US998655A - Process of generating and regulating the generation of power. - Google Patents

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G. M. s. TAIT & c. ELLIS. PROCESS OF GENERATING AND REGULATING THE GENERATION OF POWER.

APPLIGATIQN FILED NOV. 14, 1905. v 998,655. 1 I Patented July 25,1911.

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- PROCESS OF GENERATING AND RBGULATING THE GENERATION OF POWER.

' APPLICATION TILED NOV. 14, 1905.

1 998,655. I Patented July 25,1911.

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1 MMJZ-q 3 UNITED STATES I PATENT OFFICE. l

GODFREY M. S. TAIT, OFIMONTCLAIR, NEW JERSEY, AND CARLETON ELLIS, OF WHITE PLAINS, NEW YORK.-

PROCESS OF GENERATING AND REGULATING THE GENEIB.A'.[IOI\I' OF POWER.

I Specification of Letters Patent. Patented J uly 25, 1 91 1 Application filed November 14, 1905. Serial No. 287,240.

To all whom it may concern:

Be it known that we, (ionrum' M. S. TAIT,

a British subject, residing in Montclair, [65- l z-tex county, hcw J er.- ey,and CARLETOX ELLIS, t

5 residing in 'hite Plains, 'cstchester count y, New York, have invented a certain i new and useful Process of Generating and Regulating the Generation of Power, of which the following is a specification.

In Our invention relates to a process of regulating the development of power in internal combustion engines, apd particularly in engines operated on producer gas and similar gas of low or variable thermal value, or

comprising gaseous ingredients having quite 'diti'cient properties as regards self-ignition, fiame-propagation, etc.

The methods heretofore employed for regulating the operation of 'internal combustion engines have all proved unsatisfactory. The hit-and-miss method of regulation produces excessive speed fluctuations, so that it is entirely impracticable in many ases, and in many ofits forms is extremely wasteful of fuel. All methods of regulating involving variation in the quantity of gas and air taken into the cylinder, such as throttling and variable opening or closing of the admission valve (the latter method sometimes termed variable cutott') produce extreme variation in the compression pressure, such pressure increasing at different rates'according to the total quantity of gas and air taken into the cylinder. Such variation in compression is extremely detrimental as regards economy, for it is well known that for highest. cllicieucy high compression is necessary, and obviously an engine which at light loads compresses only 40 to relatively low pressures, is unecomnnieal at such light loads and low compression pressures. Variation of the compression is particularly detrimental, however, in the case of engines operating on producer gas.

or similar gas of low or variahle thermal value. Such gases require high compression to insure thorough and prompt ignition, or even to insure ignition at all. If the engine be regulated by varying the total amount of fluid taken into the cylinder, it may easily, and frequently does, happen, that at light loads and low compression pres- ,sures ignition is uncertain or fails altogether. It is of course substantially im- 5 practicable to supply a richer fuel'to an engine when operating at light load than when operating atheavy load, and to do so would still further decrease the etticieney at light loads. The extreme of this disadvantage of varying the quantity of fluid taken into the cylinder is experienced when the engiue is supplied with gas by a single producer the only, or substantially the only, function of which is to supply gas to that particular ongine. Irregularities in the quality of gas.

furnished by the producer then produce their maximum etfect, and if it happens, as is apt to be the case, that the producer furzishes the poorest gas when the engine is running on light, load and with low con1prcs sion pressure, the engine is apt to stop.

When starting up such an engine also, the gas from the producer is apt to be of especially low thermal value, and since theengine is then without load, usually, and its valve sear is adjusted so that the compression is low, it is often ditlicult to start an engine operating on producer gas. All of these ditlicultics we obviate by taking into the cylinder substantially the same total quantity of Fluid at all times, regulation being etl'ectcd by varying the richness of the charge by anlnulatically varying the amount of air admitted, or by admitting and similarly regulating a neutral diluent gas, such as products of combustion, but the total quantity ofthoreughly mixed gases or vapor and gases ad mitted always being the same. 'lheconipressieu is then substantially the same .at all b ads. To compensate for the variation in the rate ofllame propa' aticu with varying amounts of air or neutral diluent gas in the riiarge, we autmnaticallyvary the point ofpression engines, it. has been noted thatfuels which are nothomogeneous as to combustible ingredients are not as advantageous for engine purposes as, fuels containing substantially only one combustible, particularly in high-com ncssing engines- In such engmes, gases containing considerable percentages of hydrogen appear particularly disadvantageous, the hydrogen being apt to ignite spontaneously during the compression stroke, producing excessive back pressure tending to ignite spontaneously under high compression. When the gas used is homogeneous or nearly so, we may use air alone as the diluent.

The objects of our invention are, to regulate the development of power in internal con'zbustionengines in an improved manner, to obtain higher economy of operation at all loads. but particularly at light or variable loads, to avoid variation in the (our pression with variation in load or speed, to prevent prc-iguition. to insure complete ignition, and to permit the use of. fuel of ow and variable thermal value.

In the accompanying drawings we illustrate apparatus in which our said process may be carried out, the same comprising an internal combustion engine which in general is of ordinary construction.

In the said drawings: Figure 1 is a cenlral vertical sectional view of the engine; Fig. 2 is a side view and partial secti n of the feed pipes, mixing device, and automatic. regulating device; and Fig. 3 is a detail view of the mechanism for regulating the point of ignition.

In the said drawings 23 designates the engine cylinder, 22 the jacket therefor, 13 the clearance or compression space. 1:2 the piston, 11 the connecting rod, and 14 the crank. V

1 and i2 designate, respectively, exhaust and admission valves, which may be operated by any suitable valve gear, that illusl rat cd com prising a rocking lever 4 operated, through suitable connections, by a can: 9, which may be understood to be driven in the usual way from the crank shaft by means of gcaring.- 'lhe rocker 4 alternately presses in first one of said valves and then the other, and is adjustable longitudinally to vary the opening and closing of the. valves. The operation of this valve gear is obvious and requires no further description.

3 designates a com-'cntioual electric igiiiting device, operated by a link 16 from an eccentric on sh:- ft 18, which shaft may be understood to be driven by suitable gearing from the crank shaft. as is common in engines of this type. p

6 designates the admission port of the cylinder, and 7 the discharge p rt thereof.

-24 designates the gas supply pipe of the 1 engine, and may be understood to baconuccted to a gas producer of ordinary type.

25 is a pipe supplying the air for combustion and also for dilution of the charge for regulation. Said pipes are provided with ordinary regulating valves, adjustable by hand, numbered 20 and 19 respectively. Pipe 25 terminates in a collar 5 surrounding pipe 24, the latter being perforated within said collar, so that the fluid from pipei25 is mingled thoroughly with the gas entering through pipe 24. Regulation of the amount of fluid from pipe 20 flowing to pipe 2-} is etlcctcd by a valve 21 operated automatically by a speed governor 8, which may be understood to be drivenjrom the crank shaft or other suitable partof the engine.

This valve may also control a port 26, indicated in dotted lines in Fig. 2, connected to a source of supply of products of combustion, such for example. as the exhaust pipe of the engine.

T he eccentric on shaft 18 which operates the iguiter 3'through the link 16, is engaged by a spiral spline 17 on said shaft, and an automatic governor 27, which will be understood to be driven from some moving part of the engine, such as the crank shaft, is arranged to move shaft 18 longitudinally, thus varying the angular advance of the eccentric and the time of ignition in accord ance with, and in exaetrelation to,variation in the amount of diluent admitted through valve 21, the advance of the spark corresponding to the decrease in richness of the mixture admit-ted.

The method of regulating the. develop ment of power is as follows: Supposing the engine to be operating under maximum load. valve .21 will be substantially half open as regards passage of air from pipe 25 to pipe 524, and a charge of maximum richness will cuter the engine cylinder during each admis sio'n stroke, and will there be compressed, ignited, and caused to expand. in the ordinary way. lf now the load on the engine be reduced, the centrifugal governor 8 will open valve it still further, admitting more air from pipe .55 to pipcfill, and also opening port :30 and admitting products of combustion, which mingle with the air. and gas, diluting the latter and retarding the com bustion of hydrogen and similar substances in the final ignition of the charge. The total amountof fluid takcri into the cylinder remains the same, it'vi'ili be seen, whatever the load, and therefore the compression is substantially the shutout all loads: but the richness of the charge will be dcc e d,

The rate of "combustion lacing thereby changed, the governor 27 automatically advances the point of ignition to compensate duce the amount of diluent admitted and will retard ignition to correspond with the increased rate of combustion of the charge. It will be seen -therefore, that by theaction of the two automatic goi erning'devices the character of the charge and the point of ignition will be varied to suit thelvoad on the engine and to maintain constant speed. without varying the compression. \Ve are enabled. therefore, to employ very high compicssion at light loads as well as at intermediate and heavy loads, and to employ fuel of low thermal value at all loads, the ignition of such fuel bcingreiatively certain because of the very high compressioncnr ployed. This compression we prefer to be from say 95 to 16 atmospheres, preferably not below 11 atmospheres. At this high compression mixtures which cannot be depended 'upon to ignite at lower pressures ignite readily.

Producer gas such as we especially contemplate using has for its principal conihustible cmistituent, carbon inonoxid; but many types of producers or generators of fuel gas produce large quantities of hydro- 'gen as well, giving rise to the .prc-ignition trouble above mentioned when the enginc operates with high compression. 'hen the gasuscd contams little or no hydrogen,

3 we commonly employ air alone as the dilucut. it. being understood that any excess of air mixed with the gas above that required for combustion is a mere diluent, and is substantially neutral. \Yhcn the gas used contains considerable quantities of hydrogen or other readily igniting gases which tend to give ri-c to pro-ignition troubles. we preferabl v mix more or less products of combus tion with the air. Such products of combustion may be drawn from the exhaust pipe 'cf the engine, or from the stack of any conicnicnt furnace or the like. and are preferably cooled before being mixed with the air and gas. on account of the greater density at low temperatures. The specific heat, by volume. of products of combustion rela tively high, as ompared with air, and such products exert a marked intlucnce tending to hold back the ignition of lrvdrogcn and like constituents which tend to ignit pr maturctv under the conditions of neat and pressure prevailing in the engine cylinder during compression; such holding back being due, probably, in great measure to the presence of considerable quantities of carbon dioxid in the products of combustion. Hy properly diluting the charge to correspcnd with the lead on the engine,. without varying the amount of the charge. by cor-re spondingly varying the point of ignition, and when um ssary holding back the igniing greater miles-4 quantities tion by employ of pr ducts of (OllllHIStlpll 1n the charge, we

are able to insure proper ignition, without so much combustion before the piston reaches the end of its compression stroke as results the, charge of an explosion engine is highly.

prejudicial. as tending to make ignition in regular or to prevent it altogether, and very often elaborate measures have been taken to produce very complete scavenging ot' the cylinder; but we have found that the ob-.

jcctions heretofore found to unavoidable or unintentional retentlon of a portion of the products of combustion within the cylinder do not: apply when the products of combustion are used in carefully regulated proportions and are thoroughly mixed with the entering air and gas, but that to the contrary very decided advantages result from the proper mixing of suitably regulated proportions of products of combustion with the charge, as before stated.

In the case of engines which operate by the injection of fuel into the cylinder or combustion chamber of the engine, the products of combustion for diluting the mixture and retarding combustion will be introduced, ordinarily, with the entering charge of air.

' \Vhat we claim is 1. The process of generating power and of regulating the same, in internal combustion engines, which consists in drawing into the engine cylinder successive charges of substantially uniform amount comprising producer or like gas, air for combustion aml a diluent. gas all substantially uniformly admixed with each other, mixing outside of said cylinder air and products of combust ion together to make the szlitl diluent gas of the charge and then mixing the same with the rcn'iaindcr of the charge, varying the proportion of diluent in the charges in accordance with the work required, compressing the mixture, and igniting the same at a variable point corrcs mnding to the. amount of diluent present.

2. The process of generating power and of regulating the same, in internal combustion engines, which consists in drawing into the engine cylinder successive charges of substantially uniform amount comprising producer or likegas, air for combustion and a diluent gas all :-.-ubstantially uniformly admixed with each other, mixing outside of said cylinder air and products of eombust ion together to make the said (lilaits ent gas of the charge and then mixing the same with the remainder of the charge, varying the proportion of diiucntin the charges in accordance with the work required, compressing the mixture, and igniting the same ata variable point correspouding to the rate of flame propagation through the mixture.

3. The process of operating and reguiating the speed of internal combustion engines which consists in diluting and thoroughly admixing the entering charge of mixed air and combustible with a diluent mixture of air and products of combustion in variable amount to form a charge of constant hulk, compressing the diluted mixture and causing combustionthereof. 4. The process of operating and regulating the speed of internal combustion engines which consists in diluting and thor oughly admixing the entering charge of mixed air and combustible with a diluent mixture of air and products of combustion in variable amount to make a charge of constant volume, compressing the dilute-cl mixture and igniting the same at a variable point corresponding to the amount of diluent. v

5. The process of operating and regulating the speed of internal combustion engines which consists in diluting and thoroughly admixing an entering charge of air and cmnbustihle with a mixture of air and products of combustion, in variable amount, to make a charge of constant voiumc, compressing the mixture and causing the com- I I 4 bastion thereof.

6. The process of operatinginternal combustion engines which consistsjn diluting tron thereof.

7. The process of operating internal coinbustion. engines which consists in introduc ing therein mixture of air and products of combustion with a mixture of air and combustible uniformly admixed, and compressing the mixture and causing combustion therein.

8. The process of operating internal combustion engines and regulating the speed thereof, which consists in introducing there in a mixture of air and products'of com bustion, uniformly admixed with a mixture of anand combustible, the products of combustlon being introduced in variable quantity according to the work desired, compressing the mixture and causing combus tion therein.

In testimony whereof we hereunto afl'ix our signatures in the presence of two it ncsses.

GODFREY M. s. TAIT. CARLETOX ELLIS.

\Vitnpsses:

Faun. 1. SMITH;

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