operation whereby the hot gases in the waste
heat tunnel incinerate the pushing emissions so captured.
In the attainment of the foregoing and other
objects and advantages, an important feature of the invention
resides in providing a plurality of nonrecovery coal coking
ovens constructed in side-by-side relation in a battery
~0 with a stack providing a draft to the ovens to withdraw the
partially burned and burning distillation products from the
ovens and discharge them to the atmosphere. ~ plurality of
the ovens are connected to a stack through a common waste
heat tunnel which provides an increased retention time for
the distillation products. The increased retention time,
combined with the mixin~ of the hot effluent from a plurality
of ovens, results in substantially complete incineration of
the combustible distillation products.
An elongated pushing emission control shed
extends along the coke side o the battery o ovens, with
the end wall of the battery forming a portion of one sidewall
of the shed and with the shed extending substantially above
the top of the oven chambers. The shed encloses the coke
guide track and quench car track along the length of the
battery. Preferably the shed has a width substantially
greater than required to enclose these tracks in order to
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~9'71!3~4
,provide a large enclosure for containing the gaseous and
particulate emissions released during pushing and during
removal of the pushed coke to a ~uenching station located
adjacent one end oE the battery. The large internal
volume of the shed reduces turbulence and provides a
greater opportunity for solid particulate matter to precipi-
tate to the floor of the shed under influence of gravity.
Also, the concentration of emissions in the shed is reduced,
providing a safer atmosphere.and better vision for personnel.
A plurality of conduits are provided to connect
the interior o the coke side shed to the waste heat tunnel
at points spaced along the length o~ the shed, and valves
in the conduits can be opened`to establish a gas flow path
from the interior o the shed into the waste heat tunnel.
The draft established by the stack draws smoke and particu-
late matter from the shed into the waste heat tunnel to be
incinerated during the pushing operation. The conduits
have their inlet located above the level of the crown o
the ovens so that the hot gaseous material and finer
particulate matter are drawn into the waste heat tunnel
from the top region of the shed. A plurality of such
valves may be opened simuitaneously at spaced intervals
along the length of the shed, as required, to draw the
desired volume of air and pushin~-emissions from the shed
without admitting so much air into any tunnel section to
reduce the draft to the ovens to such a level as to substan-
tially affect their operation.
_g_
' . ' `'
~97~04
In a preferred embodiment of the invention, the
coke ovens are of the sole ~lue type wherein the partially
burned distillation products are drawn from the crown of
the oven through downcomers in the oven walls to a system
of sole flues extending beneath the ovens. Combustion air
admitted in the sole flues enables further combustion of
the par~ially burned distillation products to provide heat
to the bottom of the oven to cause coking to proceed from
the bottom up. From the sole flues, the hot effluent is led
to a waste heat tunnel which may extend longitudinally of
the battery above the top of the ovens. The effluent from
at least two and preferably three or more adjacent ovens is
discharged into and intermixed in a common waste heat tunnel
leading to each stack, and a plurality of stacks may be pro-
vided in a battery which may e~tend for an indefinite lengthand contain any desired number of ovens. When a plurality
of stacks are employed, conduits connected to waste heat
tunnels leading to more than one stack may be opened to
withdraw a larger volume of air and emissions from the shed
without adversely afecting operation o the ovens.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention
will become apparent from the detailed description contained
hereinbelow, taken in conjunction with the drawings, in
which:
~10--
~7~Q~
FIG. 1 is an isometric view o a portion of a
coke oven battery embodying the ~resent invention;
FIG. 2 is a vertical sectional view schematically
illustrating the operation of the apparatus of FIG. l;
FIG. 3 is an enlarged, fragmentary end sectional
view of the apparatus;
FIG. 4 is a sectional view taken on line 4-4 of
~IG. 3;
FIG. S is an isometric view of a coke guide car
suitable for use in the invention;
FIG. 6 is a sectional view, on a reduced scale,
taken along line 6-6 of FIG. 3; and
FIG. 7 is a sectionàl view taken on line 7-7 of
FIG. 3.
Description of the Preferred Embodiments
Referring now to the drawings in detail~ a coal
coking plant embodying the invention is designated generally
by the reference numeral 10 and includes a plurality of
coke ovens 12 constructed in side-by-side relation in a
battery, with adjacent ovens in the battery having common
sidewalls 14. The individual ovens 12 each have an elon-
gated coking chamber 16 defined by the opposed vertically
extending sidewalls 14 (see FIG. 4), a generally arch-
shaped roof 18 supported on the sidewalls 14, and a
horizontal floor 20 which supports the charges of coal to
be coked. The opposed open ends of the oven cha~ber are
closed during the coking process by removable doors 22.
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: .
~L~9781~
The sidewalls 14, roof 18 and floor 20 of the oven
chambers are constructed of a suitable heat resistant
material such as refractory brick or castable refractory
material capable of withstanding the high temperatures encoun-
tered in the coking process and the thermal shock resulting
from the deposi~ of fresh charges of coal in the heated oven
chambers. The doors include a structural steel framework
supporting a refractory lining which projects into the door
openings, with ~he refractory lining serving to insulate
and protect the steel frame. This construction of the oven
chambers and doors is conventional.
In the preferred embodiment, the arch-shaped roofs
18 are closed and the oven chambers are charged through the
open door at the front, or pushing end of the oven by a
charging and leveling machine of the type disclosed in U.S.
Pa~ent NoO 3,784,034, reference to which may be had for a
complete understanding of ~he charging and leveling operations.
Such machines also carry door handling means and a pushing
ram for pushing a cake of coke from an oven into a hot car,
or quenching car 24 movable on rails 26 e~tending adjacent
the coke side of the batteryO
A combined door machine and coke guide 28 is movable
along rails 30 supported on à platform 32 at the coke side
of the battery and is operable to remove the
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~37~
coke side door and to guide the hot coke from the oven
into the car 24. ~n enclosed, air conditioned o~erator's
cab 34 is carried on the coke guide to shield and protect
the operator from the intense heat and from the fumes
released as the incandescent coke breaks up and falls into
the waiting ho-t car. An arch-shaped heat shield 36 extends
above the coke guide adjacent the coke side of the oven to
direct flame and hot emissions away from the oven during
the pushing operation for reasons pointed out hereinbelow.
If desired, the door machine may be constructed and
operated independent of the coke quide.
Although the present invention is applicable to
all types o~ nonrecovery coke ovens, the ovens 12 illus-
trated in the drawin~s are of the sole flue type which
include a system of sole flues 38 e~tending beneath each
oven. The individual elongated flues 38 are defined by
the sidewalls 14 and a system of elongated divider walls 40
extending beneath and supportin~ the floor 20. The 1ues
38 are connected at alternate ends progressively across
2~ the width of the oven to define a continuous serpentine
path traversing the oven throughout its length and width
beneath the floor 20. The sole flues may be constructed
in two sets with one extending beneath and heating each end
portion of the oven chamber.
The battery of ovens is preferably constructed
on a continuous base slab 42 formed of a castable refractory
material supported at spaced intervals along the length of
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.97~0~
the battery by a plurallty of wide flange structural steel
beams 44 extending transversely Qf the battery beneath the
walls 14 and 40. Beams 44 are, in turn, supported on a
rigid foundation slab 46 of reinforced concrete material or
the like with the beams providing a space 48 beneath the
refractory slab 42 which is open to atmosphere~ Natural
air currents through this open space 48 provides an effec-
tive insulator or heat barrier substantially reducing the
transfer of heat from the refractory base slab 42 to the
.
structure therebelow.
A plurality of vertically extending downcomers
or channels 50 are formed in the sidewalls 14, with the
respective downcomers 50 having an inlet 52 in the crown
or top portion of the oven and an outlet 54 opening into
the sole flue system beneath the oven chamber 16. As best
seen in FIG. 4, an uptake or chimney 56 is formed in each
sidewall 14, with the respective chimneys 56 having an inlet
58 opening into the system of sole flues on the side of the
oven opposite to which the downcomers are connected to the
sole flue system of the particular oven. Where two sets
of sole flues are employed beneath each oven, two such
uptakes are provided in side-by-side relation near the
center of each sidewall with one uptake connected to each
set of sole flues.
Predetermined numbers of the ovens 12 in the
battery, for example, 6, 8, or 10 ovens, have their uptakes
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71~
connected to a common~stack 60 through a waste heat tunnel
62 extending longitudinally of the battery above the arch-
shaped roo~ 18. The stack 60 extends above and is supported
by the sidewall 14 at the center of the group of the ovens
connected thereto, with the waste heat tunnel 62 including
a section connected to and extending from the base of the
stack in each direction above the ovens in the ~roup. A
substantially right-angled uptake extension 64 supported on
the top of each sidewall 14 connects the tunnel 62 with the
uptakes 56 in the respective walls 14.
In the arrangement illustrated in ~IG. 1, three
ovens 12 are connected to the section of the waste heat
tunnel 62 extending thereabove to the chimney 60. Similarly,
three additional ovens would be connected to the same stack
60 through the section of the waste heat tunnel 62 extending
in the opposite direction so that six ovens are serviced by a
single stack. Any number of ovens can, of course, be con-
structed in the battery, with an appropriate number of stacks
and waste heat tunnels constructed above the battery to
accommodate the number of ovens. However, it is important
that a plurality of ovens be connected in each waste heat
tunnel section so that the effluent from a plurality of ovens
is intermixed to assure substantially complete consumption
of combustible material in the effluent from the sole 1ues.
If desired, the battery can be constructed with a single large
waste heat tunnel and stack.
--15--
A charging gas bypass opening 66 is formed in
the roof 18 of each oven 12, forwardly of the waste heat
tunnel structure 62, and a reinforced support pad 68 formed
of a suitable refractory or concrete ~aterial is cas-t on
top of the roof around each opening 66. Support pads 68
each support an elbow-shaped flue 70 connected to the waste
heat tunnel ~2 to provide an open channel communicating
between the bypass opening and the interior of the waste
heat tunnel. The bypass flue 70 is formed from a suitable
refractory material to withstand the intense heat
encountered during opeartion of the oven. A refractory
valve plate 72 is supported wlthin a guide slot in the top
wall of the flue 70 and extends into the flue opening. The
valve plate 72 is supported ~or ~ertical movement between
a closed position shown in FIG. 2 completely closing the
bypass and an open position in which the valve plate is
raised to provide a direct gas flow path through the bypass
into the tunnel. The valve plate 72 can be opened by any
suitable means such as an electrically operated winch or
hoist, not shown.
The bypass valve plate 72 is normally maintained
in the lowered, fully closed position throughout coking of
a coal charge, and is raised to the open position only during
charging of the oven to permit charging gases to ~e drawn
directly from the oven crown into the waste heat tunnel
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~97~0~
where they are mixed with and bùrned by the hot gases from
the sole Elues of the other ovens connected in the tunnel
section. Thus, the charging emissions from one oven are
mixed with hot gases from the sole flues of at least one
other oven which provide-the necessary heat to incinerate
the charging emissions.
One or more air inlet openings 74, each including
a valve ~not shown) for controlling the flow of air there-
through, are provided in the doors 22 to permit the
addition of a controlled amount o~ combustion air into the
- crown of the respective oven chambers. During the coking
process, only enough air is admit~ed through openings 74
to partially burn the volatile distillation products in
the crown of the oven to provide heat for the coking process
lS while avoiding excessive consumption of the carbon in the
sole flues. AddLtional combustion air is admitted through
- openings 76 to enable substantially complete combustion of
.. . .
the distillation products in the sole 1ues~ Any combustible
material not burned in the sole flues is consumed in the
uptakes, waste heat tunnel and stack, before being dis-
charged ~nto the atmosphere. Preferably the combustion air
- is preheated in order to increase the temperature in the
i system to ~hereby accelerate the coking process and assure~
substantially smokeless operation. The preheating can be
accomplished by drawing the combustion air through conduits
,
78 in the base slab 42 in the r-nner described in ~n~ n
Patent 1~139,707,
- .
.
~ -17-
978~
Althou~h coking ovens constructed in the manner
described above have been successfully operated to produce
coke at a very high rate while maintaining stack emissions
well within the stringent standards established by current
state and federal environmental control agencies, the
control of pushing emissions has presented difficulties.
As is well known, when a cake of incandescent coke is
pushed and breaks up in the atmosphere, flame and rapidly
expanding gas rising from the coke mass entrains substan-
tial quantities of particulate matter. This problem isfurther aggravated when a charge contains even a small
quantity of green or uncoked coal which produces lar~e
volumes of smoke. In accordance with the present invention,
such pushin~ emissions are captured in a coke side shed 80
and the heavier particulate matter is pe~mitted to settle
to the ground while at the same time a mixture of air and
emissions are withdrawn from the shed into the waste heat
tunnel for incineration.
The shed 80 extends along the full len~th of the
battery and includes one sidewall 82 supported on and
extending upwardly from the top of the ovens at the coke
side of the battery and a second sidewall 84 extending
parallel to and spaced a substantial distance from the
wall 82. A roof 86 is supported on the sidewalls at a
distance substantially above the top of the ovens, and
end walls 88, 90 are provided at the opposed ends of the
.~
-18-
shed. ~he shed extends over and encloses the coke guide
-tracks 30 and the ~uenchin~ car t'racks 26, with the interior
of the shed being substantially greater than necessary to
cover and enclose the coke guide quenching car. Prefer-
ably the width of the shed is sufficient to provide spacefor trucks and other vehicles to maneuver within the shed
outboard of the quench car tracks. The large volume of
the enclosed shed thus permits pushing emissions to expancl
with hot smoke and combustible gases rising and being
dispersed within the shed without creating excessive turbu-
lence. This greatly facilitates precipitation of heavy
particulate matter onto the floor or ground inside the shed~
A plurality o conduits or ducts 92 extend
between and are connected to the waste heat tunnel 62 and
the shed 80 above the ovens 12, and valve means 94 is
provided to open or close each duct selectively. The ducts
92 may be of any configuration,. but are illustratecl in the
drawings as being rectangular in cross section and formed
from a thin metal plate. Similarly, the valve 94 can be
of suitable construction but must be capable of withstanding
the high temperature of gases in the waste heat tunnel 62.
In the embodiment illustrated, the valve 94 is in the form
of a rectangular refractory plate 96 slidable within a
groove within a short refractory valve body section 98
extending laterally from the sidewall of the waste heat
tunnel 62 and connected to the duct 92. Suitable means
71~04
such as a small electric wi~ch 100 and cable 102 may be
provided to raise or lower the valve plate 96 as required.
During the normal coking cycle, the valves 94 in
the ducts 92 will all remain completely closed so that there
is no flow of air from within the interior of the shed 80
into the waste heat tunnel 62. During pushing, however, one
or more of the valves 94 are opened to permit the draft from
the stack to induce flow of a mixture of air and pushing
emissions from the shed into.the waste heat tunnel where
combustible material in the mixture is incinerated. Opening
of valves 94 will, of course, reduce the draft through the
uptakes, sole fl~es and downcomers to the crown of the oven,
and care must be taken not to reduce this draft to the extent
of producing a positive pressure within the oven. When this
occurs, smoking around the oven doors can result.
Although the location of the inlet of ducts 92 is
not critical, it is desirable to have one such inlet located
directly above the coke side door of each oven 12. During
pushing, the valve in the duct closest to the oven being
pushed is opened since the inlet to this duct will be closest
to the heaviest concentration of pushing emissions. It may
also be desirable to open the valve in one or more ducts a~
locations spaced from the oven being pushed, although care
must be taken not to admit enough air into any tunnel section
during pushing of an oven to reduce the stack draft to the
extent that a positive pressure can develop in other ovens
-20-
connected to that tunnel section. It is possible, however,
to operate the system with the valves of any number of
ducts leading to a tunnel section only partially open so
that the total flow of air and pushing emission effluent
5 into that tunnel section will not be sufficient to eliminate
the draft to the associated oven crowns.
As shown in FIG. 6, the shed 80 has an opening
or door 104 in end wall 90, which door leads directly into
a quenching tower 106. The tracks 26 extend into the
quenching tower through door 104 so that the quenchin~ car
24 can be pushed directly from the shed into the tower
where water supply means 108 discharges quenching water
onto the coke contained in the hot car to quickly cool the
coke. Suitable impingement baffles and/or scrubbing means
110 is provided in the tower for discharging a spray of
cooling water into the steam and particulate matter liberated
during quenching to thereby control quenching emissions.
Also as seen in FIG. 6, the shed 80 has its end
opposite the quenching tower extending outwardly past the
end of the battery to provide enclosed storage space for
the hot car pushin~ locomotive, the coke guide, and other
equipment. Door means (not shown) may also be provided in
this extended section to permit the ramoval of such
equipment from the shed~ or to permit access to the interior
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~ ~97~ilal4L
of the shed by ~ersonnel and e~ulpment such as trucks,
loade~s, or the like.
While the pushin~ emission control system has
thus far been described in combination with sole flue type
nonrecovery ovens, it is equally applicable to the operation
of nonrecovery ovens which do not employ sole flues. In
such ovens, the partially burned distillation products are
led directly from the crown of the individual ovens into
the waste heat tunnel through a flue in the top of the
oven. Referring to FIG. 2, for example, if the sole flue
system of the illustrated coking plant were eliminated,
the partially burned distillation products from the crown
of the oven would be led directly into the waste heat
tunnel through the flue 70. In such an arrangement, the
15. valve plate 72 would, of course, be eliminated.
In one coking plant now being tested, the ovens
are of the type which do not employ sole flues, and the
ovens in the battery have their coking chan~0rs connected
in pairs to the waste heat tunnel. A common flue connects.
openings in the roof of adjacent pairs of ovens, with the
connecting flue in turn being connected to the waste heat
tunnel so that the partially burned dis~illa~ion products
from the crowns of the connected ovens are intermixed in
the flue be~ore reaching the waste heat tunnel. At least one
and preferably two pair of such ovens are connected to
the waste heat tunnel section on either side of the common
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~ 9~
stack so that each ~tack services at least four ovens.
~lso, in this arrangement, the waste heat tunnel and stack
are preferably constructed near the end portion of the
ovens adjacent the shed 80 so that the interconnecting flue
system provides additional retentlon time for the incompletely
burned distillation products discharged from the oven crowns.
Combustion air can be admitted r as required, either in the
connecting flues or the waste heat tunnel to enable complete
incineration of combustible material before it is discharged
to the atmosphere at the top of the stack during the coking
process~ During pushing, the mixture of air and pushing
emissions drawn into the waste heat tunnel through the
duct system interconnecting the shed and waste heat tunnel
is sufficient to support combustion so that the effluent from
lS the top of the stack is substantially completely inciner-
ated.
From the above it is seen that the nonrecovery
coking emission control system of the present invention
is effective in controlling atmospheric emissions through-
out the coking process including charging of the ovens,coking the charge in the oven, pushing the hot coke from
the oven, and quenching of the coke. The harmful emissions
are incinerated without the requirement o~ elaborate and
expensive oil fired afterburners or ignition chambers,
By employing a coke side shed having a very large
internal volume, substantial solid particulate matter is
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~9~
permitted to precipitate or settle harmlessly to the ground
inside the shed. ~lso, water sp~ay means ~not shown) is
provided to wet the floor or ground in the shed prior to the
pushing operation so that any particulate matter settling
5 in the shed will become wet and therefore will not be
reentrained in the air.
It should be apparent that various modifications
could be made to the described structure. For example,
while the waste heat tunnel is illustrated and described as
10 being constructed on top of the battery, this arrangement is
not necessar~ and it may be desirable to locate the tunnel
below ground especially where it is desired to extract
heat energy fr~m the gases pa~sing therethrough. Also, when
heat is to be extracted and used, it may be desirable to
15 employ a single large tunnel extending the full length of
the battery, with a single stack at one location in the
tunnel or alternatively, a plurality of stac]cs which may be
isolated or selectively used in combination with a single
large stack. Pushing emissions from the shed would still
20 be led into the waste heat tunnel at various points along its
length in essentially the manner described. Thus, while I
have disclosed and described preferred embodiments of my
invention, I wish it understood that I do not intend to be
restricted solely thereto, but rather that I do intend to
25 include all embodiments thereof which would be apparent to
one skilled in the art and which come within the spirit and
c scope of my invention.
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