US922509A - Compound explosive-engine. - Google Patents

Description

I M s. A. REIB VEL courounn EXPLOSTVE mews, APPLICATION FILED JUNE 18, 19 0 8.

922,509, Patented May 25, 1909;

@3 32 Y J m hi ,ittlilfl Q'TtATES rrrcrnnzr tll l l i COMPOUND EXPLOSIVE-ENGINE.

Application filed 33111618, 1906.

/'o ull' iii/mm it may concern:

Be it knoon that l, Smxnv A. ltrlizvic. ...a citizen of the l'nited States, residing at ll'orcester, in the county of \l'orcester and State of IcilttlfiiltlfUStftS, have invented certain new and useful improvements in Compound ExplosiveEngines, of which the following specification and accompanying drawings illustrate the invention in a form which l novv regard as the best out of the various forms in vvhich it may be embodied.

This invention relates to internal combustion engines having outside compression and;

I using tvvo or more stages of pressure in order that a high maximum pressure, high elli- "-ciene and high power per unit of enginevveight may he attained. In a prior application, Ser. No. 267,719, I have claimed the general type of apparatus in connection with which my present improvements are prefera bl y employed.

Among the objects of the present invention are the following matters: first, the provision of means for employing liquid fuel and supplying it within the pressure circuit in such manner that its gas or vapor will be in a desired ratio to the uantity of compressed air vvhich enters into the explosive charge. Secondly, the improved manner of controlling, distributing and metering the air supply, to the end that a single air compressor may supply to the motor both pure air and earlnirized or fuel-laden air, and to the further end that a compressor vvi th a lixed intake may properly charge the explosion cylinder at all pressures without loss of fuel. 'ihirdly, the attainment in a'system of this kind, using an explosion motor of the t .vocycle type, of an extended expansion within the explosion cylinder. lrourthly, an

improved plan of governing the engine according to load. Some of these objects also apply broadly to solid as well. as liquid fuel as will he hereinafter pointed out.

Of the accompanying dravvings, Figure 1. represents a diagrammatic section and elevation of an internal-comlmstion motor system constructed according to my invention. Fig. 2 represents a cross-sectionof the Q-position valve included in the starting arrangements.

'lhc same reference characters represent the same parts in both vievvs.

In the drav-- ings, It) is an explosion motor Specification of Letters Patent.

Patented May 25, 1909.

Serial No. 322,204.

and Water-jacket l2, and a piston 13 arranged vvith the usual liallle H l)(l\.'((ll the ports in the halls of the cylinder. aid piston is. formed at one end of a moving piston structure 15 having at its opposite end the piston lti of the air compressor 17.

18 is the aircompressor cylinder and i its vvater-jacl et The air compressor l7 supplies the first stage of compression of th charge, vvhich latter enters the explosion motor to at the termination of the vvorking stroke and is compressed therein to a second and higher stage of compression and then exploded atthe top of the stroke by an iginter it).

The exhaust moves out through an exhaust-pipe 21 into a cooling t'litlllllHJ 22 containing a body of vvatcr 23 where steam is made. the steam and gases having an exit through a. continuation 24 of the exhaust-pipe into a lovvqiressnrc expander 35 of the steam-engine type. I have here shovvn the explosion motor t0 connected by a rocking lHIlIIt 2t; and piii'inan-JT with a crank-plate on a shaft 28, and have shovvn the pitnian it) of the lowpressure cylinder connected with a crank-plate which is shovvn as geared to the same shaft 28. "flats both higl'i-prcssure and low-pressure motor cylinders drive the sameshaft and have stroke for stroke. This drawing however is; for illustrative purposes, made somevvhat more complex in relation to crank-conncclions than would he necessary in practice. Other component parts also, where they come within the skill of the designer, or where their sp'ecilic organization is not of the essence of my pres ent invention, are shovvn of a form to illustrate the invention in the clearest manner and do not necessarily represent the best engineering practice of the present day.

Tvvo exits are provided from the air comp-ressor 17 by way of pipes 530 31 the outlets to which are controlled respectively 'by check-valves 101 10.2. the latter lieing loaded more heavily than the former by a spring. 1

31. is the compressor admission-valvc.

It will be seen that the port of valve In] is located some distance from the head of the'cylinder while the port of valve to: is located at the very end. llcnic the valve 101 is overrun before the termination of the compressing stroke and thcrczl'tir the rcof the t .\ocyclc type having a cylinder ii, i in. tiling air must. pass out through valve float 41 therein partly balanced in weight struction here perature than the' t-empe1 'ature of the first supplies more fuel than the carbureter 34 intercooling, may be thirty-six atmospheres 102. The general object of this arrangement is to supply at all pressures a fixedv volume of air adapted l'or earburization.-

In the pipe 31 leading from valve 102 is a carbureter 34 having a fuel-supply pipe 35 and an overflow pipe 36. Pipe 35 is connected-with a fuel pump 37 driven from a counter-shaft 38. The overflow pipe 36 contains a trap 39 for releasing liquid but not gas. This trap includes a reservoir .40, a

by .a s ring 32, and a check-valve 42- operate by the float for obstructingthe overflow or by-pass pipe 36. The pump 37 evaporates, the excess collecting in trap 39 and flowing back to the suction side of the pump when float 41 lifts the valve 42. Thus a constant level of fuel is maintained within the carbur'eter, and the air passing through or over the volatile ,fuel, takes up a quantity of vaporin -su'bstantial proportion to the quantity of This method of carbureting, namely entraining liquid fuel in substantial proportion to the quantity .of air passing. through the carburetor, from a constant-level pool containing an excess quantity of the fuel and maintained under the pressure of the air-conduit or some derived pressure,'gives an automatic propor-' tion between air and fuel in the combustible charge which cannot be attained without considerable complication by fuel pump metering 'expedients. As various kinds of carbureters having the characteristics just mentioned would be suitable for this situation, I am not' confined to the exact con given as an illustration of the principle. I In the compressor discharge-pipes 30 31 re placed inter-coolers 43 44 for bringing the temperature of tl'iecompl'essed air back to or toward its initial point. If the intercoolers restore the temperature of this first stage to atmospheric, then (neglecting surplus heat of the explosion cylinder 11)the explosion cylinder may give a further compression in the same proportion to the first-stage pressure as the first-stage pressure was to atmosphere without-resulting in a higher terncompression. Thus it the first stage was six atmospheres the second stage, by reason of Without attaining a final temperature b'e. yond the preignition point. This of course results in enormously high explosion pressures, say 2000 to'3000 pounds per sq. in., but, taking place in asma ll;cylinder-they may be handled without producing exce ive strains or requiring massive parts. pl pressures given are illustrative merelv'and may'rbe departed from in pract ce w t hput depriving the cycle ol its essential character.

Air enters the explosioncylinder1 1 through an adn1issiont ort 45 at or near the oute. end of the stroke and leaves through an opposite exhaust-port 46 the same as in the ordinary two-cycle engine.

valve 49 and a puppet exhaust-valve 50,-

actua'ted through tappets 51 by an eccentric 52 on the counter-shaft 38. \"fhen the piston 13 on its out-stroke uncovers the main entranceand exhaust-ports 45 46, the exploded charge is exhausted through the port 46 and a charge of air enters through port 45 and assists in driving out the dead gases. Meanwhile the auxiliary exhaustvalve 50 has opened and later'the fuel-valve 49 has opened so that although the piston starts on its'return stroke and covers the ports 45 46 there is still a free exhaust through auxiliary port 48 and a free fuel entrance through fuel-port 47 the effect of which is to charge the explosion cylinder 11 with fresh charge to the extent of less than its full volume and permit an expansion of the exploded charge to a greater final volume at the point of exhaust than the initial volume of charge. This improves the eiliciency. On the out-stroke the auxiliary exhaustvalve 48 keeps the cylinder closed for this super-expansion until the main exhaust-port 46 has become uncovered. I further provide an ante-chamber or vestibule 53 to the first, the auxiliary exhaust-valve 50, then the auxiliary air-valve 54, and finally the fuel-valve 49, and the closing is in the inverse order, fuel-valve closing first, next airvalve, and finallv exhaust-valve.

I have shown a shaft governor 55 on' the counter-shaft 3S controlling the eccentric 52, its primary object being to var v the time of opening of the fuel-valve \49 according to the load on the engine. Thus, at maximum load the fuel-valve would have it. longest opening, while at zero load it might have no opening at all. The governor, in

addition, may have some useful eil'eet on the exhaust-valve 50, causing it to close early at light loads and thus increasethe compression pressure and maintain power and Ollir-iencv when the fuel charge is very light.

The intrml'uetion ol' the governor action on In addition, I. provlde a fueladmission port 47 and an fue waive 49 makes desirable the use of a loaded check-valve 56 connecting the compressor delivery-pipe 31 with compressor delivery-pipe 30, so that when the fuelvalve chokes exit into the explosion cylinder through pipe 31 the back-pressure in said pipe may be released into the pipe 30.. This check-valve 'may be loaded to, say lbs.

pressure. -The governor 52 also acts on an eccentric 57 which operates the valve of the steam cylinder 25 and times it conformably with thefuel valve 49 and exhaust-valve 50, thus making the draft of heat and fluids from cooling-chamber 22 conform. with the supply thereto and keeping the intermediate pressures stable under varying loads.

W'ater flows in a serial order through the jackets and pistons and the cooling chamber as follows. It is forced by a pump 58 first through pipe 59 into the water-jacket 19 of the air-compressor, and thence passes through a telescopic fitting 60 into the compressor-piston end of the moving piston structure 15. A vertical partition 61 divides the interior upper half of this piston structure into compressor-piston end and exploder-piston end, and a horizontal partition 62 separates the upper half from the lowerhalf but permits water passagearound the ends of the partition and from one end to the other of the iston-structure. The water which enters t e compressor-piston 16 from the compressor-cylinder acket bathes the inside of and cools said piston and then flows to the opposite end of the piston structure and cools the exploder-piston 13. It then passes out through a second telescopic fitting 63 and divides at 64, a part going through pipe 6.5 to the explosion cylinder jacket 12 and thence through pipe 66 to the cooling chamber 22, and anot ier part going by a pipe 67 to a re lease valve 68 operated by a diaphragm controller 69 which issubjeet to the water-level in chamber 22. Any iuitable water-level controller will perform this office, which is to maintain a substantially constant level of water in chamber 22 by releasing any excess through the valve 68.

In addition to the jacket and pistrtp watersupplies of the explosion cylinder 1 I have shown three s )ray injections, one by way of a pipe 70 in t e head of the ex losion cylinder 11 for spraying water into t 1e cylinder at the moment of maximum pressure, thus cooling the gases, conserving their heat in the form of steam, and assisting in the expansive power by reason of the large volume of steam; and a second injection at the moment of exhaust through a pipe 71 upon the back of the exhaust-valve 50 in order to cool said valve and also absorb some of the heat of the exhaust. The first of these water injections is supplied by a pump 72, connected with pipe 70 which contains an a1r-chan1ber73 for storing elastic air-pressure above an accun1u &

lation of water. A valve 74 at the water outlet of this chamber is controlled by a tripcam 75 on the shaft 38 which opens the valve and injects a spray of water into the explosion cylinder at or about the time of maximum pressure. A valve 76 in the pipe 71 operated by a similar cam-trip 77 injects a spray against the exhaust-valve 50 at or just after the time of exhaust. An. additional spray may be had from the water-jacket through an inwardly-opening check-valve 78 by the water pressure at the time of exhaust, for the purpose of aiding in the scavenging by the formation of a large volume of steam, .at the instant of exhaust, at the end of the cylinder farthest from the port-s 4.7 and 48. All of these sprays serve to relieve the cooling chamber 22 of part of its duty and thus reduce its size and cost. The cooling chamber, however, preserves a dominant pool into which any excess of water from the sprays is merged and afterward evaporated by the exhaust gases, whereby I am enabled to greatly simplify the problem of regulating the quantity of sprayed water to the quantity and temperature of heat in the exploded gases.

Storage of exploded gases under pressure for starting purposes is effected by connecting a reservoir tank 79 by a pipe SOwith the interior of the explosion cylinder 11 at a point between the beginning and end of the stroke of piston '13, thereby abstracting a portion of the exploded gases after they have performed useful work upon piston 13. A check-valve S1 in said pipe prevents the return of the gases, and when tank 79 has been. filled to a balancing pressure the gases no longer flow to the tank. Outlet from the tank 79 is by way of a pipe 82 leading to the casing of a 2-position valve 83 which has other pipes 24: R4 and $5 leading respectively to the low-pressure cylinder 25, to the cooling chamber 22, and to the atmosphere. When in one position, illustrated in full lines in Fig. 2, this valve connects the explosion cylinder 1 1 withthe low-pressure cylinder 25 by way of the cooling chamber and shuts of. the pressure-tank 79. This is its normal running position. In the other position, shown in dotted lines inFig. 2, the explosion cylinder is connected with the atmosphere and the low-pressure cylinder 25 is connected with tank 79. This is the starting position. In this latter position the motor is started by stored pressure from the tank 79 admitted to the low-pressure motor 25, while the highpressure cylinder ll'exhausts to the atmos phere. Starting is thus efl'ected without any interference with the functions'of the explosion cylinder and the starting pressure may be left on througl'i several revolutions or as long it will last. The cooling chamber also a preliminary warming by the exhaust gases passing to atmosphere. As the in the head of the cylinder which is opened no I flywheel acquires speed the valve 83 may be turned to its running position. Compression-pressures will then pick up and the engine will go into normal operation under high pressure with compound compression and com ound expansion.

T16.Wat61 system and start-ingdevices above set forth, while desirable features, are not essential to my present invention.

Describing more fully the cycle of opera tions, it will be seen that the compressor 17 engine 25 and do further useful wor on the" piston of the latter. In'passing from the compressor to the explosion cylinder the air is inter-cooled both in the pipe 30 and in the ipe 31 by means of the intercoolers 43' 44 so that the further stage of compression in the explosion cylinder will not cause preignition.

On theexpansion side, the products of combustion are cooled both by the body of water 23. and by the sprays from the nozzles 7 Q, 71

and ,78. The watei cooling is effective in" transforming the heat to a lower-temperature, more usable form. Under special con-' ditions, l1owever,.I may omit cooling on the expansion s de.

Compressor 18 is preferably of such capacity that at the maximum pressure permit ted in the system it will-furnish a slight excess of air over that required for the explosive charge. At lower pressures a greater air excess 1s PIOVlClGd, as will be later explained. This arr rsused-for scavenging and it escapes into the cylinder 11 as soon as admissionort 45 is uncovered by the piston and before uel-valve 49 is opened. It thus clears out the revi-ous charge and a part'of it may pass on through the exhaust 4.6 and perform work in the low-pressure engine 25/ .Such air as thus passes on ahead of the charge is some what warmed by the cylinder and gives back most of. he work ex ended incompressing it; By tiis means provide a substantial improvement over ordinary single-expansion scavenging engines which ar'enot capable of using either the exhaust gases or the scav enging air which passes out of the exhaust for further useful expansion At the lower or sub-maximum. pressures the excess alr w ll be larger in volume, S1nce the same quantity ofgcompressed -air-at a lower pressure will have a larger volume than at a higher-pressure-and this volume in the resent engine must be accommodated long tudinally, it is plain that the explosion The entering charge valve 49 sent out by thebompressor 17, the cubic contents of which are shown as considerably in excess of cylinder 11, 'It will now be apparent that if all of the air which compressor 17 delivers were charged with fuel some of it at low pressures would escape into the exhaustpipe 21 unburned when the iorts'lz'i .40 are uncovered by the piston as shown in Fig. 1. ,S'uch waste of fuel would be very objectionable and I- avoid it by the arrangen'ient of the compressor discharge-valves 101 102. ()n the compressing stroke of piston 16 air will begin to escape past valve 101 as soon as the pressure in the compressor has overcome the )ack-pressure, and it will continue to escape t iroughthe same valve until this valve has been 'overrun by the piston; Up to that timethe stronger loading of valve 102 prevents the air from choosing the path past 1 02, but as soon as valve-101 is overrun their all of the discharge takes place past 102. It is this final volume of air which, passing through pipe 31, becomes ormay become fuelcharged in the carbureter 3-1, the -,arrangr. ment being such that more fuel will be taken up than is necessary to form an explosive mixture and the final ingredientof air must be supplied to the explosion cylinder through the admission-porter) (or through port- 47). The fuel on entering, findssoinc air already in thecylinder; ,sOme-airenters through 53 simultaneously with the vapor, and the wholeforms an explosive mixture. It will be seen that the 101 1 2mm arrangement effects a metering of the fueLcharge to the explosion cylinder, which metering the cylinder 1]. is unableto perform for itself, being of the two-cycleftype where both admission andexhaust-passages are open at the same time. It can take onl what is blown into it. The volume of air which goes out through valve 102 is bound to enter cylinder 11 and remain there without overflow, because it has been squeezed up into a definite compass which-is so calculated asnot to exceed the ca )acity of cylinder 1'1.

ln the arrangement here given the metering device limits the fuel volume to adefinit'e maximum irrespective of r'essure and prevents overflow of unburne fuel fromthe'explosion cylinder; but by reasonof the introduction' of relief-valve 56 and governing of the fuel-valve 49 the'metering device does notinsure the same volume of fuel in the explosion cylinder at all times or loads'upon the engine. Thus if the governor shuts down the entirely, at'no load or negative load, no fuel reaches the explosion cylinder, and all of the air which'we nt but past valve 102- is shunted. across through valve 50 into the pipe 30 and goes into and through the explo sion 0 linder as scavenging air or as 1111- burne air. "The action of the governor,

therefore changes the proportions of the mixcylinder willfnot' hold tl e whole volume ture according to load and imposes a limitation upon the rise of pressures due to combustion. It is' not essential to vary the mixture but such. variation is useful in many instances.

It is obvious that the described means for by-passing compressed air around the point of fuel-supply into the low-pressure pipe 21 in varying quantities according to the backpressure in said pipe is a useful energy-conserving and regulative expedient regardless of the particular method of compressor discharge, or of fuel supply, and regardless of whether or not the air is by-passed through the .combusti0ncylinder..

The plural-stage compression and expansion here provided enable me to effect a new distribution of heat between the jacket and exhaust of the explosion cylinder. In the ordinary Otto or in any single-stage-expansion internal-combustion engine it is an object to have as little heat as possible go out of the exhaust. Hence, owing to the high temperatures, much of the total heat goes into the water-jacket or through the cylinder walls. In the ordinary gas engines the proportion of waste heat going to the exhaust and acket respectively is about equal, being about 40% of the total to each. I aim to bring about a new proportion; that is, by decreasing the cubic dimensions, and hence the hcat-transmitting surface of the explosion cylinder per unit of fuel in the charge, I am able to send less heat to the jacket and more to the exhaust. If this new proportion of jacket-heat to exhaust-heat be made about 1 :4, that ratio will substantially correspond to the quantities of heat required respectively to raise a given weight of cold water to the boiling point {and to evaporate it at that temperature. Therefore, since the waterjacket 12 feeds the cooling chamber 22, I am able to evaporate in the cooling chamber, by means of the heat which goes out of the exhaust, nearly if not q uite all of the water which has been required to keep the cylinder walls cool. This ratio, if approximately attained, need not be rigidly observed, since I may .provide for a passage of water through the jacket 12 supplementary to that called for by the chamber 23. The proportion of jacket water and cooling-chamber water is somewhat varied by the action of the water sprays hereinbefore described. It is obscrvable however that the hotter the exhaust gases and hence the higher the temperature within the explosion cylinder, the more water will be evaporated in cooling chamber 22 and the more water will flow through the jacket 12 to keep down the temperature of the cylinder walls, since under such conditions the .controller- 69 closes the by-pass valve 68 until normal level is restored in coolii'ig chamber 22 through the pipe 66.

'motor operated by the It will be seen that the carbureter 34 in its representative aspect is a device for carbu- What I claim as new and desire to secure by Letters Patent is:

1. A,compound heat engine comprising an internal-combustion motor, a low-pressure ressure of the haust gases from said h1ghpressure motor, an air-compressor driven by thehigh-pressure motor for char ing the latter, a compressed-air conduit I pressor to the high-pressure motor and haveading from said coming a fuel-entraining device, and means for v by-passing a portion of the compressed air unburned around said fuel-entraining device to the low-pressure motor against the backpressure of the high-pressure exhaust.

2. A compound internal-combustion en- "gine comprising a low-stage air-compressor, a I

high-stage-compressi'ng explosion cylinder and piston for driving the compressor, a lowstage motor operated by the high-stage exhaust, a liquid-fuel carbureter interposed between the compressor and explosion cylinder, and means controlled automatically by the back-pressure of said exhaust for bypassing variable quantities of compressed air unburned to the low-stage motor.

3. A compoundinternal-combustion engine comprising an air-compressor, a highpressure explosion-motor connected to drive thesame, a low-pressuremotor operated by the high-pressure exhaust, and a liquid-fuel carburetor located in the compressed-air line between compressor and high-pressure motor and having means for automatically maintaining a constant-level pool of fuel under the compressed-air pressure subject to entrainment by the passing air-current.

4. A compound internal-combustion engine comprising a high-pressure internalcompressing explosion motor, a low-pressure motor operated by the high-pressure exhaust, an air-compressor driven by said highpressure motor for imparting the first stage of charge-compression and having a combustion-air outlet to the high-pressure motor and an excess-air outlet to the low-pressure motor, and means whereby said combustionair outlet is opened at a predetermined point in the compression stroke.

5. A compound internal-combustion engine comprising a two-stroke-cycle explosion motor adapted to receive its combustible charge during or about the exhaust period of the preceding charge, a low-pressure motor operated by the high-pressure exhaust, an

air-compressor driven by the high-pressure I gine comprising a'two-stroke-cycle internalcompres'sing explosion motor charged during or about its exhaust period, a low-pressure motor operated by the high-pressure exhaust,-an air-compressor coupled to the highressu re' motor, a combustion-air,conduit eadingfrom the compressor to 'the highpressure motor and containing a liquid-fuel carbureter, a by-pass compressed-air con duit, and automatic pressure-operated valves controlling the discharge from the com-' pressorto said conduits and so arranged. that the- OOIIlbIlStlOlI-ztll discharge begins at a predetermined point in the compression I stroke after the discharge of the by-pass air.

'7. A compound heat engine comprising an internal-combustion higl1-pressure motor, a lowpressure motor operatedby the highpressure exhaust, an air-compressor coupled to the high-pressure motor for charging the and containing an automatic pressure-operated relief valve,

In testimony whereof Ihave hereunto set my hand in the presence of two subscribing witnesses, the thirteenth day of June 1906.

SIDNEY A; REEVE.

Witnesses ARTHUR H BROWN, A. D;- HARRISON.

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