Patent Publication Number: US-3880967-A

Title: Method for lining gun brick in coke ovens

Description:
United States Patent 1 1 [111 3,880,967  
 Loggins et al. Apr. 29, 1975 [54l METHOD FOR LINING GUN BRICK IN 2.851.760 9/1958 Taylor 264/30 X C K OVENS 3.458.607 7/l969 Sullivan 4. 264/30 [75] Inventors: Joseph R. Loggins, Hueytown;  
 Marlin M. Maddox, Birmingham, both of Ala.  
 [73] Assignee: United States Steel Corporation, [57 1 ABSTRACT Pittsburgh A method of lining gun brick in gun-flue type coke [22] Filed: Aug. 23, 1973 ovens in which a refractory tube is inserted in the gun brick, and sealing clay is placed around the inner end 121] APPL 390978 of the tube to form a liquid-tight cylinder which is then fitted with grout. After the grout sets, gas ports Primary E.\&#39;aminer.lan H. Silbaugh Assistant Examiner-Thomas P. Pavelko [52] U.S. Cl. 264/30; 264/36; 264/262 are p ne to allow gas ommunication between the [51] Int. Cl. F27d 1/16 in r or of the refractory tube and the coke oven flues. [58] Field of Search 264/30, 32, 35, 36, 262, The preferred embodiment includes a packing collar 264/269; 202/139-144 for packing the sealing clay around the refractory tube. Elements of the required apparatus are assem- [56] References Cited bled on a mandrel and properly positioned by the use UNITED STATES PATENTS that mandrel-v 2,216,983 l0/I940 Otto 202/!42 6 Claims, 5 Drawing Figures PFTENTEBAPMSITUS 3.880.967  
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 METHOD FOR LINING GUN BRICK IN COKE OVENS This invention relates to the lining or relining of refractory tubes which are used in extremely high temperature applications, i.e., in excess of 2000F. More particularly, the invention relates to the lining of gun brick in gun-flue type coke batteries, such as Koppers- Becker coke ovens. Such ovens are heated with either blast furnace gas, coke oven gas or a combination of the two. Coke oven batteries include a number of ovens with vertical heating flues in the oven walls. In the gunflue type oven the fuel gas is introduced through a horizontal gas duct extending the length of each wall a little below the oven floor line. Short connecting ducts lead vertically upward to a replaceable nozzle brick at the bottom of each of the vertical heating flues.  
  The heating of individual ovens is controlled so that the temperature at the base of the heating flues does not exceed 280()F. The maximum safe temperature range to which silica coke oven refractories should be heated is 2600 to 280()F. The firing of coke ovens is generally reversed every to minutes. This maintains the temperature level on the coke oven walls below, but near, the maximum permissible temperature.  
  It is relatively common for the gun brick in the gun flue to develop cracks or leaks during use. If these leaks are not stopped, the oven may have uneven temperatures throughout, coking of the coal may be incomplete (which will create a pollution problem when the uncoked coal is subsequently introduced to a blast furnace for use as fuel), and the flame will produce localized hot spots in the gun brick which may result to the melting of the brick. Obviously, the useful life of the battery is reduced when such leaks are present in the gun flues. We have found that these leaks are only present in the six feet of gun brick nearest the end of the coke oven at which the fuel gas is introduced. Therefore. only that length of gun brick need be considered for repair or other method of gas leak control.  
  Heretofore a number of remedies have been attempted for controlling the leaks in the gun flues without a great deal of success. These methods include:  
  A. Pointing by using a long handled trowel with various refractory materials. This method is successful for a short distance into the flue gun but no further than the first flue.  
  B. Spraying the gun brick with a wet adhesive refractory material. It is very difficult to determine whether the spraying is complete. i.e., whether all cracks have been covered. Further, the wet refractory materials usually crack readily and the leaks develop again relatively quickly.  
  C. Replacement of the first gun brick. Each end gun block casting weighs well over 200 lbs. It is very difficult to manipulate. Further, only the first gun brick can be replaced successfully without shutting down the coke oven for an extensive period of time.  
  D. Flooding gun brick by sealing the nozzle openings inside the gun brick and installing a dam then forcing grout into the gun brick under pressure. It is very difficult to bond the grout to the used gun brick. Therefore. this method is usually unsuccessful resulting in the grout flaking. spalling and falling off the gun brick.  
  E. Dismantling the oven wall down through the gun brick and replacing the gun brick in its entirety. This method is time consuming and extremely expensive,  
 and is only justified for extensive end flue repair when the oven is scheduled for a long period of down time.  
  It is the primary object of this invention to provide a method for lining gun brick in gun-flue type coke ovens to extend the operating life of the gun brick.  
  It is also an object to prevent gas leaks from gun bricks.  
 Another object is to reduce costs of repairing coke ovens.  
  It is another object to reduce atmospheric pollution from unburnt gases.  
  Another object is to provide a method of lining gun brick that can be accomplished without requiring the coke oven to be out of service for any extended period of time.  
  We have invented a method of lining gun brick with a non-contracting, non-expanding thermal refractory which achieves each of the aforementioned objects.  
  This invention will be better understood by referring to the following detailed specifications and the appended drawings, in which:  
  FIG. I is a longitudinal cross section of a portion of a coke oven taken on the center line of the flues.  
 FIG. 2 is a transverse cross section of a coke oven taken along the line IIII of FIG. 1.  
  FIG. 3 is a cross section of the gun brick portion of a coke oven on a larger scale than that of FIG. 1, showing a step in the method of our invention.  
  FIG. 4 is a cross section of the same gun brick section of the coke oven as in FIG. 3, lined in accordance with the invented method.  
  FIG. 5 is an isometric view of the equipment necessary to carry out the invented method.  
  As shown in FIG. I, a coke oven battery 10 consists ofa number ovens ll alternating with vertical combustion flues 12 in which gas is burned over an entire oven wall simultaneously. Vertical flues 12 are connected by short bus flues l4 and cross over flues (not shown) to a companion series of vertical flues on the opposite side of the coke oven chamber. Beneath the vertical combustion flues lies a gun flue 16 made of a series of interfitting gun bricks. The interior of the gun flue communicates with the vertical combustion flue by connecting duct 17 (FIG. 3) and gas nozzle 18. Access ports 20 atop the coke oven allow a rod to be inserted into the flues for various reasons, such as cleaning the flues or reaming nozzles.  
  As best shown in FIG. 5, the apparatus for lining gun brick comprises a mandrel 30, which is a hollow steel tube, having a mandrel pin 32 inserted therethrough and a long handled manipulator rod 34 having a hook or flange 36 on one end.  
  Basically the steps in lining the gun brick are as follows: Connecting ducts 17 in gun bricks 16 are sealed with grout. A non-contracting and non-expanding fused silica refractory sleeve or liner, such as a Silfrax (made by Carborundum Co.) tube 40 has a collar 42 on one end and a number of slotted holes 44 which are so located to be in alignment with the nozzles 18 of the flues when the tube 40 is inserted in the gun brick 16. Holes 44 are sealed with grout and the liner 40 is placed on mandrel 30. Sealing clay 45 is placed on the mandrel and packed around the outside end of collar 42 as shown in FIG. 3. A slip-on collar 46 is then placed on the mandrel against the sealing clay. The lining assembly thus formed is inserted in the gun brick and slipon collar 46 is moved toward collar 42 by the manipulation of rod 34 which packs sealing clay 4S tightly around the end of the tube. One type of clay referred to herein as primary grout 48 is placed around the end of tube 40 opposite collar 42 to hold the tube level. An open space is left atop the tube. The nozzle of a long nozzled caulking gun (not shown) is inserted through the open space in the primary grout into the space 50 (FIG. 3) between liner 40 and the wall of gun brick 16, and this space 50 is then filled with secondary grout 52. such as 90% Hatfield clay sodium silicate. The secondary grout is of sufficiently lovv viscosity that it will fill the entire space 50 without undue effort. When the grout has set, a long nozzle rod is inserted through openings in the top of the coke oven to push the grout out of the slotted holes 44 and the nozzles 18 to clear the gas ports 17 between the inside of the tube 40 and the vertical combustion flues 12 to allow a free flow of gas therethrough.  
 Mandrel pin 32 is used to locate holes 44 in the tube 40. The pin fits into slots in the end of the tube. This gives both a measuring reference and a means for turning the tube within the gun brick 16.  
  It is readily apparent from the foregoing that we have invented a method for lining gun brick that can be achieved relatively easily, inexpensively and quickly, that extends the operating life of the coke oven battery, and reduces atmospheric pollution from the resulting coke product.  
 We claim:  
  1. A method for lining gun brick in coke ovens having vertical flues and openings in said gun brick communicating with said flues, said method comprising:  
 a. providing a tubular refractory liner insertable in said gun brick, said liner having holes which upon insertion will be in proper alignment with said openings to said flues, said liner having an outside diameter less than the inside diameter of the gun brick and said liner having a fixed collar at one end;  
 b. sealing the holes in said liner and the openings in said gun brick;  
 c. inserting said liner in said gun brick, collar end first, with said sealed holes in said liner in alignment with said sealed openings in said gun brick;  
 d. packing sealing clay between said collar and the walls of said gun brick to form a seal around said collar. and an annular space between said liner and said gun brick;  
 e. filling said annular space with grout:  
 f. permitting said grout to set; and  
 g. opening the holes in said liner and the openings in said gun brick to allow a free flow of gas between the inside of said liner and said flues.  
  2. A method according to claim 1 further comprising inserting a short length of tube, having substantially the same outside diameter as that of the collar on said liner. into said gun brick ahead of said liner. placing sealing clay against the trailing edge of said tube, and moving said tube against said collar to pack said sealing clay around said collar to form a seal between said collar and the walls of said gun brick.  
  3. A method according to claim 1 further comprising after step d, packing a thick consistency grout around the end of said liner opposite said collar to position said liner substantially concentrically with said gun brick.  
  4. A method according to claim 1 wherein said refractory tube is a non-contracting, non-expanding, fused silica refractory.  
  5. A method according to claim 1 wherein said grout is a high-temperature silica clay.  
  6. A method for lining gun brick in coke ovens having vertical flues and openings in said gun brick communicating with said flues. said method comprising:  
 a. providing a tubular mandrel insertable in a tubular refractory liner,  
 b. forming a lining assembly on said mandrel by;  
 l. placing said tubular refractory liner on said mandrel, said liner having a fixed collar at one end;  
 2. placing sealing clay on said mandrel around said mandrel at the collar end;  
 3. placing a packing collar having the same inside diameter as said liner on said mandrel adjacent said sealing clay;  
 c. inserting said lining assembly and said mandrel in said gun brick;  
 d. inserting through said mandrel a rod having a hook thereon, and engaging said hook with the edge of said packing collar beyond said clay;  
 e. moving said packing collar towards said fixed collar by manipulating said rod thereby forcing said sealing clay against the gun brick to form a gastight seal between said fixed collar and said gun brick;  
 f. packing sealing clay around the end of said liner opposite said collar to position said liner centrally within said gun brick. and forming an annular space between said gun brick and said liner;  
 g. filling said annular space with grout;  
 h. permitting said grout to set; and  
 i. clearing the openings in said gun brick and the holes in said liner to allow free flow of gas between the inside of said liner and said flues.