US2427547A - Furnace door frame - Google Patents

Description

Sept. 16, 1947.

w. c. BLJLMER FUENACE DOOR FRAME Filed Nov. 24, 1945 2 Sheets-Sheet 1 INVENTOR William C. ulmer Sept. 16, 1947. w, c, BULMER 2,427,547

FURNACE DOOR FRAME Filed Nov. 24, 1945 2 Sheets-Sheet 2 17 I 22 17b II 14 I I I l I I D I i 5 H u; q E /8 0 532-) I INVENTOR Patented Sept. I6, 1947 FURNACE DOOR FRAlVIE William C. Bulmer, Aspinwall, Pa., assignor to Reliance Steel Products Company, McKeesport, Pa., a corporation of Pennsylvania Application November 24, 1943, Serial No. 511,551

2 Claims.

My invention relates to door frames for industrial furnaces, particularly metallurgical furnaces, such as the open hearth furnaces of the steel industry, and consists in certain new and useful improvements in fluid-cooled frames for protecting the structure of the doorways of the furnaces from the destructive effects of furnace heat.

The primary, but not the sole, object of the invention is to provide a door frame in which maximum protection against heat is obtained in those regions of the frame exposed to highest furnace temperatures, all with economy in frame construction, and ready adaptability of the frame to the variou characteristics of furnace design and conditions of operation encountered in industry.

The invention will be understood upon reference to the accompanying drawings, in which, by way of example:

Figure 1 is a fragmentary view in elevation of the front wall of an open hearth furnace, showing a doorway of the furnace equipped with a frame embodying the invention;

Figure 2 is a view of the frame alone, as seen in plan from above, with a portion of the frame wall broken away to reveal a detail of internal construction;

Figure 3 is a View of the frame in vertical section, the plane of section extending transversely of the furnace front wall and medially of the doorway therein, with adjacent parts of the furnace indicated fragmentarily, and with a furnace door shown in closed position on the frame; and

Figures 4 and 5 are fragmentary sectional views, each shown on a plane corresponding to the plane of Figure 3. In these views certain modifications in structure are illustrated.

The invention will be described as it is applied to an archless doorway of an open hearth furnace. Referring to Figures 1 and 2 of the drawings, the doorway 3 comprises a rectangular opening that extends between two spaced jamb walls or piers 4 of refractory masonry, and is bounded above by the lower edge of the skew channel 5 and skew blocks 6 that support the arched furnace roof 1 along its front edge, and bounded below by the fore-wall 8. The front wall of the furnace below the doorway is protected by means of the conventional breast plate 9 upon whose upper edge is borne the usual metal fore-plate or sill ID. The door frame, indicated generally b the reference character F, is as usual designed to perform a two-fold service. It provides a seat for the door D, Figure 3, that closes the furnace doorway, and, being internally cooled by circulating cooling fluid, typically water, the frame protects the furnace structure surrounding the doorway from the destructive effects of the heat generated and maintained within the furnace. Herein the furnace door D is shown simply as a metal shell H lined with refractory [2, but it will be understood that a more elaborate door structure, probably a Water-cooled door, may be used in conjunction with the frame F of the invention.

In accordance with known practice the frame is of hollow construction, ordinarily formed of steehand preferably of sheet or plate steel, cut andshaped into appropriately patterned sections and united in fluid-tight welded seams. The door frame includes a vertical lintel portion l3, from the opposite ends of which jamb portions I4 extend downward, and a horizontal lintel portion [5 extends laterally from the vertical lintel portion. The vertical lintel portion I3 is positioned against the outer face of the furnace structure at the top of the doorway; the jamb portions l4 overlie the outer faces of the brick jamb walls 4 at the two sides of the doorway; and the horizontal lintel portion I5 extends inward immediatel beneath the skewback channel and skew blocks at the top of the doorway. Cooling water is circulated within the hollow bod of the door frame, and as thus organized the frame provides an armor and reinforcement around the doorway, and not only protects the doorway structure from rapid deterioration under furnace heat, but forms a guideway and seat for the vertically movable furnace door D. It will be noted that at the two sides of the frame are formed vertical rib portions I6, l6. These rib portions extend vertically along the outer edges of the jamb and vertical lintel portions of the door frame, and the surface of the frame portions between the ribs provide a seat upon which the door D may be raised and lowered between open and closed positions, the rib portions serving as guides to prevent the door from becoming laterally displaced from its seating or sliding surface. It will be further noted that the surface upon which the door seats is slightly inclined downward and outward from the upper edge of the lintel portion I3, whereby the effect of gravity upon the door structure at the top of the doorway 3. This being so, it is the horizontal lintel portion l of the door frame that is subject to greatest destructive influence, and must dissipate greatest quantities of heat. In adapting the door frame to these conditions, the outer peripheral edge of the horizontal lintel portion is constructed as a duct ll, which is of U-shape in plan, as may be seen in Figure 2. This duct extends in the line of flow in which cooling water is introduced to the hollow body of the frame, and thus a stream of cooling water, at the low temperature at which the water is supplied, is caused to flow in a confined stream along the peripheral edge of thelintel portion I5, and maximum heat dissipation is obtained. The stream of cooling water is introduced from an external supply line (not shown) connected to an inlet [8, and from such inlet a conduit I9 communicates with the duct I! at its left-hand end, as the frame appears in Figure 1. From the duct I! an outlet opens into the interior of the frame, and a discharge passage 29 opens from the frame at the top of the vertical lintel portion l3 and is connected to a suitable drain line, not shown. A circulating body of cooling water is thus maintained within the hollow frame. Advantageously, the outlet from the duct ll comprises two conduits 2| and 22 that extend from the end of the duct, opposite to that into which the inlet conduit l9 opens, downward into the jamb portions I lv of the hollow frame, whereby the water emerging from the primary course of flow within the duct I1: i delivered in divided stream to the bottoms of the hollow jamb portions. The water rises through such jamb portions into the vertical and horizontal lintel portions l3 and I5, whence the overflow escapes by way of discharge passage 2!].

It is important to note that not only is the entire inner surface of the duct ll, which forms the outer edge of the horizontal lintel portion, subject to the cooling effect of the primary or inflowing stream of cooling water, but a substantial part llaof the outer surface of the duct is in immediate contact with the body of circulating cooling water within the frame. Only the portion [lb of the outer surface of the duct is exposed to the most direct heat of the furnace. Thus, maximum protection and durability of structure are obtained in the region where it ismost needed.

The duct I! is formed by the provision of a partition with in the sheetrnetal body of thelintel portion I 5, the reference numeral Ila being immediately applied to this partition, The partition is formed ofsheet steel, and parallels the peripheral edge of the lintel portion I5; as may be seen in Figure 2. The partition iswelded to. the top and bottom walls of the lintel portion, and the ends of the duct I! thus: formed are closed by means of sheet metal disks 23 welded in place, as illustrated.

At the lower ends ofthe two jamb portions M of the frame cleanout openings are; provided, and these openings are normally closed by means ofremovable screw-plugs 24.

Whereas in the structure described, both the top and bottom walls of the laterally extending lintel portion extend horizontally, I'show in Figure 4 that the lower wall I5a may be inclined to facilitate the circulation of Water from. the wall Ila of the tube H, and prevent the accumulation of sediment or scale on the inner surface; of such wall.

Figure 5 serves to illustrate that the duct which 4 forms the outer edge of the horizontal lintel portion [50 may comprise a preformed steel tube I'lc of circular cross section, the tube being bent at its ends and shaped in plan to the form of the duct 11 shown in Figure 2. The upper and lower walls of the horizontal lintel portion are at their outer edges welded to the body of the tube He, and the portion of the. wall of the tube between the welds, the portion which is exposed to the cooling water circulated within the hollow lintel portion, forms the counterpart of the partition 11a of the structure shown in Figure 3. The ends of the tube are closed in the same man- 'ner as the ends of the duct I! are closed, and

suitable openings are provided in the wall of the tube for the ingress and egress of cooling water through the conduits l9, 2| and 22 within the hollow door frame.

These and other modifications and variations are permissible within the terms and spirit of the invention defined in the appended claims.

In conclusion it may be noted that the lintel structure of this invention may be readil designed to meet the requirements and specifications of various furnace builders and operators. Some builders and operators prefer that the lintel portion [5 shall extend inward beneath the skewback channel and the skew blocks for substantially the entire thickness of the furnace wall, whileothers require that the extent of such lintel portion shall be less. In any event the various specifications can be met with minimum departure from a standard of door frame construction.

I claim as my invention:

1. In a furnace door frame comprising a lintel having hollow vertical and horizontal portions of expansive areas, a hollow jamb portion extending downward from each end of said lintel, the hollow ;interiors of said lintel portions and jamb portions standing in open communication within the door frame structure and being adapted to contain a relatively large volume of circulating cooling water, and an inlet and an outlet for such circulating cooling water; the invention herein described comprising a partition member spaced from and extending'substantially parallel to the outer peripheral edge of said horizontal lintel portion to. provide a tube for confining a stream of cooling water of relatively small volume along said peripheral edge, said inlet opening into said tube at one end to supply said stream, and a passageway opening at the other end of said tube for delivering the stream into the relatively large volume of water in said hollow frame structure, said partition member being on one side exposed along the peripheral extent of said horizontal lintel. portion to the cooling effect of said stream and on the opposite side to the cooling effect of said relativelylarge volume of cooling water in the hollow frame structure.

2. In a furnace door frame comprising a lintel having hollow vertical and horizontal portions of expansive areas, a hollow jamb portion extending downward from each end of said lintel, the hollow interiors of said lintel portions and lamb portions standing in open communication Within th door frame structure and being adapted to contain a relatively large volume of circulating cooling water, and an inlet and an outlet for such circulating cooling water; the invention herein described comprising a partition member spaced from and extending substantially parallel to the outer peripheral edgeof said horizontal lintel portion to provide a tube for confining said pe- 5 6 ripheral edge, said inlet opening into said tube REFERENCES CITED at one end to Supply 5am stream two dlscharge The following references are of record in the conduits extending from the opposite end of said tube downward into said hollow J'amb Portions file of thls patent severally for delivering the water of said stream 5 TED STATES PATENTS thereinto, said partition member being on one Number Name Date side exposed along the peripheral extent of said 1,864,762 Robinson June 28, 1932 horizontal lintel portion to the cooling efiect of 2246402 lvmDonnel1 June 17 1941 said stream and on the opposite side to the 0001- 2,246 403 McDonnell June 1941 g effect of said relatively large Volume of cool- 10 1,9153% Baden June 1933 mg Water n e hollo frame structure. 2 074 57 Chandler Mar- 23) 1937 WILLIAM BULMER- 2,107,185 McAfoos Feb. 1, 1938

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