US 2289008 A
Description (OCR text may contain errors)
July 7, 1942.
A. E. GESSLER FOOD cormxmm Original 'F iled Jun: 14, 1939 INVENTOR ALBERT E. GESS LER BY m A NEY Patented July 7, 1942 FOOD CONTAINER Albert E. Genler, Scandale, N. Y., assignor to Intel-chemical Corporation, New York, N. Y., a
corporation of Ohio Original application June 14, 1939, Serial No.
Divided and this application February 20, 1912, Serial No. 431,635
2 Claims. ((71. 126-263) about between chemicals maintained in separate compartments in the container. Specifically, this invention relates to a novel construction for such containers. Many investigators have worked on the problem of producing a practical yet economical foodstuff container which would generate its own heat to a suilicient degree to heat the contents to the desired point, without the necessity for using a fire. Such foodstuff containers would have obvious advantages for use in hunting, camping and picnic trips, and in time of war. High cost, and the considerable increase in weight occasioned by the chemicals required have contributed to the failure of this idea heretofore; but the principal objection to the containers available has been their failure to react rapidly and completely when the reaction is under control at all, so that a great deal of heat is lost during the heating process.
I have discovered that a very rapid and controlled evolution of heat can be obtained in such cans by reacting water with a dry mixture of alkali metal monoxide, particularly sodium monoxide, and aluminum, in granular or powder form, and preferably diluted with an inert carrier; and that relatively small quantities of this reaction mixture will effectively warm up relazigely large quantities of foodstuffin a short The reaction proceeds in two stages. In the first stage, the sodium monoxide is converted to caustic soda almost instantaneously as the water drips on it, this reaction being accompanied by considerable evolution of heat, according to the equation, in gram-molsv 2Na2O+2HaO=4NaOH+l34 kg. calories. As this reaction is substantially instantaneous,
the heat produced not only starts to warm the' Because of the fact that the reaction produces a considerable quantity of gas, I prefer to conduct the reaction in a special can shown in the accompanying drawing; which is a section through the can.
In the drawing, II is a cylindrical can of conventional design, provided with a top II, to which is attached a smaller can body II, separated by a plate into a top compartment II and a bottom compartment IS. The plate is preferably a segment of an inverted cone, as shown in the drawing. A mixture of chemicals I6 is placed in the bottom compartment, and water I! is placed in the top compartment. A cork float or rubber disk l8, covering most of the area of the compartment, is inserted into the water compartment.
In the operation of the device, a hole is punched through the top H of the can, the disk l8 and the plate 20. Water drips onto the chemical mixture l6, and the reaction commences with evolution of gas. The disk I8 covers the .hole punched through the plate 20, and since it is moveable, the gases which emerge throughthe holes lift it while simultaneously passing under and around the disk to reach the corresponding hole in the top plate l2. Because of this baiiling action of the disk,'the pressure in chemicals to be able to raise the food from 0 F.
to F., to provide for thorough warming of the food under even very adverse conditions. For a can holding a quart of food in the outer compartment, I find a mixture of 30 grams N820, 20 gram aluminum powder and 20 grams of a diluent such as pumice, may be placed in the bottom compartment, and 50 grams of water placed in the top compartment. With a plain cylindrical shape such as is most economical to prepare, the inner can should occupy about Y3 of the total volume. With such a mixture of chemicals in such a can, there is a heat evolution of 94.8 kg. calories and an actual rise in temperature obtained of 110 F. This represents an unusually high thermal emciency of 50%, which I attribute to the instantaneous initiation and controlled speed of the reaction.
The diluent used in the chemical mixture may be any inert powder or granular material; I may I use pumice, infusorial earth, fullers earth, or any other inert substance. This inert substance serves a twofold purpose-it reduces the violence of the exothermic reaction, and it serves to absorb errcess water which doe not escape as steam, thus ensuring a dry, non-flowing spent reaction mass.
The aluminum and mono-sodium oxide are preferably powdered or granulated, since they react more easily in this condition. I may, however, use small aggregates of the oxide, and aluminum turnings, or other aluminum of high surface. In such case, the amount of diluent must be varied to insure proper rate of reaction.
The sodium monoxide may be replaced by other alkali-metal monoxides, such as potassium monoxide. The water used should preferably be mixed with alcohol or other freezing point depressant, to insure its flow in cold weather.
While I prefer to employ a'can of the type shown herein, my improved results can be obtained in many'cans of types used heretofore for similar purposes.
This application is a division of my co-pending aaeopoa application seriar'mnnber' 279,002, filed June I claim:
1. A self-heating food container comprising an outer container, a second container within said outer container attached to the top thereof, said second container comprising a bottom compartment containing a dry mixture of chemicals ment containing a dry mixture of chemicals t adapted to develop heat when admixed with a liquid reactant, and a top compartment containing said liquid reactant and a freely movable buoyant bafiie carried on the surface of'the liquid reactant in the upper compartment.
ALBERT E. GESSLER.