WO1991008273A1

WO1991008273A1 - Oven door seal

Info

Publication number: WO1991008273A1
Application number: PCT/US1990/006915
Authority: WO
Inventors: Robert Walter Highley; Stephen Joseph Stanczak
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-11-27
Filing date: 1990-11-26
Publication date: 1991-06-13
Anticipated expiration: 1992-05-27
Also published as: CA2071203A1

Abstract

A coke oveN door seal structure for mounting on the inner peripheral surface of a coke oven door (10) and which in a preferred embodiment is a continuous spring ring member (25) formed to resilient heat resistant material having a generally U-shaped cross-section with inner and outer planar end sections which extend laterally and parallel to the oven door. The inner planar end section (26) of the U-shaped spring ring is adapted for mounting on the inner surface of the oven door adjacent the periphery, and the outer planar end section (28) of the U-shaped spring ring resiliently supports a free-standing scraper-sealing blade element (29) which extends forwardly and laterally in a plane making an angle of less than 90 degrees and preferably about 45 degrees with the plane of the outer planar end section. The scraper-sealing blade element (29) sealably engages a planar contact surface of (14) an oven jamb (13) at an angle of less than 90 degrees and preferably at an angle of about 45 degrees as the oven door (10) with the spring ring mounted thereon is moved into latching engagement with the oven doorway.

Description

OVEN DOOR SEAL

The present invention relates generally to oven doors and sealing means for oven doors and more particularly to coke oven doors and coke oven door seals which automatically seal a coke oven so that noxious gases do not escape into the surrounding atmosphere during a cokeing process.

From an operating standpoint it is important to prevent the escape of coke oven gases during a coking process, because the gases are highly combustible and cause oxidation damage to the oven doorway, the door insulation and the door sealing means. Damage caused by escaping gases requires frequent repair and replacement of coke oven doors or door sealing elements.

A further important reason for providing a coke oven door seal capable of significantly reducing or preventing coke oven gases escaping into the atmosphere is the harmful effect the gases have on the environrnent and the gases are carcinogenic. The United States Environmental Protection Agency has issued regulations limiting the amount of coke oven gases which may be lawfully emitted and heavy penalties are levied for violations.

A majority of about seventy-five percent of the coke ovens currently in use in the United States are of the Koppers design. The coke oven door seals presently used on the Koppers coke oven doors and other Koppers-type coke oven doors, such as the improved coke oven doors of United States Patent No. 4,574,035, have self-sealing means in the form of a peripheral continuous sealing ring detachably mounted on the inner planar surface of the oven door designed to make a resilient metal-to -metal sealing contact between the door and a planar contact surface on the oven door frame (i.e. jamb) .

The unitary continuous sealing ring presently used on a Kbppers-type coke oven door is formed entirely of a uniform strip of resilient mild steel or 304 stainless steel with the seal having a cross-section generally referred to as S-shaped and having an outer end flange or sealing edge extending perpendicularly toward the oven jamb for making a sealing metal- to-metal contact with the jamb. A Koppers-type door has at spaced points along the entire periphery a plurality of adjustable spring-loaded plungers are provided which press against the back of the S-shaped sealilng ring to force the sealing edge of the ring into a sealing engagement with the jamb. With a Koppers- type coke oven door having the door and jamb substantially planar and the sealing edge free of large distortions, the S-shaped sealing ring in combination with the spring-loaded plungers are able to effectively seal the coke oven against gas leakage, at least for a limited time, but only under conditions where there are initially only relatively small gaps or no gaps between the sealing edge and the oven jamb.

While the Koppers-type coke oven door with an S-shaped spring sealing ring is cosidered one of the most efficient self- sealing means prensently available and is used on between 70 and 80 percent of the coke ovens in the United States, these doors with their S-shaped seals have serious deficiencies which can result in seal failure and permit gas leakage, frequently after only a relatively short period of use. These failures are primarily the result of physical and thermal damage to the sealing ring and warpage of the jamb due to thermal and physical stresses during the coking operation. The distortions can be the result of an outwardly or an inwardly bow of the door or the jamb. Other distortions can have an hour-glass configuration, and there can be various combinations of the foregoing distortions, some of which can cause large gaps to be formed between the sealing edge of the ring and the jamb.

A Koppers-type coke oven door having an S-shpaed sealing ring has difficulty sealably closing relatively large gaps between the oven and the jamb, particularly where the gap is due to the jamb being bowed away from the door. The S-shaped ring with its sealing edge extending perpendicularly toward the jamb behaves like a relatively stiff inflexible colmn which resists bending in the plane of the sealing edge where there is an inwardly extending depression in the jamb. Some gaps can be sealably closed by an S-shaped dealing ring only by making time consi-irdng adjustments in the mounting means for the seal, the oven door or the jamb and further adjusting the spaced spring- loaded plungers which bear against the surface of the S-shaped sealing ring. In some instances where excess pressure is applied to the S-shaped sealing ring, permanent distortion of the sealing ring or sealing edge can result.

A further deficiency of the S-shaped door seals is the inability of the perpendicular sealing edge to exert any scraping action on the oven jamb to remove objectionable deposits of tar and carbonaceous material on the seal contact surface of the jamb. During the coking operation deposits of tar and hard carboanceous material are formed on the jamb. The deposits of hard carbonaceous material on the jamb can cause large gaps to be formed between the sealing edge and the contact surface which are difficult to remove. Where there is no scraping of the jamb to remove the hard deposits, the sealing edge of the S-shaped sealing ring is frequently unable to form a sealing engagement with the jamb or the sealing engagement is formed only after exerting excessive pressure on the sealing ring which can result in permanent damage to the sealing ring or sealintg edge.

With an S-shaped sealing ring presently used on a Koppers- type coke oven door it is also very difficult to provide in an ecxa mical manner a coke oven door seal having the required flexibility and resilience along with the desired heat resistance and stability at the elevated temperatures encountered during a coking process. In some instillations an S-shaped sealing ring formed of mild steel or 304 stainless steel is able to function efficiently for a limited time, but is unable to withstand the occasional temperature excursions as high as 427 degrees C. (800 degrees F.) without being damaged by plastic deformation under load. And, with the inherent deficiencies of an S-shaυed sealing ring, it is not cost effective to form the entire S-shaped seal of an expensive alloy steel.

It is therefore an object of the invention to overcome objectionable features of the present Koppers-type coke oven doors and door sealing means by Drσviding an irrproved self- sealing self-cleaning oven door and door sealing means capable of closing gaps between an oven door and jamb more efficiently and economically.

It is also an object of the invention to provide a coke oven door with a self-cleaning coke oven door seal having a resilient spring ring with a resilient sealing-scraper blade supported thereon which forms a scraping engagement with a coke oven jamb and provides a smooth contact surface area on a coke oven jamb when the door is mounted in latching engagement with a coke oven.

It is a further object of the invention to provide a self-cleaning coke oven door seal with a sealing-scraping blade which is highly resistant to being damaged by physical and thermal stresses.

It is still another object of the invention to provide a coke oven door seal which can be retrofitted on a Koppers-type coke oven door presently using an S-shaped sealing ring without making any changes in the coke oven door or change in the method of handling or maintaining a Koppers-type coke oven door.

Other objects of the invention will be apparent to those skilled in the art from the following detailed description and claims when read in conjunction with the ac∞t anying drawing wherein:

Fig. 1 is a front elevational representation of a Koppers- type coke oven door partilly broken away having a scraper-sealing means of the present invention detachably mounted on the inner surface of the door,

Fig. 2 is an enlarged sectional view partially in elevation taken along the line 2-2 of Fig. 1 and showing in phantom the relative position of the scraper-sealing means of Fig. 1 and the oven jamb before and after the oven door is placed in latching engagement with the coke oven,

Fig. 3 is a fragmentary enlarged view of a detail of Fig. 1,

Fig. 4 is a cross-sectional view of a Koppers-type coke oven door in latching engagement with a coke oven and having the scraper sealing means of Fig. 1 detachably secured to the oven door.

Fig. 5 is a fragmentary sectional view partially in elevation of a modified form of a scraper-sealing means of the present invention and showing in phantom the relative postion of the scraper-sealing means and the oven jamb before and after the oven door is placed in latc±ing engagement with the coke oven. and

Fig. 6 is a fragmentary sectional view partially in elevation of a further modified form of scraper-sealing means of the present invention and showing in phantom the relative position of the scraper-sealing means and oven jamb before and after the oven door is placed in latching engagement with the coke oven.

A self-sealing self-cleaning oven door and door seal embodying the present invention is provided by mounting a scraper- sealing means on a peripheral planar inner surface of a coke oven door having slightly larger dimentions than an oven doorway frame (i.e. jamb) which has a generally planar contact surface facing outwardly from the oven. The scraper-sealing means is constructed of a continuous peripheral spring ring of resilient heat resistant material with interconnected inner and outer planar end sections extending laterally and parallel to the plane of the door and preferably having a generally U-shaped cross-section. The inner planar end section or inner leg of a U-shaped spring ring is adapted to be secured to the inner surface of the oven door adjacent the periphery of the door. The outer planar end section or outer leg of the U-shaped spring ring resiliently supports a free-standing scraper-sealing blade formed of resilient heat resistant material. The scraper-sealing blade extends laterally and forwardly toward the contact surface of the jab and lies in a plane which makes an angle of less than 90 degrees and preferably

SUBSTITUTE SHEET about 45 degrees with the plane of the outer leg and the planar contact surface of the jamb. As the door is moved into latching engagement with the oven, the scraper-sealing blade resiliently engages the contact surface of the jamb with the outer end of the scraper-sealing blade moving laterally over the contact surface of the jamb at an angle less than 90 degrees scraping objectionable amounts of tar and deposits of hard carbonaeous material from an area of the contact surface. The scraping action of the blade forms a smooth contact surface area on the jamb and reduces the number of large gaps between the scraper-sealing blade and the contact surface. When the scraper-sealing blade moves laterally over the contact surface, tar-containing material piles up in front of the outer end of the scraper-sealing blade and forms a sealing barrier layer along the outer end of the scraper-sealing blade which serves to prevent gases escaping from the oven. While the door is being moved into latching engagement with the oven, the scraper-sealing blade also conforms with distortions in the contact surface by bending laterally along the length thereof (as opposed to bending in the plane of the blade) and closes gaps between the scraper-sealing blade and the contact surface of the jamb so that a sealing engagement is formed. Because of the improved gap closure capabilities of the scraper-sealing means of the present invention, use of the spring- loaded plungers on a Koppers-type coke oven door is not required en a properly maintained oven door to form a sealing engagement with the contact surface of the jamb.

By having the scraper-sealing blade supported by a resilient U-shaped spring ring, the scraper-sealing blade is protected from being over stressed when force is applied to effect a satisfactory scraping and sealing engagement with the jamb. The U-shaped spring ring is able to conform with distortions in the planar surface of the door when the sealing means is mounted on the door without causing the scraper-sealing blade to assume a form which makes it difficult or impossible for the scraper-sealing blade to sealably conform with distortions in the contact surface of the jamb, particularly when the spring- loaded plungers are used to apply additional pressure on the U- shaped sealing ring.

The structural details of a preferred embodiment of the present invention are shown in Figs. 1-4 of the accotnpanying drawing wherein a scraper-sealing means 15 is shown mounted on a rigid generally rectangular pusher side Koppers-type coke oven door 10 typically having dimentions of about 6.7 meters(22 feet) long and 0.64 meters (25 inches) wide so as to overlie the pusher side of a coke oven 11 having a doorway 12 about 6.1 meters (20 feet) high and 0.43 meters (17 inches) wide. The coke oven door 10 can be formed of cast iron but preferably is a warp-resistant fabricated steel structure as shown in United States Patent No. 4,574,035. The doorway 12 is enclosed by a frame (i.e. jamb) 13 having a planar contact surface 14 which the scraper-sealing means 15 is adapted to sealably engage. The contact surface 14 faces outwardly from the oven and lies in a plane parallel to the plane of the peripheral planar inner surface of the door 10 when the door is operatively positioned in the doorway 12 of the oven 11. A plurality of spring boxes 20 with spring-loaded plungers 21 and adjustable means 22 are provided at spaced intervals along the periphery of the door 10. A latching mechanism 24 is provided for applying latching pressure to the door 10 when the door is moved into operative latching engagement with the oven 11.

The scraper-sealing means 15 is comprised of a continuous spring ring 25 formed of relatively heavy gauge resilient heat resistant material, such as mild steel or stainless steel, having a generally U-shape cross-section (i.e. a U-shaped spring ring) with parallel inner and outer legs in the form of planar end sections. The parallel inner and outer planar end sections

(i.e. legs of the U-shaped spring ring) are interconnected by resilient section 27 having a length about the same as the leg

26. The legs 26, 28 extend laterally in planes which are parallel to the plane of the door 10 when the inner planar end section (i.e. leg 26) is detachably secured to the door 10. The outer planar end section (i.e. leg 28) has a free-standing scraper-sealing blade element 29 secured to the outer end portion thereof, preferably by welding as at 29a, and at a point spaced inwardly from the outer end of the leg 28. The scraper-sealing blade element 29 extends laterally and forwardldy so that it is able to just engage the contact surface 14 of the jamb 13 before latching pressure is applied to the door 10. The scraper-sealing blade element 29 lies in a plane which makes an interior angle of about 45 degrees with the plane of the leg 28 and with the plane of the contact surface 14 on the outer surface of the jamb 13. The scraper-sealing blade element 29 is formed of a relatively thin gauge material preferably having high heat resistance and high tensil strength, such as a nickel based alloy steel, so as to provide good lateral flexibility (i.e. good lateral bending properties) along with the ability to resist the elevated temperatures to which the blade element 29 is exposed during a coking operation.

The outer leg 28 of the U-shaped spring ring 25 extends laterally beyond the point of attachment of the scraper-sealing blade element 29 a distance such that the outer end 23 of each of the plungers 21 can contact the outermost end portion of the leg 28. The outer portion of the leg 28 extending beyond the point of attachment of the blade element 29 functions as a lever arm when the plungers 21 are used to apply pressure on the ring 25 and serves as a leveraged bearing surface for the outer ends 23 of the spring-loaded plungers 21. By having a leveraged bearing surface on the outer end of the support for the scraper-sealing element 29, the plungers 21 are more effective in applying pressure on the blade element 29, and the likelihood of damaging the blade element 29 or the spring ring 25 due to "point loading" is reduced. Also, by having the blade element 29 resiliently supported by the spring ring 25 there is less danger of permanently stressing the scraper-sealing blade element 29, because the spring ring 25 is able to yield and relieve excess pressure which can be applied to the blade element 29 by plungers 21, for example, and by the door latching force when the plungers 21 are not used to form a sealing engagement with the jamb 13.

While the U-shaped spring ring 25 and the scraper-sealing blade element 29 can both be made of the same resilient heat resistant material, in the preferred enbodiment of the invention when maximum performance and longevity are desired at minimum cost, the U-shaped spring ring 25 and the scraper-sealing blade element 29 are preferably provided with distinctly different properties so that improved scraping and sealing of the coke oven

10 can be provided in a very efficient and ecx_mατtical manner.

More particularly, with the U-shaped spring ring 25 and the scraper-sealing blade element 29 formed as distinct parts and the scraper-sealing blade element 29 replacably connected to the

U-shaped spring ring 25, the parts forming the scraper-sealing means 15 can be given physical properties enabling each of the parts to exhibit optimum performance under the different conditions which each is required to function during a coking operation. The U-shaped spring ring 25 is preferably formed of relatively heavy gauge inexpensive material having moderate heat resistant properties, such as 0.635 cm (1/4 inch) strip mild steel having a tensil strength of about 248,040 kRa (36,000 pounds per square inch) or 304 stainless steel. The physical properties and gauge of the material used for the spring ring 25 are combined to provide resilient properties which are best suited for transmitting the door latching force to the scraper- esaling blade element 29 without causing damage to the scraper- sealing blade element 29.

The scraper-sealing blade element 29 can be made of the same material specified for the U-shaped spring ring 25 where longevity of service is a secondary consideration to cost, but the scraper-sealing blade element 29 is preferably formed of a relatively thin gauge resilient heat resistant material which has a high tensil strength, such as a nickel based alloy steel, for added flexibility (i.e. lateral bending) . The sealing blade element 29 formed of a nickel based alloy steel (or a similar superalloy steel material having properties similar to Inconel X -750) can withstand the flexing stresses of repeated lateral bending and the high temperatures in the immediate area of the jamb, as where a stringer of flames erupts, without being permanently damaged by oxidation. Inconel X-750 (made by Huntington Alloys, -iintington, West Virginia) is readily formable before heat treatment and is aged by a precipitation hardening heat treatment at about 704 degrees C. (1300 degrees F.) for about 20 hours. The aged Inconel X-750 metal has a yield strength at about 427 degrees C. (800 degrees F.) of about 130 ksi and is stable for prolonged periods at about 427 degreees C. (800 degrees F.) . The Inconel X-750 metal welds are fast-annealed by rapidly heating the weld to about 983 degrees C. (1800 degrees F.) for about 15 minutes followed by air cooling.

The scraper-sealing blade element 29, when made of an alloy steel, such as Inconel X-750, is highly resistant to physical and thermal damage but in the event the blade element becomes unusable for any reason, the blade element 29 can be repaired by welding or can be readily removed and a new blade rewelded on the outer leg 28 so that the entire sealing ring 25 does not have to be replaced.

The scraper-sealing means 15 of the present invention can be detachably secured to the inner surface of a Kbppers-type coke oven door 10 in the same space occupied by a Koppers S- shaped sealing ring. As best shown in Fig. 4, the scraper- sealing means 15 is mounted on a plurality of studs 30 held in apertures 31 at spaced intervals adjacent the periphery of the oven door 10. Openings are formed in the inner leg 26 of the U- shaped spring ring 25 corresponding to the spacing of the studs 30. The inner leg 26 is retained on the studs 30 over a gas impervious gasket strip 33 by a steel retaining bar 34 having openings matching those in the leg 26 and by retaining nuts 35 threadably mounted on the outer ends of the studs 30.

The scraper-sealing means 15 of Figs. 1-4 when mounted on a Koppers-type coke oven door 10 forms a scraping and sealing engagement with the contact surface 14 of the jamb 13 by having the outer end of the scraper-sealing blade element 29 engage the contact surace 14 as the door 10 is moved into latching engagement with the oven 11. As a latching force is applied to the door 10 by the latching mechanism 24 (with additional pressure being applied by the spring-loaded plungers 21 engaging the lever arm portion of the outer leg 28 when plungers 21 are employed) , the outer end of the blade element 29 moves laterally over a portion of the contact surface 14 scraping tar and hard carbonaceous material on the contact surface 14 so as to provide an area on the contact surface 14 substantially free of clumps of hard carbonaceous material which otherwise would cause large gaps forming between the blade element 29 and the jamb 13. While the blade element 29 is scraping the contact surface 14, tar and carbonaceous material pile up along the outer end of the blade element 29 and form a barrier layer of tar contairύng material which serves to prevent gases escaping from the oven 11. When the scraper- sealing means 15 is moved into latching engagement with the oven 11, the blade element 29 bends laterally (i.e. perpendicularly to the plane of the blade element 29) to close gaps between the blade element 29 and the jamb 13 and form a sealing engagement with the contact surface 14.

While the use of the spring-loaded plungers 21 is not required with the scraper-sealing means 15 on a properly maintained coke oven door in order to form a scraping sealing engagement with the jamb 13, it is recognized that some will continue to use the plungers 21 provided on all Koppers-type coke oven doors as a safety factor. And, when the spring-loaded plungers 21 are used to form a sealing engagement with the jamb 13, the scraper-sealing blade element 29 is moved a greater distance laterally over the contact surface 14, because of the combined effect of the resiliency of the U-shaped spring ring 25 and the scraper-sealing blade element 29 (i.e. compound spring action) , and a larger sealing barrier layer of tar containing material is formed along the outermost edge of the scraper- sealing blade element 29. As a result of the ccinpound spring action of the U-shaped spring ring 25 and the angularly disposed resilient scraper-sealing blade element 29, large gaps betweeen the oven door contact surface 14 and the sealing blade element 29 are sealably closed without applying excess latching force on the scraper-sealing means 15.

In the modified form of the invention shown in Fig. 5 of the drawing the scraper-sealing means 40 is comprised of a ccπitinuous spring ring 41 having a generally U-shaped cross- section and a generally rectangular configuration. The U-shaped spring ring 41 has inner leg 42 and outer leg 43 which are interconnected by resilient section 44 having about the same length as the legs 42, 43. The legs 42, 43 have a length such that the spring ring 41 can preferably be placed in the space occupied by an S-shaped Koppers sealing ring. The U-shaped spring ring 41 is detachably connected to the door 10 by having the inner leg 42 bolted to the inner surface of the door 10 adjacent the periphery by means of gas impervious fastener means 45. The legs 42, 43 extend laterally parallel to the plane of the door 10. A scraper-sealing blade element 47 is secured, as by welding, to the outer end of the outer leg 43 and extends laterally and forewardly so that the outer end of the blade elemtne 47 just engages the contact surface 14 of the jamb 13 before a lat ing force is applied to the door 10. The scraper- sealing blade element 47 lies in a plane preferably making an angle of about 45 degrees with the plane of the outer leg 43. The outer end of the blade 47 is adapted to form a scraping sealing engagement with the contact surface 14 of the jab 13 as the door 10 with the sealing means 40 mounted thereon is brought into latching engagement with the oven 11. The U-shaped spring ring 41 is formed of any of the resilient heat resistant materials specified for the spring ring element 25 disclosed in connection with Figs. 1-4. The scraper-sealing blade element 47 is formed of any of the resilient heat resistant materials disclosed in connection with the scraper-sealing blade element 29 of Figs. 1-4.

In the further errbodiment of the invention shown in Fig. 6 the scraper-sealing means 50 is comprised of a continuous spring ring 51 having a generally U-shaped cross-section which conforms to the periphery of the generally rectangular configuration of a Koppers-type coke oven door. The U-shaped spring ring 51 has an inner leg 52 and outer leg 53 which are interconnected by a resilient section 54 having about the length of the inner leg 52. The inner leg 52 is detachably connected to the inner planar surface of a coke oven door 10 adjacent the periphery thereof. The cuter leg 53 has a length somewhat longer than the inner leg 52 and has an end flange or scraper-sealing blade element 55 formed at the outer end thereof which extends laterally and forewardly in a plane preferably making and angle of about 45 degrees with the plane of the inner leg 52 and the inner planar surface of the door 10. The outer edge of the scraper-sealing blade element 55 is adapted to form a scraper sealing engagement with the contact surface 14 of the jamb 13 when the door 10 having the sealing means 50 mounted thereon is brought into latching engagement with the oven 11. The scraper- sealing means 50 is formed of any of the resilient heat resistant materials specified for the spring ring element 25 and scraper- sealing blade element 29 disclosed in connection with Figs. 1-4.

The scraper-sealing means of Figs. 5 and 6 function in the same general manner as disclosed for the scraper-sealing means of Figs. 1-4 and are used where plungers 21 are not provided on an oven door or are not required to form a sealing engagement with an oven jamb.

Claims

WE CLAIM;

Claim 1. A seal for mounting on a door of an oven having a doorway enclosed by a jamb with an outer planar contact surface comprising: a continuous spring ring element of resilient heat resistant material having interconnected inner and outer planar end sections with the inner planar end section mountable on an inner surface of an oven door adjacent the periphery and the outer planar end section extending laterally in a plane parallel to the plane of said door when the spring ring element is operatively mounted on said door and said outer planar end section resiliently supporting a scraper-sealing blade element, said scraper-sealing blade element formed of resilient heat resistant material and supported only by said outer planar end section with said blade element extending generally forewardly and laterally from said outer planar end section substantially in a plane making an angle of less than 90 degrees with the plane of said outer planar end section and said blade element having unrestricted movement in a plane perpendicular to the plane of said blade element, and said blade element outer end adapted to scrape tar and carbonaceous deposits on the surface of the planar contact surface of the ja b forming a barrier layer of tar containing material along the outer end of said blade element as said ring element mounted on a said door is moved into resilient engagement with said oven and said blade element adapted to bend in a plane perpendicular to the plane of said blade element to close gaps beteween said blade element and said planar contact surface of said jamb as said ring element when mounted on a said door is moved into resilient latching engagement with said oven to prevent gases escaping from said oven between said blade element and said jamb.

Claim 2. An article as in Claim 1, wherein said continuous spring ring element has a generally U-shaped cross section with generally parallel inner and outer legs in the form of planar end sections.

Claim 3. An article as in Claim 1, wherein said scraper- sealing blade element lies in a single plane forming an angle of about 45 degrees with the plane of said outer planar end section.

Claim 4. An article as in Claim 1, wherein said scraper- sealing blade element extends forewardly and laterally from said outer planar end section at a point spaced inwardly from the outer end of said cuter planar end section.

Claim 5. An article as in Claim 1, wherein said scraper- sealing blade element is formed of a steel selected from the group consisting of a mild carbon steel, stainless steel and high strength alley steel which provides said scraper-sealing blade element with flexibility and heat resistance capable of resisting damage due to oxidation and stress.

Claim 6. An article as in Claim 1, wherein said spring ring element is formed of a steel selected from the group consisting of a mild carbon steel, stainless steel and high strength alloy steel which provides said ring element with flexibility and heat resistance capable of resisting damage due to oxidation and stress.

Claim 7. article as in Claim 1, wherein said spring ring element has less flexibility than said scraper-sealing blade element, whreby a large proportion of a latching force applied to an oven door is transmitted to said scraper-sealing blade.

Claim 8. An apparatus for sealably closing a coke oven doorway enclosed by a jamb having an cuter planar contact surface comprising: a coke oven door, a continuous spring ring element of resilient heat resistant material having interconnected inner and outer planar end sections with the inner planar end section mounted on an inner peripheral surface of the coke oven door adjacent the periphery and the outer planar end section extending laterally in a plane parallel to the plane of said door and resiliently supporting a scraper-sealing blade element, said scraper-sealing blade element formed of resilient heat resistant material and supported only by said spring ring element with said blade element extending generally forewardly and laterally from said outer planar end section substantially in a plane making an angle of less than 90 degrees with the plane of said outer planar end section and said blade element having unrestricted movement in a plane perpendicular to the plane of said blade element, and said blade element outer end adapted to scrape tar and carbonaceous deposits on the surface of the planar contact surface of the jamb forming a barrier layer of tar- containing material along the outer end of said blade element as said door is moved into resilient latching engagement with said oven and said blade element is adapted to bend in a plane perpendicular to the plane of the blade element to close gaps between said blade element and said planar contact surface of said jamb as the said door is moved into resilient latching engagement with said oven to prevent gases escaping from said oven between said blade element and said jamb.

Claim 9. An appratus as in Claim 8, wherein said ccntiπuous spring ring element has a generally U-shaped cross section with generally parallel inner and outer legs in the form of planar end sections.

Claim 10. An apparatus as in Claim 8, wherein said scraper- sealing blade element lies in a single plane forming an angle of about 45 degrees with the plane of said outer planar end section and engages said planar contact surface of the oven jamb at an angle of about 45 degees when said door is operatively mounted on said doorway of the oven.

Claim 11. An apparatus as in Claim 8, wherein said scraper- sealing blade element extends forewardly and laterally from said outer planar end section of said spring ring element at a point spaced inwardly from the outer end of said outer planar end section.

Claim 12. An apparatus as in Claim 8, wherein said scraper-sealing blade element is formed of a steel selected from the group consisting of a mild carbon steel, stainless steel and high strength alloy steel which provides said scraper-sealing blade with flexibility and heat resistance capable of resisting damage due to oxidation and stress.

Claim 13. An apparatus as in Claim 8, wherein said spring ring element is formed of a steel selected from the group consisting of a mild carbon steel, stainless steel and high strength alloy steel which provides said spring ring element with flexibility and heat resistrance capable of resisting damage due to oxidation and stress.

Claim 14. An apparatus as in Claim 8, wherein said spring ring element has less flexibility than said scraper-sealing blade element, whereby a larger proportion of a latching force applied to saod door is transmitted to said scraper-sealing blade element.

Claim 15. An apparatus as in Claim 8, wherein said door has a plurality of peripheral spring-loaded plungers which engage the cuter planar end surface of said spring ring element outwardly of the point of attachment of said blade element on said outer planar end section with the portion of said outer planar end section beyond said point of attachment serving as a lever-bearing surface for said plungers when said plungers are moved into engagement with said spring ring element.