||||||IIII US005611329A United States Patent (19 11 Patent Number: 5,611,329 Lamensdorf (45) Date of Patent: Mar 18, 1997 (54) FLAMELESS HEATER AND METHOD OF which are thermally bonded together to form a number of MAKING SAME pockets. Each pocket is filled with a powder mixture of Mg-Fe alloy, NaCl, antifoaming agents, and an inert filler. (75) Inventor: Marc Lamensdorf, Mt. Sinai, N.Y. The outer surfaces of the polyester sheets are preferably 73) Assignee: Truetech, Inc., Riverhead, N.Y. treated with a food grade surfactant. The polyester sheets are gas and water permeable over substantially their entire (21) Appl. No.: 511,561 surfaces and the filled pockets define intervening channels where the polyester sheets are bonded. The resulting heater (2222 FiledFiled: Aug.ug. 4,4 1995 can be made approximately 50% thinner and 50% lighter (51) Int. Cl. ..................................... F24J 1/00 than a conventional FRH. In use, both the channels and the (52) U.S. Cl. ..................... ... 126/263.07; 126/263.05 permeability of the sheets allow water to wet the powder 58) Field of Search ......................... 126/263.01, 263.05, rapidly and initiate the chemical reactions quickly. The 126/263.07 byproducts of the chemical reactions cause the pockets to inflate slightly thereby adding sufficient rigidity to the heater 56 References Cited to support a food packet. The byproducts of the chemical U.S. PATENT DOCUMENTS reactions exit the pockets through the permeable sheets and 2,533,958 2/1950 Root et al. ......................... as are directed away from the reaction via the channels. This 2,823,665 2/1958 Steinbach ..... - 126/263.05 rapid removal of the byproducts of the reaction enhances the 2,935,983 5/1960 Reik ............. - 126/263.05 efficiency of the reactions which allows a smaller, lighter 3,550,578 12/1970 Fearon ..... a - - 1261263.05 heater to produce the same heat as a larger, heavier heater. 4,106,477 8/1978 Feld ................................... 126/263.05 By avoiding sintering processes, the heater can be easily and Primary Examiner-Carroll B. Dority economically mass produced. Attorney, Agent, or Firm-Galgano & Burke (57) ABSTRACT A flameless heater includes two non-woven polyester sheets 20 Claims, 6 Drawing Sheets 42 NS NScast? NSreest ISEst ZZZZZZaat 2777-777-77-7777.277 U.S. Patent Mar 18, 1997 Sheet 1 of 6 5,611,329 U.S. Patent Mar 18, 1997 Sheet 2 of 6 5,611,329 U.S. Patent Mar 18, 1997 Sheet 3 of 6 5,611,329 0:2|| 0|| 00|| 06 08 0/ 07 uomodisel09?In?BJadual (Jo)ºslaOG U.S. Patent Mar 18, 1997 Sheet 4 of 6 5,611,329 U.S. Patent Mar 18, 1997 Sheet 5 of 6 5,611,329 2 U.S. Patent Mar 18, 1997 Sheet 6 of 6 5,611,329 ?99||2998/8|126€| eLÈL&#7 ----|-----------|---———————————--?============= 5,611,329 1. 2 FLAMELESS HEATER AND METHOD OF of water needed to activate it. It is also important to note that MAKING SAME virtually millions of FRH units are currently packed and shipped by contractors and the military every month. There BACKGROUND OF THE INVENTION fore, even minor reductions in the overall weight and volume of an FRH can effect a substantial reduction in 1. Field of the Invention shipping weight and volume and thereby reduce shipping The invention relates to a flameless heater utilizing an costs as well as storage space and costs. cxothermic chemical reaction to produce heat and a method U.S. Pat. No. 5,117,809 to Scaringe et al., the complete of making the heater. More particularly, the invention relates disclosure of which is hereby incorporated by reference to a flameless heater particularly suited for heating military 10 herein, discloses an improved FRH and method of making field rations as well as humanitarian and recreational rations it which avoids the need for sintering by containing the loose and which meets or exceeds the current U.S. military ingredients within the confines of a cover, at least one face performance specification, MIL-R-44398B. of which is rigid, or within a die-cut rigid skeleton. In lieu 2. State of the Art of the paperboard cover, the heater pad cover is made of a The U.S. Military has provided individual field rations in 15 molded rigid polymeric bottom layer and a porous non a form known as "Meal-Ready-to-Eat' (“MRE”). An MRE woven polypropylene top layer. The rigid bottom member is a food product contained within a hermetically sealed provides the rigidity equivalent to 190's sintering and the pouch. The MRE is heated in the field with a device porous top layer allows water to wet the powder and initiate militarily referred to as a "Flameless Ration Heater” the reaction. Alternative embodiments use a cardboard bot ("FRH'). The FRH contains as its active ingredient a 20 tom layer or porous bottom layer with a rigid middle layer. supercorroding alloy comprised of magnesium 5 atomic % Not every military field operation requires the use of iron. This supercorroding alloy is blended together with MREs and the flameless reaction heater. As mentioned ultrahigh molecular weight (“UHMW") polyethylene pow above, these rations are individually packaged and designed der, fillers, and electrolyte, the powder mixture being placed for use in situations where more conventional heaters cannot in a mold and the mixture heated to sinter it. After cooling, 25 be used. Moreover, it is often the case that group meals are the mixture forms a strong flexible pad with sufficient prepared in the field by one or two soldiers to feed anywhere porosity to allow water to penetrate and wet the alloy. In from 20 to 200 soldiers. Group meals are more efficient than order to provide the pad with sufficient strength for handling, individual meals because only a few soldiers need to be it has been found that the pad should contain about 50% distracted from other duties for the preparation of the meal. UHMW polyethylene powder. The pad is packaged within a 30 Recently, it has been proposed that the concepts of the MRE paperboard cover having holes die cut through each side and be applied to group meals. The proposed "Self-Heating then is hermetically sealed within a high density polyethyl Group Meal' ("SHGM") is described in U.S. Pat. No. ene bag of sufficient size to hold the heater and a filled MRE 5,355,869, the complete disclosure of which is hereby pouch. To use the heater, the top of the bag is opened and incorporated by reference herein. The SHGM described in water added until the water level reaches preprinted fill lines 35 the 869 patent utilizes a number of heating trays which are on the bag. The water passes through the holes in the pad provided with stand-offs on their bottom surfaces and a cover and by wicking through the paperboard, wets the pad corresponding number of FRH packages which are sup and initiates an exothermic chemical reaction. The reaction ported in the trays by the stand-offs. Food pouches contain takes the general form of: Mg+2HO->Mg(OH)2+H+heat ing 6.6 pounds of food are placed directly on top of the FRH (and steam). packages and water is delivered into the space, created by A typical sintered pad is approximately 3.5"x4.5"x0.125" the stand-offs, between the trays and the FRH packages. The and weighs approximately 21 grams. When the pad is placed trays are typically 13"x10'x1.5" deep and use slightly within the paperboard cover, the overall thickness increases modified versions of the FRH packages (12.75"x9.75"x to approximately 0.170". The paperboard cover adds 45 0.156") described in the above-cited 190 and '809 patents. approximately 9 grams to the overall weight of the heater, bringing the total weight of the heater to approximately 30 SUMMARY OF THE INVENTION grams. When activated with 45-65 milliliters of water, the It is therefore an object of the invention to provide a heater generates enough heat to raise the temperature of an flameless heater which weighs less than conventional FRH 8 ounce food package 100°F. above its starting temperature 50 units. within 12 minutes. This performance is required by Military It is also an object of the invention to provide an FRH Specification MIL-R-44398B (Sep. 20, 1993). The compo which meets or exceeds the performance requirements of nents of the state-of-the-art FRH and the sintering method Military Specification MIL-R-44398B. for forming a flexible structure of those ingredients are It is another object of the invention to provide an flame described generally in U.S. Pat. Nos. 4,522, 190 to Kuhn et 55 less heater which may be manufactured without sintering the al. and 4,264,362 to Sergev et al., the complete disclosures component powders. of which are hereby incorporated by reference herein. It is still another object of the invention to provide an FRH It is recognized that the weight of the FRHis an important which requires less water to activate than conventional FRH consideration. It is always desirable to reduce the total units. amount of weight and volume which must be carried by a 60 soldier or camper in the field, or by support elements. It is also an object of the invention to provide an FRH Another important consideration is the amount of water which occupies less volume than conventional FRH units. needed to activate the heater. Water is often scarce in the It is another object of the invention to provide an flame field and every ounce of water in a soldier's canteen is less heater which does not require a rigid container.