US2934806A - Apparatus for inserting a dam in a tube - Google Patents

Description

May 3, 1960 H. E. TAYLOR APPARATUS FOR INSERTING A DAM IN A TUBE Original Filed March 15, 1954 5 Sheets-Sheet 2 Hana/a! [r May 3, 1960 H. E.-TAYLOR 2,934,806

APPARATUS FOR INSERTING A DAM IN A TUBE Original Filed March 15, 1954 5 Sheets-Sheet 4 Haro/Jfrzze? 222% ,2; ATTORNEYS- APPARATUS non ,INSERTING A DAM IN A TUBE Harold E. Taylor, Norristown, Pa, assignor to Alan Wood Steel Company, Conshohocken, Pa., a corporation of Pennsylvania Original application March 15, 1954, Serial No. 416,366, new Patent No. 2,851,760, dated September 16, 1958. Divided and this application September 17, 1957, Serial No. 684,613

1 Claim. or. 25- 1 The present invention relates to the repair of lay-product coke oven guns.

This application is a division of my co-pending application Serial No. 416,366, filed March 15,1954, now Patent No. 2,851,760, issued September 16, 1958, for Patching of By-Product Coke Oven Tubular Surfaces relating to the method.

A purpose of the invention is to permit continued operation of by product coke ovens at high efliciency after gas guns have begun to leak.

A further purpose is to permit rapid and economical repair. of leaks of gas guns and other tubular refractory passages of by-product coke ovens while the refractory is still hot and without withdrawing the battery of ovens from service.

A further P e s to P rm deep pe etra i n of refractory patching materialin crevices of gas guns of by-product coke ovens so that a repair will be achieved which will restore the refractory to complete gas tightness, and permit normal response to expansion and contraction.

A further purpose in the repair of gas guns and other tubular passages in the refractory of by-product coke ovens is to dam the gun by inserting a plastic dam and squeezing the two ends of the dam relatively toward one another. I

A further purpose is to close the nozzles of the gas guns of a by-product coke oven by extruding plastic plugging material into such nozzles from the gun.

A further purpose is to insert a dispersion or slurry of leak-sealing refractory material, preferably silica, into the tubular opening of the gun under a positive pressure, and preferably to guard against excess pressure by discharging an overflow through a safety valve.

A further purpose is to restore the gun to operation by removing the excess of slurry, removing the dam and the plugs, machining the tubular opening to predetermined size and removing any foreign material.

Further purposes appear in the specification and in the claim.

la the drawings I have chosen to illustrate one only of the numerous embodiments in which my invention may appear, selecting the form shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

Figure l is a vertical section transversely of a bank of coke ovens at the fuel gun location, the figure being taken on the line 11 of Figure 2.

Figure 2 is a vertical section extending longitudinally of the bank of coke ovens, the section being taken on the line 2-2 of Figure 1.

Figure 3 to 12a are step-wise views showing the process of the invention applied to repairing the fuel gun of a byproduct coke oven.

Figure 3 is an enlarged fragment of Figure 1 showing the introduction of the dam.

Figure 4 is an enlarged fragment of Figure lshowing the expansion of the dam.

Tnitedi States Patent Figure 5 is an enlarged fragment of Figure 1 showing the dam expanding tool removed and showing the extrusion of plugging material into the nozzle.

Figure 6 is an enlarged fragment of Figure 1 showing the smoothing of the nozzle plug.

Figure 7 is an enlarged fragment of Figure 1 showing the nozzle plug completed.

Figure 8 is a side elevation partly broken away showing the tank of slurry connected to the end of the fuel gun for introduction of the slurry.

Figure 9 is an enlarged fragment of Figure 1 showing the slurry entering the fuel gun and filling a crack in the refractory.

Figure 10 is an enlarged fragment of Figure 1 showing excess slurry discharging through the safety valve.

Figure 11 is an enlarged fragment of Figure 1 showing the removal of the .dam and of one of the plugs.

Figure 12 is an enlarged fragment of Figure 1 showing the machining of the gun to predetermined size.

Figure 12a is an enlarged fragment of Figure 1 showing the blowing out offoreign material from the gun prior to restoring the coke oven to service.

In the drawings like numerals refer to like parts throughout.

By-product coke ovens are generally constructed of silica refractory brick. The service is severe, since each oven is subjected to a succession of cycles involving heating up and cooling down of the refractory parts. Generally a battery of by-product coke ovens will give many years of service. One of the limiting factors, however, is leaking of the fuel guns, which may cause fuel gases to mix prematurely with air or to commingle with products of combustion, reducing the efficiency of operation.

The problem of repair of such fuel gas guns is complicated by the faet that the refractory remains hot, and any method of repair which does not permit repair of an individual oven while its refractory remains hot and adjoining ovens are in operation would be prohibitively e pens e The present inventor has discovered that effective and l n -l s i repairs of e as' s o b -rrod stcak ovens can be accomplished during a very short period of interruption of operation of a particular oven, and without giving up normal operation of adjoining ovens. Thus the patching is done in contact with hot refractory, without furthef damaging the refractory, end to produce a repair which behaves similarly in expansion and contraction to the-original refractory. V V I In accordance with the invention, a dam is inserted to las o a y pa bf h f e a s which do 'n require repair, and the fuel nozzles are plugged. Thus the portion of the gun to be repairedis isolated. Liquid dispersion or slurry of patching material is introduced into the fuel gas gun under pressure so that it will penetrate the crevices. The slurry desirably consists of finely divided silica or Hatfield clay which is about SiO ba an e m u t and suitab a a fineti ss lo mesh per linear ingh. This is made up watery in a slurry, conveniently employing about three volumes of water to one volume of dry silica flour or the like. 1

In order to avoid excessive pressure, a simple safety valve or release valve is employed so that when a predetermined pressure in built up the excess slurry will run out and indicate that the pressure is adequate. This also serves as a release for steam.

It is then merely necessary to remove the excess of slurry, and after allowing a few minutes for the repair to harden, eliminate the dam, and the plugs, and machine the u gas 81 ack to sizel o eisn ma i a remnants of he d m d the p u nd ss ss 9 th s lis se e9 ven snfl b emo d by l wing- Considering now the construction in detail, support- 3. ing structures mounts refractory walls which form a series of coke ovens 21 and intermediate flues 28.

Each oven has two regenerators 22 which are separated at the longitudinalrniddle of the bank of ovens. On each side of the bank of ovens is a fuel gas main running longitudinally of the battery and connected to one of the generally horizontal fuel gas guns 23 which runs half way across the battery to the center line of the oven. The fuel gas guns 23 consist of refractory shapes 24, which are suitably of silica brick connected end to end by interlocks 25, having longitudinal bores which form the gun, and having lateral openings 26 at the top which receive fuel nozzles 27 which discharge the fuel upwardly into vertical lines 28, which in the combustion phase of the cycle contain air introduced through regenerator parts not shown.

The combustion gas passes up through the flues and across through passage 30 and then down through the off flues at the opposite end of the oven wall where the combustion gas passes down through the regenerator 22 and out to the stack canal. Inspection and access through the top is permitted to each flue through openings- 31, passages 32 and openings 33 as well known. Also as well known decarbonizing air is introduced through the off-gas gun for the purpose of decarbonizing the gas nozzles.

The reversal of cycle between the regenerator which is undergoing combustion of gas and the regenerator which is absorbing heat suitably occurs about every half hour, and therefore it will be evident that the change in temperature in the fuel gas guns is very violent, especially near the outside of the oven. The refractory brick of the guns undergo high volumetric expansion and contraction and therefore there are likely to be failures of two kinds. Individual shapes may pull away from one another and the refractory cement joining them at the ends may open up, causing leaks. In the second place, since internal stresses of high magnitude develop in the refractory shapes, the fuel gas gun shapes themselves may crack. The resulting leakage reduces the intensity of combustion and reduces the effective amount of air for combustion.

As many of the cracks developed extend laterally to considerable depth or entirely through the fuel gas gun shapes, it has been impossible to effectively seal them by merely swabbing with plastic refractory material, as has been attempted in the prior art.

In order to accomplish the repair in accordance with the process of the invention, the individual coke oven gun undergoing repair is temporarily taken olf service. The gas is shut 01f from the gun which is to be patched, and the decarbonizing cap casting is taken off, as well as the connection or closure at the end of the gun.

It has been found that the cracks requiring plugging are generally located close to the outside end of the gun, and therefore it is desirable in most cases to insert a dam so that it will not be necessary to plug all of the nozzle openings. Depending on the experience in the particular battery of ovens, the dam may be located at a position beyond the second, third, fourth or some other nozzle from the outside.

It will be'understood, however, that according to the broader aspects of the invention, all nozzles openings could be plugged, in which case the dam would be necessary.

Considering first Figure 3, a damming tool 34 is inserted through the gun from the outside end. This tool desirably includes a first abutment 35, which is desirably of wood so that it can burn out during the operation. There is an opening through the center of the first abutment through which extends a metallic rod 36 having a handle 37 at the end outside of the gun. The rod 36 is threaded at the end to receive a nut 38 beyond the abut- 'ment and desirably imbedded in the abutment 35 so that it can be unscrewed by turning the handle 37 due to the frictional engagement of the abutment with the dam and the gun.

On the side of the abutment 35 toward the handle end of the rod is a second abutment 40, which, like the first abutment, substantiallyfills the gun opening and has a central opening 41 through which the rod 36 passes to the handle. The second abutment 40 is desirably of metal and is mounted on the side remote from the first abutment on a tube 42 which surrounds the rod and outside the gun carries a handle 43.

Before the damming tool is inserted in the gun, a suitable fabric tube or stocking 44 is placed around the rod between the abutments and filled with a charge of damming material 45 which is conveniently a commercial plastic heat insulation such as a mixture'of asbestos fibers and plastic clay or any other suitable plastic heat insulation or refractory cement. The ends of the stocking are desirably tied or otherwise secured to the rod to hold the charge of plastic material 45. The damming tool is inserted to the desired position as shown in Figure 3 and then the abutments are pushed together. This is done by holding handle 37 and pushing on handle 43. The effect is to expand or extrude the plastic damming material into plugging engagement with the wall of the gun. At the same time, the stocking 44 and the abutment 35 desirably begin to burn. The rod 36 is now unthreaded from the nut 38 and the rod is withdrawn, its opening being filled by the plastic damming material which relieves its pressure toclose the opening. The rod 36, the abutment 40 and the tube 42 are then pulled out, leaving the gun closed by a dam 46 at the inner end of the zone to be patched.

It is desired to have a friable material at the dam so that it can readily be removed later andfor that reason high asbestos content is desirable.

The next step is to close off the flue nozzles which are located between the dam and the outer end of the flue gas gun. This is done by extruding or squeezing heat insulation cement or refractory cement into the openings, desirably using an extrusion device 47 as shown in Figure 5 which has'a chamber 48 containing plastic material subjected to pressure from a plunger 50 by a rod 51 advanced by a screw or other suitable device from outside the flue gas gun. The nozzle at the end is bent upward at 52 ,and introduces a charge of plastic cement 53 into the lower part of each flue gas nozzle 27. This plug 53 is desirably smoothed oif and pressed upwardly by a smoothing trowel 54 on a long handle 55. The final result as shown in Figure 7 is to close off openings except leak openings from the flue gas gun in the area to be patched.

The next step is to introduce the slurry or dispersion of patching material. The slurry is contained within a tank 56 provided with a stirrer 57 to keep the finely divided silica in suspense in the water. A discharge tube 58 extending to a position near the bottom of the tank connects through a suitable hose and valve 60 and a pressure gage 61 to a face plate 62 which is fastened to pipe connection 63 on the end of the flue gas gun.

A source of suitable pressure, for example compressed air, is connected through pipe 64, valves 65 and pressure regulator 66 to the top of the slurry in the tank, and the pressure is regulated to a predetermined value. Good results have been obtained with an air pressure of about 7 to 10 p.s.i., as it is not desired to burst the refractory.

A safety valve is provided at the decarbonizing opening 67 by applying a weight 68 which is desirably selected to insure the desired pressure on the slurry in the fiue gas gun, suitably about 2 p.s.i., since of course part of the air pressure is used to raise the slurry to the flue gas gun. When the slurry fills the flue gas gun and reaches the predetermined pressure the weight 68 rises as shown in Figure 10 and discharges the excess slurry, thus indicating that the proper pressure has been reached and also that the flue gas gun has been filled with the slurry. It

will be understood that the exact pressures will vary with the particular installation.

The weight 68 also allows for escape of steam which is likely to form from the heat in the refractory.

Once the space to be filled in the flue gas gun has been adequately filled, thus forcing the slurry into crack 70 to be repaired, the slurry flow is turned off by closing valve 60.

As the walls of the flue gas 'gun are very hot, the refractory sets quickly to a firm consistency and the excess can be removed after a few minutes by opening valve 59 in a T connection. A few additional minutes may desirably be allowed to permit the refractory to further harden in the cracks, and then the excess of solid material and the plugs and dam are taken out.

Pusher rods 71 are forced through the nozzles from the top as shown in Figure 11 to discharge the plugs 53. The friable dam 46 is removed as shown in Figure 11 desirably by a reamer 72 driven by a power drill 73. The abutment 35 by this time will be charred so that it will disintegrate, or burn up, and the nut will be removed with the other foreign solid material. The gun opening is then reamed or abraded to the desired size to remove the skin of excess refractory which is formed on the inside as by a wire brush or other suitable tool 74 driven by a drill 73 or the like.

The last step is normally to introduce an air blast through nozzle 75, Figure 12a, which blows out any remaining foreign material from the gun.

It will be evident that the resultant leak-sealing gives a structure which will have substantially the same expansion and contractions as the silica refractory itself and will be capable of remaining in service for a long period of time.

The gas riser can then be unplugged and the decarbonizing face plates replaced to put the oven back in service. The gas can then be turned on the gun.

The entire operation can be carried out in a period of approximately one hour for a single gun.

The result of the patching operation is a great saving in gas and accordingly a great economy in operation.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art,

to obtain all or part of the benefits of my invention without copying the process shown, and I, therefore, claim all such insofar as they fall within the reasonable spirit and scope of my claim.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

A dam setting device for a coke oven gun comprising an inflammable first partition having a contour which fits the cross section of the coke oven gun, a rod extending longitudinally of the coke oven gun through the first partition, a handle on the end of the rod remote from the first position, threaded means interconnecting the rod with the first partition, a second partition adapted to fit the cross section of the coke oven gun, spaced from the first partition along the length of the rod, and having an opening through which the rod passes, a stocking surrounding the rod and extending between the first partition and the sec- 0nd partition and adapted to engage the interior of the coke oven gun, damming material filling the interior of the stocking around the rod, a tube surrounding the rod between the second partition and the end of the rod adjoining the handle and connected to the second partition, and a second handle on the end of the tube adjoining the handle first mentioned, whereby when the device is in position in the coke oven gun the two handles can be moved relatively away from one another to form the damming material into a plug in firm engagement with the interior of the coke oven gun, and then the remainder of the device can be unscrewed from the first partition and withdrawn, leaving the dam in place and leaving the first partition in position to be ignited and burned, the coke oven gun between the dam and the person operating the device being accessible for further operations.

References Cited in the file of this patent UNITED STATES PATENTS 1,993,307 Nicholson Mar. 5, 1935 1,997,878 Wagner Apr. 16, 1935 2,750,601 Houle June 19, 1956 2,763,910 Braatelien Sept. 25, 1956 FOREIGN PATENTS 125,925 Australia Oct. 24, 1947

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