US 2123498 A
Description (OCR text may contain errors)
July 12, 1938. L. .B. M. BUCHANAN 2,123,493
' REFRIGERATING APPARATUS Filed Nov. 11, 1.936
INVENTOR v 1.551.157 5.M.5UCHHNHN Patented July 1% 193$ umrao s'mr Es PATENT oFFics v f "amass nnrnronna'rmo APPARATUS Leslie E. M. Buchanan Springfield, Mass, as-
signor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania I Application November 11, 1936, Serial-No 1103M crating apparatus employing a hermetically sealed compressor mechanism and has for an object to provide improved apparatus of this kind. A further object of my invention is to provide improved means for conducting refrigerant vaporized in high and low temperature evaporators to the inlets of a hermetically sealed compressor.
A further object dfmy invention is to provide a refrigerating system having aplurality of evaporators and a hermetically sealed compressorof the so-called, ported cylindertype wherein im-' proved meansare employed for conducting the vaporized refrigerant to the compressor.
These and other objects are effected by my invention as "will be apparent from the following description and claimstakn in connection with this application, in which:
.Fig. 1 is a diagrammatic view showing a the accompanying drawing, forminga part of 5- temperature refrigerating'system having 9. hermetically'sealedcompressor and arranged in ac- Reference will now be had to Figs. 1 and a of I the drawing, wherein relatively low and high term perature evaporators It and II are shown connected to a refrigerant condensing unit 12 having a hermetically sealed compressor l3 and a condenser shownvat. M. The compressor I3 is preferably driven by an electric motor l5, both ;of which are enclosed by a. It.
' shaft 19 that is journaled in theirame l1- and which carries a crank 2| for actuating the comprefssor. The compressor Iii-includes a cylinder A. frame I1 is carried by the casing I6 inany suitable manner and defines the'support for the motor l5and compressor l3. Openings 20 are preferably provided in the frame IT. for permitting circulation of vapor'ous refrigerant through the motor l5 for cooling the same. 7 The motor 15 includes a rotor element l8 carried by a 22 having a'piston 23 therein, the latter being reciprocated by the crank 2| through the medium of a connecting rod 24. An oil thrower 25 maybe employed for distributing lubricant; shown at 28; over the moving element s'of the motor. and com.- pressor. I I
The cylinder 22 includes a valve structure,
I d 5 Claims. (01. 02- My invention relates to two temperature refrlgshown generally at 21 and disposed between the cylinder 22 and a head 22. The valve structure 21 may be of any suitable type for controlling the passage of' refrigerant between the head 28 and the cylinder 22. The head 22 has an inlet forvaporous refrigerant shown at 29 and a conduit 3| for compressed refrigerant extends from the head 28 through the casing iii to the condenser H. A second inlet or port 32 for refrigerant vapor is formed in the wall of the cylinder 22 and a conduit-33 provides communication between the inlet or port 32 and the higher temperature evaporator ll, said conduit 33-passing through the casing l6 as shown. The inlet 29 of the compressor I3 is'in communication with the interior of the casing it which receives vaporous refrigerant from the low temperature evaporator" I0 througha conduit fit. I
Liquid refrigerant in the condenser M is sup-.
--'plied to the evaporators ill and ll through suitable expansion devices shown at'35 and 36. The flow of refrigerant from the evaporators Hland II to the conduits 34 and 33, respectively, is con trolled by suitable valves 31 and 38. Accordingly, refrigeration of both evaporators may be effected byopening the'valves 31 and 38 and operating the com-pressor l3 or the evaporator-s l0 and II may be'selectively operated byopening the valve asso--- ciated with the evaporator to be operated.
A conduit 39 is connected between the conduits 33 and 34- and includesa valve M, the purpose of which is referred to hereinafter.
V Operation 'I'l'iecompressor mechanism described in the foregoing is of the so-called. ported cylinder type.
During operation, low pressure refrigerant is drawn into the cylinder 22 as the pist'pn 23 descends, through the inlet2il and valve structure 21. l'he relatively highpressure refrigerant vapor' enters the cylinder 22 through the port 32 when the latter is uncovered by the piston 23 near the end of, its stroke. The low pressure vapor in the cylinder 22 is compressed by the higher pressure vapor so that, during the compression stroke,
the piston compresses a mixture, of the vaporshaving' a density substantially equal to the density ofthe' higher pressure vapor;
l0 and H are operated and their respective suction line valves. 31 and 38 are open. 7
When the valve 31 is open and the 'valve 38 is closed, the lower temperature evaporator only is operated. Accordingly vapor'ous refrigerant is admitted to the cylinder 22 through the inlet This operation. is effected during periods. when both evaporators pressor -mechanism. Thepresent application is' at this time is of no importance and the only result thereof is a reduction in pressure in the conduit 33 as far as the valve 38, to substantially the pressure value in the cylinder 22 at the time the port opens.
During periods when the higher temperature evaporator is operated, the valves 21 and 38 are closed and open, respectively. At this time, the
valve ll is opened to permit the higher pressure vapor from the evaporator II to enter the casing through the conduits l9 and ,34, and, therefore, to effect admission of the vapor to the cylin; der'22 through the inlet 29. This operation preventsthe compressor from pulling a high vacuumin' the cylinder 22 prior to the time that the port 32 is uncovered, which condition would prevail if the higher pressure vapor were admitted to evaporators circulates through the casing ii at all times that the compressor operates and,
therefore, cooling of the motor and compressor and the lubricant is efiected at' all times by the vapor. I
In my copending application, Serial No. 110,203,
filed November 11, 1936 and assigned to the Westinghouse'Electric 8: Manufacturing Com--, pany, I have disclosed and broadly claimed the system of controlling the flow of vapor from a plurality of evaporators to a multiple inlet comdirected to the application of such system to a hermetically sealed mechanism so that the cold gas from one or the other. of the evaporators is employed for cooling the mechanism in" the casing at all times that the mechanism is operated.
In Fig. 2, Theme shown a two temperature system wherein the evaporators are operated to- Bether at all times that thesystem is active.
. The low and high temperature evaporators are shown at ill and II, respectively, and may be suppliedwith condensed refrigerant fromythe condenser it in the same manner as shown in Fig. 1. Elements which are common to both embodiments are represented by similar numerals in both Figs. 1 and 2: The evaporators Ill and II may be connected to the interior of the casing and the inlet port 32 in' this embodiment in the same manner as shown in Fig. 1, but I prefer to show in Fig. 2 asecond method of connecting the evaporators to the hermetically sealed mechanism.
- The low temperature evaporator i is providedwith a suction conduit '48 thatextends through the casing II and commifnicates directly with the inlet 22 in the cylinder head 28. The high temperature evaporator II is connectedto a suction conduit 48 that communicates with the interior of, the casing. I. The cylinder inlet or port 22 is-in direct communication with the interior oi! the casing l8. Accordingly, low pressure vapor from the evaporator iilis conducted directly to the cylinder inlet 29 and the higher pressure vapor from the 'evaporatoril passes' through the conduit to the interior of the casing l8 and thence through the port 32 to the cylinder 22 as the compressor i3 is operated. The compressing of the low pressure gas in the cylinder 22 by the higher pressure gas entering through the port 82 'and the-subsequent compression of the mixture of gases is accomplished in the same manner as described heretofore.
4 terior of the casing. .2
3. In refrigerating apparatus, the combination 7 2,128,498 opening 29 only. The uncovering of the port 32 In the present embodiment, the interior of the casing I6 is subjected to the higher pressure vspor entering through the conduit 46 at all times. As both evaporators I 0 and II are operated together, flow of vapor through the casing I6 is effected for cooling at all times that the compressor i3 is actuated.
, From the foregoing, it will be apparent that I I have provided an improved two temperature refrigerating system employing a hermetically l0 sealed compressor mechanism having a plurality of vapor inlets wherein cooling of the elements and the lubricant withinthe hermetic casing is effected at all times that the compressor operates. As the interior of the casing issubjected to cool vapor at relatively low pressure, less contamination of the lubricant with refrigerant is obtained than with systems wherein the relatively high pressure compressed vapor prevails in the casing. A concomitant of this operation is the passage of less lubricant to the condenser with the high pressure gas, as is well understood. While I have shown a hermetically sealed com-\ pressor of the ported cylinder type, it will be understood thatmyinvention is not so limited and that other types of. multiple inlet compressors spirit of the invention. u While I have shownmy invention in two forms,
. may be employed without departing fiom the it will beobvious to those skilled in the art that 39 I it is not so limited, but is susceptible of various other changes and modifications without depart-' ing from the spirit thereof, and I desire, there- ..fore, that only such limitations shall be. placed thereupon as are imposed by the prior art or as 36 are specifically set forth in the appended claims.
What I claim is: -1. In a refrigerating system having first and second refrigerant evaporators, the combination of a compressor mechanism including a cylinder 40 and a piston movable therein, a casing for hermetically enclosing said compressor mechanism, said cylinderhaving a first inlet port-for". re-
frigerant vaporized in the first evaporator and a I second inlet port communicating withthe space within the hermetic casing for refrigerant vaporize'd in the second evaporator, a conduit for conveying refrigerant vaporized in,the first evaporator to said first inlet port of the compressor,
said conduit extending through the hermetic casing and a second conduit for conveying refrigerant vaporized in the second evaporator to the interior of said hermetic casing.
2. In refrigerating apparatus, the combination of relatively high and low temperature evapm rators, a compressor mechanism including a cylinder and a piston movable therein, a casing for hermetically enclosing the compressor mechanism, said cylinder having a first inlet port for refrigerant vaporized in the low temperature evaporator and a second inlet port communicating with the interior'of the casing for refrigerant vaporized in the higher temperature evaporator,
a conduit extending through the hermetic casing and connecting the low temperature evaporator 05 and said first inlet port of the compressor, and a second conduit providing communication between the higher temperature evaporator and the inof relatively high and low temperature evaporators, a compressor mechanism including a cylinder and a piston movable therein, a casing for hermetically enclosing the compressor mechanism, said cylinder having a first inlet port for A A arcane refrigerant vaporized in the higher temperature evaporator and asecondinletport communicating with the interior of the casing for refrigerant vaporized in the lower temperature evaporator, a conduit extending through the hermetic casing and connecting the higher temperature evaporator and thefirst inlet port of "the compressor and a second conduit providing communication between the low temperature evaporator and the interior of the casing. v
4.. In refrigerating apparatus, the combination of relatively high and low temperature evaporators, a casing, a compressor mechanism disposed within the casing and having first and second inlets for refrigerant vaporized in the evaporators, one of said inlets being in communication with the interior of the casing, means for conveying refrigerant vaporized in the high temperature evaporator to the second of said inlets, means for conveying refrigerant vaporized in the lower temperature evaporator to the interior of the casing, and means eifective during periods when thejhigher temperature evaporator only is refrigerated for conveying a portion of the refrigerant vaporizedtherein to the interior of thecasing.
5. In refrigerating apparatus, the combination of relatively high and low temperature evaporators, a casing, a compressor mechanism disposed within the casing and having first and" second inlets for refrigerant vaporized in the evaporators, one of said inlets being in communication with the interior of the casing, a first con duit providing communication between the low temperature evaporator and the interior of. the
casing, a second conduit extending through the casing for conveying refrigerant vaporized in the higher temperature evaporator to the second of said compressor inlets, a connecting conduit providing communication between said first and second-mentioned conduits and a plurality of valves for controlling the flow of refrigerant through said conduits and effective during periods when the highertemperature evaporator only is operated to terminate flow of the lower temperature refrigerant to said first conduit and to pass a portion of the higher temperature refrigerant from the second conduit through said connecting conduit to the interior ofthe casing. v
meme 3. M. BUCHANAN.