CA1197804A - Coke oven emission control method and apparatus - Google Patents
Coke oven emission control method and apparatusInfo
- Publication number
- CA1197804A CA1197804A CA000375550A CA375550A CA1197804A CA 1197804 A CA1197804 A CA 1197804A CA 000375550 A CA000375550 A CA 000375550A CA 375550 A CA375550 A CA 375550A CA 1197804 A CA1197804 A CA 1197804A
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- CA
- Canada
- Prior art keywords
- ovens
- waste heat
- coke
- shed
- coking
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
- C10B33/00—Discharging devices; Coke guides
- C10B33/003—Arrangements for pollution-free discharge
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
- Y02P20/129—Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Public Health (AREA)
- Materials Engineering (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Chemistry (AREA)
- Coke Industry (AREA)
Abstract
COKE OVEN EMISSION CONTROL
METHOD AND APPARATUS
ABSTRACT OF THE DISCLOSURE
A method of and apparatus for controlling emissions from nonrecovery coke ovens in which hot partially burned distillation products are discharged from a plurality of such ovens constructed in side-by-side relation in a battery into a common waste heat tunnel leading to a common stack which provides a draft through the tunnel sufficient to maintain a subatmospheric pressure in the coking chambers of the ovens. A substantially closed shed extends over the coke guide and quench car tracks along the entire length of the battery for confining particulate and gaseous emis-sions released during pushing of coke from the ovens. A
plurality of conduits provide fluid communications from the interior of the shed to the waste heat tunnel to enable emissions to be drawn from the interior of the shed for incineration in the waste heat tunnel. Valves in the con-duits are operable to open the conduits during pushing of coke from the ovens and for closing the conduits after completion of the pushing operation.
METHOD AND APPARATUS
ABSTRACT OF THE DISCLOSURE
A method of and apparatus for controlling emissions from nonrecovery coke ovens in which hot partially burned distillation products are discharged from a plurality of such ovens constructed in side-by-side relation in a battery into a common waste heat tunnel leading to a common stack which provides a draft through the tunnel sufficient to maintain a subatmospheric pressure in the coking chambers of the ovens. A substantially closed shed extends over the coke guide and quench car tracks along the entire length of the battery for confining particulate and gaseous emis-sions released during pushing of coke from the ovens. A
plurality of conduits provide fluid communications from the interior of the shed to the waste heat tunnel to enable emissions to be drawn from the interior of the shed for incineration in the waste heat tunnel. Valves in the con-duits are operable to open the conduits during pushing of coke from the ovens and for closing the conduits after completion of the pushing operation.
Description
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 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 ~ 3 -7~4 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 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 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 :
~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 ~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.
: .
~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 ~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
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 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 ~ 3 -7~4 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 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 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 :
~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 ~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.
: .
~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 ~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 .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 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.
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 ~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 .~
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 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 ~ ~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 ~ 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 ~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.
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 .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 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.
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 ~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 .~
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 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 ~ ~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 ~ 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 ~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.
Claims (18)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A Nonrecovery coal coking system comprising, a plurality of elongated ovens constructed in side-by-side relation in a battery having a pushing side and a coke side, each oven in the battery including a coking chamber adapted to be charged from the end through an open door and defined by opposed parallel sidewalls, a roof supported on said sidewalls, a floor for supporting a charge of coal to be coked in the chamber, and removable door means at each end and normally closing the chamber during coking and being removable to permit the charging of coal into the chamber from the pushing side and the pushing of coke from the chamber at the coke side of the battery, elongated substantially horizontal waste heat tunnel means extending transversely of said ovens along sub-stantially the full length of the battery, flue means providing a continuous gas flow path from the chamber of each said oven into said waste heat tunnel means whereby hot gases from a plurality of chambers are continuously discharged into and intermixed in the waste heat tunnel means, stack means extending above said ovens and said waste heat tunnel means, said stack means including at least one stack having its base connected in fluid communication with said waste heat tunnel means to provide a continuous draft from the coking chambers of each of said plurality of ovens through a continuous flow path defined by said flue means and said waste heat tunnel means, coke receiving means at the coke side of the battery, coke guide support tracks extending along the coke side of said battery, coke guide means supported on said tracks and movable therealong into position to guide hot coke pushed from an oven into said coke receiving means, an enclosed shed extending along the full length of the coke side of said battery and enclosing the coke side ends of said ovens, the coke guide means and tracks, and coke receiving means to capture and contain emissions from coke being pushed, and duct means establishing a gas flow path from said shed into said waste heat tunnel means during pushing of coke from said ovens whereby pushing emissions are drawn by the stack draft from inside said shed into the waste heat tunnel means to be mixed with and incinerated by hot gases from a plurality of said coking chambers connected to the waste heat tunnel means.
2. The nonrecovery coal coking system defined in Claim 1 wherein said duct means comprises a plurality of elongated ducts each extending between and opening into said shed and said waste heat tunnel means to establish a gas flow path therebetween at spaced intervals therealong, and valve means in each said elongated duct for opening and closing said gas flow path therethrough.
3. The nonrecovery coal coking system defined in Claim 1 wherein said coke receiving means comprises a movable quenching car supported on tracks extending adjacent said battery within said shed.
4. The nonrecovery coal coking system defined in Claim 1 wherein said shed comprises said first sidewall connected to and extending above said battery, a second sidewall extending generally parallel to and spaced from said first wall outwardly from said battery, a roof supported on said sidewalls, end walls enclosing the ends of said shed, and door means at least in one of said sidewalls permitting movement of quenching cars into and out of said shed.
5. The nonrecovery coal coking system defined in Claim 1 wherein said waste heat tunnel means comprises a plurality of elongated tunnel sections constructed from a heat resistant material and each extending transversely of at least two of said ovens, and wherein said stack means comprise a plurality of separate stacks spaced along the battery, said tunnel sections each having their coking chamber connected to the elongated tunnel section extending transversely thereof through said flue means whereby gases from at least two coking chambers are intermixed in each said elongated tunnel section before entering the stack connected thereto.
6. The nonrecovery coal coking system defined in Claim 5 wherein each said stack is located between and has its base connected to two of said elongated tunnel sections whereby each said stack applies a draft to at least four ovens.
7. The nonrecovery coal coking system defined in Claim 6 wherein said duct means comprises at least one elongated duct extending between and opening into said shed and each said elongated tunnel section to establish a gas flow path therebetween, and valve means in each said elongated duct for opening and closing the gas flow path therebetween.
8. The nonrecovery coal coking system defined in Claim 7 wherein said waste heat tunnel means extends above and transversely of said ovens, and wherein said duct means comprises one of said elongated ducts extending above each said oven and opening into said shed at a location above the removable door means of the oven therebelow.
9. The nonrecovery coal coking system defined in Claim 8 further comprising quenching tower means located at one end of said shed, and door means leading from said shed directly into said quenching tower means, and where said receiving means comprises a movable quenching car supported on tracks extending along said battery throughout its length in said shed and into said quenching tower means through said door means.
10. The nonrecovery coal coking system defined in Claim 1 wherein the said ovens are sole flue ovens and where-in said flue means comprises a system of sole flues extending beneath each said coking chamber, downcomer means connecting each said coking chamber to said system of sole flues extend-ing therebelow, and conduit means connecting each said system of sole flues to said waste heat tunnel means.
11. The nonrecovery coal coking system defined in Claim 10 further comprising bypass flue means extending between said coking chamber of each said oven and said waste heat tunnel means for establishing a direct gas flow bypass therebetween, and valve means in said bypass flue means for opening and closing said direct gas flow bypass.
12. The nonrecovery coal coking system defined in Claim 11 wherein said waste heat tunnel means comprises a plurlity of elongated tunnel sections constructed from a heat resistant material and each extending transversely of at least two of said ovens and wherein said stack means comprises a plurality of separate stacks spaced along the battery, said tunnel sections each having one end connected to the base of one of said stacks, said ovens each having their coking chamber connected to the elongated tunnel section extending transversely thereof through said system of sole flues whereby gases from said at least two coking chambers are intermixed in each said elongated tunnel section before entering the stack connected thereto.
13. The nonrecovery coal coking system defined in Claim 12 wherein each said stack is located between and has its base connected to two of said elongated tunnel sections whereby each said stack applies a draft to at least four ovens.
14. The nonrecovery coal coking system defined in Claim 13 wherein said duct means comprises at least one elongated duct extending between and opening into said shed and each said elongated tunnel section to establish a gas flow path therebetween, and valve means in each said elon-gated duct for opening and closing the gas flow path there-between.
15. The nonrecovery coal coking system defined in Claim 14 wherein said waste heat tunnel means extends above and transversely of said ovens, and wherein said duct means comprises one of said elongated ducts extending above each said oven and opening into said shed at a location above the removable door means at the coke side of the oven therebelow.
16. The nonrecovery coal coking system defined in Claim 15 further comprising quenching tower means located at one end of said shed, and door means leading from said shed directly into said quenching tower means, and wherein said receiving means comprises a movable quenching car supported on tracks extending along said battery throughout its length in said shed and into said quenching tower means through said door means.
17. In a nonrecovery coking operation in which coal is coked in a plurality of individual ovens constructed in side-by-side relation in a battery, the ovens each having an elongated coking chamber with oven doors normally closing the opposed ends of the chamber, said doors being removable to permit coke to be pushed from the ovens through a coke guide into hot coke receiving means at the coke side of the battery and to permit coal to be charged into the coking chamber through an open door, the method of controlling pushing emissions comprising, providing an elongated waste heat tunnel connect-ed with a stack for providing a draft in the waste heat tunnel, providing a first gas flow path between the top portion of the coking chambers of each of a plurality of the ovens and the elongated waste heat tunnel whereby the stack simultaneously applies a draft to each such coking chamber connected to the waste heat tunnel, exhausting hot partially burned distillation products from the coking chamber of said plurality of coke ovens through the first gas flow path under influence of the draft from the stack during coking of coal in the ovens, providing an elongated shed at the coke side of the battery enclosing the coke guide and hot coke receiving means, providing a second gas flow path between the shed and said waste heat tunnel, the second gas flow path including valve means operable to open and close such gas flow path, and operating the valve means to close the second gas flow path between the shed and the waste heat tunnel while coal is being coked in the ovens and to open such gas flow path during pushing of coke from the ovens whereby push-ing emissions captured in the enclosed shed flow through the second gas flow path directly into the waste heat tunnel under the draft of the stack, the pushing emissions drawn into the waste heat tunnel being mixed with and burned by hot flue gases exhausted by stack draft from the coking chambers of other ovens in the battery connected to the waste heat tunnel.
18. The method of Claim 17 wherein the gas flow path provided between the top portion of the coking chambers and the elongated waste heat tunnel includes a system of sole flues extending beneath the floor of each such coking chamber, the partially burned distillation products from the top portion of the ovens being exhausted through the system of sole flues during coking of coal in the oven, providing a gas flow bypass leading directly from the top portion of each coking chamber into the elon-gated waste heat tunnel and bypassing the sole flue system, and permitting gas to flow from the top portion of a coking chamber directly into the waste heat tunnel only during charging of that coking chamber.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US14135780A | 1980-04-17 | 1980-04-17 | |
| US141,357 | 1980-04-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1197804A true CA1197804A (en) | 1985-12-10 |
Family
ID=22495350
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000375550A Expired CA1197804A (en) | 1980-04-17 | 1981-04-15 | Coke oven emission control method and apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1197804A (en) |
-
1981
- 1981-04-15 CA CA000375550A patent/CA1197804A/en not_active Expired
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