US2020184A - Portable hood - Google Patents

Description

Nov. 5, 1935. A|;; HODSQN ET AL 2,020,184

PORTABLE HOOD Original Filed Jan. 27, 1930 Patented Nov. 5, 1935 PAT-ENT oFFIcls` PORTABLE HOOD Walter D. Hodson, Beverly Hills, Ill., and Ira J. Simmons, Clairton, Pa.

Original application January 27, 1930, Serial No. 423,811. Divided and this application May 5,

1934, Serial No. 724,170

4 Claims.

This invention relates to an apparatus for treating metal castings, and more particularly to an insulating ingot hood of dimensions of the same order as the ingot and of negligible heat 5 capacity. l Y

This application is a division of our co-pending application Serial No. 423,811, filed January 27, 1930, upon which Patent No. 1,957 ,456 issued May 8, 1934-.

In the preparing of metallic ingots or castings, particularly in connection with steel ingots, it has been the practice, after the pouring operation, to remove the molds from the ingots or castings as soon as the metal is cooled sufficiently to become self-supporting, and the ingots are then transported to large soaking pits Where they are maintained until the temperature throughout has been essentially equalzed. These soaking pits were originally unheated, but their capacity was so large thatunless the ingot was extremely hot, and unless the pit was kept practically full 0f fresh ingots at all times the metal became too cold. It therefore became the universal practice to heat the soaking pits.

By proceeding in accordance with the present invention an ingot need never leave its stool, but may be carried Vupon a carv in steady progress from pouring to the rolling mills. During all of this time the base of the ingot is never exposed to the atmosphere, and the ingot is never subjected to the strain of being .lifted by a crane while its interior is in a molten condition. At the same time the period o-f exposure to the atmosphere is reduced to practically nothing. As

`l a result the amount of pipe formed is greatly reduced, and there is an immense improvement with respect to surface cracks, formation of oxide, and other flaws or undesirable characteristics which resulted or occurredV in the former practices.

The invention comprises an insulating ingot hood of dimensions of the same order as the ingot and having negligible heat capacity so that the hood itself does not absorb so much heat that artificial heating is required'. The hood is of a sufficient size, however, that there are dead-air spaces between the ingot and the inner surfaces of the hood.

The invention is illustrated in the drawing wherein is shown apparatus embodying a preferred form of the invention:

Fig. 1 is a vertical section vthrough a car supporting a mold in which an ingot has been poured.

Fig. 2 is a central section taken through the apparatus shown in Fig. 1, the mold havingbeen connection with open hearth steel to pour the metal into ingot molds which are mounted on cars carried past the ladle, the molds being re- 10 movably mounted on a part of the car which is called the stool. As soon as the ingot has cooled suiiciently to be handled the mold is removed and the ingot is picked up and placed in a heated soaking pit where it is equalized. 15

In practicing our improved invention in connection with the production of steel, we preferably make use of the cars which carry the molds past the ladle, but our invention is limited to the use of cars and to the manufacture of steel only 20 to the extent indicated in the appended claims, as the invention may be practiced in connection with other metals.

In Figs. 1 and 2, we have shown cars d provided with suitable wheels and adapted to carry stools 25 3 and molds l past the ladle. The cars l are preferably provided with apertured platforms 4a, the apertures being adapted to receive lugs 3a formed upon the stools 3. The stools 3 are preferably formed from metal and are prefer-,30 ably provided with upwardly extending flanges 3b and 3c, the anges 3c being adapted to hold mold I in place upon the stool. It will be noted that the mold l rests upon' a thermally insulating pad 2 which is preferably formed from re- 35 fractory cementitious material, or the equivalent. This pad prevents rapid cooling of the bottom of the ingot. The flanges 3b are adapted to hold a thermally insulating hood 5 in place upon the stool when the mold l has been removed from 40 the ingot cast within the mold. In the drawing, the ingot is identified by the reference character 9.

The hood 4 preferably comprises an outer shell or housing l which is preferably formed from cast 45 iron, or the equivalent for the purposeand is preferably provided with lugs 5a to facilitate the handling thereof. A lining 6 of refractory cementitious material, or the equivalent, is preferably provided within the housing l and is pref- 50 erably held in place within the housing by inwardly extending flanges la provided in the base of the housing. As best shown in Figs. 2, 3 and 4, the outer surface of the lining 6 is preferably corrugated to provide a plurality of dead-air spaces 55 6a, between the lining and the housing. The hood is preferably of such dimensions that a deadair space 8 is provided around the sides and top of the ingot 9 when the hood is placed upon the stool in a manner illustrated in Fig. 2.

In practicing the improved method, we preferably mount a plurality of molds I on a like number of cars 4, in the manner illustrated in Fig. l, and the cars are moved past the ladle, each load receiving the usual charge of fused metal to form an ingot of the desired dimensions. When the ingots have become self-sustaining, we remove the molds I therefrom and place the hoods 5 on the stools 3 in the manner indicated in Fig. 2 so that the ingots are thermally insulated by the dead-air spaces 8 as well as by the walis of the hoods 5. Therefore, the sensible heat of the ingots is largely retained Within the hoods 5 and the temperatures thereof are equalized by making use of this heat. We find that as soon as the hoods are placed over the ingots contraction of the surfaces ceases for a relatively long' period of time as the inner or central parts of the ingots are relatively hot as compared with the outer surfaces thereof and the placing of the hoods overY the ingots retards the loss of heat from the surfaces of the ingots to such an extent that they will heat to higher temperatures by heat conducted from the interiors of the ingots. This method of equalizing the temperature of the ingots is exceedingly advantageous when compared with the usual practice of equalizing the temperature thereof in v heated soaking pits. Thus, when the ingots are to be reheated and the temperature thereof equalized in a soaking pit they-are subjected to the atmosphere before and after they have been placed in the pits. This results in the formation of oxide in relatively large quantities as compared to that which forms upon and in ingots which have their temperatures equalized in accordance with our improved method, it being readily understood that when our improved method is practiced the ingots are exposed to the atmosphere for an exceedingly short time and the amount of air with which they come in contact is afterwards limited to that in the dead-air spaces 8.

When the temperatures of ingots are equalized by the soaking pit method, they contract a relatively large amount before they are placed in the pit, and therefore a relatively large amount of gas is occluded by them. Then when the ingots expand in the heated pit they absorb much gas which results in oxidation within the ingots and also results in innumerable small gas filled pockets or holes. These conditions do not obtain when the temperatures of the ingots are equalized by retaining the sensible heat thereof during the temperature equalizing process so' that it is unnecessary to reheat them.

Another advantage of our improved method is that comparatively few surface cracks form in the ingots, and these cracks do not penetrate to any great depth. Obviously, such cracks are not as numerous and deep in a finished bar formed from an ingot subjected to our improved method as there are in a bar formed from an ingot normalized by the soaking pit method. Still another and exceedingly important advantage of our improved method is that relatively little pipe forms in ingots produced by practicing our method as the ingots need not be cooled to a temperature which permits handling thereof as is the practice in the heating soaking pit method. The savings effected 5 through the reduction of pipe when our method is practiced are considerable as our method in itself does not necessitate employing other expediente to reduce the formation of pipe.

Our method is preferably practiced so that the 10 ingots are rolled when they have been cooled to the proper rolling temperature. This practice also effects savings inv that it is unnecessary to place the ingots in asoaking pit to reheat them. If the ingots are not to be rolled promptly the hoods are preferably left in place upon the stools until the temperature of the ingots is low enough so that they can be exposed freely to the atmosphere without causing the formation of any appreciable amount of oxide.

We have found that when our method is practiced, it results in a relatively better rolling steel due to the thoroughness with which the temperature thereof is equalized. We have also noted that there is a reduction in the usual loss due to burned steel.

While we have shown and described certain embodiments of our invention, it is to be understood that it is capable of many modifications. Changes, therefore, in therconstruction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims, in which it is our intention to claim all novelty inherent in our invention as broadly as possible, in view of the prior art.

What we regard as new, and desire to secure by Letters Patent, is: Y

1. In combination with a buggy having a slot in the top thereof, a stool adapted to hold an ingot V mold, a lug on the lower surface of said stool adapted to interlock with the slot in said buggy,

a thermally insulating hood adapted to be placed on said stool while an ingot cools thereon, said hood having the same dimensions as the ingot, having negligible heat capacity and of such proportions as to provide a dead air space at the top and around the sides of the ingot.

2. In combination with a stool adapted to hold an ingot mold, a. thermally insulating ingot hood of dimensions of the same order as the ingot, of negligible heat capacity, and of proportions to provide a dead air space at the top and around the sides of the ingot, means on the stool for preventing lateral displacement of said hood relative to said stool, and an insulating pad of refractory material on the stool adapted to serve as a base for said ingot.

3. The combination as set forth in claim 2, in which a dead air space is also provided within the walls of said insulating hood.

4. The combination as set forth in claim 2, in which said stool is provided with separate means for preventing lateral displacement of an ingot mold.

WALTER D. HODSON. IRA J. SIMMONS.

Images