US3782304A

US3782304A - Furnace door assembly

Info

Publication number: US3782304A
Application number: US00232047A
Authority: US
Inventors: J Balaz
Original assignee: FLINN AND DRAFFEIN ENG CO
Current assignee: FLINN AND DRAFFEIN ENG CO
Priority date: 1972-03-06
Filing date: 1972-03-06
Publication date: 1974-01-01
Anticipated expiration: 1991-01-01

Abstract

This invention is addressed to an improved furnace door assembly including a furnace door having inwardly (toward the furnace) extending members substantially outlining the peripheral boundary of the door which, when the door is closed, form a sealing contact with corresponding outwardly extending members affixed to the furnace wall containing the door portal, said sealing surfaces being disposed perpendicular to the furnace wall containing the door portal and therefore substantially unaffected with respect to their fluid tightness by commonly encountered warpage of the door.

Description

iJnite States te Balaz [451 ,Tan.11,1974

1 1 ruRNAcE noon ASSEMBLY [75] Inventor: Joseph 1K. Ballaz, Northbrook, 111.

[73] Assignee: Flinn & Draffein Engineering Co., Northbrook, Ill.

[22] Filed: Mar. 6, 1972 [21] Appl. No.: 232,047

[52] U.S. Cl. 1110/173, 432/250 [51] Int. Cl. 1 23111 7/01), F23m 7/02 [58] Field of Search 110/173; 49/226, 49/227, 285, 289; 98/115 LH; 432/237, 242, 244, 254, 250

[56] References Cited UNITED STATES PATENTS 2,819,694 1/1958 Hartlc 232/250 3,160,404 12/1964 Potenzo et a1. 110/173 R 3,172,825 3/1965 Maloney 110/173 R 3,262,407 7/1966 Schramn et al..... 110/173 R 2,594,188 4/1952 Longenecker 110/173 R 2,254,900 9/1941 Lessmann 110/173 R 2,262,363 11/1941 Hoop 110/173 R 2,270,484 1/1942 Wallerius 110/173 R 950,983 3/1910 Abbott 110/173 R 871,421 11/1907 Koppers 110/173 c FOREIGN PATENTS OR APPLICATIONS 571,863 9 1945 Great Britain 110/173 Primary ExaminerMeyer Perlin Assistant ExaminerPau1 Devinsky Att0rneyMcDougall, Hersh & Scott ABSTRACT This invention is addressed to an improved furnace door assembly including a furnace door having inwardly (toward the furnace) extending members substantially outlining the peripheral boundary of the door which, when the door is closed, form a sealing contact with corresponding outwardly extending members affixed to the furnace wall containing the door portal, said sealing surfaces being disposed perpendicular to the furnace wall containing the door portal and therefore substantially unaffected with respect to their fluid tightness by commonly encountered warpage of the door.

5 Claims, 6 Drawing Figures FURNACE DOOR ASSEMBLY This invention relates to a furnace door assembly. and more particularly to a furnace door assembly capable of providing an improved seal.

It is well known that all furnace doors have a tendency to warp after even relatively short periods of use. It is generally recognized that warpage of furnace doors may lead to degeneration of the effectiveness of the means commonly employed for sealing the door against undesirable leakage which may permit infiltration of air into the furnace or efflux of hot atmosphere from inside the furnace. Furnace atmosphere leakage through the door seal may permit the escape of costly prepared atmosphere employed inside the furnace for beneficial metallurgical purposes. Heat carried by the effluent hot gases usually produces greater warpage of the door, thus adding to the leakage problem. Furthermore, the hot gases escaping through the door seal may deleteriously affect the seal itself resulting in a rapid and cumulative breakdown of the sealing members. Effluent prepared atmosphere escaping through faulty seals is not only costly but in some instances may expose the furnace operators to toxic gases such as carbon monoxide.

Various attempts have been made to effect fluid-tight sealing of furnace doors; such as, the employment of clamps and dogs which are designed to urge the door inward toward the furnace wall and into contact with sealing surfaces affixed to the furnace wall. While such devices have demonstrated usefulness, usefullness, their effectiveness is often adversely affected by unavoidable warpage of the structural framing of the between the stationary and moving components of the sealing members as the door is closed and opened during normal use of the furnace.

Another object of the present invention utilizes the force of gravity acting upon the door to effect compression of the resilient components of the sealing members to achieve fluid-tight sealing of the door without resort to auxiliary devices for achieving said compression of the resilient components.

These and other objects and advantages of the invention will become more apparent hereinafter, and, for purposes of illustration, but not of limitation, an embodiment of the invention is shown in the accompanying drawings in which:

FIG. l is a front elevation view of a furnace door assembly embodying the features of the present invention in an open position;

FIG. 2 is a view similar to that of FIG. 1 with the furnace door being in the closed position;

FIG. 3 is a sectional view taken along the line 3-3 in FIG. 1;

FIG. 4 is a sectional view taken along the line 4l4 in FIG. 2;

FIG. 5 is a sectional view taken along the line in FIG. 2; and

FIG. 6 is a sectional view taken along the line 66 in FIG. 2.

The concepts of the present invention reside in a furnace door assembly comprising a door having inwardly (toward the furnace) extending sealing elements along the lintel (top), sill (bottom), and jambs (sides) thereof which engage corresponding sealing elements affixed to and extending outwardly from the wall of the furnace containing the door portal whereby the door sealing elements, when the door is in the closed position, rest upon the sealing elements which are affixed to the furnace wall. Thereby, sealing surfaces are defined which are perpendicular to the plane of the furnace wall, and the weight of the door urges the sealing members of the door toward a more secure sealing relation with the sealing members affixed to the furnace wall.

Warpage of the door assembly usually causes a relative motion between the door and the furnace wall in a direction which is substantially transverse to the furnace wall. Since the sealing surfaces are also disposed transverse to the furnace wall, the warpage motion of the door will only produce a slight sliding motion between the sealing surfaces. The transverse warpage motion of the door does not, therefore, cause the sealing surfaces to move apart, and the integrity of the door seal is not impaired.

Referring now to the drawings, there is shown a door assembly embodying the features of this invention. As illustrated in FIGS. II to 3, the assembly includes a door 10 having a generally trapezoidal shape which is mounted on an inclined vertical furnace wall 12 containing a portal 14 through which materials can be passed into or out of the furnace.

In the preferred embodiment, the door It is formed by an outer wall 16. It is generally preferred that refractory material and insulation be built onto the face of wall 16 to define an inner face 18 adjacent the furnace wall. If desired, the door can be formed with a plurality of reinforcing ribs 2ll to provide increased structural strength.

As can best be seen in FIGS. 2 and 3, door if) is provided with a flange 22 extending inwardly along the lintel or top edge of the door having an inner face 24 substantially perpendicular to the plane of the door. This flange 22 may, as shown in FIG. 3, be integral with the top wall 26 of the door. Door 10 is also provided with a pair of inwardly extendingjamb flanges 23 along each jamb side of the door which similarly have inner faces 30 substantially perpendicular to the plane of the door. These jamb flanges 23 may be integral with the jamb side walls 32 of the door Ill).

The door assembly of the present invention also includes trapezoidally arranged sealing elements corresponding to the trapezoidal configuration of the door 10 and the lintel and

jamb flanges

22 and 28, respectively, extending inwardly toward the wall M of the furnace. The sealing element includes a substantially horizontal lintel seal 32 in the form of a continuous ridge member extending across the lintel, having an outer surface 34 (FIGS. 3 and 4) substantially perpendicular to the plane of the door and corresponding to face 24 of lintel flange 26. Lintel sealing element 32 can conveniently be supported by lip 36 extending along the lintel. Lintel sealing element 32 can be bonded to lip 36 and wall 12 to prevent slippage, if desired.

The sealing element may also include another horizontal sealing member 38 extending across the sill which is supported by a sill support 40. Sealing element 38 can be maintained in position by a channel member 42 on the leading edge of sill support 40.

The sealing element also includes a pair of inclined jamb sealing elements 44 which are slightly inclined from the vertical and extend along jambs of the door assembly. These jamb sealing elements 44 define outer faces 46 which are substantially perpendicular to the plane of the door and which correspond to the faces 30 of jamb flanges 28. The jamb sealing elements can be conveniently supported by lips 48 extending outwardly from the furnace wall 14.

As is evident, lintel sealing element 32, jamb sealing elements 44 and sill sealing elements 38 define a trape zoidal seal which corresponds to the trapezoidal configuration of door and the lintel and

jamb flanges

22 and 28, respectively, thereon. Door 10, in the open position as shown in FIGS. 1 and 3 is elevated above opening 14 by suitable means 50. To close the door, door 10 is lowered whereby door 10 slides along wall 12 until it reaches the closed position where lintel flange 22 rests upon lintel seal 32 and jamb flanges 28 rest upon jamb seals 44 and the sill 52 of the door rests upon sealing element 38. Since the furnace wall 12 and consequently the sealing elements are inclined with respect to the vertical, the door 10 is urged toward wall 12 by a component of force perpendicular to the plane of the door which, when vectorially combined with supporting forces parallel to the plane of the door, form a resulting force equal to and opposite to the force of gravity acting upon the door.

Door 10 in its closed position is illustrated in FIGS. 2, 4, and 5 of the drawing. As can be seen in these figures, the face 24 of lintel flange 22 rests upon the corresponding face 34 of lintel sealing element 32 extending across the lintel of the door, and the faces 30 of the jamb flanges 28 extending along the jambs of the door rest on the corresponding faces 46 of jamb sealing elements 44. Thus, since the faces of the flanges and sealing elements which are in surface contact are substantially perpendicular to the plane of the door, the seal established between these faces is likewise substantially perpendicular to the plane of the door. In addition, the weight of the door serves to slightly compress the sealelements to insure a tight seal.

If the door becomes warped, such distortion does not affect the tightness of the seal since the sealing surfaces lying in planes perpendicular to the door permit a sliding cooperation therebetween as warpage occurs, to maintain the tightness of the seal. A tight seal is still maintained where the pressure of the gases inside of the furnace is the highest, that is, along the jambs and particularly along the top or lintel, since the seal established between the flange elements and the corresponding sealing elements lies in planes perpendicular to the plane of the door.

The concepts of the present invention are not limited to the trapezoidal configuration disclosed in the drawings. For instance, the lintel and jambs of the door might usefully follow the general lines of a parabola having its directrix parallel to the door sill. Any other configuration wherein the jamb seals slope downward and away from the vertical axis of the door which would cause the door-supporting forces, when the door is in the closed position, acting upon the door through the sealing surfaces, to exert compressional forces upon the resilient components of the sealing members, would properly lie within the scope of this invention.

An important variant to the basic disclosure of this invention as above described provides a means for concentrating the compressional forces acting upon the resilient components of the sealing members in an area somewhat less than the transverse sealing surface presented by the resilient components to the mating components of the sealing members. This is accomplished by applying a bead or lip to said mating components of the sealing members which engage the resilient components of the sealing surface, said bead having a reduced area of contact. The compressional forces acting upon the resilient components of the sealing members, being concentrated by the said bead into a reduced area of contact, therefore more readily produce a compressional dimpling of the resilient components in order to compensate for unavoidable irregularities in the mating surfaces of the sealing members.

An experimental development embodiment of the door assembly disclosed in this invention has demonstrated remarkably reduced door seal maintenance requirements and has resulted in a reduction in prepared atmosphere consumption attributable to door seal leakage approximating fifty percent of that required in similar furnaces provided with less efficient door sealing arrangements.

it will be understood that various changes and modifications can be made in the details of construction and use without departing from the spirit of the invention, especially as defined in the following claims.

I claim:

1. A furnace and door assembly in which the furnace has an access opening in one of its vertically disposed walls and the door is mounted for movement relative to the furnace wall to open and closed positions with respect to said opening, means for effecting sealing engagement between said door and wall about said opening, when the door is in closed position, comprising resilient sealing members and corresponding sealing surfaces in sealing engagement one with the other about the opening to seal the opening when the door is in closed position, with the sealing members fixed to one of the elements including the door and wall with the sealing surfaces fixed to the other of said elements, the resilient sealing members and surfaces extending for a distance from the adjacent surfaces of the wall and door in the direction substantially perpendicular to the plane of the wall and door, whereby sealing engagement between the sealing surfaces and sealing members is along a plane perpendicular to the plane of the wall and door for maintaining sealing engagement therebetween notwithstanding warpage of the wall or door in a direction perpendicular to the plane of the wall and door, with the resilient sealing members and sealing surfaces diverging in a corresponding member in their side wall portions whereby the resilient sealing members and sealing surfaces are urged into sealing engagement in response to gravitational force.

2. A furnace and door assembly as claimed in claim 1 in which the sealing members and sealing surfaces are provided in the furnace wall and door in a trapezoidal configuration about the wall opening.

3. A furnace and door assembly as claimed in claim 1 in which the resilient sealing members are fixed to the furnace wall about said opening and extend from the door with the sealing portions to be engaged by the sealing surface facing in the downwardly direction in position to be engaged by the upwardly facing sealing surfaces on the wall.

5. A furnace and door assembly as claimed in claim 1 in which the furnace wall containing the opening is inclined from the lintel to the sill in the direction away from the interior of the furnace.

Claims

3. A furnace and door assembly as claimed in claim 1 in which the resilient sealing members are fixed to the furnace wall about said opening and extend from the furnace wall in a direction substantially perpendicular to the plane of the furnace wall with the sealing portions to be engaged by the sealing surface facing in the upwardly direction in position to be engaged by the downwardly facing sealing surfaces on the door.

4. A furnace and door assembly as claimed in claim 1 in which the resilient sealing members are fixed to the inner surfaces of the door to extend therefrom in a direction substantially perpendicular to the plane of the door with the sealing portions to be engaged by the sealing surface facing in the downwardly direction in position to be engaged by the upwardly facing sealing surfaces on the wall.