US2004243A - Method of and means for operating breathing apparatus - Google Patents

Description

June 1l, 1935. `A. HLOCH 2,004,243

METHOD OF AND MEANS FOR OPERATING BREATHING APPARATUS Filed Jan. 11, 1929 2 Sheets-Sheet 1 1 //////b/ V/// M m m HN////w// 0%0 ////n////// Q A k 1 2 June 11, 1935. A. HLOCH 2,004,243

METHOD OF AN-D MEANS FOR- OPERATING BREATHING APPARATUS Filed Jan. l1, 1929 2 Sheets-Sheet 2 Patented June 11, 1935 l vIJNITEI) STATES PATENT OFFICE METHOD oF AND MEANS Fon OPERATING BREATHING APPARATUS Application January 11, 1929, Serial No. 331,815 In Germany January 17, 1928 11 Claims.

My invention relates to methods of generating oxygen in accordance with requirements, more particularly for breathing and inhaling purposes.

The principal object of the invention is to produce oxygen from chemicals in a constant flow during a given period as is in particular necessary in breathing and inhaling apparatus.

It has already been proposed to produce oxygen in a more or less constant flow from chemicals evolving oxygenunder the influence of water supplied in the form of drops. The function of such apparatus is of course not independent of the position of the apparatus, hor is the production of oxygen in fact constant. In another type of apparatus the moisture contained in the exhaled air is used for decomposing the chemicals. In this case the dvelopment of oxygen is dependent on the breathing intensityinsuch manner that a period of slow breathing will be followed by a period of slow development of oxygen, when possibly a much higher breathing activity will have taken place, so that the production will be insuiicient. By this reason apparatus of this type have been provided with an auxiliary water supply.

It has also been known to produce oxygen from a body composed of solid chemicals evolving oxygen in the absence of water under the iniiuence of heat. This method, however, necessitated storage of the oxygen, as the chemical body was consumed almost at once, and this storage necessarily had to take place under a certain pressure. 'Ihe evolution of oxygen therefore was not a constant one, but often more or less explosive.

Now according to the invention the chemical mass is so composed and shaped that the evolution of oxygen takes place, after initiation,vin a reaction which proceeds continuously and uniformly through the whole chemical mass in such a way that during the whole period of use the oxygen is evolved in constant quantity per'unit time in accordance with the requirements of the apparatus. Therefore no storage is necessary andv no pressure is produced. Moreover, when employing they method in breathing apparatus, the functioningis just as independent of breathing as in the old method of supplying oxygen from high pressure steel bottles, but without needing -able amount of heat if required as, for instance,

Aupon heating.

if a loss of heat by radiation or convection is to be avoided or balanced. On the other hand I add, if required, a suitable catalyst for the purpose of reducing the decomposing temperature of the chemical substances and thereby decreasing the drop of temperature outwards, but just as well I may add any suitable catalysts for speeding the development of oxygen, since in both cases the object is to maintain an uninterrupted decomposing process.

Apparently the heat evolved by the decomposition and the heat required for maintaining the progressive decomposing process, must balance whence in case of low temperatures of the outer air a wrapping or covering of insulating material, such as an asbestos cylinder, an air jacket or the like, may be employed for ensuring a constant heat balance.

The accompanying drawings show for purpose of exemplication, several embodiments of the invention. j

In the drawingsz- Fig. 1 is a view in vertical axial section of a cylindrical chemical body accommodated in a sheath or casing constitutinga receptacle for the evolved oxygen; l

Fig. 2 is a view in top plan thereof;

Fig'. 3 is a view in vertical axial section of a modied chemical body;

Fig. 4 is a view in top plan thereof;

Fig. 5 is a lateral elevational view of a portable mine breathing apparatus with closed respiration circuit, the lateral protective sheet or cover being removed; and

Fig. 6 is a frontal elevation thereof, partly in section and with a protective cover removed.

Parts which are repeated in the several gures bear the same reference characters in each case.

' Referring to Figs. 1 and 2 the chemical body I is of cylindrical shape and both the peripheral surface and the end surfaces thereof are coated with a heat-protective covering 2 made of asbestos. As regards the substances whereof the`chemical body is composed, they comprise one, two or several chemical compounds such as perborates, perchlorates, chlorates, permanganates, bichromates, plumbates and peroxides of the alkali and alkali-earth metals, capable of evolving oxygen lIn manufacturing a chemical body of the stated kind I` subject the said chemical compounds, in moist condition to a high pressure in a suitable mold so that the compressed material when released of pressure and dried will possess a suiiicient cohesion orvphysical consistence to withstand impact and friction incidental to manipulation. For the purpose of increasing the physical consistence thereof, however, I sometimes add and mix with the chemical compounds a suitable substance which does not and cannot deliver any injurious gases when heated by the heat produced by the oxygen evolving process during theoperation of the apparatus. Preferably I use for this purpose asbestos bres which, due to the high heat capacity and the low heat conductivity thereof, at the same time contribute to ensure a slow but steady progress of the reaction or decomposing process. If a catalyzer is employed, the asbestos bre may be impregnated with the same. In order to obtain the oxygen in moist condition for inhaling purposes, I may add to the substances forming the chemical body certain admixtures such as hydroxide of calcium, containing chemically bound water which will be set free by the reaction.

Moreover this setting free of water is an endothermic process absorbing a part of the heat produced by the 4exothermic oxygen evolving reaction, thereby controlling the progress of the reaction in such a mannerthat a constant iiow of oxygen is secured.

In Fig. 1y the chemical body consists of a main portion la and an additional portion Ib composed to bring about aquicker initial decomposition combined with or resulting in a rapid production of heat and a correspondingly rapid storing up of the necessary amount of heatl indispensably required for an uninterrupted continuation of the decomposing process. The amount of the thus stored heat depends upon the volume or size of the additional portion Ib and the particular com-` position thereof, and these two factors in turn on the cross-sectional area of the chemical body and the calculated or presumed eiciency thereof in a unit of time.

The components of the chemical body are mixed with su'icient water and compressed in steel mol'ds under a high pressure, to form rods of preferably circular section. By the decomposition sufficient heat will be developed to ensure and maintain the temperature required for the gradual decomposition of the oxygen evolving substances up to final consumption thereof.

The portion Ib will after initiation develop a larger oxygen stream during a few, for instance 2 to 3 minutes, in order to have the apparatus including the breathing bag rapidly lled up with oxygen, before the slow development, in accordance with the need for respiration, takes place.

It will be seen in Fig. 1 that the top end of the portion Ib is recessed at 3 and that the bottom of the recess 3 is bored or otherwise excavated for the accommodation of an initiating primer 4 duly protected from accidental ignition during transportation or manipulation of the apparatus. In some cases I also add to the chemical compounds constituting the body I, oxidable substances lsuch as powdered aluminum and the like, or cellulose for the purpose of both reducing the compactness of the composition and thereby rendering the same more readily inflammable. The primer 4 is provided with a pin 5 having a head 6 projecting into the recess lil and consisting of a combustible or ignitable material such as used for making the head of a match, or the like.

The chemical body I is encased in a cylindrical sheath or receptacle 8 with a cylindrical partition of wire gauze 'I inserted in the annular. space between the inner wall of the receptacle'and the body I. The Wire gauze may` consist of iron,

aluminum or any other metal or alloy which under the action of oxygen will form a superficial oxydic layer acting to protect the metal from further oxidation or corrosion, while the receptacle 8 may be made of brass or preferably of aluminum in order to reduce the weight thereof. The lid 9 of the receptacle is hinged to the latter by means of a link I0 and adapted to bev locked in closed position by means of bolts II passing through peripheral bores of the lid and engaging in correspondingthreaded holes provided in an annular ange Ia of the receptacle 8, an annular downwardly projecting rib or ridge 9a of the 'lid engaging with a gasket I2 disposed on the top" edge of the receptacle and consisting preferably fectly tight seal will be attained. A similar annular ridge 9b of a shorter diameter is provided on the inner surface of the lid and adapted to engage with the top surface of the chemical body when the lid is closed, in order to secure the former in position and to thereby prevent the primer from being accidentally ignited during the manipulation of the apparatus.

The centre of the lid is shaped to form an outwardly projecting boss 9c axially bored and threaded for the reception of the threaded portion I3a of a screw I3 provided at its outer end With a small hand wheel I4, While the inner end of the screw is fitted or integral with a disk I5.

'Resiliently connected with the disk I5, preferably by means of a coiled spring I6, is a friction-disk I'I which truly projects into the recess 3 of the chemical body normally a certain distance apart from the ignition head 5' of the primer pin. The

lower surface of the depending disk I'I is serrated or knurled, so that when the screw I3 is screwed down by means of the handle I4 the knurled surface of the disk I'I will be caused to move into gripping coaction with the head 6 for the igniting purpose, the power of the spring I6 being such thatthe friction-disk I'I first, that is immediately upon engagement with the head 6, will remain motionless due to friction, until the spring I6 is suiiiciently stressed by the continued rotation of the hand wheel I4 to overcome the fric, tional engagement, when the thus retarded disk I1 will suddenly fly forward under the action of the overstrained spring and cause the head 6 and the primer to be ignited.

The irrespirable gases evolved by the combustion of the head 6 are allowed to escape into the open air through bores 9e provided for the purpose inthe lid 9, whereupon the screw or spindle I3 is to be turned in opposite direction so far that or until a gasket I8 attached to the upper surface of the disk I5, engages with a cooperating circular ridge or rib 9d integral with the lid 9, so that the evolved oxygen will be prevented' from escaping through the openings 9e or lthe thread of the screw I3. rIn breathing apparatus for use in mines the lid 9 may be provided withv a cap 'I3 of wire-gauze for-the purpose of enclosing the openings 9e so as to prevent the danger of explosion.

The ignition of the head 6 causes the primer 4 to ignite and be consumed and evolve intensive heat so as to ignite the substance or portion Ib of the chemical body I wherein the ignition still advances at a comparatively quick rate so that the oxygen evolved thereby will be in excess of the calculated normal production, for the purpose of scavenging the apparatus and fill the same with oxygen, but the excessive production of oxygen ceases when the substance or portion Ib v is a central tubular extension 24a with a lateral is completely consumed and the substance or portion la of the chemical body commences to evolve oxygen at a normal rate as required and calculated for a serviceable operation of the apparatus.

Theoxygen continuously delivered by the substance or portion la passes through the wire gauze 1 and escapes from the receptacle 8 through an outlet or duct I9 provided near or adjacent to the bottom thereof and connected with a iiltering vessel 20. Fitted in the Vessel 20 are two perforated plates or disks 2l and 22, for instance of wire gauze or perforated sheet metal, spaced apart to constitute a compartment for the provision of a filtering layer 23 of any suitable brous material, such as felt, adapted to separate out and retain from the oxygen gas solid particles such as coarse dust. Fixed to the inner side of the closing cap 24 of the vessel 20 is a cylindrical frame or basket 2E which' projects into the vessel so as to occupy the space above the upper disk 22 and which is enclosed in or covered with a closed iiltering screen 26, such as cellulose paper or a ceramic material of line porosity for the retention of the finer dust particles which have not been intercepted by the coarse screen 23. The layer 23 may be impregnated with scents, medical drugs or chemical substances for the removal of chemical impurities from the oxygen gas flowing through the filtering chamber, but obviously a separate filtering device may be provided in the apparatus' for such purposes.

The fibrous material 23 may be dispensed with if the perforations in the plates. 2l, 22 are suilclently narrow to retain the coarse impurities. Of course it will\then be advisable to provide the plate 22 with narrower perforations than the plate 2l and further ltering plates of steppeddown width of perforations may be arranged therebetween.

The oxygen developed from the portion Ib of the chemical body carries with it a considerable quantity of ne smoke which would rapidly clog the iine filtering screen. But at the same time the oxygen is charged with a considerable quantity of moisture, consequently under the influence of the low temperature of the perforated plate or wire gauze 2l a lm of water is deposited on the latter and this iilm will retain even very fine impurities, so that the ne screen will at iirst only have the object to retain those of the iinest impurities which will not have been retained `by the coarse screen. The oxygen developing from the portion la of the chemical body does not carry with 'it smoke in considerable quantities, so that the retaining action of the coarse screen on line impurities is no more necessary. At the same time this oxygen is less charged with moisture, and as meanwhile the iilter has been progressively heated the dust layer deposited on the'coarse screen will dry and crumble away, so that an automatic' cleaning of the filter will take place.

Rigidly connected or integral with the cap 24 branch 24h for the attachment of a pressure gauge 15, while the free end of the tube 24a is provided with means for detachable connection with a pipe 21 adapted to be connected with a rescue apparatus, inhaling apparatus, a mine breathing apparatus and the like, a retarding disk 14 with a. narrow central hole 14a, being inserted into the lower end of the pipe 21 to serve, in connection with the pressure'gauge 15,

pressure commences to drop. I'f the apparatus is supplied with a plurality of oxygen evolving. devices or chemical bodies disposed and adapted to be ignited in succession, the wearer will thus be able and prepared to ascertain the proper` time for igniting the next chemical body or for returning to safety if a further chemical body is not available in the apparatus. Obviously the gauge may also be adjusted for indicating the amount of gas which has flown through the system prior to the moment of indication. Instead of the gauge or alternatively in combination therewith any suitable acoustic or other alarm device of known construction and adjusted to be operated by drop of pressure may be employed with advantage in many cases. In a similar manner also the second or next following chemical body may be automatically ignitedrby suitable means to be provided and adjusted to start ignition upon a certain predetermined drop of pressure. s,

The apparatus illustrated in Figs. 5 and 6 belongs to that class of breathing devices which supplies an oxygen atmosphere to the wearer so that he can enter with safety a mine or any other room containing irrespirable gases. The oxygen evolving receptacle 8, the iiltering ves.- sel 2@ and a caustic potash cartridge 6I forl the ,absorption of. exhaled carbonio acid are accommodated in a box 59, and a second box 60 encloses a respiration bag 62 made of a iiexible air-tight material such. as rubber or rubbercloth. The receptacle 8 communicates with the ,filtering vessel 2U through a pipe $3 and a pipo @d is provided to interconnect the vessel 20 and the casing of a non-return valve 65 disposed intermediate between the caustic potash cartridge 6I and the exhaling tube t6 of the mask 61, While the inhaling tube 68 is equipped at its lower end with a non-return valve 69 adjacent to the head 1i) to which the respiration bag G2 is attached and which is connected with the caustic potash cartridge by means of a pipe 1I, a safety valve 12 being provided in the lateral connecting nipple of the head 1t.

YThe construction and operation of this mine breathing apparatus is known in general regards but for the oxygen evolving chemicalbody or cartridge and thefiltering means associated therewith in substitution for the usual steel bottle lwith condensedoxygen. Due to the respiration of the wearer the inhaled and exhaled air or oxygen is constrained to circulate, owing to the cooperation of the two non-return valves E5 and 69, from the mask 61 through the several parts 6G, 65, 6|, 1l, 10, 69, 68 back to the mask 61 and so on, while the bag 62 serves the balancing purpose. The reaction or evolution of oxygen in the receptacle 8 is to be initiated with the aid of the small hand-wheel I4 when subsequently a certain calculated quantity of oxygen per unit of time will be continuously supplied by the vreceptacle 8 or the chemical body therein and caused to ow through the parts 63, 20 and 64 into the circuit at such a point thereof that no oxygen can enter the inhaling branch 68 of the circuit Without having travelled before through thecaustic potash cartridge.

The oxygen evolving material forming the chemical body may be given -an admixture of substances which will evolve, during the decomposition of the chemical, carbonio acid, or any other sanative gas such as chlorine, which will be useful in rescue cases on account of its faculty \of irritating the respiratory centre. As regards the generation of carbonic acid in the apparatus, those carbonates or bicarbonates of the alkali metals, alkali-earth metals or heavy metals may be used for the purpose which when heated to a temperature of 800 C. or less, will partially or totally deliver the carbonio acid contained therein, but even certain organic substances may be added which under the existing conditions will combine with the nascent oxygen to form carbonio acid.

If an apparatus is intended to be used continuously for as comparatively long period of time as, for instance, a mine breathing apparatus, and a single chemical' body only is provided for the purpose, I may use a double or twin-body with an insulating partition between the tWo components, as shown in Figs. 3 and 4, so that the reaction setting in at one end of the one component will proceed to rst consume this one component and then go o ver to the other component and consume the same in reverse direction. The twin-body l shown in Figs. 3 and 4 consists of a cylindrical structure or rod formed by compressing the oxygen evolving material la in a suitable mold, and provided with a diametrical longitudinal slit 19 which extends from the top to nearly the bottom end face for the reception of an insulating partition 80, pref.- erably a compressed asbestos sheet.

The portion l'b of the chemical body composed to evolve an excess of heat for the ignition of the underlying portion of material la, is provided at the top end of the one component only and recessed at |03 as hereinbefore described with reference to Fig. 1. The primer 4 with the ignition pin 5 and head 6 is similar to that .shown in Fig. 1. The adjacent top end of the other component is reduced to a diametrical plane somewhat below the bottom surface of the recess |03 and protected from premature ignition by the covering 2. When the chemical body shown in Fig. 3 is ignited'by means of the inflammable head 6, as hereinbefore described, the oxygen evolving reaction or decomposition will slowly proceed and gradually consume the one component in downward direction and then catch the other component and consume the same slowly and gradually in upward direction. Obviously the chemical body or cartridge may be composed of more than two components in juxtaposition with insulating' partitions therebetween and with their contiguous extremities alternately connected.

Having thus fully described this invention what is claimed as new and desired to secure b Letters Patent is: l

1. A method of generating oxygen for breathing or inhaling purposes consisting in" starting by initial heating the decomposition of a solid chemical mixture capable of giving'oil oxygen in an exothermic reaction and then progressing under the inuence yof the reaction heat, said mixture containing an alkaline hydroxide absorbing a part of the heat produced by said exothermic reaction by giving off water and by evaporationl of said water.

' 2. A method of generating oxygen for breathing or inhaling purposes consisting in starting by rinitial heating the decomposition of a solid chemical mixture capable of giving off oxygen in an exothermic reaction progressing under the influence of the reaction heat, said mixture containing an alkaline earth hydroxide absorbing a part of the heat produced by said exothermic reaction by giving oi water and by evaporation of said water.

3. A solid chemical mixture capable of giving off oxygen especially for breathing or inhaling purposes in an exothermic reaction which after initiation by application of heat progresses under the influence of the reaction heat, said mixture being combined with an alkaline hydroxide as heat absorbing substance.

4. A solid chemical mixture capable of giving oif oxygen especially for breathing or inhaling purposes'in an exothermic reaction which after initiation by application of heat progresses under the influence of the reaction heat, said mixture being'combined with an earth alkaline hydroxide as a heat absorbing substance.

5. A solid chemical mixture capable of giving off oxygen especially for breathing or inhaling purposes in an exothermic reaction which after initiation by application of heat progresses un-` der the influence of the reaction heat, said mixture being combined with calcium hydroxide as a heat absorbingl substance.

6. A solid chemical mixture containing a substance selected from the group consisting of the inorganic chlorates and perchlorates capable of giving off oxygen especially for breathing or inhaling purposes in an exothermic reaction which after initiation by application of heat progresses under the inuence of the reaction heat, said mixture containing brous asbestos.

7. The solid chemical mixture claimed in claim 6, said asbestos being impregnated with a catalyst.

8. A composition of matter for producing a pure oxygen, said oxygen being particularly adapted for respiratory purposes, comprising a shaped compressed solid body containing a substance selected from the group consisting of the inorganic chlorates and perchlorates and admixed therewith asbestos fibre.

9. The composition as claimed in claim 8, with an oxidizable material to react with part of the oxygen formed and thereby provide suiicient heat to promote the decomposition of the substance selected from the said group.

10. A composition of matter for producing pure oxygen, said oxygen being particularly adapted for respiratory purposes, comprising a shaped compressed solid body containing at least one chemical which will split off oxygen when heated and admixed and with an alkaline hydroxide in an amount suiicient to absorb at least a part of the heat of reaction.

11. The composition as claimed in claim 10, in which the alkaline hydroxide is an alkaline earth metal hydroxide.

ALBERT HLOCH.

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