US2705477A

US2705477A - Furnace door with supports for monolithic lining

Info

Publication number: US2705477A
Application number: US235030A
Authority: US
Inventors: Ottwin L Braun
Original assignee: Reliance Steel Products Co
Current assignee: Reliance Steel Products Co
Priority date: 1951-07-03
Filing date: 1951-07-03
Publication date: 1955-04-05
Anticipated expiration: 1972-04-05

Description

O. L. BRAUN April 5, 1955 FURNACE DOOR WITH SUPPORTS FOR MONOLITHIC LINING 2 Sheets--Sheet l Filed July 3, 1951 IN1/EMDR. OTTWIN BRAUN.

l M y ,BY 25% la? l HIS ATTURNEYS.

O. L. BRAUN April 5, 1955 FURNACE DOOR WITH SUPPORTS FOR MONOLITHIC LINING 2 Sheets-Sheet 2 Filed July 3 lllllll IIIIHIHIIIHIIIIH HlllllllIIIIIHIHHW INVENTOR. OTTWIN L. @RAUM H35 ATTORNEYS.

United States Patent O M FURNACE DOOR WITH SUPPORTS FOR MONOLlTl-IIC LINING Ottwin L. Braun, Pittsburgh, Pa., assignor to Reliance Steel Products Company, McKeesport, Pa., a corporation of Pennsylvania Application July 3, 1951, Serial No. 235,030

9 Claims. (Cl. 122-498) This invention relates to water-cooled furnace doors having monolithic refractory linings on their inner or fire surfaces, and, more particularly, to improvements which facilitate the removal and replacement of anchoring studs commonly provided on such doors.

One common type of water-cooled furnace door for open hearth furnaces and the like is frequently referred to as a studded door because of the studs which project from its inner surface. These studs are in the nature of metal posts and are fabricated from rods usually of circular shape in cross-section. The studs serve a dual purpose in that they provide an anchor for a monolithic refractory lining applied to the inner surface of the door, and function as heat transfer elements for reducing the temperature of the lining. In service, both the lining and studs burn down necessitating their replacement.

Replacement of the studs and lining at present is a difficult operation due in part to the manner in which the studs are secured in position. The connection securing the studs in position usually includes a welded connection which must be exposed before the stud can be replaced. To expose these stud connections, the lining between the studs must be removed, and this is now accomplished by a manual chipping operation which is both tedious and time consuming. The elimination of this lining removal operation constitutes one of the principal objects of this invention.

Another object of the invention is the provision of an improved furnace door stud mounting which will reduce the time and effort required to effect the removal and replacement of studs. To this end, the door is provided with a mounting clip which is permanently secured to the door and with which a stud may be engaged and disengaged in effecting its removal and replacement. Although the use of permanently mounted fastening clips has been proposed heretofore, the mounting clip of this invention has novel structural features which provide a resilient clamping force for holding the stud in position, and which enable the surface of the door to be thoroughly cleaned prior to replacement of the stud and lining.

Other objects and advantages of the invention will be apparent from the following description:

In the drawings, there are shown several embodiments of `the invention. In this showing:

Fig. ll is a top plan view of a watercooled furnace door with a part thereof broken away and shown in horizontal section to illustrate the stud structure of the door;

Fig. 2 is a rear elevational view of the door shown in Fig. 1 with a portion of the monolithic lining broken away to expose several of the studs;

Fig. 3 is an end elevational view of the door with a portion thereof broken away and shown in vertical section;

`Fig. 4 is an enlarged fragmentary perspective view illustrating the mounting of one of the studs on the furnace door;

Fig. 5 is a side view of the stud structure shown in Fig. 4'

Fig. ,6 is a rear view of the structure shown in Fig. 4; and

Figs. 7, 8 and 9 are views respectively similar to Figs. 4, 5 and 6 and illustrating a modied form of stud Structure.

In the drawings, there is shown a water-cooled door ICC steel plate. The door comprises spaced front and back plates 1 and 2 which dene a space 3 through which cooling water may be circulated. The door is provided with an inlet 4 and an outlet 5 for circulating water through the space 3. The back plate 2 is shaped to provide a reentrant space for the reception of a monolithic refractory lining 6. This space is defined by an inner back plate 7 and marginal flanges 8. A plurality of studs 9 project outwardly from the inner back plate 7 to a point in line with the outer edge of the flange 8. The studs 9 form an anchor for the monolithic refractory lining 6 and operate as heat transfer elements to cool such lining as in conventionally studded doors. The structure thus far described is conventional, this invention being concerned with the mounting structure by which the studs 9 are secured in position on the inner back plate 7.

The stud mounting structure of this invention is designated as a whole by the numeral 10, and the preferred embodiment of this mounting structure is: best shown in Figs. 4, 5 and 6. The mounting structure 10 comprises a steel clip 11 which is permanently secured to the inner back plate 7 by a welding connection. The clip 11 is fabricated from steel plate and is shaped to provide a part 12 for engagement with the surface of the plate 7 and to which it is permanently connected as by welding 13 along one edge thereof. The clip 11 has a body portion 14 spaced from and parallel to the back. plate 7, there being an integral connecting part 1S extending angularly between the edge portion 12 and the body portion 14. The body portion 14 has a recess or notch 16 extending inwardly from its other edge 17 which divides it into two parallel arms or straps 14a and 14b. The recess 16 extends in a direction perpendicular to the edge 17 and toward the edge portion 12. Although the arms 14a and 14b are illustrated as having been fabricated from a single piece of plate, it will be understood that these arms may be fabricated from two separate strips of material respectively having welded connections to the plate 7.

The inner end of the stud 9 is enlarged as by upsetting to provide a surface 19 of frusto-conical contour. The arms 14a and 14b are spaced apart a distance slightly greater than the diameter of the cylindrical portion 20 of the stud 9 so that the stud will have a loose fit in the notch 16 as best shown in Fig. 6. The enlarged stud end 21 providing the frusto-conical surface 19 connects with the cylindrical portion 20 along the broken line 22 as best shown in Fig. 5. From this showing, it will be noted that the enlarged end 21 has an axial length slightly greater than the spacing of the arms 14a and 14b from the surface of the plate 7. lin this manner, the connecting line 22 is positioned outwardly of the surface 23 when the stud is in an operative position. By reason of this construction, when the stud 9 is moved into the notch to its operative position, the frustoconical surface 19 of the stud will be engaged at diametrically opposite points by the inner edges 24 of the arms 14a and 14b. The engagement of the edges 24 will be along the line defined by the intersection of the surfaces of the edges 24 with the inner surface 23 of the arms 14a and 14b.

In mounting the studs 9 in position, the enlarged ends 21 are placed in abutting engagement with the surface of the plate 7 and slid in a direction to :move the cylindrical portion 20 into the notch 16. As the studs are moved in this manner, the edges 24 will engage with the frusto-conical surface 19, and the spacing of the arms 14a and 14b from each other and of the line 22 from the plate 7 is such that free movement of the stud 9 to the position illustrated is prevented by engagement of the edges 24 of the arms 14a and 14h with the surface 19. To continue the movement of the studs 9 to their mounted position, it is then necessary to apply force to the studs 9 for moving them to the position shown in Figs. 4 and 5. This action causes the surface 19 to cam the arms 14a and 14b outwardly, which then exert a resilient force holding the enlarged end 19 in abutting engagement with the plate 7. Attention is directed to the fact that the arms 14a and 14b are mounted independently of each other and that the resilient forces exerted thereby are independent of each other. In this manner, the outward camming action by the surface 19 against one of the arms 14a or 14b will not effect the engagement of the other of such arms with the surface 1 To remove the stud 9, it is merely necessary to force it upwardly as viewed in Figs. 4, 5 and 6 to move it out of the slot 16. This removal action may be effected even though the surface of the plate 7 and the frustocorliical surface 19 is covered with refractory lining mater1a.

Attention is directed particularly to the fact that the clip 11 is secured to the plate 7 along only the edge 12 thereof. In this manner, there is an unobstructed space or opening extending under the arms 14a and 14b in a direction perpendicular and transverse thereto. By reason of this unobstructed space, a cleaning tool may be moved transversely underneath the arms 14a and 14b to scrape the surface of the plate 7 free of refractory lining material so that the enlarged end 21 of a new stud 9 may have good heat conducting contact with the plate 7 when a new stud .is installed.

The modified construction shown in Figs. 7, 8 and 9 is similar in structure and operation to the preferred embodiment of the invention shown in Figs. 4, 5 and 6, and like numerals have been employed to designate like parts. In the modified embodiment, the ends of the arms 14a and 14b remote from the connection at 13 are extended and turned forwardly as at 26. The forwardly-turned ends are welded to the plate 7 as at 27. The extended ends of the arms 14a and 14b are cut away as at 28 along a bias to provide clearance for movement of the enlarged end 21 to a position under the arms 14a and 14b. In addition, the downwardly-extending parts 26 have portions of their adjacent edges removed so that the parts 26 will not interfere with movement of the stud into and out of the space between the arms 14a and 14b. In this modified embodiment, it will be noted that the arms 14a and 14b exert an independent resilient holding force as in the case of the preferred embodiment. It will also be noted that there is an unobstructed space extending transversely under the arms 14a and 14b of the modified embodiment through which a scraping tool may be passed to effect a cleaning action on the surface of the plate 7. The connections of the forwardlyturned ends 26 to the plate 7 do not obstruct this transverse movement of a scraping tool under the holddown arms 14a and 14b.

In operation, the fastening clips 11 are first permanently connected to the surface of the inner plate 7. The studs 9 are then mounted in position by forcing them to their final position as Vshown in the drawings, with their cylindrical portions 20 extending through the slots 26, and opposite sides of the surface 19 resiliently engaged by the arms 14a and 14b. The monolithic lining 6 may then be filled in the reentrant space defined by the plate 7 and its marginal flange 8 While in a plastic condition. After the lining 6 and anchoring posts 9 have burned down to the point where replacement of the lining is advisable, the studs 9 may be removed without first chipping away all of the lining positioned around the mounting clips 1I. To effect this removal, it is merely necessary to pound upwardly against the outer ends of the posts 9 so as to move the enlarged ends thereof upwardly with respect to the mounting slot 16. After the studs 9 have been removed in this manner, the surface of the plate 7 is scraped clean of lining material by passing a scraping tool over the area underneath the slot 16 and particularly in a directiontransversely of the arms 14a and 14b. As soon as this small area has been cleaned of lining material, a new stud may be mounted in position, it not being necessary to chip away the lining material on the surface of the door between the several mounting clips 11. A mastic of new refractory material may then be filled in about the new posts 9 without further cleaning of the door.

From the foregoing, it will be apparent that the structure 10, in both modifications ot' the invention illustrated, provides a pair of straps 14 for holding the studs in position. The straps 14 are, in effect, independent of each other, and each, through its lower edge or corner, effects a resilient clamping force against the stud. These straps, in both modifications, are

much in the nature of a resilient beam. In the preferred embodiment, the beam is Supported at only one end, while in the other embodiment, it is supported at both ends. In both cases, the entire area under the straps is unobstructed so that a scraping tool may be moved transversely underneath the straps.

While I have illustrated and described several specific embodiments of my invention, it will be understood that this is merely by way of illustration, and that various changes and modifications may be made therein within the contemplation of my invention and under the scope of the following claims.

I claim:

l. In a studded furnace door of the water-cooled type having a back plate with a reentrant portion defining a recess for the reception of a monolithic lining of refractory material, a stud mounting structure comprising a pair of metal straps respectively spaced from and parallel to said back plate, said straps being coplanar and spaced from each other, there being an unobstructed opening extending transversely of said straps in the space between the straps and said back plate, and a Welded connection at one end of each of said straps to said plate and about which a length of the strap may resiliently flex.

2. In a studded furnace door of the water-cooled type having a back plate with a reentrant portion defning a recess for the reception of a monolithic lining of refractory material, a stud mounting structure comprising a pair of metal straps respectively having a welded connection at one end to said plate and a bodyl portion parallel to and spaced from said plate, there being an integral connecting portion extending between each of said body portions and its said welded connection, said body portions being spaced from each other, the space between said straps and said plate being unobstructed in a direction transversely of Vtheir length to provide a clean out opening, said straps being flexible about their respective welded connections.

3. The invention defined in claim 2 characterized by each of said straps having an inwardly-extending part at its other end provided with a welded connection to said plate.

4. The invention defined in claim 2 characterized by said mounting structure being formed of a single piece of metal plate, there being an integral connecting part extending between said straps at the end thereof having the welded connection to said plate.

5. In a studded furnace door of the water-cooled type having a back plate with a reentrant portion defining a recess for the reception of a monolithic lining of refractory material, a stud mounting structure comprising a pair of metal straps respectively spaced from and parallel to said back plate, said straps being coplanar and spaced from each other to provide a space therebetween, there being an unobstructed opening extending transversely of said straps in the space between the straps and said back plate, a welded connection at one end of each of saidstraps to said plate and about which a length of the strap may resiliently flex, and a stud projecting through said space and having an enlarged end of frusto-conical shape, said enlarged end having an axial length longer than the opening of said straps from said back plate whereby adjacent edges of said straps will engage with and be flexed outwardly by the frusto-conical surface of said enlarged end upon movement of said stud to a position in which it projects through said space.

6. The invention defined in claim 5 characterized by each of said straps having an inwardly-extending part at its other end provided with a welded connection to said back plate, the adjacent edges of said other ends and inwardly-extending parts being cut away to provide clearance through which said enlarged end of said stud may be moved to a position underneath said straps.

7. In a studded furnace door of the water-cooled type having a back plate with a reentrant portion defining a recess for the reception of a monolithic lining of refractory material, a stud mounting structure comprising a metal plate welded along one edge to said back plate, said metal plate having a connecting portion extending outwardly from said plate and said one edge and a body portion projecting from said connecting portion in a direction spaced from but parallel to said back plate, there being an unobstructed opening extending transversely of said metal plate in the space between said metal plate and said back plate, said metal plate having a notch extending from the edge opposite said one edge dividing said body portion into two independently exible metal straps.

8. In a studded furnace door of the water-cooled type having a back plate with a reentrant portion defining a recess for the reception of a monolithic lining of refractory material, a stud mounting structure comprising a metal plate welded along one edge to said back plate, said metal plate having a connecting portion extending outwardly from said plate and said one edge and a body portion projecting from said connecting portion in a direction spaced from but parallel to said back plate, there being an unobstructed opening extending transversely of said metal plate in the space between said metal plate and said back plate, said metal plate having a notch extending from the edge opposite said one edge and dividing said body portion into two independently flexible metal straps, and a stud projecting through said notch and having an enlarged end of frusto-conical shape, said enlarged end having an axial length longer than the spacing of said straps from said back plate whereby adjacent edges of said straps will engage with and be tlexed outwardly by the frusto-conical surface of said enlarged end upon movement of said stud to a position` in which it projects through said notch.

9. The invention defined in claim 8 characterized by each of said straps having an inwardly-extending part at its end remote from said connecting portion, each of said inwardly-extending parts having a welded connection to said back plate, the adjacent edges of said remote ends and inwardly-extending parts being cut away to provide clearance through which said enlarged stud end may be moved to a position underneath said straps.

References Cited in the file of this patent UNITED STATES PATENTS 282,846 Cole Aug. 7, 1883 1,588,566 Wismer June l5, 1926 1,951,115 Wonsowicz Mar. 13, 1934 2,103,106 Yurkowitch Dec. 21, 1937 2,325,945 Fuchs Aug. 3, 1943 2,383,068 McLean, Jr. Aug. 21, 1945 2,395,757 Peters Feb. 26, 1946