US1545587A - Refrigerating apparatus based upon the use of air - Google Patents

Description

A, C. L.. A. M. LEBLANC REFRIGERATING APPARATUS BASED UPON THE USE oF AIRV Filed April 18. 192s 2 sheets-Sheet 1 vWEA/Tali' QWMWMAMAMDAMM July 14, 1925. 1,545,587

c; 1.. A. M. LEBLANC REFRIGERATING APPARATUS BASED UPON THE US OF AIR IiIl|II|lIlllllllllllllllllllllllll HlllllllllllllIIIII'IIIII Patented July 14, 1925.

UNITED." srArEs PATENT oFFlcE.

cnAaLEs naoNAnn ARMAND MAURICE LEBLANo, oErAnrs, raANcE, AssIGNo'a y 'ro soclETE ANONYIE POUR. L'Exl?Lor'iA'rIo-Nl DES rnoons MAURICE LEBLANC-l VICKERS, F PARIS, FRANCE.

EEEEIGEBA'L'ING APPARATUS BASED UroN THE UsE or' AIE..

Application med Aprn 1s, 192af serial No. 632,929.

To all whom. t may concern.' .r

Be it known that I, CHARLES LEONARD ARMAND MAUnroE LEBLANC, a citizen of France, and a resident of Paris, France,

have invented certain new and useful Imscribed a refrigerating apparatus based u on the use of air, in which cold is produce by means of air which is rst compressed and then caused to expand in piston-operated machines combined with heat-exchanging devices termed cooling device and refrigerating apparatus whereof the lirst serves to cool the air after its compression and the second to utilize the cold ex ansion.

n the machine described in the said application, the air which is cooled by its expansion in a cylinder containing a piston, is exchanged, by scavenging by means of sepaP rate fans or pumps, for air at a like pressure which has yielded up its cold in the said refrigerating apparatus, and this air, during the succeeding stroke, is subjected in the same cylinder and by the same piston to a compression during which it becomes heated.- At the end of the compression stroke it is exchanged in like manner, by means of independent fans or pumps, for air at a like pressure which has' iven up its heat in the sa1d cooling device; is air 1s in turncaused to expand during the succeeding stroke, and so on. l

produced by the air under The said method is carried into eliect by i means of a double acting cylinder and piston device, which'is herein designated as the main compressor, this being used in connection with a compressor of known type, termedauxiliary compressor. The first device carries out exclusively the operations of compression and expansion, these taking place alternately at each end of the piston, the air being expelled from each chamber of the cylinder at the end of each piston stroke; the energy expended during the compression in the said compressor is equal to the energy recovered durmg the expansion.

An investl ation of the cycle of the air in the sald mac ine shews that the maincompresser takes more air from the cooling derefrigerating apparatus more air than it removes therefrom. The object of the auxillary compressor is to constantly deliver from the refrigerating apparatus to the cooling device this excess of air which is sent into one device to the detriment of the other. The auxiliary compressor constantly absorbs energy and does not restore the sam In application No. 502,508 of Septemberl 22, 1921, a machine is described which is based upon this principle, employing a main compressor in which the distribution of air, at the' end of each stroke, between the cylinder chambers and the circuits of the heat exchanging devices is effected by means of clack valv The present invention relates to a machine Gvice than it returns to it, and delivers to the l which is based upon the same principle, but

comprisin a main com ressor wherein the fluid distribution and t e operation of the piston are carried out -by the use of new mechanical combinations Wh reby a combined apparatus of a very simple construction can vbe obtained.

The followingk description and the appended drawings which are given by way of example set forth' the said invention". Fig. 1 is a diagrammatic vgeneral view of the machine. y

Fig. 2 is a modification of the same.

Fig. 3 is a diagrammatic view showing the manner of pivoting the connecting rods to the crankshaft.

Fig. 4 is a plan view partly in section showing the manner of mounting the "connecting rods on the crankshaft.

-Fig. 5 is a vmodification of Fig. 4.

In Fig. 1, the auxiliary compressor is spectively movable the pistons 2, and 2 whose rods 3, 3 are connected together outside the machine and are actuated by a common mechanism, so that the two pistons move in the same manner. The wall of each cylinder has three ports 4, 5, 6 each pair of ports bein oppositely situated upon the cylinder; t e ports 4 and 6 of each cylinder are connected together by a conduit. Piping starts vfrom the outerports 4 and 6 of the cylinder 1, forming part of a circuit which comprises the fan W1 and the cooling device R, and ends at the ports 4 and -6 ofthe cylinder 1'?.

Each piston has two circular ports, the left hand port is in constant communication with the left hand of the corresponding cylinder, through an annular conduit 7 formed in the body of the piston; in like manner the right hand port is in constantcommunication, with the right hand end of the corresponding cylinder through the annular conduit 8.

'I'he piston controls the movement of the fluids, as will be further set forth, by the coincidence of the ports of the cylinder and piston.' p

'When the pistonmoves to the left, or in the direction of the arrow 11, Fig. 1, it effects the compression of the air upon itsv front face and the .expansion of air at its rear face; at the end of the stroke, or in the posit-ion shewn in Fig. 1, the left hand ports of the piston have now opened thel cylinder ports, thus connecting the left hand cylinder chambers with the circuit of the cooling device R1. .At the end of the piston stroke, the air has'the pressure P, and the temperature T4; during the whole time of opening of the ports 4, the fan W1 whose speed has been calculated for the purpose, will drive the air from the cylinder into the cooling device R, and will replace it by a like volume of air at the same pres- .sure but at a lower temperature T1 obtained from R1, the air lows as indicated by the arrows 12 of Fig. 2. Since the air from` the` cooling device is colder than the air from the c linder, the scavenging action takes from t ecooling device a greater volume of air than it returns to the latter.

While these effect-s are taking place upon the left hand face of the piston, the air at the right hand face of the piston is caused to expand from the pressure P1 to the pressure P2; with the piston inthe end position, Fig. 1, its right hand ports have now opened the ports 5 of the cyllnders whereby their right hand chambers'are connected with the circuit of the refrierating air R2, the ports 6 remaining close While the ports 5 are open, the fan W2 drives the air from the cylinders, which has the temperature T2, into ,the refrigerating apparatus, and replaces it by an equal volume of air at the same pressure but at a higher temperature '1;3, dproceeding from R2. The air owsaccor 1 ng to the arrows 13. Since ther airl y:Irom' the refrigerating a paratus has a vice to the refrigerating apparatus, but when I the standard conditions are once established, this air is brought 'from the refrigerating apparatus to the cooling device by the auxilarycompressor, the latter being a known i piston compressor actuated by the main motor.

lVhen the pistons of the main compressor start towards the right, the' ports 4, .5 of the two cylinders will close 'while the ports 6 remain closed; the air expands, in the left hand chambers and. is compressed in the right hand' chambers; when the f piston reaches 'the end of the stroke, the ports 4 still remain closed, but the ports 5, '6 are open, so that the scavenging takes place exactly as before whilethe said ports are Open.'

The fans W1, W2 may be of a knownltype, and are driven for example by independent electric motors in constant rotation.

, It should be observedl that, the currents of air produced by the scavenging will enter the chambers whichare subjected to scavenging at oneend and willbedischarged at" the other, so that the whole volume of air in saidvchambers is expelled and is replaced'by air obtained from the heat-exchanging apparatus. It is for this reason that a pair of like cylinders are employed.

On the vsame principle as above'setv forth,-

a machine can be constructed in which the' single compressor serves the same purpose as the auxiliary and the malin compressors,l as shewn in Fig. 2.

The doubleacting cylinder 1b hasV three sets of ports at the sides, as before; Athe ports 4b and 6, connected together on each side, cause-the two ends of the cylndervto communicate in turn with the cooling device R, and the scavenging fan W1, through the conduits 17, 18; the middle port 5 serves for alternate connection between the cylinder endsv and the refrigerating apparatus R2 andl the fan W2 through the conduit 19.

The piston 2b,actuated bythe rod 3", is constructed as in Fig. 1, and it has ka reciprocating motion in the cylinder; asbefore,

the fluid is controlled by theports 7", 8b of the said piston which communicate respectively with each of the cylinder chambers. The cylinder has at the left a discharge Vclack valve 2O and a suction clack valve 21, and in like manner at the right are disposed the discharge valve 22 and the suc-k tion valve 23. rlhe orifices controlled by the discharge valves are connected through the pipes 24, 25 with the cooling device R1 wh1ch is at the pressure P1. The orifices 'the pipe 15 and valve 21.. l p

then acts throughout the whole time of the controlled by the suction valves communicate throughthe conduits 15 16 with the refrigerating apparatus R2 which is at the,

pressure P2. 1

In this case, the operation lis as follows. Considering the action which takes place in .the left hand part of the cylinder, with the pistonA moving to the right, all the v ports will be closed, and the piston lwill therein shall remain unalfected by the variations in the output of air, and in this event the volume of air in the left hand end of the cylinder is V2; the piston continues to move to the right until the volume becomes V3; the pressure remains 'constant during' this movement, since air withdrawn from the refrigerating apparatus bythe pist0n is admit-tedA into the cylinder; when thev volume attains the valueV1, the piston will open the port 5*? and laces it in communication with the left and portion of the cylinder. A circuit is thus opened which connects this part of the cylinder, through the conduit 7 and the port 5", with .the

.fan W2 and the refrigerating apparatus R2,

returning thence to the cylinder through The fan W2 opening of the rt 5" to ensure the' exchange between t e air in the cylinder and the air in the refrigerating apparatus.

When the piston returns to the left, the

.port 5h is closed and the compression commencers, and the valve 21 closes. When the ,pressure returns to the initial value P1, the valve 2O which connects the end of the.

cylinder with the coolin device R1, which is at the pressure P1, w

now open. From this time onward, the pressure cannot rise above P1; "the volume of air is V1; the final movement of the piston to the left will take place at .a constant pressure equal to P1 the piston delivers air into the cooling device. When the volume of the cylinder has been reduced to the initial value V1,- the piston opens the port 4"; a circuit is then openedwhich by means of the conduit 7", the port- 4" and the pipe 17, connects the left hand end of the cylinder with the fan W1 and the cooling device R1, thence returning to the cylinder through the pipe 24 and the valve 20. The fan W1 performs the scavenging of the compressed air in the cylinder, and replaces this air by cold air supplied from R1, during the time when the port 4b remains open. The pis- .l ton then moves to the right, lthe port 4" and the valve 20 are closed, and the cycle proceeds as before. 4

The operation is the same, as concerns the other face of the piston. In spite of its apparent simplicity, second arrangement is in general less advantageous than the first. In the same cylinder it is in fact necessary to perform the successive scavenging operations while the piston is close to the end of the stroke, and then to circulate the air through the clack.

valves.- In order to carry out the scavenging in the proper manner, that is to say without losing a great amount of kinetic energy when traversing the ports, and without unduly reducing the speed of the machine, it is preferable to stop the piston at the ends of the stroke and to maintainv the valves fully open during a considerable part of the piston stroke, for instance about twothirds. This result can 'be obtained, as will be set forth hereunder. Bu-t 'the valves must open fora very short time in rela tion to this time of the piston stroke, so

that it becomes preferable to control the valves by special gear.4 In the lirst arrangemet, on the contrary, the power compressor is the only one to be' this asy

fitted with clack valves, and there is no inconvenience in allowing them to open and close automatically; in this case the 4main compressor can be provided with anyv s uitable arrangements for facilitating the scavenging operation.

In both `types of machines described, the l air expands at one face of the piston of the;

,main compressor whilst it islcompressed at. f

the other face, during any one piston stroke from one dead centre to another., The ,energy of expansion is in the 'first' place greater than the energy of compression, and the piston thus supplies energy; then the energy of compression becomes greater than that of expanslon, and the piston absorbs energy until the end of the stroke. The energy of4 expansion supplied during the first part of the vstroke is stored up in a flywheely mounted on the\driving shaft which operates the piston rod; the said iiywheel will giveback this energy during the second part of the stroke.

Further, in these machines, the heat ex- .changed between the air and the cylinder e walls is very small; on the contrary to what takes place in refrigerating machines usin saturated steam, the eilciency of a smal cylinder is aboutthe same as for a large cylinder, by reason of this small action of the cylinder walls. To obtain high power machines, these can now be constructed with multiple cylinders whose pistons are mountf ed on a common crankshaft as for internal combustion engines, and combinations can 'thus be had which are powerful as well as i lis supposed to be actuated simply by a crank and piston rod, and this has the advantage of simple construction.

1A drawback is however observed in this case. The time of opening of the ports is a rather` small fraction of the time of the piston stroke; but it ywould be most advantageous to increase to the maximum the time during which the said ports remain open, and conversely to accelerate the movement of the piston from one dead centre to the other, thereby 'reducing the speed to be given to the air to enable it to clear the said ports during the scavenging and thus rea duce thespeed of scavenging, whichis 'proportional to the square of the speed of the air; or otherwise, should the scavenging speed be predetermined, one may increase the speed of the machine, other factors being equal, and thereby augment the power.

In vorder to increase the duration of the scavenging by slowing up the piston when near the ends of the stroke, use can be made of the kinematic arrangement shewn diagrammatically in Fig. 3.

The crank is provided with an eccentric which turns about thecrank by means of the gearing A, B; in the figure, the gear wheels are shewn only by their pitch-circles.

The gear set comprises a stationary wheell with radius 2 1' mounted. coaxially upon the driving shaft O which actuates the piston, and a gear wheel B with radius r which rolls upon A. The end of the piston rod, which isxmounted upon the said eccentric, pivoted at the point P of the gear Wheel B which is situated at the distance p from the centre C of`said wheel. The arrangement is operated so that the centre P of the end of the piston rod shall ap roach the axis of rotation when passing t rough the dead centres. In these conditions, by suitably selecting the eccentricity p, the end of the piston rod P will describe a shortened epicycloid D. Let Po Q represent the height h of the cylinder ports, and P1 P2 the points at which the line perpendicular to O a: drawn through the point Qintersects the curve D; the ports will remain open'atA one end of the stroke, while the end of the piston rod covers the distance P1 P2 upon the curveyD. When the end of the rod is at P1, the centre of the wheel B is at'Cuand when .the end of the rod is at P2, the centre of the wheel is at` C2; it is thus observed that the ports will remain open during the time in which the shaft O. rotates through the angle 2 Q.

It is shewn in the figure that this angle is great, and that the ports will thus'remain open during a considerable fraction ofthe half revolution of the shaft C.

As shewn in the plan view, Fig. 4, the

driving shaft :c o y is rovi'ded with the stationary gear wheels l, C21 and is divided Aso as to form a combination which is symmetrical with respect to O X; the said s aft carries two cranks discs D1 D-2 having respectively a anion B1 rolling upon C11 and -a pinion 2 rolling u on C21; to the said pinions is connected t e eccentric rod E which communicates the motion to the piston rod.

The preceding arrangement can be used when the trunnion of the crank is in the overhangJ position, but the usual crankshaft cannot e employed; this would however represent a serious drawback in the case of multicylinder machines, 'analogous to internal.

. of a connecting rod which is connected with two gear wheels B1 B2 having the radius R centered upon the saidv trunnion or axle and Ievoluble thereon. 'The said gear wheels are not in direct en agement with the wheels C11, C21, as in t is case they would turn in contrary direction to the crank and not in the same direction, as in the receding case; the lanetary gears s of dlameter D are there ore interposed between the wheels B1 Bz and the wheels C11, C21, said planetary gears bein .mounted upon axles disposed upon extensions K Kof the arms of the crankshaft, and they engage the wheels C11 C21 as well as the wheels B1 B2, so that the wheels BIVBz will turn in the same direction as the crank and through an angle 2 when the crank turns through Obviously, the arrangements hereinbefore set forth are susceptible of all desired modifications in detail without departing from the principle4 of the invention.

What I claim is 1. In an apparatus jfor accomplishing refrigeration by means of air, an air cooler,.

a refrigerator, a compressor and. expander having ports communicatlngwith said air cooler, and other ports communicating with said refrigerator, and a reciprocating piston ving a radius of 2 R,

closing of said .prevailing in the refrigerator, said piston having `conduits adapted to permit `the passage of `said compressed air to said air cooler, and conduits adapted to-permit the passage o frigerator.

y 4. In an apparatus for accomplishing refrigeration by means of air, an air cooler, a refrigerator, a compressor having ports communicating ports commumcating with said refrigerator,

a piston adapted to reciprocate in said com- I pressor so as to compress air to the pressimultaneously sure prevailing in the air cooler and to expand air to the pressure prevailing in the refrigerator, said piston having conduits adapted to passage 'of said compressed air to said air cooler and conduits adapted to simultaneously permit the passage of said expanded air to said` refrigerator, and means for driving said piston so as-to cause it to dwell at each end of its stroke.

5. In an apparatus for accomplishing refrigeration by means of air, an air cooler, a refrigerator, a combined vdouhleacting compressor and expander having ports communicating with said air cooler and ports communicating with said refrigerator, a piston adapted to reciprocate in said compresser and expander so as to compress air `on one s'ide thereof to the ypressure pre- `vailing in the air cooler and lto simultaneously expand air on the otherside thereof to the pressure prevailing in the refrigerator, said piston having conduits in each end adapted to alternately communi- ,cate with the ports communicating with `said air cooler and the portscommunicating with said refrigerator so as to permit the passage of said compreed air to said air cooler and the passage of said expanded air to Said refrigerator. 6. In` an apparatus flfor accomplishing refrigeration by means of air, an aii'. cooler, a rator, a combined double acting compressor and expander having ports communicating with said air cooler and ports communicatin with`- said refrigerator, a piston adapted presser and expander so as to compress air sor by air at the same f said expanded air to said rewith' said air cooler andpermit the to reciprocate in said comon one side thereof to the pressure prevailing inthe air cooler'and to simultaneously expand air on the other side thereof to the pressure prevailing in the refrigerator, said piston having conduits in each end ada d to alternately communicate with the ports communicating with said air cooler and with the ports communicatin with said refrigerator so as to permit ie passage of said compressed air to said aircooler and the simultaneous passage of said expanded air to said refrigerator, means fornimpelling the compressed air from said comprespressurefrom said air cooler, and means for simultaneously impelling expanded air from said compressor by air at the same pressure from said refrigerator. Y

7. In an. apparatus for accomplishing refrigeration by means of air, an air cooler, a refrigerator, a combined double acting compressor and expander having ports com-l municating with said refrigerator, a piston adapted to reciprocate in said compressor and expander so as to compress airv on one side `thereof to the pressure prevailing in the aircooler and to simultaneously expand air on the other side thereof to the ressure ,prevailing in the refrigerator, sai piston having conduits in each end adaptedto alternately communicate. with the ports communicating with said air cooler andthe ports communicating with said erator so as to permit the passage of sai compressed air to said cooler and the simultaneous passage of said expanded air to said refrigerator, means for impellmg the compressed air from said compressor by air-.at the same pressure from .said air cooler, means for simultaneously 11mgl expanded air lfrom said compreor yair vat the same pressure from said refrigerator,

simultaneously expand air to the pressure prevailing in the refrigerator, aid piston having conduits adapted to p ermit thepa'sf sage of' said compressed air to said air cooler and conduits adapted to permit the a e of said expanded air to said re- ?rielittor, a crankshaft for driving said piston, and means for connecting saidl piston to said crankshaft so as to cause s aid piston to dwell at each end of thestroke.

9. Inan apparatus for accomplishingerefrigeration by means of air, an air cooler,

a refrigerator, a. compressor having ports communicating with said cooler and ports communicating with said refrigerator, a piston adapted to reciprocate in said compressor-so as to compress air to the pressure prevailing -in the air cooler and to simultaneously expand air to the pressure prevailing in the refrigerator, said piston having conduits adapted to permit the passage of said compressed air to said air cooler and conduits adapted to permit thepassa'ge of said. expanded air to said refrigerator, a crankshaft for driving said piston, a connecting rod and mean for ivotng the connecting rod to said crank aft so that the Aend of said rod is moYed in an epicyclodal path, whereby7 said piston is caused to dwell at each end of its stroke.

In testimony whereof I'have signed this specification.-

CHARLES LONARD ARIANDIAURICE LEBLANC.

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