US2663920A - Hot top cover - Google Patents

Description

Dec. 29, 1959 B. F. ANTHONY 2,663,920

' HOT TOP COVER Filed Jan. 4, 1951 JNVENToR. M/N/F'I/vr/favy any convenient means and lined with refractory blocks I2 and I3 and a single use bottom ring I4. In some cases a refractory veneer I5 may be applied to the inner surfaces of blocks I2 and I3. The refractory lining material i2, I3 and I5 insulates the side Walls of the hot top, and in order to insulate the upper end of the hot top an insulating cover embodying the present invention is mounted on the housing, being designated generally by the reference numeral I5. y

The cover I'comprises a slab of rigid refractory I'I which may consist of a single block shaped to fit loosely Within the upper end of the hot top, or it may be built up of two or more blocks cemented together. Any refractory material may be employed including concrete, but preferably this slab should be constituted of a refractory material having high insulating qualities. Porous fire brick is the presently preferred'material.

It has been found that fire brick of the grade known in the trade as 2600 F. brick is verysatisfactory for the purpose. Its insulating qualities are much superior to those of ordinary high grade fire brick rated at 2800 F., but it is porous and fragile. Its comparative light weight is advantageous but it is easily damaged by shock and abrasion. Fire brick of still higher insulating qualities are obtainable, but are less desirable for the purposes of this invention.

In order to protect the slab I'I and hold it together in case of any breakage or deterioration, the slab is encased in what may be termed an inverted pan I8 of retiform metal, preferably expanded metal. While this couldenclose the slab completely it is preferred to have the pan encase onlythe upper flat surface and the side walls, as shown in the drawing. A sheet of such material cut to the proper size is bent to provide the downwardly extending side portions I9. The slab I1 is placed within this pan. The free edges of the side portions I9 may be bent inwardly slightly to grip the slab, or other means may be employed to secure the slab` and casing together. At the present time it is preferred to rely exclusively upon a layer of mortar 20 applied to each side of the cover and scraped oii flush with the outer surface of the retiform metal as shown best in Figs. 3 and 4. The mortar which is used for this purpose is a high temperature air setting mortar capable of withstanding the heat to which the cover is exposed in use.. This mortar fills the interstices in the -mesh of the retiform material, adheres firmly to the slab and thus forms a tight bond between the slab .and the casing.

To form a handle for the cover and a means to support it upon the hot top there is provided a strip of sheet metal bent upwardly in its middle section to form the handle 22. This strip extends entirely across the cover and has end portions 23 which extend beyond the cover and are adapted to rest upon the top of the hot top casting II. Intermediate the handle and the ends 23 this strip is tack-Welded to the top I8 of the retiform casing. Although this is a preferred arrangement it is practical to omit the handle strip or its exposed ends 23 and permit the cover to enter the hot top and rest directly on the ingot metal. It is also permissible tobuild the cover large enough to rest upon the hot top housing rather than to extend down into it as herein illustrated. It should be understood also lthat the application of the cover is not limited to coml posite hot tops as herein illustrated but that it may be extended to hot tops built of clay exclusively. 1

The cover of this invention may be used repeatedly. If it suffers any damage due to thermal or mechanical shock it may be repaired between heats, that is any cracks or breaks in the refractory slab may be filled with high temperature cement and if some of the mortar 20 cracks off of the cover it may be renewed. It is good practice furthermore to coat the cover with thin slurry between heats by dipping or spraying or otherwise.

In practice as the ingot molds on a train of buggies are set up with reusable hot tops, a cover is hung in each hot top. This helps to keep the hot top warm and dry until it is ready for use. When the drag is pulled away from the pouring platform the covers ride with the hottops and they are not removed until the hot tops have been stripped from the sinkheads and set on the handling means. The covers when taken out of the hot tops can be piled on a buggy, placed on a conveyor or by any other means moved to where reconditioned hot tops are ready to be set on molds again. If the covers require any attention they can be patched or slurried as are the refractory parts of the hot tops.

In case it is desired to employ bulk exothermic material, such material may be shoveled onto the freshly poured sinkhead and the cover then immediately placed on the hot top. The casing or pan of the cover is of expendable material so that in special cases where the covers are subjected to excessive abuse and are relatively short-lived the loss is not great as compared with covers in which fabricated metal frames subject to warping are employed. Because any warping tendency is absorbed in themesh of the retiform material, stresses that would be developed in the warping of a fabricated structural cover are absent and mechanical damage to the brick or concrete slabs is greatly reduced or entirely eliminated. y

The, retiform material of which theV pan or casing is made may be woven metal or round wire or other cross-sectional form, but the preferred material as previously stated is expanded metal made from sheet metal by `a well-known slitting and stretching procedure. This material is cheap and it yields readily to stresses which may be imposed upon it. Furthermore in its expanded condition the individual elements of the mesh are angularly disposed andconsequently their retention by the mortar especially good.

Having thus described the invention, I claim:

1. A light weight hot top cover comprising a slab -of rigid refractory material encased upon its sides with retiform metal, whereby the refractory material is protected against physical damage and whereby expansion and contraction of the retiform metal due to thermal changes cause no strains in the refractory material.

V2. A light weight hot top cover as defined in claim l, comprising high temperature air setting mortar on the sides of the cover engaging and adhering tothe slab andto the retiform metal.

3. A light weight hot top cover comprising a slab of porous fire brick of high insulating qualities encased upon its sides with retiform metal, whereby the re brick is protected and expansion and contraction of the retiform metal due to thermal changes cause no strains in the refractory material.

4. A light weight hot top cover comprising a slab of insulating fire brick of substantially the grade known atV 2600 F. brick, encased upon its sides with retiform metal, whereby the slab is protected against physical damage and whereby expansion and contraction of the retiform metal due to thermal changes cause no strains in the refractory material.

5. A light Weight hot top cover comprising a slab of rigid refractory material of high insulating qualities combined with an expanded metal casing covering the sides of the slab and secured thereto along the sides thereof.

6. A light Weight hot top cover as defined in claim 5 comprising high temperature air-setting mortar lling the interstices of the expanded metal along the sides of the slab and forming a rm bond between the expanded metal and the sides of the slab.

7. A light Weight hot top cover comprising a slab of rigid refractory material and a retiform metal casing covering the sides of the slab and secured thereto along the sides thereof, and a sheet metal handle Welded to the top oi' said casing and having fiat ends projecting beyond the cover for engagement with the upper surface of a hot top.

BENJAMIN F. ANTHONY.

References Cited in the file of this patent Number Number UNITED STATES PATENTS Name Date Conniff June 11, 1918 Sadwith Nov. 25, 1930 Morlock July 26, 1938 Seaver July 11, 1939 Goldschmidt Oct. 8, 1940 Hensel Jan. 20, 1942 Giles Apr. 27, 1943 Duncan July 20, 1943 Turner Nov. 30, 1943 Charman Feb. 22, 1946 Dausson Apr. 1, 1952 FOREIGN PATENTS Country Date France Nov. 19, 1942

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