US3212749A

US3212749A - Consumable hot top with inserts of exothermic material

Info

Publication number: US3212749A
Application number: US355998A
Authority: US
Inventors: Bate Micheal Donald La
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-03-24
Filing date: 1964-03-24
Publication date: 1965-10-19
Anticipated expiration: 1982-10-19

Description

Oct. 19, 1965- M. D. LA BATE 3,212,749

CONSUMABLE HOT TOP WITH INSERTS OF EXOTHERMIC MATERIAL Filed March 24, 1964 &

IN V EN TOR.

Micheal Dona/d LaBale ATTO ENE).

United States Patent 3,212,749 CONSUMABLE HOT T01 WITH INSERTS 0F EXOTHERMIC MATERIAL Micheal Donald La Bate, Kay St., Wampum, Pa. Filed Mar. 24, 1964, Ser. No. 355,998 9 Claims. (Cl. 249200) This application is a continuation-in-part of my copending application Serial No. 114,162, filed June 1, 1961, now abandoned.

This invention relates to a hot top and more particularly to a totally consumable hot top for application to an ingot mold in which ingots of metal are formed.

The principal object of the invention is the provision of a consumable hot top incorporating inserts of exothermic material for maintaining molten metal poured in the mold and hot top in a molten state to eliminate piping and cracks forming the ingot.

A further object of the invention is the provision of a hot top with inserts of exothermic material capable of creating temperatures in excess of 3100 F.

A still further object of the invention is the provision of a hot top incorporating sections of exothermic material positioned therein so as to create areas of higher temperature than that of the molten metal in the hot top in desirable locations within the hot top to maintain the metal therein in a molten state and permit cooling and setting thereof progressively from the lower portion of the hot top upwardly therein.

Consumable hot tops have been heretofore proposed in the art and thye have been generally ineffective in use in that they would not always hold the molten metal adequately and more particularly in that their use was limited to molten metal within certain restrictive temperature ranges. Such hot tops as well as those formed of nonconsumable material as known in the art did not provide any means of preventing the cooling of the metal in the hot top by adding to the temperature thereof. On the contrary, while they slowed down the cooling ratio as compared with the body area of the ingot it was frequently in such limited relative temperature range as to preclude the maintenance of molten metal within the hot top area as necessary to fill piping and cracks forming in the solidifying ingot. Consumable hot tops to be completely effective must therefore be capable of withstanding temperatures of various molten metals and retaining their position on the ingot mold despite tendencies to float on the metal poured therein and more importantly they must delay the cooling action of the metal whereby piping and cracks otherwise formed in the ingot mold are eliminated and at the same time they must be formed of a material that will become totally consumed and/or disintegrate shortly after the ingot has set. These problems present a complex situation as the means for meeting some of the problems seem to be contrary to the means for accomplishing the others.

The present invention provides a consumable hot top that meets all of these problems successfully.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being the intention to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention.

FIGURE 1 is a perspective view of a consumable hot top formed in accordance with the invention.

FIGURE 2 is a plan view of one portion of the hot top shown in FIGURE 1.

3,212,749 Patented Oct. 19, 1965 FIGURE 3 is a plan view of another portion of the hot top shown in FIGURE 1.

FIGURE 4 is a vertical section through FIGURE 2.

FIGURE 5 is a vertical section through FIGURE 3.

FIGURE 6 is a vertical section through a portion of an ingot mold showing the hot top positioned thereon and an ingot poured therein.

By referring to the drawing and FIGURE 1 in particular, it will be seen that a consumable hot top has been disclosed which comprises a pair of oppositely disposed elongated side sections 10 and 11 and a pair of oppositely disposed

end portions

12 and 13. The side portions 10 and 11 and the

end portions

12 and 13 are duplicates and they are all formed of material which will be totally consumed and/ or disintegrate shortly after the solidifying of an ingot poured therein. The side portions 10 and 11 have

end extensions

14 and 15 formed therein midway between their upper edges 16 and their lower edges 17 and the

end portions

12 and 13 have oppositely disposed pairs of

extensions

18 and 19 thereon adjacent their uppermost and lowermost edges 20 and 21 respectively. The side portions 111 and 11 have rectangular metal clips 22 partially embedded in their lower edges 17 and the

end portions

12 and 13 have rectangular metal clips 23 partially embedded in their lower edges 21. Alternately, notches may be formed in the lower edges 17 and 21 and the

metal clips

22 and 23 positioned within the area of the notches.

The side portions 10 and 11 and the

portions

12 and 13 of the consumable hot top are formed of material which include ingredients that will burn such as sawdust, Wood chips, rice hulls, wheat kernels or the like and ingredients that will disintegrate to a fine powder or granular form, such as sand, granulated slag, powdered dolomite or powdered fired clay. Suitable ingredients from either of these groups are combined in the presence of a binder which may comprise sodium silicate or a resin base binder such as urea-formldehyde. An example of a desirable material mix comprises a batch including 40 lbs. of sawdust, 140 lbs. of raw dolomite and lbs. of sodium silicate. It is apparent that the foregoing mixture consists essentially of about 15% by weight of sawdust, about 54% by weight of dolomite, and about 31% by weight of sodium silicate. This mixture may be altered by substituting an equivalent quantity of wood chips, rice hulls, or wheat kernels for the sawdust or it may be varied by substituting an equivalent quantity of sand, or granulated slag, or ground fired clay for the dolomite. Such combinations may be held together by 50 lbs. of the resin urea formaldehyde rather than the 80 lbs. of sodium silicate. It is apparent that the last-mentioned mixture may consist essentially of about 17% by weight of sawdust, about 61% by weight of dolomite and about 22% by weight of resin urea-formaldehyde. These mixtures tend to dry and set and form a reasonably durable structure capable when assembled into a hot top or directly formed in a hot top shape of holding molten metal during its cooling and setting period and thereafter being consumed and/or disintegrated.

Those skilled in the art will observe that hot tops formed of the materials such as disclosed will not contribute to the temperature of the molten metal by their consumption but will merely act as efiicient hot tops in the usual manner and conveniently dispose of themselves when their utility has ceased. It will occur to those skilled in the art that it is desirable to maintain the molten metal in the hot tops in a molten state over a sufiicient period of time to permit the cooling and setting of the metal in the mold therebeneath thereby avoiding the formation of cracks and piping and other flaws in the cast ingot.

In order to accomplish this, the consumable hot top disclosed herein has

sections

24 and 25 of exothermic material positioned therein in locations where it will most effectively contribute to the maintenance of temperatures capable of maintaining the metal in the hot top in a molten state.

An example of the exothermic material may comprise:

FeO 9.50% Al 23.48% F6 35.39% A1 0 14.46% SiO 2.48% C'uO 1.20% MnO .37% NaCl 4.75% CaO 1.40% Ign. Loss 5.02% MgO 2.06%

By referring to the drawings and FIGURES 2 and 3 in particular, it will be seen that broken line outlines of the

exothermic sections

24 and 25 will be seen and that the section 24 of exothermic material is positioned adjacent the lower edge 17 of the side portions and 11 while the sections 25 exothermicmaterial are positioned relatively closer to the central area of the

end portions

12 and 13 of the hot top. In order that the hot tops shown in FIGURE 1 may be formed and held in assembled relation the side sections 10 and 11 and

end sections

12 and 13 are molded or otherwise formed of the material hereinbefore specified with the

clips

22, 23 positioned therein along with the

sections

24 and 25 of exothermic material. The formed sections are then assembled in oppositely disposed pairs as seen in FIGURE 1 and it will be observed that the sections are provided with longitudinally extending

grooves

26 and 27 respectively in their outer sides and which

grooves

26 and 27 are arranged to register in end to end engagement so that bands of steel strapping 28, 28 may be positioned about the four sides of the hot tops and secured to one another as by

clips

29, 29. It will be seen that the

end extensions

14 and 15 overlie the adjacent ends of the

end sections

12 and 13 and that the

end extensions

18 and 19 overlie the adjacent ends of the side sections 10 and 11 and are positioned above and below the

extensions

14 and 15.

The consumable hot top is thus securely assembled and when positioned in an ingot mold M as seen in FIGURE 6, it will become attached thereto when the molten metal flows through the

clips

22 and 23, and it will hold the molten metal while the inner surfaces of the hot top burn away and expose the

sections

24 and 25 of exothermic material which will then ignite and add temperature to the molten metal to maintain the same in a molten state for a desirable interval. The hot top is so formed and the materials thereof so chosen that its rate of consumption is controlled so that it will retain the metal while it is in molten state and that immediately after the metal has solidified following the successful formation of a perfect ingot the remaining portions of the hot top will be consumed and/or disintegrated including the steel strapping. Metal handles as seen in FIGURES 1, 2 and 4 may be used if desired to facilitate handling the hot top.

It will thus be seen that a hot top meeting the several objects of the invention has been disclosed, and having thus described my invention, what I claim is:

1. A consumable hot top comprising a walled structure having open upper and lower ends wherein said walled structure is formed of solid shaped sections of consum- 4 able and disintegratable material, said material consisting essentially of about 15% by weight of sawdust, about 54% by weight of dolomite and about 31% by weight of sodium silicate, and inserts of exothermic material disposed within said solid shaped sections.

2. A hot top as defined in claim 1 wherein the inserts of exothermic material are located in the lower half of each of said solid shaped sections.

3. A hot top as defined in claim 1 wherein the inserts of exothermic material comprise:

FeO 9.50% Al 23.48% Fe O 35.39% A1 0 14.46% SiO 2.48% CuO 1.20% MnO .37% NaCl 4.75% CaO 1.40% Ign. Loss 5.02% MgO 2.06%

4. A consumable hot top comprising a walled structure having open upper and lower ends wherein said walled structure is formed of solid shaped sections of consumable and disintegratable material, said material consisting essentially of about 17% by weight of sawdust, about 61% by weight of raw dolomite, and about 22% by weight of resin urea-formaldehyde, and inserts of exothermic material disposed within said solid shaped sections.

5. A hot top as defined in claim 4 wherein the inserts of exothermic material are located in the lower half of each of said solid shaped sections.

6. A hot top as defined in claim 4 wherein the inserts of exothermic material comprise:

FeO 9.50% Al 23.48%

F6203 A1203 S10 2.48% C 1.20% MnO 37% NaCl 4.75% CaO 1.40% Ign. Loss 5.02% MgO 2.06%

7. A consumable hot top mixture consisting essentially of about 15 by weight of sawdust, about 54% by weight of dolomite and about 31% by weight of sodium silicate.

8. A consumable hot top mixture consisting essentially of about 15 by weight of sawdust, about 54% by weight of raw dolomite, and up to about 31% by weight of sodium silicate.

9. A consumable hot top mixture consisting essentially of about 17% by weight of sawdust, about 61% by weight of dolomite, and about 22% by weight of resin ureaformaldehyde.

References Cited by the Examiner UNITED STATES PATENTS 1,819,364 8/31 Firth 22147 2,841,843 7/58 Nouveau 22147 3,103,045 8/63 La Bate 22147 FOREIGN PATENTS 799,798 8/58 Great Britain.

J. SPENCER OVERHOLSER, Primary. Examiner.

MARCUS U. LYONS, Examiner.

Claims

7. A CONSUMABLE HOT TOP MIXTURE CONSISTING ESSENTIALLY OF ABOUT 15% BY WEIGHT OF SAWDUST, ABOUT 54% BY WEIGHT OF DOLONITE AND ABOUT 31% BY WEIGHT OF SODIUM SILICATE.