Heated chambers provided with sealing means for openings therein and method of sealing them

Description

[0001] This invention relates to the sealing of heated chambers. More particularly, the invention relates to a heated chamber provided with improved sealing means, and to a method of sealing a heated chamber.

[0002] It is well known especially from Environmental Reports and the news media that the sealing of ovens which produce noxious fumes, smoke, dust, etc., is a difficult art. Only recently the coke industry in the major steel producing area of the United States has been threatened with a complete shutdown because of its inability to comply with the new Environmental Regulations of the Environmental Protection Agency of the United States of America and the Department of Environmental Resources of the Commonwealth of Pennsylvania.

[0003] An example of a coke oven which presently has sealing problems, is a coke oven with a so- called Koppers Door. The coke oven with the Koppers Door utilizes an S-shaped seal for sealing the door against the jamb of the oven. Because of irregularities in the jamb and the seal, gases from within the coke oven readily leak past the jamb. In cases where the seal has been damaged by loading and unloading of coal and coke, gouges occur therein, which greatly increase the flow of noxious gases and fumes from the coke oven to the surrounding air. This leakage from damaged ovens is especially undesirable since the degree of pollution caused thereby is many times that of an oven in an undamaged condition. However, during long use, coke ovens are damaged by the constant loading and unloading and seal cleaning. Therefore, a larger and larger percentage of the ovens leak at ever increasing rates.

[0004] Another door widely used in the coke industry is the Wilputte Door. The Wilputte Door has a diaphragm seal and a jamb with an adjustable screw for making contact more readily between the jamb and the door. The Wilputte Door also suffers from the same sort of problems as does the Koppers Door. A great need is also felt for an improved arrangement therein.

[0005] Recent tests have shown that many of these doors in present operation in their present configurations do not permit operation within the guidelines set by the Department of Environmental Resources and the Environmental Protection Agency. The fact of the lack of capability of meeting these requirements is well known and has threatened to shut down the steel industry for lack of coke. Therefore, a great need is felt for an improved door sealing arrangement which would permit operation within the guidelines of the Environmental Protection Agency or the Department of Environmental Resources.

[0006] There are a great number of other applications where leakage from ovens and other heated chambers can be cured by the use of the present invention such as soaking pits, used for the soaking of iron ingots during the manufacture of iron and steel, furnaces and other examples which are too numerous to mention herein.

[0007] A means of attempting to seal a coke oven is disclosed in U.S. Patent No. 3,875,018 in which a colloidal mixture is injected into a passage from which it teaks out in such a way that during the coking cycle the mixture becomes gummy and sticky, so as to seal crevices between the door and the jamb. The mixture dehydrates and develops non-wetting and non- adhering properties by hardening into a strong solid mass. This method requires a special door design which incorporates channels for receiving the mixture. Problems have been discovered in the injection of the mixture into the channel because the mixture has a tendency to leak out of the channel and past the seal before it has an opportunity to harden sufficiently.

[0008] A novelty search conducted prior to the preparation of this application revealed U.S. Patent No, 2,279,791, which does not form the prior art but only teaches the application of a material which expands when subjected to elevated temperatures. This material is used to coat the individual wires of a fire screen. The fire screen thus coated, when exposed to elevated temperatures causes the material to expand. The expansion closes the openings between the individual wires of the screen, thereby restricting the flow of air at these elevated temperatures through the fire screen.

[0009] Another result of the mentioned novelty search is U.S. Patent No. 3,814,613 which discloses the use of a refractory composition for patching the walls of a coke oven. This refractory composition comprises siliceous aggregate, plastic clay, a chemical binder such as sodium silicate, chromic acid, boric acid, sodium sulfate, magnesium sulfate, sodium phosphate, and organic binders and finally, a source of manganese dioxide. The patching material may be applied by troweling or plastering over a cracked area in the wall of the coke oven or by pumping or injecting the material into cracks in the wall or by pneumatically gunning. U.S. Patent No. 3,814,613 has the object of providing a patching material for coke ovens which has a long lasting bond with used silica brick.

[0010] The present invention relates to the sealing of heated chambers from which gases, fumes and other noxious materials may escape. These chambers have at least one opening therein for receiving contents to be processed therein in some manner. This opening has preferably some sort of closing element for the gross sealing thereof from the surrounding atmosphere. This element may be a door. This door has a primary seal for making at least a rudimentary seal between the door and the jamb which reduces the leakage of gases, fumes and other noxious materials from the chamber to the surrounding environment. In addition to the primary seal, a secondary seal is provided which is placed or disposed in such a way as to enhance the sealing function of the primary seal. In addition, this secondary seal is made from a material which changes dimensions such as to expand when exposed to heat and preferably expands to complement or surround the primary seal, thereby greatly improving the ability of the primary seal to contain the gases, fumes and other noxious materials. Materials which expand upon the application of heat are known as intumescent materials.

[0011] This secondary sealing means comprises sodium silicate and is preferably applied in a liquid state. It provides a sealing capability which improves as the temperature rises because of its property to expand when heated.

[0012] The sealing mixture or medium is formed by mixing an intumescent material comprising sodium silicate to a desired viscosity which when applied at temperatures before the chamber is heated will permit an accumulation thick enough to surround the primary seal when making a seal against the jamb, upon the closing of the oven door.

[0013] Reference will now be made to the accompanying drawings which are given by way of example and in which:-

Figure 1 is a cross-sectional view of a Koppers oven door having an S shaped seal and a jamb according to the prior art.

Figure 2 illustrates the invention applied to the Koppers oven door of Figure 1.

Figure 3 is a cross-sectional view of a Wilputte door according to the prior art.

Figure 4 illustrates the invention applied to the Wilputte door of Figure 3.

Figure 5 is a three dimensional view of a segment of an S shaped seal showing gas leakage gaps as in the prior art.

Figure 6 illustrates the present invention applied in Figure 5.

[0014] Referring now to Figure 1, oven walls 10 are shown with flues 12 therein. Abutting the walls are jambs 14. Making contact with the jambs 14 are S shaped seals.

[0015] Plungers 18 have springs 20 for urging the S shaped seals 16 against the jambs 14. The opposite ends of the S shaped seal 16, not making contact with the jambs 14, abut a door frame 22 which has a latch 24 for opening, closing, and locking the door. Also attached to the door frame 22 are retainers 26 which hold a plug 28 therebetween. A brickstay 30 abuts the jambs 14 on the sides opposite the oven walls 10.

[0016] Referring now to Figure 2, a partial cross section of the Koppers door of Figure 1 is shown, having one of the S shaped seals 16, one of the door jambs 14 and the plug 28. In the area of the jamb 14 onto which the S shaped seal 16 abuts, an intumescent material 110 is applied. The intumescent material expands upon exposure to the elevated temperature during the making of coke. This expansion provides a gas- tight seal between the jamb 14 and the S shaped seal 16.

[0017] As an alternative embodiment also shown in Figure 2 between the plug 28 and the oven wall 10 a mass of intumescent material 112 is applied. This mass of intumescent material 112 has the same function as the intumescent material 110, and will expand upon exposure to elevated temperatures.

[0018] If there are any gouges or cracks or other irregularities in the jamb 14 or as in the alternative embodiment as shown in this same Figure 2 in the oven wall 10, the intumescent material either 110 or 112, as the case may be, will fill those gouges, cracks, or other irregularities both upon application and subsequent thereto, during expansion in the heating process and form an extremely efficient seal even under these adverse conditions where the primary seal, the S shaped seal 16 is not operative satisfactorily.

[0019] Figure 3 is similar to Figure 1, in that it shows a prior art Wilputte door instead of a Koppers door. Moreover, it has a similar jamb 214 with a diaphragm seal 216 which makes contact with the jamb 214. The Wilputte door has a plug 218 similar to the Koppers door of Figure 1.

[0020] Figure 4 shows the placement of an intumescent material 310 with the diaphragm seal 216 and the jamb 214 as shown in Figure 3.

[0021] Also in Figure 4 an alternative embodiment of the Wilputte door according to the present invention is shown, that is, between the oven wall 10 and the plug 218 another body of intumescent material 312 is placed for the sealing of the opening therebetween.

[0022] The intumescent material comprises sodium silicate and may also comprise a pulverant cellulatable glass such as ground glass with a high carbon content, mixed with the silicate and a clay. The clay is preferably ball clay or china clay which are used because of their fine texture.

[0023] Another formation of intumescent material which has been shown to be satisfactory is liquid sodium silicate having a viscosity of 400 centipoise (m Pa s) when blended. The liquid sodium silicate is preferably applied directly to the horizontal surfaces with a pressurized spray gun which produces a fine atomized discharge, such as a portable pressurized sprayer. The material sprayed on the horizontal surfaces may also be sprayed with a pressurized spray gun which produces, a finely atomized discharge and is permitted to coat these surfaces to a thickness of about ten-thousandths of an inch (0.254 mm) in one pass or, yet more preferably, in two passes to a thickness of twenty-thousandths of an inch (0.508 mm). It has been shown that there is little or no running of the material when applied in this manner. The sodium silicate adheres to the oven and will produce a seal upon the application of heat to the intumescent material which has the property in its present form of enlarging or expanding upon being heated thereby making a good seal. On vertical surfaces the liquid sodium silicate is preferably blended to a viscosity of approximately 950 centipoise (m Pa s) or combined with granular sodium silicate to achieve higher viscosities and thixotropic behaviour and applied to a heated surface at or above 100 degrees C. in certain applications other materials may be added to the liquid sodium silicate such that it will more readily adhere to vertical surfaces and inhibit the tendency to run thereon.

[0024] The applicant has found that a viscosity of between 400 to 950 centipoise (m Pa s) is adequate for the applications that he has investigated. However, even lower viscosities may be adequate and can be determined by experimentation. The applicant also believes that mixtures having viscosity which decrease as the shear rate increases will reduce the tendency of the sealer to run off the surface after it has been applied thereto. Other methods of applying the intumescent material may be by the formation of a gasket, the application of the mixture with a brush or any other applicable method, even aerosol sprays may be useful under certain sets of circumstances and conditions. The applicant has additionally found that the intumescent material mixture may be applied to the goose neck portion of a coke oven to effectively seal it as well as a door.

Claims

1. A heated chamber having at least one opening; closure means for closing said at least one opening, said closure means having at least a closed and open position; said closure means and said opening having surfaces disposed for coming into proximity of one another in said closed position, said surfaces forming a primary sealing means for said heated chamber in said closed position, there being a substance comprising sodium silicate applied to at least one of said proximate surfaces, said substance being an intumescent substance, that is to say, forming and expanding upon the application of heat, thereby forming a secondary sealing means between said proximate surfaces in said closed position, when said substance is in a formed and expanded condition.

2. A heated chamber according to claim 1, wherein said substance, when applied, has a viscosity between 400 and 950 centipoise (m Pa s).

3. The heated chamber according to claim 1 or 2, wherein said substance is a mixture comprising sodium silicate and glass.

4. A heated chamber according to claim 1, 2 or 3, wherein said primary sealing means has voids therein permitting gases to leak therethrough, the substance forming the secondary sealing means having properties of adhering to at least one surface of said at least one opening or said closure means, said secondary sealing means being disposed in relationship with said primary sealing means such that upon application of heat, said sealing means foams and expands and at least partially fills a portion of said voids in said primary sealing means whereby sealing of said heated chamber is enhanced.

5. A method of sealing a heated chamber having at least one opening with closure means therefor, said closure means forming a primary sealing means for said chamber, comprising the steps of: applying an intumescent substance, that is to say a substance which foams and expands upon heating, to at least one surface between said at least one opening and said closure means, said substance on foaming and expanding, forming a secondary sealing means for said chamber, said substance comprising sodium silicate.

6. A method as claimed in claim 5, wherein said substance is applied to said surface with the temperature of said surface being at or above 100 degrees centigrade.

7. A method as claimed in claim 5 or 6, wherein said applying is accomplished by spraying or trowelling the substance onto said at least one surface.

8. A method as claimed in claim 5, 6 or 7, wherein said substance is applied at a viscosity between 40 and 950 centipoise (m Pa s).

9. A method as claimed in claim 8, wherein said substance is applied as a layer between 10 and 20 thousandths of an inch (0.254 and 0.508 mm) in thickness.

Ansprüche

1. Eine mit mindestens einer zu verschliessenden Öffnung versehene beheizte Kammer, bei der ein Verschluss mit mindestens einer Schließ- und einer Offenstellung vorgesehen ist, wobei Oberflächen des Verschlusses und der Öffnung so angeordnet sind, dass sie in Schießstellung nahe beieinander zu liegen kommen und dabei eine Hauptdichtung für die beheizte Kammer bilden, auf mindestens einer der nahe beieinander liegenden Oberflächen eine Natriumsilikat enthaltende blähfähige Masse aufgebracht ist, die bei Erwärmung schäumt und sich ausdehnt und im geschäumten und ausgedehnten Zustand zwischen den nahe beieinander leigenden, in Schließstellung befindlichen Oberflächen eine Sekundärdichtung bildet.

2. Eine beheizte Kammer nach Anspruch 1, dadurch gekennzeichnet, dass die Masse beim Aufbringen eine Viskosität zwischen 400 und 950 cP (m Pa s) aufweist.

3. Eine beheizte Kammer nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass die Masse aus einem Natriumsilikat und Glas enthaltenden Gemisch besteht.

4. Ein beheizte Kammer nach Anspruch 1, 2 oder 3, dadurch gekennzeichnet, dass die Hauptdichtung feine Lücken aufweist, durch die Gase entweichen können und die die Sekundärdichtung bildenen Masse Eigenschaften hat, an mindestens einer Oberfläche der mindestens einen Öffnung oder des Verschlusses zu haften, wobei die Sekundärdichtung in Bezug zur Hauptdichtung so angeordnet ist, dass die beim Erwärmen schäumende und sich ausdehnende Dichtungsmasse zumindest teilweise einen Teil der Lücken in der Hauptdichtung ausfüllt und dabei die Abdichtung der beheizten Kammer verbessert.

5. Ein Verfahren zum Abdichten einer beheizten Kammer, die mindestens eine Öffnung aufweist, der ein Verschluss zugeordnet ist, der eine Hauptdichtung für die Kammer bildet, dadurch gekennzeichnet, dass ein blähfähige Masse, die beim Erwärmen schäumt und sich ausdehnt, auf mindestens eine Oberfläche zwischen der mindestens einen Öffnung und dem Verschluss aufgebracht wird, die nach Schäumen und Ausdehnen eine Sekundärdichtung für die Kammer bildet, wobei die Masse Natriumsilikat enthält.

6. Ein Verfahren nach Anspruch 5, dadurch gekennzeichnet, dass die Masse auf eine auf 100°C oder mehr erwärmte Oberfläche aufgebracht wird.

7. Verfahren nach anspruch 5 oder 6, dadurch gekennzeichnet, dass die Masse auf mindestens eine Oberfläche ausgesprüht oder mit einer Kelle aufgetragen wird.

8. Verfahren nach Anspruch 5, 6 oder 7, dadurch gekennzeichnet, dass die Masse mit einer Viskosität zwischen 400 und 950 cP (m Pa s) aufgebracht wird.

9. Verfahren nach Anspruch 8, dadurch gekennzeichnet, dass die Masse in einer Schicht zwischen 10- und 20-tausendstel eines Zolls (0,254 und 0.508 mm) Dicke aufgebracht wird.

Revendications

1. Chambre chauffée comportant au moins une ouverture; un moyen de fermeture pour fermer ladite ouverture, ledit moyen de fermeture présentant au moins une position fermée et une position ouverte; ledit moyen de fermeture et ladite ouverture comportant des surfaces disposées pour venir à proximité l'une de l'autre dans ladite position fermée, lesdites surfaces formant un moyen d'étanchéité principal pour ladite chambre chauffée dans ladite position fermée, une substance comprenant du silicate de sodium étant appliquée à au moins une desdites surfaces voisines, ladite substance étant une substance étant une substance intumescente, c'est-à-dire subissant une expansion et une dilatation lors de l'application de la chaleur, en formant de cette façon un moyen d'étanchéité secondaire entre lesdites surfaces voisines, dans ladite position fermée, lorsque ladite substance est dans un état expansé et dilaté.

2. Chambre chauffée selon la revendication 1, dans laquelle ladite substance, lorsqu'elle est appliquée, a une viscosité comprise entre 400 et 950 centipoise (mPas).

3. Chambre chauffée selon la revendication 1 ou 2, dans laquelle ladite substance est un mélange comprenant du silicate de sodium et du verre.

4. Chambre chauffée selon la revendication 1, 2 ou 3, dans laquelle ledit moyen d'étanchéité principal comporte des interstices permettant aux gaz de s'échapper par leur intermédiaire, la substance formant le moyen d'étan- chéite secondaire ayant la propriété d'adhérer à au moins une des surfaces de ladite ouverture ou dudit moyen de fermeture, ledit moyen d'étanchéité secondaire étant disposé par rapport audit moyen d'étanchéité principal de telle manière que lors de l'application de la chaleur, ledit moyen d'étanchéité subit une expansion et une dilatation et remplit au moins partiellement une partie desdits interstices dans ledit moyen d'étanchéité principal, l'étanchéité de ladite chambre chauffée se trouvant ainsi renforcée.

5. Procédé d'étanchéification d'une chambre chauffée comportant au moins une ouverture avec des moyens de fermeture pour cette dernière, ledit moyen de fermeture formant un moyen d'étanchéité principal pour ladite chambre, comprenant les phases: d'application d'une substance intumescente, c'est-à-dire d'une substance qui subit une expansion et une dilatation lors de sont chauffage, à au moins une surface entre ladite ouverture et ledit moyen de fermeture, ladite substance, lors de son expansion et de sa dilatation, formant un moyen d'étanchéité secondaire pour ladite chambre, ladite substance comprenant du silicate de sodium.

6. Procédé selon la revendication 5, dans lequel ladite substance est appliquée à ladite surface, la température de ladite surface étant égale ou supérieure à 100°C.

7. Procédé selon la revendication 5 ou 6, dans lequel ladite application est effectuée par pulvérisation ou application à la truelle de la substance sur ladite surface.

8. Procédé selon la revendication 5, 6 ou 7, dans lequel ladite substance est appliquée à une viscosité comprise entre 400 et 950 centi- poises (mPas).

9. Procédé selon la revendication 8, dans lequel ladite substance est appliquée sous la forme d'une couche d'une épaisseur comprise entre 0,254 mm et 0,508 mm (10 et 20 millièmes de pouce).

Drawing