US2789086A - Decarbonizing of the rich gas nozzles of coking or other chamber ovens - Google Patents

Description

April 16, 1957 Filed Aug. 19, 1952 v H. SCHRHOFF ET AL DECARBONIZING OF' THE RICH GAS NOZZLES OF vCOKING OR OTHER CHAMBER OVENS 4 sheets-sheet 1 April 16, 1957 H. scHURHoFF ETAL 2,789,086

nEcARBoNIzING oF THE RICH GAS NozzLEs oF coxING oR OTHER CHAMBER ovRNs 4 Sheets-Sheet 2 Filed Aug. 19, 1953 any? 2309 April 1e, w57

H. scHURHoFF ETAL 2,789,085 DECARBONIZING OF THE RICH GAS NOZZLES OF' COKING OR.0THER CHAMBER OVENS Filed Aug. 19, 1953 4 Sheets-Sheet 5 April 16, 1957 H.

' DECARBONIZI COKING 0R 0TH 4 Sheets-Sheet 4 Filed Aug. 19, 1953 United States Patent DECARBNZING 0F THE RICH GAS NOZZLES F COKING 0R OTHER CHAR/EER GVENS Heinrich Schiirhol, Essen-Stadtwald, and Franz Boll, Essen, Germany, assignors, by mesne assrg,a ments, to Kappers Company, Inc., Pittsburgh, Pa., a corporation of Delaware Application August 19, 1953, Serial No. 375,273

3 Claims. (Cl. 2112-38) The present invention relates to the decarhonizing of the rich gas nozzles of regeneratively-heated coking chamber ovens or similar ovens by the induction of air during the reversal of the direction of heat llow, using ilap valves operated by the reversing gear (usually a winch).

ln the heating of coking or other chamber ovens by means of rich gas, deposits of graphite are formed in the portions of the rich gas nozzles of the heating system which are located in zones of high temperature, owing to the decomposition of the hydro-carbons therein, these deposits producing variations in the free cross-section of the nozzle which impair the uniform heating eiect which is aimed at, and consequently such deposits have to be removed from time to time. Hitherto this removal has been carried out by opening, at specific intervals at which the reversal mechanism has cut oit the rich gas and only half of the regenerators are open to their waste gas channels, air inlet llaps which are furnished on the outer rich gas supply conduit, the air which is accordingly drawn in producing combustion of the graphite deposits while the rich gas is cut oli.

Where normal coke oven gas is utilized as the rich gas, such an expedient suices to remove the graphite deposits in the rich gas nozzles, but where ovens are heated by means of a rich gas with a high content of heavy hydrocarbons such as residual synthesis gas, the amount of deposited graphite is such that the usual manner of introduction of relatively small quantities of air is inadequate to deal with the problem and some of the deposits have to be removed eventually by a diiicult manual operation.

The present invention aims at the provision of apparatus for the automatic removal of the graphite deposits in the rich gas nozzles of coking or other chamber ovens, in which the graphite deposits formed as a result of heating by a gas having a higher content of heavy hydro-carbons are completely banished by the drawing in of larger quantities of air for short periods by the natural draft of the oven with all of the regenerators open to their stack draft channels.

in accordance with the present invention this aim is achieved by connecting the decarbonizing air inlet iiap valves, which are located outside the oven in the rich gas supply conduits, in such a way with the reversing gear for effecting the change over of the direction of heat flow that, at a speciiic period in the reversing procedure, air only is drawn through all the rich gas nozzles, under the action of the liue draught by the waste heat conduits of all regenerators.

.In accordance with a further feature of the invention reversing members for the regenerator air valves and Waste heat valves are operated by the reversing gear in such a way as to cause an acceleration in the closure of the regenerator air valves at one regenerator side, relatively tothe opening of the air valves for the other regenerator side. which is to be opened, thus providing a time interval in which the Waste heat valves of all the regenerators of both sides are partially opened and all the air inlet ap 2,789,086 Patented Api. 16, 1957 valves forv the decarbonizing air are fully opened since these regenerator air valves conventionally arehooked up with the waste heat valves, so that when the air valve is opened the waste heat valve is closed, and vice versa, i. e., when the air valve closes the Waste heat valve automatically opens. Since neither the combustion air for burning gas for the underliring nor the combustible. gas for underiiring can enter the heating system in this period, the whole of the suction effect of the ilue draught, of about 25 mm. W. S. (water column), is made available for a sudden inlux of a larger amount of decarbonizing air through all the rich gas nozzles to all the waste heat conduits, so that a short intermission of `about l second or less, during the interval of reversing of the direction of heat ilow, is suihcient for the complete combustion 0f the greater amounts of graphite deposits resulting from such a rich gas of higher hydrocarbon content than that of coke oven gas,

According to a further feature of the invention the deearbonizing air inlet flaps are controlled through a cam disc which is coupled to the reversing gear and has, running over the cam surface thereof, a roller cam follower `connected to a draw member of the reversing gear. Preferably in accordance with yet another feature of the invention, special cam discs are used on the one hand for closing the air inlet aps of the rich gas conduits which, at that particular instant, were just closed to gas flow and 0n the other hand for holding open the decatbonizing air inlet llaps of the rich gas conduits which were at that time close tov such rich gas llow but are next to be turned on. By this feature, the air flaps of the rich gas conduits previously open to gas ilow are opened while the air flaps provided in the rich gas conduits closed against the inflow of gas are also open during the end of the purge period.

Yet another feature of the invention resides in the connecting of two cam discs for controlling the ilap valves for the decarbonizing air, by means of two bolts, with the shaft of the reversing gear so that they can be brought stepwise into the position necessary for the closure of the decarbonizing flaps during the change over of the heating to lean gas.

A preferred embodiment of the invention is illustrated in the drawings in which:

Figure 1 is a vertical section through the heating llues and through the regenerators of a coke oven battery, taken on the line l-I of Figure 2 and indicating the heating mechanism;

Figure 2 is a vertical section on the line lI-Il of Figure l with apart shown in elevation;

Figure 3 is a diagram showing the movements of the control members effected during the reversal operation of the heating system;

Figure 4 is an elevational view of the mechanism for reversing the decarbonizing flaps, which mechanism is coupled to the reversing gear;

Figure 5 is a vertical section through the mechanism taken on line V-V of Figure 4; and

Figures 6 to 8 illustrate different positions of the reversal mechanism illustrated in Figure 4.

The coke oven battery illustrated in Figure l is of the twin tlue oven type in which the rich gas for effecting the heating is supplied. through distribution pipes 1 arranged along both the pusher machine and coke discharge lsides of the loven battery. Therich gas passes in one phase ofa regenerative cycle through vertical pipes 2 at both sides or" the oven battery and through horizontal channels 5 and nozzles 6, located below the heating ues 3 and 4, to the foot of one set of tlues 3 and in the next phase upon reversal of the heat llow, through pipesV 20 at both sides of the battery and channels Sato the foot of another set of lines 4. The regenerators are in two sets as indicated lat 7 and 15, and associated with each regenerator is an elbow 22, the elbows on one side, the pusher machine side, ofthe battery each having -an air inlet flap 21 and a waste heat valve 23, while those on the opposite coke discharge side of the battery each have an air flap 24 and waste heat valve 25.

When rich gas is used for heating, combustion air for burning the same is preheated in a regenerator 7 and for this is admitted to the regenerators through openings 8 in elbows 22, and is supplied by the regenerator 7 through regenerator ducts 9 to the heating flues 3 in the regenerative heating period or phase in which these ues 3 are tired upwards. At the inner end 10, the regenerators 7 are connected each with a horizontal conduitY 11 which delivers preheated air therefrom to the heating ues 3 on the coke side half of the battery through regenerator ducts 12. Waste heat from iiues 3 ilows downwards through the other set of heating ues 4 and through regenerator ducts 13 in the left-hand pusher machine side half of the heating walls into counterpart horizontal conduits 14 then into the other set of regenerators 15 connected to these conduits 14. The waste gases from the ues 4 on the right hand coke side half of the heating wall also pass through conduits 17 directly into the other set of regenerators 15. From thelatter regenerators 15, the waste gases are drawn oi into the waste gas passage 16 through the opened Waste heat valve 25 of their elbows 22.

The rich gas pipes 2 and 20, which are respectively connected to the gas distribution pipes 1 at both sides of the battery and with the respective rich gas channels and 5a are equipped with individual shut-off cocks 18 and 19, Fig. 2, which are adapted to Vbe opened or closed by reversing gear according to the direction of heat llow. The reversing cocks 18 for pipes 2 at both sides of the oven battery are thus opened when the upward firing of the heating tlues 3 takes place, and during the same heating period the reversing cocks 19 for gas pipes 20 on both sides of the battery are closed. During this regenerative heating phase, moreover, the air llaps 21 of the elbows 22 on the pusher machine side of the battery indicated by M. S. in Figure l, are opened for regenerators 7 and the waste heat valves 23 for said 'elbows 22 are closed, while the aps 24 of the elbows 22 at the coke discharge side of the battery, marked C. S., are then closed for regenerators and the waste heat valves 25 opened.

When the direction of heat llow has been changed over the ilow program is correspondingly reversed for iniow through regenerators 15 and flues 4 and outflow through tlues 3 and regenerators 7.

Openings for inow of decarbonizing air, closable by aps 26, are formed in the vertical rich gas pipes 2 and 20. The iiaps 26 are connected to a lever arm 30 by means of a chain 28 and a shaft 29 (Fig. l). At the pusher machine side M. S. of the battery the lever arm 30 is engaged by a draw member 31 and on the coke discharge side C. S. by a draw member 32, which are connected to the reversing mechanism of the reversing gear as illustrated in Figures 4 to 7. Only one decarbonizing air inlet opening, adapted to be closed by the hap 26, need be provided per duct 5 or 5a. The aps 26, for example on the M. S. side, operated for the gas pipes 2, and on the C. S. side only the gas pipes 20, are provided with these aps 26 so that decarbonizing air enters from one end only of the ducts 5 and 5a.

The combustion regenerator air flaps 21 and 24 and the regenerator waste heat valves 23 and 25, and also the rich gas cocks 18 and 19, are changed over, reversed, by means of the customary reversing equipment 33 as conventionally indicated in Figures 4 and 6 to 8. To this end the reversing equipment is connected to the regenerator valves through a draw member 34 of the 4 elbows 22 to a draw lever 35 which is fastened to a shaft 36 mounted on a plummer block 37.

The air aps 21, 24, and waste heat valves 23, 25, of the elbows 22 are so interconnected by chains 38 that, on opening the air flaps 21 or 24, the Waste heat valves 23 or 25 are closed and vice versa. lf for example the air flaps 21 on the machine side M. S. are opened during a heating period, the waste heat valves 23 are closed against discharge of the heat, and the air aps 24 are closed and the waste heat valves 25 opened at the coke side C. S. When the regenerator air aps and waste heat valves are thus set, the reversing cocks 18 of the rich gas pipes 2 on the two sides of the battery are opened for ducts 5, while the reversing cocks 19 for the gas admission pipes 20 connected to the ducts 5a, which are arranged to operate in alternate succession with pipes 2 and ducts 5, are closed. This means that when air streams in through the opened regenerator flaps 21 into the regenerators 7 it also flows through the connecting regenerator ducts 9 directly, and indirectly through the horizontal conduits 11V and regenerator ducts 12 to the heating ues 3, the rich gas flows to the latter in through the nozzles 6 from the horizontal gas duct or channel 5. Waste gas resulting therefrom is then Withdrawn through the heating ues 4 indirectly through regenerator ducts 13 of the left hand half of the oven battery and horizontal conduit 14, and through regenerator ducts 17, directly into the regenerators 15, whence it passes out into the waste heat passage 16.

In accordance with the invention, in Figure 5, a spindle 44 is rigidly connected to the shaft 42 of the reversing gear 33 by means of screws 43. Slidably disposed on spindle 44 is a cam disc 45 and also, through the agency of a spacing ring 46, a further cam disc 47. The spacing ring 46 is rmly keyed on the spindle 44. The cam discs are rigidly connected to the shaft 42 of the reversing gear 33 by means of two bolts 48 and 49 of different cross-sectional size which pass through the two cam discs and 47 and the spacing ring 46, are held against axial displacement by means of a screw 51 rotatable by a buttery 52 and threaded into the spindle 44. An indicator welded to the bolts 48, 49 enables the position of the decarbonizing flaps 26 to be shown on a stationary scale 53 on the reversing gear.

The cam discs 45 and 47 have a circular peripheral part 54 and a recessed part 55. Mounted pivotally on the stationary frame of the gear 33 in pivots 56 are two cam follower arms, 57 being associated with cam disc 47 and the arm 58 with the cam disc 45, through rollers 76 and 77, respectively, which are also articulated to links 59 and 60 connected to the draw members 31 and 32 which run over a roller 61.

The link 59 is connected by draw members 31 va the roller 61, with the levers 30 of the decarbonizing air aps 26 of the rich gas admission pipes 2 at the M. S. side of the battery. These decarbonizing flaps are closed during the heating period under consideration since the gas pipes 2 are then delivering rich gas to the heating ues 3. The link 60 through draw member 32, is connected via the corresponding roller 61 with the lever arms 30 of the decarbonizing aps 26 for the pipes 20 on the C. S. side of the battery, the rich gas supply pipes 20 at this time being closed by valves 19 to the admission of gas, and the aps 26 for pipes 20 are opened by member 32 since no air can ow from the counterpart regenerator 15 to ues 4 during this heating period.

The reversal of the direction of heat ow takes place in the manner indicated in the diagram of Figure 3. The gas cocks 18 for channels 5 are rst closed at the machine side by operation of the reversing gear, this closure movement being identified by the curve 66 which terminates at the point 67. After the closure of the cocks the reversing gear continues to turn until the moment represented by the vertical line 68. At this moment a purge pause starts, this being represented by the vertical line 69.

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-When the gas cocks 18 have been thus closed' as at 68, a partial opening of the decarbonizing aps 26 on the machine side to the gas supply pipes 2 for channels 5 starts at the point 70 in the diagram. As a result of the limited degree of opening of these llaps 26 a certain amount of air tlows in at 26 andV Vgradually drives ahead with it the residual gas in channel to the heating tlues 3, the so produced mixture of air with the gas in channel 5 being however below the explosive limit.

The' reversing of the regenerator waste heat and air valves begins at the end of the purge pause as at 69 in the change over procedure. In this phase of the reversal operation the opened air aps 21 for regenerators 7 for flues 3 close more rapidly, by means of member 34, than the closed air aps 24 for regenerators 15 can commence to open, through member 34, for ues 4, thus opening up waste gas valves 23 for regenerators 7 while waste gas valves 25 for regenerators 15 are still open to tunnel 16, so that there is a short intermission, for example of about one second, between the end of the closure movement of the regenerator air aps 21 and the beginning of the opening of the regenerator air aps 24.

This relative faster closure operation, by draw member 34 of the air aps 21, as at the machine side on the left hand of Figure l, is effected by an accompanied connecting of the aps, as ap 21 with the shaft 36 through slackage in the chain 38, at a point which imparts, at the moment indicated in the diagram at 71, with certainty a certain acceleration to the closure movement of the air aps of each regenerator set, which also, of course, alects the quicker opening of the waste heat valve 23 which is conjugated therewith before the opening operation of the air flaps of the other regenerator set. The closure of the air ilaps 21 terminates at the point 72, whereas the air ap 24 at the coke side does not begin to open until the point 73 is reached. In the period separating these two points 72 and 73, a period of about one second, all the air aps 21 and 24 at both sides of the oven battery are therefore closed. The waste heat valves 23 and 25 at both sides of the battery are however, as is apparent from the diagram, approximately half open, since the waste heat valves 25 have not yet been fully closed and the waste heat valves 23 not yet fully opened due to excess chain slackage take-up.

At the conclusion of the pause however, the decarbonizing flaps 26 of the vertical gas pipes 2, which hitherto have only been slightly opened for channels 5, begin at the same time to open further as a result of the continued rotation of the reversing gear shaft 42. The opening is concluded when the air aps reach the closure position at the vertical line 72, as can also be seen from the diagram, so that in the cam-determined period between the closure of the regenerator air aps 21 and opening of the regenerator air flaps 24, which are designated by the points 72 and 73, comparatively larger quantities of air are drawn through the ducts 5 and Sa and every one of their rich gas nozzles 6 under the elect of the direct ue draught of their regenerators 7, with tunnels 16 through valves 23 and 25, instead of all draft being through only one valve, 23 or 25, as heretofore. This excess air provokes a combustion of the greater amounts of graphite deposits in the nozzles 6 and, after leaving the nozzles, passes directly to the immediately adjoining connecting conduits 9, 12 and 13, 17 leading to the regenerators 7 and 15 without passing through llues 3 and 4 and through waste heat valves 23 and 25 to the waste heat passage 16.

The reversing procedure is now terminated by the uninterrupted continued rotation of the reversing gear shaft 42, in that the air flaps 24 open, the waste heat valves 25 close and the waste heat valves 23 are fully opened. When this change over procedure is concluded the gas cocks 19 of the gas pipes 20 for channels 5a and ues 4 are opened. The decarbonizing liaps of the gas admission pipes 2 for channels 5 and ues 3 remain open since these 'are still shut olf from the gas supply, while the decarbonizing aps of the gas pipes 20. are closed, as is also apparent from the diagram.

In Figure 4, arms 57 and 58 of the draw members 31 and V32 connected to the. decarbonizing flaps are in a position in which the decarbonizing flaps of the gas pipes 2are closed and those of the gas pipes 20 are open. Figure 7 illustrates the position in which during a rotation of the reversing gear in the direction of the arrow 75 (Figure 4), the recessed surface 55 of the cam disc 47 has actuatedV the roller 76 for member 31 to produce .the limited opening of the decarbonizing aps of the conduits 2 aty the beginning of the purge pause which is represented in the diagram of Figure 3 by the vertical line 63. The roller 77 of the lever 58 of the cam disc 45 for member 32 at that time runs over the circular periphery of the cam disc so that the opened condition of the decarbonizing tiaps 26 of the rich gas pipes 20 is consequently not altered but kept open also.

In Figure 8 the roller 76 of the lever 57 for member 31 has reached the circular periphery of the cam disc 47, so that the corresponding decarbonizing aps 26 for gas pipes 2 are fully opened, as is disclosed in the diagram of Figure 3 by the vertical line 72. The roller 76 runs over this circular peripheral part of the cam disc 47 until the conclusion of the reversing procedure, while from this time onwards the roller 77 of the lever 58 enters the corresponding recess in the edge of the cam disc 45 and thus closes the associated decarbonizing aps of the gas pipes 20.

In changing over from heating by rich gas to heating by lean gas it is necessary to close all the decarbonizing flaps. This is effected by turning the butterfly 52 of the screw 51, causing the nut 78 to act on the indicator 5i) and withdraw the bolts 48 and 49 connected to the latter out of the path of the cam disc 45. When the decarbonizing aps 26 associated with the cam disc 45 are opened it is necessary before carrying out this step to await the succeeding reversing procedure in which the aps are closed. Since, during the next reversal the cam disc 47 has reached the position corresponding to the closure of the corresponding Idecarbonizing aps, the bolts 43 and 49 can be fully withdrawn. Since the cam discs 45 and 47 are now loose on the spindle 44 they can no longer participate in the rotation of the reversing gear. The use of bolts 48 and 49 of different size guarantee that these always enter the same openings, and thus ensure the correct relative positioning of the cam discs.

The invention can be applied to any kind of regeneratively heated oven, such as those heated with rich gas, or optionally with rich gas and lean gas.

What we claim is:

l. A regeneratively-heated coking chamber oven with two sets of rich gas nozzles and two sets of regenerators, and an arrangement for decarbonizing the rich gas nozzles `during the reversal of the 'direction of heat flow, using valves to the nozzles which are operable by the reversing gear to open and allow the drawing-in of air to the nozzles, and valves associated with the two sets of regenerators for inow of air to, and outow of waste gas from, the regenerative system of the oven, characterized by all said valves being coupled with the reversing gear in such a manner that, at a specific time in the reversing procedure, air only is drawn in the heating system only through all the rich gas nozzles of both sets and exhausted through both sets of regenerators into the waste heat passages for both sets by the action of the liuc draught.

2. An arrangement according to claim l, characterized in that air inlet valves and waste heat valves associated with the two sets of regenerators are operatively coupled with the reversing gear such that the air inlet valves of one set of the regenerators is closed in advance of the opening of the corresponding air valves of the other set of regenerators, thereby establishing an intermission in which the waste heat valves of both sets of regenerators Y `and the decarbonizing valves for both sets of nozzles are open.

' 3. An arrangement according to claim 2, characterized References Cited in the le of this patent s UNITED STATES PATENTS Re. 15,992 Wiiputte Feb. 3, 1925 8 V'Ischudy Apr. 21, 1914 Sperr e May 19,1914 YAckeren Mar. 2,8, 1922 Roberts Mar; 13, 1923 Adam' Nov. 4, 1930 Reiner Apr. 14, 1936 Hoeven May 16, 1939 Ackeren Ian. 7, 1941 Weidauer et a1. July 3, 1945 Hebl Mar. 3, 1953 FOREIGN PATENTS Germany Nov. 2, 1933

Claims (1)

1. A REGENERATIVELY-HEATED COKING CHAMBER OVEN WITH TWO SETS OF RICH GAS NOZZLES AND TWO SETS OF REGENERATORS, AND AN ARRANGEMENT FOR DECARBONIZING THE RICH GAS NOZZLES DURING THE REVERSAL OF THE DIRECTION OF HEAT FLOW, USING VALVES TO THE NOZZLES WHICH ARE OPERABLE BY THE REVERSING GEAR TO OPEN AND ALLOW THE DRAWING -IN OF AIR TO THE NOZZLES, AND VALVES ASSOCIATED WITH THE TWO SETS OF REGENERATORS FOR INFLOW OF AIR TO, AND OUTLOW OF WASTE GAS FROM THE REGENERATIVE SYSTEM OF THE OVEN, CHARACTERIZED BY ALL SAID VALVES BEING COUPLED WITH THE REVERSING GEAR IN SUCH A MANNER THAT, AT A SPECIFIC TIME IN THE REVERSING PROCEDURE, AIR ONLY IS DRAWN IN THE HEATING SYSTEM ONLY THROUGH ALL THE RICH GAS NOZZLES OF BOTH SETS AND EXHAUSTED THROUGH BOTH SETS OF REGENERATORS INTO THE WASTE HEAT PASSAGES FOR BOTH SETS BY THE ACTION OF THE FLUE DRAUGHT.

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