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Publication numberUS3160537 A
Publication typeGrant
Publication dateDec 8, 1964
Filing dateOct 12, 1961
Priority dateOct 12, 1961
Publication numberUS 3160537 A, US 3160537A, US-A-3160537, US3160537 A, US3160537A
InventorsJr Thomas R Trafton
Original AssigneeCatalyst Research Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Heating composition
US 3160537 A
Abstract  available in
Images(2)
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Claims  available in
Description  (OCR text may contain errors)

United States Patent 3,160,537 HEATlllG COMPOSITIGN Thomas R. Trafton, Jr., Middle River, Md., assignor to Catalyst Research Corporation, Pittsburgh, Pa, a corporation of Pennsylvania No Drawing. Filed Oct. 12, 1961, Ser. No. 144,552 1 (Jlaim. (Cl. 149-37) This invention relates to autogenous heating compositions for use in heating elements for supplying limited amounts of heat for such diverse purposes as heating canned foodstuffs, heating water, defrosting, sterilization.

Heretofore a variety of autogenous heating devices have been proposed and used for readily portable heat sources in which a combustible chemical mixture is placed within a vented or hermetically sealed container. The combustible compositions in use generally consist of a combustible metal and an inorganic oxidizing agent, many of which react extremely rapidly and generate extremely high temperatures. For many purposes, such as heating water, the heat is generated faster than it can be transferred to the object to be heated, which results in heat waste and the possible failure of the container due to the high temperatures reached. Heretofore, it has been customary to add substantial amounts of inert diluents, such as powdered glass, mica or silica, to the combustible composition which slows and cools the reaction by acting as a heat sink and by lowering the concentration of the active ingredients. The use of an inert diluent, however, requires a larger and heavier charge to provide a given amount of heat. I

It is an object of this invention to provide a heating composition having a modified burning rate. Another object is to provide a heating composition with a modified burning rate which contains a high proportion of active ingredients. Another object is to provide a heating composition compact which is freely releasable from forming dies. Other objects will be apparent from the following description and claims.

According to this invention, a finely divided oxidizable metal, e.g., flaked or powdered, and a finely divided inorganic oxidizing agent, preferably in substantially stoichiometric proportions, are mixed together with a minor proportion of finely divided crystalline lubricant such as graphite and/or molybdenum disulfide and, if desired, a finely dividedinert diluent. The mixture is compressed to form an autogenous combustible consolidated body which is used to provide heat in the same general manner as similar compositions have been used heretofore. The new compositions containing graphite and/or molybdenum disulfide burn at a slower rate than corresponding compositions not containing them. The graphite and/ or molybdenum disulfide also function as a die lubricant, prolonging the life of dies used in the compression of the mixtures and making the consolidated body freely releasable from the dies.

The burning rate of any of the wide variety of heretofore known combustible compositions comprising a finely divided metal and an inorganic oxidizing agent may be modified by the addition of a minor amount of graphite and/ or molybdenum disulfide. Examples of suitable metals are finely divided aluminum, zinc, nickel, antimony, zirconium, iron and their alloys, as well as various intermetallic compounds such as calcium silicide. Examples of the wide variety of suitable oxidizing agents include the pcrmanganates, such as potassium permanganate; the chlorates and perchlorates, such as those of the alkali and alkaline earth metals; inorganic oxide and peroxide, such as barium peroxide, iron oxide, litharge, manganese dioxide, and others; the chromates, such as barium chroma-te; as well as sulfur and other elements that will combine exothermically with metals. When proportioned ice stoichiometrically, or with an excess of the metal, these known compositions liberate no appreciable amount of gaseous products on burning. I have found that the new compositions of this invention do liberate a slight amount of gas on burning, so that'they should be used in vented containers or in hermetically sealed containers "having sufiicient free air space to accommodate the gas generated.

The following comparison of an old autogenous combustible composition with new compositions are illustrative of this invention. Stoichiometric portions of ZOO-mesh powdered aluminum and ferric oxide having an average particle size of about 2 microns were intimately mixed. Portions of the mixture were intimately mixed with 32 5-mesh silica fiour and/or similarly finely divided crystalline lubricants in the amounts set forth in Table I.

.The various mixtures were compacted into pellets under a pressure of 4900 p.s.i. The pellets were ignited on one side and the rate of travel of the burning front was measured. The burning rates for the various compositions are set forth in Table I.

Table I Percent, Component by Weight Component Ex.2 Ex.3 Ex.4 Ex.5

Aluminum Ferric Oxide Hone 9NPN!" coon-:00

Hone N92? 0001000 KIM E N??? OOOr-WO plute Molybdenum Disulfide- Burning Rate (inches/seea rate as one containing sixteen percent inert diluent.

Even slower burning rates may be achieved by using larger amounts of crystalline lubricant or by using both a crystalline lubricant and inert diluent. By proper selection of the type and amount of crystalline lubricant and, if desired, inert diluent, the heating composition can be tailored to provide at a desired rate the amount of heat required for a specific application.

The amount of retardation of burning rate increases with increasing amounts of lubricating additive and any amount desired may be used. Generally I prefer to use between about 0.1 and 5.0% lubricating additive; amounts smaller than 0.1% retard the burning rate only slightly, and the addition of amounts beyond 5.0% do not significantly increase the efiect of the additive.

As in the prior combustible compositions, the burning rate may be adjusted slightly by varying the pressure at which the mixtures are compressed; increasing the compression pressure will decrease the burning rate, although the effect is slight in comparison to the modification of burning rate obtained by using the crystalline lubricant.

Generally mixtures are compressed under about 1000 to 10,000 p.s.i. pressure.

The new compositions are generally enclosed in a'cartridge provided with an igniting primer, in the same manner as similar previous compositions used for heating purposes. The combustible composition mixture may be compressed directly in the containing cartridge or it may be separately compressed and the consolidated body then placed in the cartridge. Ignition may be accomplished 3 by use of an ordinary cartridge primer or a fuse. Ignition of some combustible compositions may require a supplementary starter charge which is easily ignited by primer or fuse; e.g., a stoichiometric mixture of electrolytic iron and manganese dioxide. According tothe provision of the patent statutes, I have explained the principle and method of operation of my invention and have illustrated what I now consider to represent its best embodiment. However, I desire to have it understood that, Within the scope of the appended claim, the inyention may be practiced otherwise than as specifically illustrated and described.

I claim: An autogenous combustible composition consisting 4 essentially of a compacted intimate mixture of the following finely diyide'd ingredients: about 22 to 25% aluminum, about 62 to 73% ferric oxide, 0 to about 15% inert diluent, and about 0.1 to 5.0% combustion retardant selected from the group consisting of graphite, molybdenum disulfide and mixtures thereof.

References Cited in the file of this patent UNITED STATES PATENTS 1,901,313 Mann Mar. 14, 1933 2,424,937 Linzell July 29, 1947 2,716,599 Heiskell Aug. 30, 1955 2,976,136 Heiskell Mar. 21, 1961

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1901313 *Nov 11, 1931Mar 14, 1933Harry Dexter PeckHeat-producing compound
US2424937 *Feb 22, 1943Jul 29, 1947United States Gypsum CoIncendiary composition
US2716599 *Dec 1, 1949Aug 30, 1955Raymond H HeiskeilDark burning igniter composition
US2976136 *Feb 10, 1959Mar 21, 1961Raymond H HeiskellComposition for tracer unit
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3325316 *Mar 29, 1965Jun 13, 1967Macdonald Gilmour CPyrotechnic compositions of metal matrix with oxide dispersed therein
US3344210 *Dec 30, 1965Sep 26, 1967 Method of making. solid thermite pellets
US3374127 *Aug 5, 1966Mar 19, 1968Aquitaine PetroleCompressed metal containing ternary explosive composition
US3503814 *May 3, 1968Mar 31, 1970Us NavyPyrotechnic composition containing nickel and aluminum
US3515072 *May 2, 1968Jun 2, 1970Us ArmyTracer projectile
US3634153 *Feb 3, 1970Jan 11, 1972Us ArmyNoncorrosive pyrotechnic composition
US3664898 *Aug 4, 1969May 23, 1972Us NavyPyrotechnic composition
US3769106 *Sep 17, 1971Oct 30, 1973United Aircraft CorpIgniter composition
US3890168 *Nov 29, 1972Jun 17, 1975Shumway Harold AExothermic welding composition
US3982929 *Feb 9, 1973Sep 28, 1976Esm, Inc.Composition for a fluidizing flux in the production of iron and steel
US4000022 *Oct 17, 1974Dec 28, 1976The United States Of America As Represented By The Secretary Of The NavyFast-burning compositions of fluorinated polymers and metal powders
US4013061 *Mar 26, 1975Mar 22, 1977Thermology, Inc.Ignition system for chemical heaters
US4043314 *Sep 22, 1975Aug 23, 1977Thermology, Inc.Food heaters
US4055881 *Dec 22, 1976Nov 1, 1977Bate Micheal DonaldMethod of rebuilding an ingot mold
US4208226 *May 1, 1978Jun 17, 1980Cundari Sante MEnergy producing waste material composition
US4216041 *Jul 10, 1978Aug 5, 1980Cundari Sante MEnergy producing waste material composition and method of preparation
US4297303 *Jan 14, 1980Oct 27, 1981Deardorff Paul APreparation and reaction of energy producing waste material composition
US4536237 *Jan 20, 1984Aug 20, 1985United States Steel CorporationAluminothermic reduction reaction mixture
US4708913 *Jul 8, 1981Nov 24, 1987Alloy Surfaces Company, Inc.Pyrophoric process and product
US5454363 *Oct 14, 1994Oct 3, 1995Japan As Represented By Director General Of Agency Of Industrial Science And TechnologyHigh-temperature exothermic device
US5490888 *Dec 6, 1993Feb 13, 1996Erico International CorporationMixture of reactants for use in welding
US7650840Feb 6, 2006Jan 26, 2010Dyno Nobel Inc.Delay units and methods of making the same
US8245643Nov 20, 2009Aug 21, 2012Dyno Nobel Inc.Delay units and methods of making the same
US8794152Mar 9, 2011Aug 5, 2014Dyno Nobel Inc.Sealer elements, detonators containing the same, and methods of making
US20060236887 *Feb 6, 2006Oct 26, 2006John ChildsDelay units and methods of making the same
US20100064924 *Nov 20, 2009Mar 18, 2010John ChildsDelay units and methods of making the same
Classifications
U.S. Classification149/37
International ClassificationC22B5/04, C10L5/40, C22B5/06
Cooperative ClassificationY02E50/30, C22B5/04, C22B5/06, C10L5/40
European ClassificationC22B5/06, C22B5/04, C10L5/40