US693871A - Generation of power from compressed air. - Google Patents

Description

No; 693,871; Patented Feb. 25, I902.

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.GENEQBATIUIII OF POWER Fnom COMPRESSED AIR.

(Application filsd Doc. 12, 189B.) (No Model.)

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FRANK M. LEAVITT, OF BROOKLYN,-NEW YORK, ASSIGNOR TO E. WV. BLISS COMPANY, OF BROOKLYN, NEV YORK, A CORPORATION OF WEST VIR- GINIA.

GENERATION OF POWER FROM COMPRESSED AIR.

SPECIFICATION formingpart of Letters Patent No. 693,871, dated February 25, 1902. Application filed December 12, 1898. Serial No. 699,006, (No model.)

To all whom it may concern:

Be it known that I, FRANK M. LEAVITT, a citizen of the United States, residing in the borough of Brooklyn, county of Kings, city and State of New York, have invented certain new and useful Improvements in the Generation of Power from Compressed Air, of which the following is a specification.

My invention provides an improvement on to the means heretofore in use for storing and generating power from compressed air for the propulsion of automobile torpedoes. Heretofore it has been customary to store the air under a high degree of compression in a res- !5 ervoir, whence on the launching of the torpedo the compressed air was led to the engine and there expanded to drive the engine and propel the torpedo. According to my invention I increase the power which could be developed from a given quantity of air at a given pressure under the former system and also overcome the fall of temperature, which formerly occurred upon expansion of the compressed air. These results I obtain by heating the air, preferably by the combustion of a liquid hydrocarbon in the compressed-air reservoir, before conducting it to the engine. 7

In the practice of my invention I prefer- 0 ably store a suitable quantity of combustible material, such as alcohol or some similar liquid hydrocarbon, in a chamber communicating with the reservoir, and I compress air in the reservoir and retain such compressed air 3 5 therein for as long a time as is desired-that is, until the torpedo is to be used. In the use of the torpedo and substantially simultaneously with the opening of the valve which admits compressed air to the motor I cffeet the ignition of the combustible material within the reservoir or within a chamber communicating therewith and cause the combustible material to burn therein in such manner that the air compressed in the reser- 5 voir serves to supply the oxygen for maintaining such combustion, and in such manner also that the combustion itself effects an increase of pressure in the reservoir both by heating and expanding the air confined therein and also by adding to such air the gaseous products resulting from the combustion. By this means not only is the pressure greatly increased at the time of utilization of the power, but the air which is undergoing an expansion in the motor instead of undergo- 5 ing a serious fall of temperature, as heretofore, so that all the \vorkingparts are rendered extremely cold, is so heated that the fall of temperature accompanying its expansion leaves it still hot or at least warm enough to avoid such objectionable chilling of the parts. I eflcct the combustion of such material in a gradual and progressive manner, by preference commencing the combustion preferably coincidently with the fall in pressure due to the first admission of air to the motor and continuing the combustion'at a rate proportionate to the fall of pressure, so that any sudden or extreme increase of pressure of the already highly-compressed air in the flask or reservoir at the commencement of the operation is avoided, and the rapid or excessive fall of pressure which ordinarily occurs in utilizing compressed air as a source of power is also avoided, since the added pressure due to the combustion is progressively applied to in great part neutralize the falling pressure of the compressed air.

Having thus indicated the nature of my invention, Iwill now proceed to explain the pre ferred mode of applying the same with reference to the accompanying drawings, where- 1n Figure l is an elevation, on a small scale, showing the exterior of the apparatus. Fig. 2 is a vertical longitudinal mid-section of the compressed-air flask or reservoir and its ap purtenances on a larger scale. Fig. 3 is an enlarged fragmentary section showing in detail the igniting means. 0

The torpedo used being of any well-known compressed-air-driven type, such as the Whitehead automobile torpedo, is not illustrated, except as to the parts which are requisite in illustrating the operation of my in- 5 vention.

In Fig. 1, A is the compressed-air reservoir or flask. B is the engine or motor to be driven therefrom and which drives the propeller of the torpedo. Ois the chamber for containing I00 the combustible material, and CL is the pipe conveying compressed air from the reservoir to the motor.

Fig. 2 shows the interior of the reservoir A. In this the preferred construction an innor receptacle or vessel D is placed therein, having an open top, but being partly covered over or inclosed by a hood E. A pipe 5 connects the bottom of the receptacle 0 with the bottom of the chamberD, passing through the wall of the reservoir at some suitable point. The chamber 0 has a removable cap or fillingplug 0 at top. A tube (Z communicates from the receptacle D through the end of the flask A, and its outer end is fitted with a cap 6, through which an electric wire may be led. The pipe a, by which the compressed air is conducted out of the reservoir A to the motor 13, leads from the interior of the hood E, as shown. This pipe is provided with the usual throttle-valve a. An electric igniting-fuse F (shown detached in Fig. 3) is introduced through the tube (Z by removing its cap e, the fuse F being pushed down through the tube into the receptacle D, as shown in Fig. 2. As a means of ellecting electric connection through the cap 6 and at the same time withstanding the heavy pressure within the reservoir I may adopt the construction shown in Fig. 3, wherein the cap 6 is a plug having a conical portion ground to a seat with the end of the tube (1 and pressed tightlyagainst such seat by a screw-coupling f. A metal pin g, preferably conical, passes through a hole in the cap or plug e, being surrounded bya conical insulating-sleeve h, the cone being so arranged that the internal pressure tends to tighten it. Two insulated electric wires 2' and j are soldered, respectively, to the inner end of said pin and to the metal plug e or other metal surface, and these wires ex tend thence in through the tube (1, their opposite ends being joined by an incandescing bridge or loop 7c of fine platinum wire. The fuse F may be variously constructed according to any known meansfor constructing electric fuses for blasting; but I prefer the incandescing loop 70, and I prefer to embed this loop in loose gunpowder or in fulminate or other easily-ignitible material at Z, and preferably I lead the wires through fine holes in a block m of gunpowder, preferably molded smokeless powder. I prefer also to arrange adjacent to this another block or mass it of highly-combustible inaterial as, for example, soluble cotton formed into a cake with paraffin. EX- terior, to the reservoir the electric circuit is completed by means of a wire i, joined to the opposite end of the pin g, interrupted by any suitable sort of circuit-closer or switch p and leading to one pole of a battery or other electric generator G, from the other pole of which a wire q may lead to any metal part of the apparatus by which communication may be established with the other wire j, already referred to. The circuit thus made is com plctc except at the circuit-breaker 19.

The mechanical construction being now understood, I will proceed to describe the preferred mode of operation.

Assuming the flask A to be open or air within it to be at atmospheric pressure, the cap 0 of the chamber 0 is removed, and a measured quantity of alcohol (or other suitable liquid hydrocarbon) is poured into this chamber so as to fill it preferably to the level shown in Fig. 2, so that no portion of the alcohol will run out through the tube 1) into the receptacle D. The tube 7), as shown in Fig. 2, is carried up to a height equal to the level 00 0c of the liquid, whatever be the height of location of the chamber 0. The chamber 0 should be proportioned to leave a suitable airspace above this level. After introducing this liquid the cap 0 is tightly closed. The fuse F is then or may previously have been introduced through the tube at and its cap or plug 6 tightly screwed down by the union f. Air is then pumped in either through the pipe at or through a separate admission-cock 0' until the desired pressure is obtainedas, for example, fifteen hundred pounds per square inchwhereupon the admission-cock is closed, and the air thus introduced is left stored in the reservoir until the torpedo is launched. During this introduction of air as ,fast as its pressure exceeds that in the chamber C it will flow through the tube 1) and bubble up through the hydrocarbon in said chamber, so that the air in the upper part of this chamber is compressed to the same pres sure as that in the reservoir A. When it is desired to generate the power thus stored, the throttle-valve a is opened to admit the compressed air to flow to the niotorB, and either just before or at any suitable time subsequent to this the circuit-closerp may be actuated, (by anysuitable means,) whereby the circuit from the battery G is closed through the fuse F, thereby sendinga current of suiflcient energy to incandesce the loop and ignite the powder or fulminate Z, this in turn igniting the gunpowder m and the combustible plug it. As soon as the air begins to escape from the reservoir A its diminution of pressure below that of the air compressed in the chamber 0 results in an expansion of the latter, and the consequent forcing over of a portion of the alcohol through the tube b in the chamber D. The operations are so timed that the ignition of the fuse F willnot occur or at least the combustion resulting therefrom will not cease until after this flow of alcohol into the receptacle D has commenced, so that the alcohol thus entering this chamber will be ignited as it enters and will burn, its combustion being supported by the oxygen of the compressed air, so that it burns rapidly and fiercely, and its heat being given up to the compressed air the latter is increased. in temperature and in pressure. The hot gases and flames resulting from this combustion mingle with the stream of air which is flowing out from the tube a, the direction. of the ICO IIO

fiow being indicated by the arrows in Fig. 2. Thus the heat of the combustion is concentrated within the receptacle D and hood E and within the tube C6. ,The annular space between the receptacle D and hood E is made amply wide to permit a flow of air so slow as to avoid blowing out the flame of the burning alcohol. The alcohol enters the receptacle D gradually and progressively in proportion to the diminution of pressure in the reservoir, since it is only in this proportion that the expansion of the air confined in the chamber O is able to take place, and it is due solely to this expansion that the alcohol is expelled from this chamber and fed into the.combustion chamber or receptacle D. By suitably proportioning the volume of the air-space in the chamber 0 to that of the reservoir Aand to the quantity of alcohol the flow of the latter into the reservoir may be graduated in any manner desired. I prefer to so proportion the parts that the flow of alcohol shall be continuous during nearly the entire period of generation of powerlhat is, during the entire run of the torpedo-so that the last of the alcohol will not be consumed until shortly before the pressure falls to a minimum, at which it is no longer practically available for power purposes. By this means not only is the fall of pressure of the compressed air less rapid, but there is a great increase of pressure due to the heat which is liberated within the mass of compressed air, and subsequently the'pressure falls much more slowly for a much longer time or at a greatly in-' creased rate for the same time. In the practical application of my invention in connection with an automobile torpedo I have in proportion to the amount of air compressed to a given pressure increased the generated horse-power by fifty per cent. as compared with the ordinary use of compressed air alone or unheated. At the same time my invention avoids the disadvantage of the cooling of the engine and passages due to the expansion of the compressed air.

My invention maybe applied with any suitable combustible materialas, for example, any liquid hydrocarbon or any combustible gas'which may be compressed to the extent to which the airhas to be compressed, or even a solid combustible may be used. I prefer, however, the use of a liquid combustible, as it is most easily managed and controlled, and I prefer to control its rate of combustion by introducing it progressively into the compressed-air reservoir or preferably into an open combustion-chamber located therein, as described.

My invention may begreatly modified in its practical application, and I do not limit myself to any one means of applying my invention. The means herein described is considered preferable from a practical point of view to any other which I have tried or devised compressed air which consists in means controlled by the pressure for heating the compressed air.

2. In compressed-air propelling mechanism for automobile torpedoes, the described means. for increasing the energy of the stored compressed air which consists in the combination of means controlled by the pressure in said reservoir for feedinga combustible thereinto and means for igniting said combustible in said reservoir.

8. In compressed-air propelling mechanism for automobile torpedoes, the described means for increasing the energy of the stored compressed air which consists in the combination of means operated by a reduction of pressure in said reservoir for feeding a combustible thereinto and means for igniting said combustible in said reservoir.

4. I11 compressed-air propelling mechanism for automobile torpedoes, the combination of means for igniting a combustible within the stored compressed air, with means for introducing a fluid combustible gradually during the run of the engine in proportion to the consumption of the compressed air, said means adapted to suspend its introduction and thereby stop the combustion in case of the stoppage of the engine.

5. In compressed-air propelling mechanism for automobile torpedoes, the combination of means for igniting a combustible within the stored compressed air, with means for introducing a fluid combustible gradually during the run of the engine in proportion to the consumption of the compressed air, said means adapted to suspend itsintrodnction and thereby stop the combustio t sation of fall in pressure, or upon 1 pressure, of the compressed air.

6. In compressed-air propelling mechanism for automobile torpedoes, the described means for increasing the energy of the stored compressed air which consists in the combination of a chamber for holding a combusti ble charge, said chamber opening into the compressed-air reservoir, means controlled by the pressure in said reservoir for supplying a combustible charge from said chamber to said reservoir, and means for igniting said combustible in said reservoir.

7. In compressed-air propelling mechanism for automobile torpedoes, the described means for increasing the energy of the stored ICC means for igniting said fluid in the reservoir, and means acting as the pressure in the reservoir falls to feed combustible fluid from said chamber into the reservoir at a rate proportional to the fall of pressure therein.

8. In compressed-air propelling mechanism for automobile torpedoes, the described means for increasing the energy of the stored compressed air which consists in the combination of a compressed-air reservoir, a chamher for holding a charge of combustible liquid, a pipe leading therefrom into said reservoir, adapted to leave an air-space in said chamber above said liquid, and means for igniting said liquid in the reservoir, whereby as the pressure in the reservoir falls the consequent expansion of the air in said air-space expels the liquid from said chamber into the reservoir at a rate proportional to the fall of pressure therein.

9. I11 compressed-air propelling mechanism for automobile torpedoes, the described means for increasing the energy of the stored compressed air which consists in the combination of a compressed-air reservoir adapted to receive a charge of compressed air and to be disconnected from the source thereof, and a chamber for holding a charge of combustible liquid opening into said reservoir and adapted as air is compressed into said reservoir to admit air to said chamber under equal compression in an air-space above said liquid.

10. In compressed-air propelling mechanism for automobile torpedoes, the described means for increasing the energy of the stored compressed. air which consists in the combination of a compressed-air reservoir, a motor connected thereto to be driven by compressed air therefrom, means for heating the air at a point in said reservoir and means for conducting air from such point alone to said motor whereby the air which is most highly heated is continually used.

11. In compressed-air propelling mechanism for automobile torpedoes, the described means for increasing the energy of the stored compressed air which consists in the combination of a compressed-air reservoir, a motor connected thereto to be driven by compressed air therefrom, means for igniting and burning a combustible at a point in said reservoir: and means for conducting air and the products of combustion from such point alone to said motor whereby the air which is most highly heated is continually used.

12. In compressed-air propelling mechanism for automobile torpedoes, the combination of a heating-receptacle in free communication with the interior of the compressedair reservoir, means for igniting a combustible therein, means for feeding a fluid combustible gradually thereinto, and a passage for conducting the heated air and products of combustion therefrom to the engine.

13. The combination of a compressed-air reservoir, a motor connected thereto, to be driven by the compressed air therefrom, means for gradually feeding a combustible fluid into said reservoirat a rate proportional to the reduction of pressure therein during the outflow of compressed air, and means for igniting said combustible within said reservoir.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

FRANK M. LEAVITT.

Witnesses:

FRED WHITE, THOMAS F. WALLACE.

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