US2975106A - Coke quenching stations and methods - Google Patents

Description

March 14, 1961 J. BECKER 2,975,106

COKE QUENCHING STATIONS AND METHODS Filed June 4, 1956 2 Sheets-Sheet 1 I N V EN TOR. JosEP/ BEG/(E6 ms arr-021M502 March 14, 1961 J. BECKER ,97

COKE QUENCHING STATIONS AND METHODS Filed June 4, 1956 2 Sheets-Sheet 2 a TTOEA/.E Y,

United States Patent O M COKE QUENCHING STATIONS AND METHODS Joseph Becker, Pittsburgh, Pa., assignor to Koppers Company, Inc., a corporation of Delaware Filed June 4, 1956, Ser. No. 589,117

3 Claims. (Cl. 202-37) The present invention relates to improvements in wet quenching coke stations for horizontal coking oven plants, and more particularly to improvements in such quenching stations of the offset stack or tower type of H. Koppers US. Patent 2,234,826 and J. Becker US. Patent 1,848,- 818.

In general, such quenching stations are operated as a part of the sequence operation of the coking plant and must conform to the pushing schedule of such plants in which an oven chamber is discharged and recharged in sequence about every ten to fifteen minutes. For quenching the hot coke, the contents of an oven is pushed into a quenching car, which is then speedily run into'a chamber for quenching with water. In general practice, the contents is showered with water in a large enough volume in the form of a spray to quench the glowing coke without water logging it. This requires the expeditious entrance and withdrawal of a quenching car about every ten to fifteen minutes into the station, with spraying of water for about one to three minutes. Consequently, it is customary practice in this art to have an opening or entranceway for entrance of the car with incandescent coke, and withdrawal of the car with the coke quenched for discharge of the coke to storage, and return of the car to the coke oven battery to receive the contents of thenext oven chamber to be emptied in the sequence or schedule, and usually another opening or entranceway is provided opposite such first-mentioned opening, depending on the track layout for removing the quenching car from the saturating or overloading the quenched coke with water,

there customarily results every ten to fifteen minutes a violent evaporation of quenching water within the quenching hood or chamber as steam in amounts as high. as

' 340,000 c.f.m. within the one to three minutes of spraying ,along with the evolution of a great amount of small particles in the form of ash and coke dust which is carried along with the steam formed in quenching.

Insofar as the proper quenching of the cokeitself is concerned, this steam and dust may billow out of the quenching chamber through the open entranceways, but this is an objectionable practice, since it resultsin deposits of spray and dust from the clouds of quenchingsteam in dential area.

The application of means in the form of water scrubice factory or entirely practical because of the largevolume of water required, and the pumping and other operating costs involved, to wash down the irnpalpable ash, coke dust, or breeze in the vapors, or to condense some of the steam in the vapors as water droplets on the dust particles to precipitate a substantial amount of the solids from the steam quenching. The use of more effective filtering or packing medium for contacting the scrubbing liquor for the quenching steam vapors or for filtering of such vapors has likewise been regarded as impractical or too expensive for the same purpose, because they increase the pressure drop through the tower or stack, which must be kept very low for rapidity of off-flow of vapors from the hot coke, and for sufiicienteconomy of operation to warrant use to attain the desired end result of discharging the products of quenching into the atmosphere in an unobjectionable manner and composition.

I have now found that the cause of these defects, in practice, is due to the fact that with the entranceway left open during the prompt off-flow of the quenching vapors through the stack or tower, large quantities of .air also entered the quenching chamber through the open entranceways and mixed with the steam. Hence, the amount of washing liquid and pumping costs therefor, required with the open entranceway, as the quenching has heretofore been carried out, necessarily was proportional to the total volume of air and steam, whereas the actual amounts involved for precipitation of the dust and condensation of some of the steam to provide water droplets to precipitate the dust from the quenching vapors alone, is much less.

The present invention therefore has for its object to improve such quenching tower systems of coking plants in such manner as to reduce the volume in which suchsteam and dust exists, as it rises from the hot coke and ascends the tower, to a minimum and by extremely simple means, thereby reducing substantially the amount of liquid and pumping cost, to the minimum required to remove the solids insufiicient amount to eliminate or minimize a nuisance in the immediate area or more remote surrounding community.

- According to the invention a door or doors are provided to completely close the entranceway at the entrance'end of the quenching chamber with the quenching car on the usual trackway in said chamber. The door or doors are movable to provide a clearance for insertion of the quenching car with its load of incandescent coke, and. for

its removal after quenching. When the door or doors are closed, during quenching of coke in a car in the chamber, they act as a barrier to the entrance of the large objectionable quantities of air as heretofore occurred into mixture with the steam given off on contact of the water spray with the incandescent coke, thus reducing to a negligible amount the inward flow of steam-diluting air. When the doors are closed the violent evaporation of the water of the spray generates pressure of steam which builds up in the chamber thus forcing the .vapors actively upwardly through the tower, and the spray washing of such steam vapors may be more economically carried out sincethe volume of the vapors to be sprayed is greatly reduced in amount as compared with the volume that heretofore had to be sprayed due to the influx of air through the open entranceway or entranceways when kept open as heretofore during the quenching. V

In the normal operation of a coke plant each charge of coke to be quenched is alike. It therefore produces'the same amount of steam to be scrubbed from each quench:

ing operation, provided the doors are closed on each end of the tower. This quantity cannot be affected by air entering into this quenching system, since the closeddooifs prevent entrance of air in an amount to effect the volume Patented Mar. 14, 1961 of the quenching steam. Thus operated the quenching station tower is similar to towers in which solids are removed from gaseous substances, i.e. blast furnace gas or producer gas, both of which contain similar solids which are removed by water scrubbing. The incidental condensation of some steam is of value for precipitation of dust, since only enough spray water is used to remove the solids in sufiicient amount to eliminate a nuisance in the immediate area or more remote surrounding community. The quantity of water required to condense all the steam would be too large to be used practically.

In general, the best mode is to utilize the novel door feature with the tower in offset relation as in the aforesaid H. Koppers and I. Becker patents. However, the invention is also of utility with the tower immediately over the quenching chamber in vertical alignment therewith. The former offset arrangement is preferred over the latter vertical alignment arrangement since the offset arrangement eliminates the restriction to flow which is imposed by use of the vertical alignment of the tower, due to the absence of provision of means to collect the condensed steam and spray liquor from the tower or stacks, which is necessary with the vertical alignment arrangement in order to prevent the scrubbing liquid from passing down onto the quenched coke.

Other objects and advantages of the invention will be apparent as it is better understood from the following description when considered in connection with the accompanying drawings illustrating a preferred embodiment thereof.

On the drawing:

Figure 1 is a vertical sectional view taken longitudinally of a quenching station showing the essential features of the preferred embodiment of my invention in sequential coaction with a battery of horizontal coking retort ovens;

Fig. 2 is a top plan view of the station shown in Fig. l; r

Fig. 3 is avertical section taken on the line III-H of Fig. 1 showing the tower or stack portion thereof;

Fig. 4 is a horizontal cross sectional view taken on the line IV--IV of Fig. 1;

Fig. 5 is an end elevational view partly in vertical section, taken on the line'V-V of Fig. 1.

Fig. 6 is a horizontal sectional view taken on the line VIVI of Fig. 1.

Referring to the drawings the quenching chamber 1 is constituted of a hood or housing composed of a roof 2 and supporting columns 3 of reinforced concrete. The chamber 1 is of a length to wholly contain a quenching car 4 of a size to contain the contents of at least one of the complete charges of one of the coking chambers 5 of the horizontal coke oven battery 6. The car runs on tracks 7 which extend alongside the coke side bench 8 of the battery 6 of horizontal coking retort ovens of the general type illustrated in I. Becker US. Patent No. 2,447,837 of 1948, where it receives the white hot coke cake of an entire oven charge when pushed out of said battery. After the coke is filled into the quenching car 4, the car is propelled along the trackway 7 into the quenching chamber 1 by means of the motive means 9.

The hood or housing of chamber 1 is extended at the end opposite the end where the car 4 enters from the coke oven battery 4 to constitute one bay 13 beyond that necessary to accommodate the whole length of the quenching car 4, and the tower or stack 10 is surmounted on the extended bay to form an offset washing or treating tower or stack, for off-flow of the quenching vapors from the chamber 1 to the atmosphere at a level high enough to scatter any residual products of quenching more widely throughout the surrounding atmosphere. With this offset design any condensate of steam in said tower 10, and any scrubbing water used therein, will by-pass the coke in aquenching car 4 in the chamber 1 when falling through the same, without requiring deflectors which would impose a resistance to flow of vapors passing from the chamber 1 to the stack tower 10. For contact to precipitate dust from the steam in the tower 10, two banks of widely spaced wooden grids 11 with two sets of spray heads 12 are provided therein for distributing acqueous quenching liquid or scrubbing water over the packing 11.

The chamber 1 communicates through the bay 13 unrestrictedly with the lower portion of the tower 10 at its lower part for upward outflow from the chamber and through the tower, and is provided with quenching spray heads 14 distributed along the car length portion of chamber 1 at a level above the level of the top of a car 4 therein. The spray heads 12 and 14 are fed with scrubbing water from an overhead tank 15 by means of a downcomer 16 and branch lines 17 and 18. Water draining from the quenching car and from the scrubbing tower 10 is collected by an inclined fioor having a discharge trough 19, from whence the spent quenching liquor is returned to the overhead tank 15 in a conventional manner.

In general practice the operation of the water system is performed manually as well as automatically as is well known in this art and hence need not be further described.

In accordance with the present invention, an entranceway 20 which is customarily open, is closed during quenching by means of door 21. As shown, the door 21 completely closes the so constituted doorway from top to bottom and side to side of the doorway 20. At the end of the bay 13 under the tower 10 the end of the chamber is customarily either closed by a solid wall, or left open for exit of the quenching car, depending on the track layout for removing the car from the quenching track to a shop for repairs. When the track layout requires a doorway for the opposite bay end of the chamber for access to a shop for repair, a door conveniently constituted as a hinged door 21 is provided to swing outwardly, whereas at the coke oven end of the chamber 1, the door 21 is constituted of the vertically sliding type, which is preferably counterweighted and provided with a motor lift means 22. It is to be understood, that this door 21 may also be manually operable as is the hinged door 21 at the opposite bay end.

As will be seen in Figs. 3, 5 and 6, the basal supporting structure of chamber 1 and its end bay is also constituted of reinforced concrete 23 with end walls 24 reaching up to the top level 25 of the tracks 7. These walls 24 have recesses therein for the reception of the tracks 7. The door 21 at the end at which the quenching car is inserted into the chamber 1 with hot coke from the ovens 5 is provided with a slit to permit the door to fully close around the link 26 between the car 4 and motive means 9, without disconnection during quenching. In this manner the door 21 can seal close to the tops 25 of the supporting basal wall structure 24 and thus prevent ingress of air during the autogenous pressure conditions that are set up in the chamber 1 during quenching.

The operation of the structure is substantially as follows:

The charge of hot coke from an oven 5 is conveyed by the car 4 to a point below the spray nozzles 14 and the quenching water supply to the nozzles 14 in the chamber 1, and to the nozzles 12 in the tower 10, are set into operation, either manually or automatically as conventional. When the car 4 is fully inside the chamher 1, the doorways 20 are simultaneously fully closed by the doors 21, also either manually or automatically. 7 The quenching,'which is usually completed in one to three minutes, results in the evolved steam being pressed out through the stack 10 under the autogenous pressure induced as a result of the complete closing of the chamber 1 and bay 13 by the closing of the doors 21, 21'. The tower 10 and the upper portion of the areas of the chamber 1 are completely closed off from the outer atmosphere preferably, for example, by'an upper wooden siding V 27 and a lower side area by a brick wall, and the sides of the end bay 13 under the tower is likewise closed off, for example, by an upper wooden siding and, a lower brick lining and the bay is openonly to the-tower above, although obviously other materials are within the contemplation of the invention. As a result substantially only the minimum volume of gaseous vapors and solids that arise from the quenched coke pass upwardly through the tower 10 concurrently with the spraying of the packing 11. This reduction in volume of gas orvapor passing through the tower or stack reduces the tendency of the dust particles to be carried past the scrubbing zone in 10 and out into the atmosphere. In spraying the packing 11 in the scrubbing tower 10, a much smaller quantity of water, approximately equal tothe quantity of water used for the quenching ,of the coke in the car in chamber 1, is required for scrubbing out the solids. This very much smaller volume of scrubbing water in combination with its intensive spray contact with the vapors, due to the dispersion action of the spray heads 12, results in partial condensation around entrained dust particles of a small percentage of the steam.

This novel method of scrubbing solids from a much smaller volume of such quenching steam that results from the absence of such doorway air, results in a more economical and hence a more effective removal of a larger percentage of impalpable dustparticles than has heretofore been possible with the prior art tower or stack systems requiring treatment of such large volumes 'of coke quenching steam due to the influx of air during quenching.

In the normal operation of the system of the present invention, the volume of steam to be treated and the volume of water spray required is limited to the much smaller amount of steam given off in the actual quenching, since each coke charge from an oven chamber of a coke plant to be quenched is always the same and produces the same amount of steam to be scrubbed. With the doors, this volume is not enlarged as heretofore by air entering the quenching chamber. Hence, only enough spray water is needed to remove the solids from such smaller volume of steam by an amount to eliminate a nuisance in the immediate area of the quenching chamber or the remote areas of the surrounding community.

The invention also contemplates, in operation, carrying out the quenching with the roof of the hood or chamber 1 and the supporting columns 3 also being made of pressure treated wood, as well as the siding, doors, and stack, in order to eliminate the erosive and corrosive action of the quenching water and steam on exposed concrete or brick surfaces as heretofore obtained in commercial practice. In such case, to prevent any possibility of damage to the wooden roof of the hood with this type of construction, the invention contemplates one of the quenching sprays 14 at the inlet end of the hood chamber 1 to be connected to the line 17 feeding the scrubbing sprays 12, with an automatic means comprising a four way valve 35 with a solenoid 36 and a limit switch 33 operable by car 4 to then open a valve 30 in the line to the scrubbing sprays and to the end quenching spray as the quenching car 4 enters the hood 1. This provides a preliminary wetting of the surface of the coke as the car 4 enters the hood. A timing mechanism 34 with an adjustable delay period is included in the automatic means then actuates a valve 32 in the line 18 to the balance of the quenching sprays 14 after suflicient time for the quenching car 4 to have fully entered the hood 1 and the door 21 to have been lowered into the closed position. After a further adjustable period, the timer 34 cuts 01f the water to both the quenching sprays 12 and the scrubbing sprays 14.

The excess quenching water from 14 and scrubbing Water from 12 drains from trough 19 to a settling sump of the conventional type and the settled water is recirculated' to the quenching-tank of chamber 1; As-the scrub bing water utilized in tower 10 is approximately equalto the quantity of water used for quenching inchamber .1,

the two quenching pumps of the sizenormally provided 5 maybe used in a normal operation to keep the quenchingtank 15 filled. During periods of maintenance of one of these'pumps the scrubbing sprays are taken out of service I in tower 10 and only the quenching sprays 14 used. At this time, of course, little or no dust would be removed from the quenching steam.

- Preferably, however, the water in the tank 15 is conlocated in the portion of the branch line below the header. With this arrangement there is no lag in time between the opening of the valve 32 and the discharge of water from the spray heads 14 onto the top surface of the coke as would result in a chance of the heat of the coke in the car igniting any wooden or otherinfiammable matter in the quenching station. With this arrangement the header 31 is always filled with a reserver of water for discharge through the spray heads 14. The spray heads are connected with theheader above the lower half and preferably with the upermost diametric half of the headerso as to insure a reservoir of water to the outlets of the .header to the conduits therefrom to the spray heads 14. Locationbf the valve32 in the portion of the line 18Ibelow the header 31 insures hydrostatic pressure of liquid in tank 15 on the entire line from the tank to the conduits for all of the'spray heads immediately upon opening of valve 32, with the result that there is no time lag between the opening of said valve 32 and the discharge of liquid from the spray heads 14 as obtains with prior quenchingsystems which have the spray head" in draining relation at all times with the lower diametric half of the header 31 and the valve 32, and connection of line 18 with the header 31, at a level above the upper.

diametric half of the header 31.

The invention as hereabove set forth is embodied in j a particular form of construction but may be variously embodied within the scope of the following claims.

I claim: I

1. In combination with a Wet coke quenching chamber adapted for quenching of coke therein with liquid and having a doorway through which a car of coke may travel 7 into and out of said chamber for quenching of coke there- I in, and spray means for discharging liquid in the form of a spray onto hot coke in a car in said quenching cham ber, a tower at a level above said quenching chamber and communicating at its lower part with the upper part of said quenching chamber for upward outflow through said chamber to said tower of the products of vaporous and 7 solid nature which may arise from the quenched coke, means for collecting and returning to said spray means most of the spray liquid as unvaporized spray which drains from said coke in a car in said chamber, said tower communicating at its upper part with the atmosphere so as to discharge said products from the quenching chamber upwardly through the tower into the atmosphere at the; top of the tower during the quenching operation, sprayer means and contact means in said tower for washing steam therein to remove dust from said steam products in said tower concurrently with discharge of any residuum of said products into the atmosphere from the tower at the top thereof, means for off-flow of liquid from said tower with by-passing of coke being quenched in a car in the quenching chamber by said liquid, said quenching chamber being completely enclosed against the entrance of atmospheric air except for a doorway for passage of said car, and having a door substantially closing all said doorway of said chamber while a coke quenching car is within said quenching chamber, to prevent the entrance through said doorway and upflow of large quantities of atmospheric air through said chamber and tower during the quenching of, and upflow of quenching vapors from, coke in a said car in said quenching chamber.

2. In combination with a wet coke quenching chamber adapted for quenching of coke therein with liquid and having a doorway through which a car of coke may travel into and out of said chamber for quenching of coke therein, and spray means for discharging liquid in the form of a spray onto hot coke in a car in said quenching chamber, a tower at a level above said quenching chamber and communicating at its lower part with the upper part of said quenching chamber for upward outflow through said chamber to said tower of the products of vaporous and solid nature which may arise from the quenched coke, means for collecting and returning to said spray means most of the spray liquid as unvaporized spray which drains from said coke in a car in said chamber, said tower being offset from said quenching chamber and communicating at its upper part with the atmosphere so as to discharge said products from the quenching chamber upwardly through the tower into the atmosphere at the top of the tower during the quenching operation, sprayer means and contact means in said tower'for washing steam therein to remove dust from said products in said tower concurrently with discharge of any residuum of said products into the atmosphere from the tower at the top thereof, means for ofi-fiow of liquid from said tower with by-passing of coke being quenched in a car in the quenching chamber by said liquid, said quenching chamber being completely enclosed against the entrance of atmospheric air except for a doorway for passage of said car, and having a door for closing all of said doorway of said chamber while a coke quenching car is within said coke quenching chamber, to prevent the entrance through the doorway and upflow of atmospheric air through said chamber and tower during the quenching of and upflow said car in said quench said coke that there is drainage of most of the sprayed liquid as unvaporized liquid from the coke for recycling for further spraying which method comprises: flowing said products and the heat thereof from the chamber upwardly through the tower then outwardly into the atmosphere during quenching of the coke in said chamber; passing said products during such flow into contact with a descending spray of aqueous liquid and thereby precipitating objectionable solid products therefrom in said tower; and closing a door in said doorway during the descent of the quenching liquid spray onto the coke in the car in said chamber, to prevent the entrance through the doorway and upflow of large quantities of atmospheric air through said chamber and tower during the quenching of hot coke in a said car in said closed quenching chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,810,322 Moetteli June 16, 1931 1,848,818 Becker Mar. 8, 1932 FOREIGN PATENTS 573,867 Germany Apr. 6, 1933 725,454 Great Britain Mar. 2, 1955

Claims (1)

1. 3. THE METHOD OF REMOVING THROUGH A TOWER PRODUCTS OF A VAPOROUS AND SOLID NATURE THAT FROM AND RISE AND FLOW UPWARDLY THERETHROUGH TO THE ATMOSPHERE BY REASON OF SPRAYING IN A CLOSED QUENCHING CHAMBER AT A LOWER LEVEL THAN THE TOWER AND HAVING A DOORWAY THROUGH WHICH A CAR OF INCANDESCENT COKE MAY TRAVEL INTO AND OUT OF SAID CHAMBER FOR WET QUENCHING OF COKE IN A SAID CAR IN SAID CLOSED CHAMBER A QUANTITY OF LIQUID OF SUCH VOLUME TO QUENCH SAID COKE THAT THERE IS DRAINAGE OF MOST OF THE SPRAYED LIQUID AS UNVAPORIZED LIQUID FROM THE COKE FOR RECYCLING FOR FURTHER SPRAYING WHICH METHOD COMPRISES: FLOWING SAID PRODUCTS AND THE HEAT THEREOF FROM THE CHAM-

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