US2414996A - Charge support for the base of cover-type furnaces - Google Patents

Description

Jan. 28, 1947. H. H. ARMSTRONG CHARGE SUPPORT FOR THE BASEOF COVER-TYPE FURNACES 4 Filed Feb. V1, 1945 2 Sheets-Sheet l Patented Jan. 28, 1947 CHARGE SUPPORT FOR THE BASE 0F COVER-TYPE FURNACES Harry H. Armstrong, Lakewood, Ohio, assignor to Lee Wilson Engineering Company, Inc., Cleveland, Ohio, a corporation of Ohio Application February 1, 1945, Serial No. 575,680

This invention relates tometallurgical furnaces and, in particular, to furnaces of the cover type which are noW widely used for the annealing of steel strip or sheets.

In the processing of steel strip, there is a great advantage to be obtained by making coils of the largest size which can be handled conveniently. In the annealing of coils, furthermore, the higher the coils are piled, the smaller the floor space required for processing a given tonnage. According to present proposals, coils may be made as large as 72" in diameter and piled for annealing to a height of over l2. With smaller coils and lower pile heights, it has been found that the use of a charge support resting on the rebrick laid on the base which is fabricated from structural shapes and sheathing plate, causes rapid deterioration of the brick. In addition, the brick absorbs a great amount of heat which is lost when the charge is cooled.

I have invented a novel charge support partioularly adapted for coils of the maximum size and the extreme piling height indicated above, which overcomes the objections to theprevious construction and permits the brick layercovering the metal parts of the base to serve for a much longer period than has been possible heretofore. In a preferred embodiment, a charge sup-portaccording to my invention comprises a table-like member o-r platform carried on a plurality of supporting posts and having rolling engagement therewith. lThe posts are pivoted to the metal plate of the base and are thus free to move as may be necessary to accommodate expansion and contraction of the platform with changes in ternf perature. Certain of the posts have spaced pivot bearings and restrict bodily movement of the platform as a whole. By'this construction, the charge is carried on metal supports instead of on the brick layer covering the base.

For a complete understanding of the invention, reference is made to the accompanying drawings illustrating a preferred embodiment which is fully described and explained herebelow. In the drawings, I

Figure 1 is a partial transverse section'through a cover-type furnace, the base of which incorporates a charge support according to my invention;

Figure 2 is a partial plan view;

Figures 3 through 5 are sectional views taken along the planes of correspondingly numbered lines of Figure 1; and

Figure 6 is, a partial sectional view taken along the plane of line VI-VI of Figure 1.

is claims. (c1. 263-10) A Referring in detail to the drawings, .a covertype furnace Il) includes a base Il and a cover I2. The base comprises a frame composed of structural members I3 and sheathing plate I4. The cover I2 is indicated somewhat diagrammatically. Itis of conventional construction comprising a lining of refractory brick laid up within a binding composed of structural members and sheathing plates. When the cover is lowered over the base, it rests on supports I5.

A charge-supporting platform or table I6 may conveniently comprise a. circular casting having a centr-al opening IEa therethrough. The casting has a top ISb, concentric Walls IBc and ltd and radial ribs 16e extending therebetween. The platform is supported on a plurality of posts I1 and I8. Both the platform and the posts are preferably composed of a suitable heat-resistant alloy. The posts have rounded heads I9 which fit into concentric grooves 20 formed in flanges 20c extending laterally from the walls I6c and Id. v

The posts Il' and I8 are pivoted tothe base II. A pivot bearing 2| for each of the posts I'I A is secured to the plate I4. Each of the posts I3 which are located 90 apart 'around the circumference of the platform, has two spaced pivot bearings 22 secured to the plate I4 as shown in Figure 6. The posts I8 are bifurcated at their lower ends for cooperation with the bearings 22.

By reason of the pivotal mounting of the posts on the base, they arefree to swing through the small angles necessary to accommodate radial eX- pansion and contraction of theplatform `IE5 on heating and cooling. During such movement, of course, the platform rolls on the rounded heads I9 of the posts. The spaced pivot bearings for the posts I8 restrict bodilymovement of the platform without limiting its freedom for radial expansion and contr-action.

Bolts 23 secure the platform to lateral lugs Illa formed on the posts I3 to prevent the plate form from being lifted off of the posts by a crane magnet. Y

A layer of insulating brick 24 is laid on the plate I4 to protect it from the heat of the interior of the furnace. In laying the brick forming the layer 24, spaces 25'are left `about each of the posts I1 and I8 and these spaces are filled with granular` thermal insulation which permits the slight angular movement of the posts necessary to accommodate the expansion of the platform. A surface layer 26 of thermalinsulation is laid on top of the layer 24.

. Furnace bases may be designed to accommocycle.

a reasonable value.

date one or more charge supports according to my invention. It is usually more efcient to design a base for a number of piles of coils, say 6 or 8, if the tonnage of strip to be processed is suiiicient to fill the furnace on each annealing It will be evident that charge supports according to my invention may be used in various forms of cover-type furnaces, regardless of the source of heat, i. e., electric resistors, radiant tubes or open llames. I provide the usual inner cover 2 for protecting the charge from the air when the heating cover l2 is removed. I also provide a fan 28 mounted on a shaft 2S projecting upwardly through a tube 3l! Xed in the base, for circulating the atmosphere Within the inner cover through and around the coils forming the charge.

It will be apparent from the foregoing description that the load imposed on the charge-supporting platform I6 by the weight of the coils disposed thereon, one of which is indicated at -3|, is transmitted directly to the structural framework of the base by the-postsr il' and i8. While this load is great, the use of a large number of posts, `as illustrated, distributes it over a substantial area and prevents the load on each of thepivot bearings 2l and 22 from exceeding Since the lweight of the charge is not carried on the brickwork, the latter is not subject to rapid deterioration and thus has a much longer life than in the construction previously employed, As a matter of fact, the insulating layer 2li is preferably composed of light insulating brick instead of rebrick since no mechanical load is applied thereto. The charge support, furthermore, is free to expand and contract since the posts have rolling engagement therewith and are pivoted to the base. This prevents the development of any stresses resulting from expansion or contraction. At the same time, the charge support is held against excessive bodily movement by the dual bearings for each of the four posts ilocated at the 9 points. Because of the relatively small section of the posts, the heat lost therethrough is small. The surface layer 26 laid on the layer of insulating brick 24 may be of such` material as to prevent the absorption by the latter of a substantial amount of heat.

Although I have illustrated land described but a preferred embodiment of the invention, it will be recognized that changes in the details of construction thereof may be made Without departing from the spirit of the invention or the scope of the appended claims.

I claim:

l. A charge support for a furnace base comprising a platform adapted to receive the charge, a plurality of posts pivoted to the base supporting said platform, and means for limiting horizontal shifting of the platform,

2. The apparatus defined by claim 1 characterized by said posts having rounded heads providing bearing surfaces for engagement by the platform.

3. A charge support for afurnace base comprising a table-like member, a plurality of posts pivoted to said base, said member resting on 4 the upper ends of said posts, and means limiting bodily movement of said member.

4. The apparatus defined by claim 3 characterized by said posts being arranged in concentric circles beneath said member.

5. A charge support for a furnace base comprising a table-like member, a plurality of posts below said member having rolling engagement therewith, and pivot bearings on said base for said posts, certain of said posts spaced circumferentially of said member each having a pair of spaced pivot bearings preventing tilting thereof except on the axis through the bearings.

`6. The apparatus defined by claim 5 characterized by the axes on which said bearings pivot being tangent to an inscribed circle coaxial With said member.

7. A charge support for a furnace base comprising a table-like member, recesses in the under side of said member, a plurality of posts having bearing heads seated in said recesses, and pivot bearings on the base forsaid posts, certain of said posts spaced circumferentially of said member having a pair of spaced pivot bearings.

8. A charge support for a furnace base comprising a generally circular platform, a plurality of supporting posts spaced circumferentialiy beneath the platform, and pivot bearings on the base for said posts, some of said posts having a pair of spaced pivot bearings on the base.

9. A charge support for a furnace base comprising a generally circular platform, a plurality of rockable studs supporting said platform, and means for restricting bodily movement of the platform in a horizontal plane.

10. The apparatus defined by claim 9 characterized by said studs having their lower ends pivoted to the base.

11. A charge support for a furnace base comprising a platform adapted to receive the charge, and a plurality of posts extending upwardly from the base for supporting said platform, certain of said posts having single pivot bearings on the base and others having two spaced pivot bearings on the base.

12. In a base for a cover-type furnace, a platform above the base adapted to receive a charge of material, a plurality of pairs of bearings on said base spaced about a common axis therethrough, rocker posts extending` upwardly therefrom, said platform resting on said posts, each pair of bearings being disposed on aline substantially tangent to a circle drawn about said axis as a center whereby the posts afford stable support for the platform while permitting free radial expansion and contraction thereof.

13. In a base for a cover-type furnace, a platform above the base adapted to receive a charge of material,v a plurality of pairs of bearings on said base spaced about a common axis therethrough, rocker posts extending upwardly therefrom, Vsaid platform resting on said posts, said pairs of bearings being disposed on lines at an angle to each other whereby the posts afford stable support for the platform While permitting free radial expansion and contraction thereof.

HARRY H. ARMSTRONG.

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