US2220777A - Valveless chemical heater - Google Patents

Description

NOV. 5, 1940. D F OTHMER 2,220,777'

vALvELEss CHEMICAL HEATER Filed Feb. l, 1959 3 Sheets-Sheet l ATTORNEY Nov. s, 1940. D, F OTHMER' 2220,777

VALVELESS CHEMICAL HEATER Filed Feb. 1, 1939 3 S'heets-Sheet 2 ATTORNEY NOV. 5, 1940. D |Q||||V|ER 2,220,777

vALvELEss CHEMICAL HEATER Filed Feb. 1, 1939 5 Sheets-Sheet 3 INVEN-rog waa/d JY' f/n'ner BY waa ATTORNEY 0 zml m f Patented Nov.

UNITED ysfraras f PATENT OFFICE vanvamss chameau HEATER Donald F. Othmer, Coudersport, Pa. Appunti@ February 1, 1939,v serial No. 253,949

i Claims.. (C l. 126-204) This invention generally relates to hermetically sealed chemical'heater units suitable for the same .purposes as the hot water bottles now commonly existent or like devices employing heat, and

5 :herein heat of crystallization .generates the eat.

Heretofore varied forms of chemical heaters have -been suggested particularly those employing supersaturated solutions of sodium acetate 10 where heat was developed yby crystallizing the solution, but all of these heaters have been objectionable because they have had lopeningsA therein; namely, these heaters had apertures through which a seed crystal could be introduced i5 to stm thecrystamzauon, or had valves ausw'- ing the introduction oi' air or of solid crystal to commence the crystallization process. Ifair was introduced through the valve, in certain instances avalvestemwasprovideduponwhichathin 20 layer of the crystalline solution dried into solid crystals which latter, by manipulation, would be later dropped into the solutionto lire the same. All oi the former containers which employed the heat or crystallization of supersatu'rated so- 25lutious,wereopentooneormoreoftheti'ollrm-` ins objections:- (1) '111e leaked s olutions, clogging the valves and making movements bili; required repeated mi `lllid (4) Solidcrystalsitoseedthesoiutions'werenotai- Mconvenimtlyathand. il .,itisanobjectdmyinventinnto eliminateailvalvesopmlmammchclnsoi'" heaters.

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It is a further objects! my-invention toptovide'suchchemicalheaterswithapleormetai interiorlyotthesamesothatthemetalwiil 1 and a:

and so that objects in contact with the heater. or encompassed thereby in whole or in part, will receive a predetermined amount of heat.

It is a further object of my invention to provide such chemical heaters inthe i.'orm of vbody 5 cal heaters in which heat is generated from crysl5 tallizing supersaturated solution, and which is preferably iiredl by a metallic rubbing action occurring' within the container, but which may be red, it desired, through other rubbing A s 4means and possibly certain vibrations. 2Q It is a tlnther object to provide an economical and convenient form or sheet metal hotwater r bottle which is f easible'for quantity production Withtheseandihetobjectsinview'thein- '.ventionconsists in the construction and novel combination and, ent'o! parts; herein` described, illustrated in the Iugeimi-V "panying drawings'in reference to specific em-V Yboriimeuisthfereoi,igimipoiutedout-intheclaims M hereto appended. it being understood that yar!- 1 narmamr bottiV myinvention;

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111g'.4in-averties!orarurtlieu'-V Hon-ot thehot waterbottleshownin Parksmania-eenmaal heatertohtmilkbottlesrrblblel:

containerandhavlngamhlmnh awlm l Itisafactknowntophysicalchemiststhatthe presence of an impurity in a liquid material lowers the temperature at which crystallization occurs. Thus namely, the freezing point of water is lowered by the presence of ordinary salt, or in other words the water is less apt to crystallize, Aor is more .stable In order to obtain the desired stability in the solution, I have found that it is desirable to introduce certain impuritiesin the sodium acetate or other suitable solution, whereas in the past attempts have been made tol utilize highly pure solutions of the respective salts. I have discovered that pure solutions are undesirable because they are less stable .than more impure solutions. For example, if sodium acetate is used as the crystallizing salt, I have found that a small amount o i sodium formate, sodium propionate, sodium butyrate, or anyone or more ofthe sodium salts of the homologous series oi acids to which acetic belongs, is eiective' in stabilizing the salt solution so that it will not crystallize under conditions of cooling below room temperature or of rough handling. Furthermore, I have found that under some conditions of purification the sodium acetate made from the relatively impure acetic acid containing all of the above mentioned sodium salts and. certain other impurities is vdesirable as such a because of the impurities which it naturally contains. A material soformed and used in conjunction with the known art is found to be considerably more stable so as to allow the cooling'of the solution to the freezing. point and considerable rough handling.

Generally speaking the amounts of sodium salts ofacids other thanacetic mentioned should be not more than two or threeper cent of the total n material. Also, small amounts of sodium carbonate or sodium hydroxide may be present in the sodium acetate and these also may likewise increase stability. Also, I have found that sodium acetate prepared from acetic acid obtained in wood distillation is suitable for use in my heaters and the impurities which are naturally prent in thesodimnaetatepreparedinthiswaygreatly increase the stability of the product. Thus, a

lower grade of acetic acid anda cheaper form of sodium acetate may be utilized than hithert Vthere'areknnwntobetracesofcertainotherllia- Aterlalssuchasalcohols,esters,ketones,cresols,

andotherorganicchemicalswhichareprescnt unchangedbythe neutralisationprooess. These.'

traces of organic matterhavebeenfound-to in-I crease the stability of the liquid solution, inmyheaters'` Inthe varlant forms ofmy invuitionsholnin Figs. 'I-l4, Eig'. 'l illustrates a-container'll seuferallysimilartothe containershownin 1|1g.'1,

except that top'and bottom portions Il andpl may besoldered together, as'at 8l. ilishereillusiratedas provided witha vertically tiring trigger 82, having ahook" mdasatilwhichextendsdomiwardtnanopen-.- ing'ilin circularblock Il ofsodium acetate inbottom portlonltthetop' water in thedesired proportions. The block 68 with by being immersed therein.

standard rubber'hot water bottles.

portion Il permanently aiiixed'A thereto: the

heater can then be made ready for use by being boned in minus. water for approximately ten minutes, subsequently cooled, and maybe then is a chemical heater for warming' liquid solutions.

and aording an eilicient heat exchange there-V Fig. 9 illustrates a iiber board, or other convenient form of insulated container 14 having4 a removable chemical heater unit 18 therein, the

similar to that shown in Fig. l except that there is a middle partition 84 dividing. the unit 82 intoy two compartments 86 and 88 respectively, there.

being two individual firing mechanisms provided,

indicated 'as 80 respectively, thereby providing an integral unit. 82 having two compartments which may be nred one after the other, giving heat for a longer time than the Aunit shown in Fig. l.

Fig. 11 is'a fragmentary cross-section of a preierably flexible sided rubber 'bottle 82 having a stopper 94 with a exible portion 98. The stopper 8l may be provided with a metal collar 98 having a partition |88, a -spring- |82, and a metal scraping armv I 8l, all as clearly indicated in the said iigure. It .will be recognized that stopper means 98, providing. metal friction device as indicated, may be adapted to various types of containers, iie'xible w'alledor not as desired.- which may be iilled'with a salt solution and the .iiring stopper means associated therewith; in fact, such "rlng" stopper means could be utilized with Fig. 12 shows an alternate formfor a fully flexible sided container and indicates in cross-sec-k tional view a rubber container |88 of generally rectangular cross-section and provided with two metal inserts-188 and ||8 respectively, so positlonedJll 01113081138 Wallsjhat thetwu may be.

brought together and ulation oftheuser.

Fig. 13 illustrates in vertical on an `integral metal unit |12, of commontin can type,

scraped by proper manipwith lock seamed portions as indicated at lI M. nA'

manen is indicated at ne to provide a seperate liquid comparhnent III, suitable for holding, for

example, liquid soup, as indicated, and a lower compartment .|28 for the chemical heater solutbn |22 and :Bring mechanism lndicatddas |28.

iig. 14 illustrates generally triple compartmented unit suitable-for picnic lunches or the like, having a heater unit indicated generally as |28, a compartment for liquids or other materials to be heated indicated as |28, above heater imit |28, and a storage compartment |38 suitably insulated as still from compartments |28 and |28,

Although r have described a spense form or and theuse of sodium acetate plus certain impuritiesin detail, it isobvious that certain othersalts and may be utilized in either pure or' slightly impure `iorm for the heating uniis. Inessence my invention includes the use in hermeticaliy cled containers of a :m '-1. ted solution of sodium acetate in slightly impure form which is adapted t0 generate aheat o! crystallization, and the startingcf crysvarious modincations ci invention `may he made by those skilledln the ar't vincluding the utilization of other iorms'of. containers, the starting of thefcrystallization or iiring" possibly by vibrations, includins sonic vibrations, and also the placing of various pieces of metal within-a container which contains a supersaturated salt soluboilings and crystallizations of the solution that tion and the starting of the crystallization by merely shaking the container. Also by making chemical heaters with two or more self-contained cells, each with its individual firing means, it is apparent that sustained heats can be obtained from such chemical heaters. Also if desired a three or four legged tripod form of firing/mech@ anism maybe placed within the shell, arranged under slight tension and so that with repeated heater formed of a substantially rigid metal shell having an integral flexible diaphragm and which includes a supersaturated salt solution Within-- the heater which causes the temperature oi the unit to rise when crystaihzed, and means which upon manual manipulation oi the flexible dieH phragm without opening Athe container are adapted to cause e, metal to metal friction within the container, thereby erystailiing said solution.

2. permanently closed and hermetically sealed chemical heater which includes a substam tially metal shell iorrceel of two generally assieme circular portions each having a convex cross-seci tion, a e'xible diaphragm in one of said'portions, a supersatureted salt solution having heat of crystallization within said heater,and metal friction means larrangeci to scrape a wall of the container upon manual manipulation of said diavhrew- 3. A heater as defined in claim 2 which additionally includes a permanently capped and hermetically sealed filling orifice for said heater.

4. A heater as dened in claim 2 wherein said diaphragm is vdepressed below the convex surface of the .portion o! the heater of which'it forms a part, thereby ahordinga degree of protection to the heater against accidental discharge. Y

5. A permanently closed and hermetically sealed chemical heater which includes a substantially rigid metal shell body, a exible diaphragm portion formed integrally in said substantially rigid metal shell body, a supersaturated salt solution having heat of crystallization within said 6. A- structme es dened in claim 5 wherein said dexlble. diaphragm is formed by means of concentric grooves and ridges formed in the rigid. VWalle-:d metal Jody 7. A structure es dedned in claim 5 wherein seid metal friction means comprises s metal mem har movable by seid diapam and extending irem one side of the container to another, said metal lmerano-.r heinz; sss-ld internally to a portion the heater. 1

l ED'AL'D Y @TREK

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