US1994037A

US1994037A - Evaporator system for refrigeration

Info

Publication number: US1994037A
Application number: US642802A
Authority: US
Inventors: Norman H Gay
Original assignee: Individual
Current assignee: Individual
Priority date: 1932-11-15
Filing date: 1932-11-15
Publication date: 1935-03-12
Anticipated expiration: 1952-03-12

Description

March 12, 1935.

N. H. GAY

EVAPORATOR SYSTEM FOR REFRIGERATION 3'Sheets-Sheet 1 Filed Nov. 15, 1932 March E2, 1935. N. H. GAY

EVAPORATOR SYSTEM FOR REFRIGERATION Filed Nov. 15, 1952 3Sheets$heet 2 N. H. GAY

EVAPORATOR SYSTEM FOR REFRIGERATION March 12, 1935.

Filed Nov. 15, 1952 5 Sheets-Sheet 3 llllll'l UNITED STATES.

PATENT OFFICE EV APORATOR SYSTEM FOR REFRIGERATION Norman H. Gay, Los Angcles, Calif. Application November 15, 1932, Serial No. 642,802

29 Claims.

The present invention relates to improvements in refrigerating plants, and more particularly r'elates to the evaporating systems employed therewith.

In my United States Letters Patent #1,836,318 and #l,878,694, I have described ways of employing the energy of the refrigerant itself for maintaining an evaporator in operation, and for separating refrigerant liquid which has passed through the evaporator and returning it in the circuit.

The present invention relates to evaporator supply systems of this nature, and further pro-' poses the employment of a top-fed or trickle-type evaporator, and more specifically, a top-fed or trickle-type evaporator. in which multiple gas outlets are provided for the release of gas from the evaporator at intermediate points of the length thereof.

Other features of the invention reside in the forms of construction and arrangement of the several parts, and will appear in the course of the following specification and, claims.

Illustrative forms of practicing the invention are set forth in the accompanying drawings, in

which:

Figure 1 is a diagrammatic view showing the association of the several parts, in the conjunction of an evaporator feeding system of the present type and a top-fed or trickle-type evaporator.

Figure 2 is a detail view, on a larger scale, showing a means for regulating the rate of feed in one evaporator coil. I

Figure 3 is a similar detail view showing a permissive modification in the arrangement of the evaporator coil.

Figure 4 is a diagrammatic view, on a larger scale, showing a modified arrangement of expan-' sion valve system and liquid lift.

Figure 5 shows a further modification of these 6, 7 and 8 are similar views, on the same scale of Figure 1, showing other arrangements of the expansion valve system, and upper and lower liquid vessels.

18 to the interior of the ejector nozzle 19 located within the lower liquid vessel 20 which is sealed against the atmosphere. terminates below the normalliquid level in vessel 20 and has its upwardly directed nozzle end located within the expanded end of the liquidli ft pipe 21 which communicates with the upper liquid vessel 22 above the normal liquid level therein. This normal liquid level is determined in part by the overflow pipe 23. A gas equalizing pipe 24 provides communication between the top of the lower vessel 20 and the upper vessel 22 at a point above the normal liquid level in the upper vessel, but below the mouth of pipe 21. The operative cross section of the aperture in nozzle 19 may be, varied. by the manually regulatable stem 25.

Gas collecting in the upper vessel 22 is drawn off through the return conduit 26 to the compressor 10.

The liquid flowing from the upper vessel 22 through the overflow pipe 23 enters a header 27 which communicates with a plurality of coils of thetype shown in Figure 1, for example. These coils each "comprise a plurality of

runs

30a, 30b, 30c, 30d 30:: which may be formed, for example, of a single length by rebending it from point to point. It will be noted that such a coil may be constructed in a single plane and supported by pairs of

uprights

31, 32 which are bolted'together between the runs of the coil. The top run 30a is supplied by an up-comer pipe from the inlet liquid header 27, this header being located below thenormal liquid level in vessel 22, while the upper run 30a is substantially at this level. The ends of the upper run 30a which are opposite the liquid header 27, however, may be adjusted as to its height by the bolts 33. when this left-hand end of the upper run 30a is at a low level a larger quantity of liquid refrigerant flows through the coil than when it has been raised, as for example, in the position shown in Figure 2, corresponding to the full line position in Figure 3. It will be noted that this regulation is accomplished without any telescoping or relative mechanical movement of independent parts, and aifords an easy and direct manner of regulating the quantity of refrigerant entering each coil of a bank, and hence of equalizing the effect of the bank of coils.

The lower runs 30c, 30d may be horizontal, or each may have a slight incline to assist the flow of liquid refrigerant through the coil from its upper to its lower end. At the lower end, the final run 30:: extends below a normal liquid level in the lower liquid vessel 20, so that its low- The nozzle 19 v mitted to escape into a gas collector pipe 3'7 01' this coil, and thence to the gas outlet or header 38 for the bank of coils, and thence by conduit 39 into the upper liquid vessel 22 at a point above the mouth of the pipe 21. It is preferred to provide a battle 40 in the upper vessel 22 to assure a segregation of gas and liquid in this vessel.

In order to shut off a particular coil of a bank, a valve 41 is provided, for operation in conjunction with the adjustment bolt 33 of this coil.

The lower end of the gas collector pipe 37 is joined to a liquid return header 42 and thus to the lower vessel 20 at a point below the liquid level therein, so that the liquid level in the lower run 301: and in the gas collector pipe 37 is in correspondence with the level existing in the lower level 20. Hence, the pipe 24 and thegas collector pipe 37 both operate as balancing or equalizing pipes in the system.

The upper vessel 22 preferably extends downward for a distance below the overflow pipe 23 suflicient to provide a pool for the collection of oil. This upper vessel 27 is desirably of suflicient size to avoid rapid currents, and to afford the oil a sufficient time to settle out, whereby this upper vessel operates as an oil trap in the system. The oil thus collected may be drawn off through pipe 44, by opening valve 45 from time to time as desired.

In the operation of this system, with the compressor' 10 operating and the liquid refrigerant collecting in the receiver 14, the float valve 15 operates as an expansion control valve to permit the flow of liquid refrigerant at a. temperature corresponding to the temperature of the means employed for cooling condenser 12, toward the nozzle 19. The release of pressure occurring at the expansion valve results in the evaporation of a portion of this liquid refrigerant and the cooling of the remainder to a temperature determined by the pressure drop in passing from the high pressure to the low pressure portions of the system. This evaporation gives rise to flash gas and an increase in the volume of refrigerant vfluid (i. e. mixed gas and liquid) in the nozzle 19, and thus results in a jet of fluid moving upwardly in the liquid-lift pipe 21, which draws with it liquid from the lower liquid vessel 20 and delivers the final mixture into the upper liquid vessel 22, where it separates into liquid and gas, and attains the low liquid temperature of the system. The gas returns to the compressor in circuit. The liquid collects, yields off any oil there in; and as the level rises in the upper vessel 22, part of this liquid flows through overflow pipe 23 into the liquid inlet header 27 and thus into the evaporator coils, trickling down through these coils and evaporating in proportion to the heat As this trickling liquid evaporates, the gas moves to the

multiple outlet

34, 35, 36, and thus into the gas collector pipe 37 and to the upper vessel 22 and thus back to the compressor. If the coil is already at low temperature, and its regulation permits the delivery of a portion of itsliquid into the bottom run 30:11, the liquid level'in the lower vessel 20 tends to build up, and this liquid is then lifted into the upper vessel 22 for re-circulation through the evaporator. Any gas forming in vessel 20 immediately escapes through the equalizing pipe 24. If too great a level of liquid is built up in the upper vessel 22, tending to flood the evaporator system, it may escape downwardly through the equalizing pipe 24 into the lower vessel 20 for re-circulation: but it will be understood that in a closed system, this can only occur momentarily, as there is then so little gaseous refrigerant that the compressor is drawing a considerable vacuum and the receiver 14 soon becomes emptied and no longer delivers liquid into the system. The evaporator operates at a greater degree since more liquid is present in each of the runs, and the evaporated gas passes back to the compressor in response to the greater degree of vacuum produced thereby. The operation is, therefore, selfcorrective.

It is also possible to operate the system as shown in Figure 1 with the elimination of the floatvalve 15, and with the employment of the manual valve 17 as the expansion valve. In this event, if the operation of the device indicates that too much liquid is entering the evaporating coils, and adjustment of the bolts 33 has been suchthat the coils are operating at uniform effectiveness, then the partial closing of valve 17 will result in a correction of the tendency for increase of liquid level.

In the form of construction shown in Figure 4, the evaporator coil, headers and upper vessel are assumed to be the same as in Figure 1. The lower vessel 20 is likewise substantially identical with that of Figure 1, but an electrically ope ated expansion valve 15a is provided, which opens upon energization of its solenoid 50. The ener- V gization of the solenoid may be accomplished from battery 51 in various ways. In Figure4, the float 52 within the receiver 14 is connected to a circuit controlling switch arm 53 which closes a circuit by conductor 54 to conductor 55 and thence by switch 56 and conductor 5'7 to the solenoid 50. Hence the valve 15:; will be operated to open when the level in receiver 14 rises to a predetermined level: and the valve closes automatically in the usual manner again, when this level drops until the circuit is broken at switch 53. However, by moving the switch 56 to another position, current will flow from conductor 54 through a manually closable remote switch 60 and thence by conductor 55a, switch 56 and conductor 59 to the solenoid 50 for opening the valve. Likewise, in another position of the switch 56, current will flow from conductor 54 when the thermostat element 61 closes its contacts in response to a definite high temperature, and thence by conductor 55b to switch 56, and ultimately to the solenoid 50 to produce an opening of the valve 15a. These forms indicate the possibilities of establishing a remote control of the system, with the operation of the structure as already described for Figure 1.

In Figure 5, a further formjof the invention is shown in which the lowervessel. 20a is provided with the gas equalizing pipe and the liquid equalizing pipe 71 which communicate through shut off valve 70a, 710. with the interior of a valve float chamber 72, which thus is equalized with the lower vessel 20a. The liquid conduit 18 from by the needle valve 74. This needle valve is opened by the action of float when the liquid level falls in the lower vessel 20:: and the float chamber 72, thus'permitting further refrigerant to enter from pipe 18 and pass through the pipe 76 to the interior of the nozzle 19 of the ejector. In general, the operation ofthis system is the same as that already described with respect to Figure 1, except that the system is automatic in reducing the quantity of liquid which is, admitted to the system, and controlling it on the basis of the liquid level in the lower vessel 20a, and hence the head of liquid pressure existing in the liquid header 42.

In the form of execution shown in Figure 6,.the pipe 16a from the receiver is connected through an electrically actuated valve 15b and the manually operable valve 17a. with the lower vessel 20b, and merely delivers its mixed gaseous and liquid refrigerant thereinto, without the employment of ejector action. The flash gas, however, accumulates in the lower vessel 20b so long as the relief valve 80 between the liquid outlet header 42 and the lower vessel 20b is closed, and oper ates to force the liquid from the lower vessel 20b through the liquid lift pipe 21a into the upper vessel 22a as before, from which it passesby the overflow pipe 23 into the evaporating coils. This, however, results in a collection of liquid in and above the header 42. To relieve this liquid, the valve 80 is opened from time to time: and if desired the electrically operated expansion valve 15b is simultaneously closed. The valves may,

for-example, be controlled in opposition from -a rotating switch 81 which closes a circuit from a battery 82 to the conductors 83 and thus to the control solenoids 84, 85 ofvalves 15b, 80. During the opening of valve 80, the liquid flows from the header 42 and the gas collector pipe 37 to the lower vessel 20b and flashgas may pass upwardly into gas collector pipe 3'7 and thus into the vessel 22a and back to the compressor. It is not, however, essential to shut off the expansion valve 15b in order to establish this balancing effect, but expansion valve 15b must be open when relief valve 80 is closed.

In Figure 7 a further modification is shown which the lower vessel 200 has an ofl'z-set containing a portion of the conduit 18 and a needle valve 91 controlling the conduit and thus regulating the passage of refrigerant from the receiver. This needle valve '91 is connected to a float 92 located in the lower vessel 20c itself so that the needle valve opens as the level rises in the lower vessel 20c. The mixed liquid and gas passing the needle valve 91 (operating as an expansion valve) flows through pipe 93 into the upper vessel 22 at a point above the normal liquid level therein. The operation of this system is substantially the same as before, except that the liquid in the lower vessel 20c is not delivered as such into the upper vessel 22b but is balanced in pressure therewith by the equalizing pipe 24a which permits the free escape of gas. An accumulation of liquid in the lower part of the system results in a lesser delivery of liquid through the pipe 93 into the upper vessel 22b, and hence a lesser flow of liquid to the liquid inlet header 2'7 and thus to the evaporating coils-so that the existing condition of over-supply tends to correct itself.

This same result can be attained, by manual supervision and control in the form shown in Figure 8, in which the manual valve 1'7 is connected by pipe 93a to the upper vessel 22c. This manual valve 17 is, for example, opened or closed as the liquid level rises or falls in the gage 95 of the lower vessel 20d.

' Figures 1, 4, 5, and 6 operate by energy liberated in passage from high pressure to low pressure at expansion valve to lift the refrigerant liquid.

It is obvious that while specific types of float valve control are shown at Figures 1, 4, 5 and 7 the various types are interchangeable, and that electric types can replace mechanical types or vice versa.

' It is obvious that the invention is not limited solely to the forms of construction shown, but that it may be modified in many ways without departing from the scope of the appended claims.

Having thus described the invention, what I claim asnew and desire to secure by Letters Patent, is:

1. In a refrigerating system, an evaporator including a plurality of successively superimpomd runs each arranged substantially horizontally and connected in series for the free flow of liquid refrigerant downwardly from one run to the other, an-upright gas collector pipe, and a plurality of gas outlets connected to runs at different levels and to said gas collectorpipe.

2. In a refrigerating system, an evaporator including a plurality of successively superimposed runs arranged substantially horizontally and connected in series for the free flow of liquid refrigerant downwardly from one run to the other, an upright gas collector pipe, a plurality of gas outlets connected to 111118 at different levels and to said. gas collector pipe, and means for supplying liquid refrigerant to the top run.

3. In a refrigerating system, an evaporator including a plurality of successively superimposed runs arranged substantially horizontally and connected in series, an upright gas collector pipe, a

plurality of gas outlets connected to runs at different levels and to said gas collector pipe, means for supplying liquid refrigerant to the top run. and means for raising and lowering the and of said top run remote from the supply means.

4. In a refrigerating system, an evaporator including a coil providing a plurality of runs connected in series, a substantially vertical gas collector pipe, multiple gas outlets extending-from rims at different levels to said gas collector pipe, means for supplying liquid refrigerant into the top runfrom which it may pass successively downward through the runs in series, means for supporting the runs in substantially fixed position adjacent said supply means, and a device for raisingand lowering the connected end of the too run and next succeeding run which is remote from the said supply means.

5. In a refrigerating system, an evaporator including a length of pipe rebent into a plurality of superimposed substantially horizontal runs located in a vertical plane, a gas collector pipe located substantially in saidplane and arranged substantially in a vertical position, and a plurality of gas outlets connected with said gas collector pipe at different levelsand with said rims at different points of height.

6. In a refrigerating system, an evaporator including a plurality of superimposed substantially horizontal rims connected 'in series, a vessel ,for

containing liquid refrigerant to a level corresponding to that of the top r n. and a supp y conduit establishing communication between said vessel and the top run and including an upwardly extending end which opens into said vessel.

7. In a refrigerating system, an evaporator including a plurality of superimposed substantially horizontal runs connected in series, a vessel for containing liquid refrigerant to a level corresponding to that of the top run, a supply conduit establishing communication between said vessel and the top run and including an upwardly extending end opening into said vessel, and means for bodily raising and lowering the end of said top run remote from the connection of the supply pipe thereto.

8. In a refrigerating system having a compressor, a condenser, a top-feed trickle-type evaporator and conduits for connecting the same in circuit, a vessel interposed in the conduit between the condenser and evaporator, an expansion valve for controlling the flow of refrigerant from the condenser into said vessel, and means operated by the transfer of refrigerant through said expansion valve from the high pressure portion to the low pressure portion of the system for raising refrigerant'from the evaporator outlet into said vessel.

9. A refrigerating system having a compressor, a condenser, a top-feed trickle-type evaporator, a first vessel for receiving liquid refrigerant from the bottom of said evaporator, a second vessel connected to the top of said evaporator to deliver liquid refrigerant thereto and to a plurality of points thereof to receive gaseous refrigerant therefrom, a conduit connecting the gas space of said second vessel with the compressor, a conduit including an expansion valve for connecting the condenser and said second vessel, and an equalizer pipe for connecting the gas spaces of said vessels.

10. In a refrigerating system having a com-- pressor, a condenser, a top-feed trickle-type evaporator and conduits for connecting the same in circuit, a low-level vessel connected to the bottom of the evaporator for receiving liquid refrigerant therefrom, a high-level vessel interposed in the conduit between the condenser and evaporator for supplying liquid refrigerant to the top of the evaporator, an expansion valve in said condenser-evaporator conduit for separating the high and low pressure portions of the system, and means operated by the transfer of refrigerant from the high pressure to the low pressure portion of the system for raising liquid from the low-level vessel to the high-level vessel.

11. In a refrigerating systemhaving a comp"essor, a condenser, a top-feed trickle-type evaporator and conduits for connecting the same in circuit, a vessel connected to the bottom of the evaporator for receiving liquid which has passed through said evaporator, an expansion.

valve located in the conduit between the condenser and evaporator, and ejector means operated by the refrigerant passing through said valve toward said evaporator and serving to raise the liquid from said vessel.

12. In a refrigerating system having a compressor, a condenser, a receiver, a top-feed trickletype evaporator and conduits for connecting the same in circuit, a valve operated according to the liquid level in said receiver for controlling the passage of refrigerant from the receiver toward said evaporator, a vessel connected to the bottom of said evaporator for receiving liquid which has passed through the evaporator, and means operated by the refrigerant passing through said valve for raising the liquid from said vessel. v

13. In a refrigerating system having a compressor, a condenser, a top-feed trickle-type evaporator and conduits for connecting the same in circuit, a firstvessel connected to the bottom of said evaporator for receiving liquid which has passed through the evaporator, a second vessel located at a higher level than said first vessel and connected to deliver refrigerant to the top of said evaporator, a gas equalizer pipe connecting the gas spaces of said vessels, a valve for controlling the passage of refrigerant from said condenser toward said evaporator, and means operated by the refrigerant passing through said valve for raising liquid from said first vessel into said second vessel.

14, In a refrigerating system having a compressor, a condenser, a top-feed trickle type evaporator and conduits for connecting the same in circuit, a first vessel connected to the bottom of said evaporator for receiving liquid refrigerant from the bottom of said evaporator, a second vessel connected in the conduit between said condenser and evaporator for deliveringliquid refrigerant into the top of said evaporator and also connected in said conduit between said evaporator and compressor, and a gas equalizer pipe for connecting the gas spaces of said vessels and operative to permit reflux of liquid from said second vessel into said first vessel before liquid in said second vessel rises to the level of the connections in said evaporator-compressor.

15. In a refrigerating system having a compressor, a condenser, an evaporator and conduits for connecting the same in circuit, a first vessel for receiving liquid refrigerant which has passed through the evaporator, a second vessel located at a level above that of the first vessel and connected in the conduit between the condenser and evaporator for delivering'refrigerant into said evaporator, an ejector operated by refrigerant passing from said condenser to said second vessel for raising liquid from said first vessel into said second vessel, a valve located betweensaid condenser and said ejector, and remote control means for actuating said valve.

16. In a refrigerating system having a compressor, a condenser, an evaporator and conduits for connecting the same in circuit, a first vessel for receiving liquid refrigerant which has passed ,through the evaporator, a second vessel located at a level above that of the first vessel and connected in the conduit between the condenser and evaporator for delivering refrigerant into said evaporator, an ejector operated by refrigerant passing from said condenser to said second vessel for raising liquid from said first vessel into said second vessel, a valve located between said condenser and said ejector, and thermostatic valve control means for actuating said valve.

17. In a refrigerating system having a compressor, a condenser, an evaporator and. conduits for connecting the same in circuit, a first vessel for receiving liquid refrigerant which has passed through the evaporator, a second vessel interposed in the conduit between the condenser and the evaporator, an ejector connected in the conduit between the condenser and said second vessel and operated by the refrigerant flowing toward said second vessel for raising liquid from said first vessel into said second vessel, a valve located in the conduit between the condenser and ejector, and means responsive to the rise andfall of liquid level in said first vessel for closing and opening said valve.-

18. In a refrigerating system having a compressor, a condenser, an evaporator and conduits for connecting the same in circuit, a first vessel for receiving liquid refrigerant which haspassed through the evaporator, a second vessel interposed in the conduit between the condenser and the evaporator, an ejector connected in the conduit between the condenser and said second vessel and operated by the refrigerant flowing toward said second vessel for raising liquid from said first vessel into said second vessel, a valve located in the conduit between the condenser and the ejector, means responsive to the rise and fall of liquid level in said first. vessel for closing and opening said valve, and a gas equalizer pipe for connecting thegas spaces of said vessels.

19. In a refrigerating system, acompressor, a condenser, an evaporator and conduits for connecting the same in circuit, a first and low-level vessel for receiving liquid refrigerant which has passed through the evaporator, a second and high-level vessel connected in the conduit between the condenser and the evaporator for supplying liquid refrigerant to the evaporator and alsoconnected in the conduit between the evaporator and compressor, and a valve operated in response to the liquid level in said first vessel .for controlling the fiow of refrigerant from the condenser into said second vessel.

20. In a refrigerating system having a compressor, a condenser, an evaporator and conduits for connecting the same in. circuit, low-level and high-level vessels connected in series for liquid flow between the condenser and evaporator, a valve-controlled conduit means for permitting the movement of liquid refrigerant which has passed through the evaporator into said low- .level vessel and the escape offiash gas'from said low-level vessel, and valve means for controlling the passage of refrigerant from said condenser into said low-level vessel.

21. In a refrigerating system having a compressor, a condenser, an evaporator and conduits for connecting the same in circuit, low-level and high-level vessels connected in series for liquid flow between the condenser and evaporator, conduit means having control valve means for permitting the movement of liquid refrigerant which has passed through the evaporator into said lowlevel vessel and the escape of flash gas from said 1ow-level vessel, an expansion valve for controlling the passage of refrigerant from said condenser into said low-level vessel, and means for intermittently opening and closing said control valve.

22. In a refrigerating system having a compressor, a condenser, an evaporator and conduits for connecting the same in circuit, low-level and high-level vessels connected in series for liquid fiow between the condenser and evaporator, conduit means having control valve means for permitting the movement of liquid refrigerant which has passed through the evaporator into said lowlevel vessel and the escape of flash gas from said low-level vessel, an expansion valve for controlling the passage of refrigerant from said condenser into said low-level vessel; and means for intermittently and coordinately opening and closing said valves, in opposition to each other. 23. In a refrigerating system having a compressor, a condenser, an evaporator and conduits for connecting the same in circuit, a first vessel for receiving liquid which has passed through the 24. In a refrigerating system a compressor, a condenser, a top-feed trickle-type evaporator and conduits for connecting the same in circuit, a first vessel connected tothe bottom of the evaporator for receiving liquid refrigerant which has passed through the evaporator, a second vessel connected in the conduit between the condenser and evaporator for supplying refrigerant into said evaporator, a valve for controlling the fiow of refrigerant from the condenser into said second vessel, and a gas equalizer pipe for establishing open communication between the gas spaces of said vessels.

25. In a refrigerating system having a compressor, a condenser, and a top-feed trickle-type evaporator, a first vessel for receiving liquid refrigerant which has passed through said evaporator; a second vessel located at a higher level than said first vessel, a gas equalizer pipe for connecting the gas spaces of said vessels, a gas collector pipe connected with saidevaporator for delivering gaseous refrigerant into the gas space of said second vessel, 2. gas return conduit from said second vessel to the compressor, a conduit for connecting the condenser with said second vessel including a control valve, and a supply conduit for connecting said second vessel to the top of said evaporator.

26. In a refrigerating system having a com- I pressor, a condenser, a top-feed trickle-type evaporator, a gas collector pipe connected to said evaporator at a plurality. of vertically spaced points thereof, a high-level vessel in communication with said gas collector pipe, a gas' con- .duit connecting said high-level vessel with the compressor, a liquid supply conduit for connect-' ing said high-level vessel with the top of the evaporator, a low-level vessel connected with the bottom of the evaporator for receiving liquid refrigerant which has passed through the evaporator, a liquid conduit for connecting said vessels whereby the liquid in said low-level vessel may be raised into said high-level vessel, and means' operated by the transfer of refrigerant from a high pressure portion to a low pressure portion of the system for raising liquid from the lowlevel vessel to the high-level vessel.

27. In a refrigerating system, a compressor, a condenser, a conduit for connecting said compressor and condenser, an evaporator, a first.

vessel for receiving liquid refrigerant which has passed through said evaporator, a scondvessel located at a higher level than said first vessel, a conduit between the second vessel and the evaporator for supplying liquid refrigerant to the latter, a conduit for establishing communication between said second vessel and said first vessel at a point below a predetermined liquid level in the latter, an ejector nozzle located in said first 28. In a refrigerating system having a compressor; a condenser, anevaporator, a conduit for connecting said compressor and condenser, a first vessel for receiving liquid refrigerant which has passed through said evaporator, a second vessel located at a higher level than said first vessel and connected with the evaporator for supplying liquid refrigerant to the latter, a conduit for establishing communication between said second vessel and said first vessel at a point below a predetermined liquid level in the latter, an ejector nozzle located in said first vessel in operative relation with the mouth of said communication conduit, a conduit for connecting said condenser with said nozzle and including an expansion valve, an equalizing conduit for connecting the gas spaces of said vessels, and gas conduits for connecting said evaporator, second vessel and compressor.

29. In a refrigerating system having a compressor, a condenser, an evaporator, a conduit for connecting said compressor and condenser, a first vessel for receiving liquid refrigerant which has passed through said evaporator, a second vessel located at a higher level than said first vessel and connected with said evaporator for supplying liquid refrigerant to the latter, a conduit for establishing communicationbetween said second vessel and said first vessel at a point below a predetermined liquid level in the latter, an ejector nozzle located in said first vessel in operative relation with the mouth of said communication conduit, a conduit for connecting said condenser with said nozzle and including an expansion valve, externally operable means for regulating the cross-section of passage in said nozzle, and gas conduits for 'onnecting said evaporator, second vessel and compressor.

NORMAN H. GAY.