CA1037894A - Method and apparatus for sealing a coking chamber - Google Patents
Method and apparatus for sealing a coking chamberInfo
- Publication number
- CA1037894A CA1037894A CA214,892A CA214892A CA1037894A CA 1037894 A CA1037894 A CA 1037894A CA 214892 A CA214892 A CA 214892A CA 1037894 A CA1037894 A CA 1037894A
- Authority
- CA
- Canada
- Prior art keywords
- sealing
- door
- edge
- sealing surface
- high temperature
- 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
Links
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
- C10B25/00—Doors or closures for coke ovens
- C10B25/02—Doors; Door frames
- C10B25/16—Sealing; Means for sealing
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Chemistry (AREA)
- Coke Industry (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method and apparatus for providing a good seal between sealing edges and sealing surfaces of a coke oven door includes placing a high temperature resistant, compressible and deformable sealing member on the door between the sealing edge and sealing surface.
A method and apparatus for providing a good seal between sealing edges and sealing surfaces of a coke oven door includes placing a high temperature resistant, compressible and deformable sealing member on the door between the sealing edge and sealing surface.
Description
~037~94 This invention relates to a method and apparatus for sealing a coking chamber or the like. A by-product coke oven includes a large number of spaced apart coking chambers with heating chambers therebetween and doors for sealing the door openings at the pusher and discharge ends of each coking chamber.
Coal is charged into the coking chambers and heated to or above the coking temperature of about 1300F. The door at the pusher 3 side is provided with a smaller leveler door which is removed to provide an opening through which leveler apparatus is inserted 3 10 to level the charged coal prior to coking. It is important to have a tight seal at all of the doors to prevent heat from escaplng, but stlll more important to prevent the gases from ~; escaping to the air and contaminating it. For these reasons the i door jambs are provided with flat peripheral sealing surfaces and 4 the doors with peripheral sealing edges for engaging the sealing -~ surfaces. There are several types of doors of this construction in which the sealing surface is metal and the sealing edges are - formed by steel strips extending outwardly from the door and urged -or pressed into engagement with the sealing surface. ~Jhile such doors have been in use for many years with relatively good results when new they are still one of the major causes of air pollution at a coke plant. One reason for this is that the sealing surface and/or sealing strips become warped in use.
Another reason is that the evolved gases, which include tar, builds up on the sealing surfaces and edges in spite of the fact that expensive scraperslare used to remove the materials deposited.
Many attempts have been made to overcome these problems without success.
It is therefore an object of my invention to provide apparatus for providing a good door seal to prevent or greatly-decrease escape of gases from a coking chamber.
Another object is to provide such apparatus which ~i1l ;- ~k protect the door from the heat of the oven.
Still another object is to provide such apparatus which 1 greatly reduces build up of material on the sealing surfaces and edges.
A further object is to provide a method of providing a good seal to prevent escape of gases from a coke oven chamber which method is not expensive in cost and which can be preformed without undue delay of the operation of the coke ovens. ~ -~ These and other objects will become more apparent when ; 10 referring to the following specification and drawings, in which -3 Figure 1 is a sectional view of a leveler door in place in a coke oven and having my seal incorporated therein;
~ Figure 2 is a perspectiye view of the door of Figure 1 -a with the seal in place thereon;
Figure 3 is a perspective view of the seal prior to installation; .
Figure 4 is a view, similar to Figure 3, but showing a slight modification;
Figure 5 is a perspective view of a corner of the seal .
with parts broken away and shown in section;
Figure 6 is a sectional view of a main coke oven door utilizing my seal in place in a coke oven;
Figure 7 is an enlarged sectional view of a portion of Figure 6;
Figure 8 is a perspective view of a seal of my invention with attached fastening means;
I . .
Figure 9 is a perspective view of an installed seal;
Figure 10 is a perspective view of one element of the fastening means; ~:
3 30 Figure 11 is a perspective view of another element of 3 - the fastening means; and :~
Figure 12 is a perspective view of the seal of Figures ' - ' - ' 6 and 7 showing its shape prior to installation.
Referring more particularly to Figures 1 to 5 of the drawings, reference numeral 2 indicates an oven door on the pusher side of a coking chamber of a coke oven. The door 2 has a door 1 opening 4 therein for receiving a door jamb 6 having a peripheral ~ sealing surface 8 surrounding the door opening. A leveler door j 10 is provided with a peripheral steel strip 12 forming a sealing edge 14 adapted to engage the sealing surface 8. The door 10 is ~ moved into position with the edge 14 held against surface 8 by -~ 10 spring tensioning means 16. The apparatus and operation so far ~ described are conventional.
,J According to my invention I provide a high temperature ~ resistant, deformable and compressible sealing member 18 which is -~- positioned between the surface 8 and edge 14. While the member 18 may be formed by a number of separate strips I prefer that it be a single unit as shown in Figures 2 to 5. I also prefer that it be made of two outer layers of steel foil 20 (Figure 5) with a layer 22 of high temperature resistant insulating material there-between. A combination of alumina and silica is very suitable ~0 for layer 22. One commercial product of this nature is sold under the trademark FIBRE FRAX. For best results it is preferred that the overall thickness be between 1/16 and 1/8 inch. As best ; shown in Figure 2 to 5 the member 18 has a base 24 which is co-extensive with the outside of door 10, a flange 26 which extends along three sides of the base 24, a flange 27 extending inwardly ~ from flange 26 and a balse extension 28 which is of the same length 7 as flange 26 plus flange 27. As shown in Figure 4 cutouts 30 may be provided in extension 28 for door hinges when present.
In operation, the member 18 of Figure 3 or 4 is placed over the door 10 with the flange 26 around three sides thereof ~ and the base extension 28 is then bent around the remaining side thereof as shown in Figures 1 and 2. After the coal is leveled 1037~94 in the usual manner the door 10 is positioned in the usual manner - against the door jamb. Because the member 18 is deformable and compressible it will form a good seal regardless of slight irregularities in the sealing surface or sealing edge. I have also found that the seal eliminates or greatly reduces the build-up of materials on the sealing surface and sealing edge. In addition since the seal extends completely across the door opening it protects the door from the heat of the oven. Thus it is seen that the sealing member in addition to providing a better seal ~ 10 helps eliminate the conditions that have caused poor seals in the past. It has been possible to use the sealing member for a period ~, of two weeks without substantial reduction in its efficiency.
Figures 6 to 12 disclose a main coke oven door which requires a modified type of sealing member. As best shown in ~, Figures 6 and 7 a door jamb 40 having a flat peripheral sealing surface 42 surrounds door opening 44 into coking chamber 46. Door 48 includes a metal frame 50 having a peripheral bent steel plate 52 fastened thereto. The plate 52 has a sealing edge 54 formed ,~
at the inner end of an outwardly extending surface 56. Also fastened to frame 50 are inwardly extending metal flanges 58 for ¦ receiving a refractory plug 60 which extends into the door opening ~ -44 beyond sealing surface 42. Spring pressed plungers 62 mounted on frame 50 in spaced apart relationship about its periphery bias the sealing edge 54 into engagement with sealing surface 42. This construction and other parts shown as well as the door handling apparatus are conventio~al.
According to my invention I provi~e a sealing member 64 which is of the same material as sealing member 18. The member 64 is positioned between the sealing surface and sealing edge. In this embodiment the sealing member is preferabiy made of two over-~ lapping pieces, one for each side and a portion of the top and bottom as shown in Figure 12. Each piece includes a first portion ~ 4 --- - ,; ., ~ :
. . - .:- . ~ ~. .
:: : . . - :-- : : : . :, . .
or flange 65 adapted to be placed between the sealing edge and sealing surface and a second portion or flange 66 adapted to be placed against or adjacent surface 56. Extending from flange 65 are connecting flanges 67 and 68. The outer steel foil layers at the end of flanges 66 and 68 are bent to form flanges 70. The separate pieces of sealing member 64 are secured to the door 48 by a plurality of fastening means 78 spaced apart as best shown in Figure 12. Each fastening means includes a steel wire 80 having ;~ a bent inner portion 82 adapted to be received between flanges 66 and 70. A tab 84 slidable on wire 80 is pressed over the outside of flanges 68 and 70 for better attachment. The outer end 86 of each wire 80 is wound around the adjacent plunger 62 to secure , the sealing member 64 to the door.
In operation, the sealing member 64 is attached to door 48 as described above and the door 48 is then positioned in the usual manner against the door jamb. After the flanges 65, 66, 67 and 68 are wrapped around the door frame a plurality of plates 88 are placed in spaced apart relationship with one end bearing against the adjacent flange 58 and the other against the seal at the junction of flanges 67 and 68 so as to further hold the ; sealing member 64 on the door. These plates are preferably made of 20 gauge cold rolled steel with the end bearing against the seal either bent over as shown or at least free of sharp edges which would cut the foil. It will be seen that the seal protects only a portion of the metal of the door. The operation and advantages of this seall are essentially the same as in the first embodiment except that the entire door is not protected from the heat of the oven. The life of this seal is not as long as that of the first embodiment since it requires more careful handling which is difficult to obtain from the workmen. ~owever, it can be used ~. .
~ ~ for several pushes.
While several embodiments of my invention have been shown and described, other adaptations and modifications may be made without departing from the scope of the following claims.
, ~. .
. .
j 30 ~ .
- . .
. .
.. -. - , -..
Coal is charged into the coking chambers and heated to or above the coking temperature of about 1300F. The door at the pusher 3 side is provided with a smaller leveler door which is removed to provide an opening through which leveler apparatus is inserted 3 10 to level the charged coal prior to coking. It is important to have a tight seal at all of the doors to prevent heat from escaplng, but stlll more important to prevent the gases from ~; escaping to the air and contaminating it. For these reasons the i door jambs are provided with flat peripheral sealing surfaces and 4 the doors with peripheral sealing edges for engaging the sealing -~ surfaces. There are several types of doors of this construction in which the sealing surface is metal and the sealing edges are - formed by steel strips extending outwardly from the door and urged -or pressed into engagement with the sealing surface. ~Jhile such doors have been in use for many years with relatively good results when new they are still one of the major causes of air pollution at a coke plant. One reason for this is that the sealing surface and/or sealing strips become warped in use.
Another reason is that the evolved gases, which include tar, builds up on the sealing surfaces and edges in spite of the fact that expensive scraperslare used to remove the materials deposited.
Many attempts have been made to overcome these problems without success.
It is therefore an object of my invention to provide apparatus for providing a good door seal to prevent or greatly-decrease escape of gases from a coking chamber.
Another object is to provide such apparatus which ~i1l ;- ~k protect the door from the heat of the oven.
Still another object is to provide such apparatus which 1 greatly reduces build up of material on the sealing surfaces and edges.
A further object is to provide a method of providing a good seal to prevent escape of gases from a coke oven chamber which method is not expensive in cost and which can be preformed without undue delay of the operation of the coke ovens. ~ -~ These and other objects will become more apparent when ; 10 referring to the following specification and drawings, in which -3 Figure 1 is a sectional view of a leveler door in place in a coke oven and having my seal incorporated therein;
~ Figure 2 is a perspectiye view of the door of Figure 1 -a with the seal in place thereon;
Figure 3 is a perspective view of the seal prior to installation; .
Figure 4 is a view, similar to Figure 3, but showing a slight modification;
Figure 5 is a perspective view of a corner of the seal .
with parts broken away and shown in section;
Figure 6 is a sectional view of a main coke oven door utilizing my seal in place in a coke oven;
Figure 7 is an enlarged sectional view of a portion of Figure 6;
Figure 8 is a perspective view of a seal of my invention with attached fastening means;
I . .
Figure 9 is a perspective view of an installed seal;
Figure 10 is a perspective view of one element of the fastening means; ~:
3 30 Figure 11 is a perspective view of another element of 3 - the fastening means; and :~
Figure 12 is a perspective view of the seal of Figures ' - ' - ' 6 and 7 showing its shape prior to installation.
Referring more particularly to Figures 1 to 5 of the drawings, reference numeral 2 indicates an oven door on the pusher side of a coking chamber of a coke oven. The door 2 has a door 1 opening 4 therein for receiving a door jamb 6 having a peripheral ~ sealing surface 8 surrounding the door opening. A leveler door j 10 is provided with a peripheral steel strip 12 forming a sealing edge 14 adapted to engage the sealing surface 8. The door 10 is ~ moved into position with the edge 14 held against surface 8 by -~ 10 spring tensioning means 16. The apparatus and operation so far ~ described are conventional.
,J According to my invention I provide a high temperature ~ resistant, deformable and compressible sealing member 18 which is -~- positioned between the surface 8 and edge 14. While the member 18 may be formed by a number of separate strips I prefer that it be a single unit as shown in Figures 2 to 5. I also prefer that it be made of two outer layers of steel foil 20 (Figure 5) with a layer 22 of high temperature resistant insulating material there-between. A combination of alumina and silica is very suitable ~0 for layer 22. One commercial product of this nature is sold under the trademark FIBRE FRAX. For best results it is preferred that the overall thickness be between 1/16 and 1/8 inch. As best ; shown in Figure 2 to 5 the member 18 has a base 24 which is co-extensive with the outside of door 10, a flange 26 which extends along three sides of the base 24, a flange 27 extending inwardly ~ from flange 26 and a balse extension 28 which is of the same length 7 as flange 26 plus flange 27. As shown in Figure 4 cutouts 30 may be provided in extension 28 for door hinges when present.
In operation, the member 18 of Figure 3 or 4 is placed over the door 10 with the flange 26 around three sides thereof ~ and the base extension 28 is then bent around the remaining side thereof as shown in Figures 1 and 2. After the coal is leveled 1037~94 in the usual manner the door 10 is positioned in the usual manner - against the door jamb. Because the member 18 is deformable and compressible it will form a good seal regardless of slight irregularities in the sealing surface or sealing edge. I have also found that the seal eliminates or greatly reduces the build-up of materials on the sealing surface and sealing edge. In addition since the seal extends completely across the door opening it protects the door from the heat of the oven. Thus it is seen that the sealing member in addition to providing a better seal ~ 10 helps eliminate the conditions that have caused poor seals in the past. It has been possible to use the sealing member for a period ~, of two weeks without substantial reduction in its efficiency.
Figures 6 to 12 disclose a main coke oven door which requires a modified type of sealing member. As best shown in ~, Figures 6 and 7 a door jamb 40 having a flat peripheral sealing surface 42 surrounds door opening 44 into coking chamber 46. Door 48 includes a metal frame 50 having a peripheral bent steel plate 52 fastened thereto. The plate 52 has a sealing edge 54 formed ,~
at the inner end of an outwardly extending surface 56. Also fastened to frame 50 are inwardly extending metal flanges 58 for ¦ receiving a refractory plug 60 which extends into the door opening ~ -44 beyond sealing surface 42. Spring pressed plungers 62 mounted on frame 50 in spaced apart relationship about its periphery bias the sealing edge 54 into engagement with sealing surface 42. This construction and other parts shown as well as the door handling apparatus are conventio~al.
According to my invention I provi~e a sealing member 64 which is of the same material as sealing member 18. The member 64 is positioned between the sealing surface and sealing edge. In this embodiment the sealing member is preferabiy made of two over-~ lapping pieces, one for each side and a portion of the top and bottom as shown in Figure 12. Each piece includes a first portion ~ 4 --- - ,; ., ~ :
. . - .:- . ~ ~. .
:: : . . - :-- : : : . :, . .
or flange 65 adapted to be placed between the sealing edge and sealing surface and a second portion or flange 66 adapted to be placed against or adjacent surface 56. Extending from flange 65 are connecting flanges 67 and 68. The outer steel foil layers at the end of flanges 66 and 68 are bent to form flanges 70. The separate pieces of sealing member 64 are secured to the door 48 by a plurality of fastening means 78 spaced apart as best shown in Figure 12. Each fastening means includes a steel wire 80 having ;~ a bent inner portion 82 adapted to be received between flanges 66 and 70. A tab 84 slidable on wire 80 is pressed over the outside of flanges 68 and 70 for better attachment. The outer end 86 of each wire 80 is wound around the adjacent plunger 62 to secure , the sealing member 64 to the door.
In operation, the sealing member 64 is attached to door 48 as described above and the door 48 is then positioned in the usual manner against the door jamb. After the flanges 65, 66, 67 and 68 are wrapped around the door frame a plurality of plates 88 are placed in spaced apart relationship with one end bearing against the adjacent flange 58 and the other against the seal at the junction of flanges 67 and 68 so as to further hold the ; sealing member 64 on the door. These plates are preferably made of 20 gauge cold rolled steel with the end bearing against the seal either bent over as shown or at least free of sharp edges which would cut the foil. It will be seen that the seal protects only a portion of the metal of the door. The operation and advantages of this seall are essentially the same as in the first embodiment except that the entire door is not protected from the heat of the oven. The life of this seal is not as long as that of the first embodiment since it requires more careful handling which is difficult to obtain from the workmen. ~owever, it can be used ~. .
~ ~ for several pushes.
While several embodiments of my invention have been shown and described, other adaptations and modifications may be made without departing from the scope of the following claims.
, ~. .
. .
j 30 ~ .
- . .
. .
.. -. - , -..
Claims (10)
1. In a coke oven having an elongated heating chamber for receiving coal to be coked, a door opening at an end of said chamber, a door jamb surrounding the door opening and having a flat sealing surface extending around its periphery, and a door having a sealing edge extending around the periphery thereof and adapted to engage said sealing surface, said sealing edge being at the end of a metal strip arranged generally normal to said sealing surface, the improvement comprising a detachable relatively thin high temperature resistant,de-formable and compressible sealing member adapted to be re-ceived between said sealing surface and said sealing edge for the full extent of the edge, said sealing member including a plurality of contacting layers with one outer layer adapted to rest on said sealing surface and the other outer layer adapted to bear against said sealing edge.
2. The combination of claim 1 in which said deformable sealing member is normally flat and includes outer layers of steel foil one adapted to rest on said sealing surface and the other adapted to bear against said sealing edge, and a layer of high temperature resistant insulating material between the layers of steel foil.
3. The combination of claim 2 in which said layer of high temperature resistant insulating material is a combination of alumina and silica.
4. The combination of claim 1 in which said deformable sealing member extends completely across said door opening.
5. The combination of claim 2 in which said door in-cludes a refractory plug extending into said chamber and a sur-face on said metal member extending outwardly from said sealing edge, said deformable sealing member includes a first portion adapted to bear on said sealing surface, a second portion ex-tending from said first portion along said outwardly extending door surface, and an inwardly extending portion at the outer end of said second portion formed by a portion of said outer layers of steel foil, and means secured to said inwardly extending portion of said sealing means to secure said sealing means to said door.
6. In a coke oven having an elongated heating chamber for receiving coal to be coked, a door opening at an end of said chamber, a door jamb surrounding the door opening and having a flat sealing surface extending around its periphery, and a door having a sealing edge extending around the periphery thereof and adapted to engage said sealing surface, the improvement comprising a detachable relatively thin high temperature re-sistant, deformable and compressible sealing member adapted to be received between said sealing surface and said sealing edge and extending across said edge in its peripheral extent, said deformable sealing member including outer layers of steel foil one adapted to rest on said sealing surface and the other adapted to bear against said sealing edge, and a layer of high temperature resistant insulating material between the layers of steel foil.
7. The combination of claim 6 in which said layer of high temperature resistant insulating material is a combination of alumina and silica.
8. A method of sealing a coking chamber having a door jamb having an opening into said chamber and a peripheral flat sealing surface which comprises providing a door having a periph-eral sealing edge on the end of a metal member generally normal to said sealing surface and adapted to engage said sealing surface, attaching a high temperature resistant relatively thin deformable sealing means to said door with a portion thereof bearing against said scaling edge, and then moving said door into closed position with said sealing means in tight engagement with said sealing surface and said sealing edge.
9. The method of claim 8 in which said sealing means completely covers said door opening to protect the door from heat.
10. The method of claim 8 in which said sealing means is normally flat and comprises a layer of high temperature resistant insulating material between outer layers of steel foil.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US425303A US3881995A (en) | 1973-12-17 | 1973-12-17 | Method and apparatus for sealing a coking chamber |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1037894A true CA1037894A (en) | 1978-09-05 |
Family
ID=23685971
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA214,892A Expired CA1037894A (en) | 1973-12-17 | 1974-11-28 | Method and apparatus for sealing a coking chamber |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US3881995A (en) |
| JP (1) | JPS5092902A (en) |
| CA (1) | CA1037894A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5314242B2 (en) * | 1974-10-31 | 1978-05-16 | ||
| US3996110A (en) * | 1975-09-16 | 1976-12-07 | Patsie Carmen Campana | Coke oven leveler door |
| US4033827A (en) * | 1976-02-02 | 1977-07-05 | White Jr Herbert A | Apparatus for sealing a coking chamber |
| US4186055A (en) * | 1978-06-26 | 1980-01-29 | Saturn Machine & Welding Co., Inc. | Coke oven door |
| EP0108818A1 (en) * | 1982-11-10 | 1984-05-23 | FS-Maschinen- und Stahlbau | Apparatus and process for sealing coke ovens, and process for cleaning the sealing surfaces |
| US5803021A (en) * | 1994-10-11 | 1998-09-08 | Combustion Engineering, Inc. | Boiler access door construction |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2662053A (en) * | 1950-09-26 | 1953-12-08 | Walter T Brown | Hermetic seal for coke oven doors |
| US3149615A (en) * | 1962-06-25 | 1964-09-22 | Forsans Pierre Eugene | Vaporizing jamb frame for oven door |
-
1973
- 1973-12-17 US US425303A patent/US3881995A/en not_active Expired - Lifetime
-
1974
- 1974-11-28 CA CA214,892A patent/CA1037894A/en not_active Expired
- 1974-12-17 JP JP49144159A patent/JPS5092902A/ja active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5092902A (en) | 1975-07-24 |
| US3881995A (en) | 1975-05-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1072039A (en) | Coke oven door construction | |
| US4445977A (en) | Coke oven having an offset expansion joint and method of installation thereof | |
| US4749446A (en) | Horizontal coke-oven battery | |
| CA1037894A (en) | Method and apparatus for sealing a coking chamber | |
| US4217177A (en) | Vented coke oven door apparatus | |
| US4033827A (en) | Apparatus for sealing a coking chamber | |
| US2478215A (en) | Coke-oven door | |
| US4110173A (en) | Sealing closure for an opening of a coking oven | |
| US4793900A (en) | Universal coke oven door liner | |
| AU2009250125B2 (en) | Wall protector for a heating wall head between two oven chamber openings of a coke oven battery | |
| US3172825A (en) | Triple-seal oven door sealing means | |
| US4596197A (en) | Coke oven door | |
| JPS61118493A (en) | Operation of coke oven | |
| US1399594A (en) | Coke-oven door and doorway | |
| US5279713A (en) | Door | |
| US3990950A (en) | Leveler door for coke ovens | |
| CA1309373C (en) | Universal coke oven door liner | |
| CA1143690A (en) | Coke oven chuck door | |
| US4080266A (en) | Closure for an opening of a coking oven | |
| US3977125A (en) | Device for sealing steel doors of coke oven | |
| CA1165269A (en) | Door of a coking oven | |
| US4389284A (en) | Charging hole cover seal | |
| US4599142A (en) | Coke oven door lining | |
| JPH0459353B2 (en) | ||
| US1582233A (en) | Carburizing box |