Refrigeration system

Nov. 11,1958 d. l. EVANS 2,859,596

REFRIGERATION SYSTEM Filed June 1, 1955 2 Sheets-Sheet 1

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Nov. 11, 1958

D. L. EVANS

2,859,596

REFRIGERATION SYSTEM

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2,859,596

Patented Nov. 11, 19S8

United States Patent-Office oil, scale and other foreign matter separated from the refrigerant, and from which sump such materials may be easily removed from the refrigeration system.

It is a further object of this invention to provide in a 5 closed circuit refrigeration system an improved, simple and effective arrangement in means for collecting and discharging, in an inexpensive and reliable manner with a minimum loss of refrigerant and without interfering with a refrigerant jet pump, the accumulated oil and 10 other foreign matter, such as scale, from a relatively undisturbed portion of the refrigeration system, such as the accumulator or surge tank of a refrigeration system.

Another object of the present invention is to provide, in a refrigeration system of the type described, an im15 proved arrangement for the recirculating of refrigerant, wherein, a cylindrical jet type of refrigerant recirculation pump is demountably housed for easy interchange in the lower portion of the surge tank and is operatively connected to and supported in the adjacent spaced ends ²θ of cylindrical tubing forming part of the refrigerant flow system fixed in the walls of the surge tank, for the ready assembly and disassembly of the complete pump or essential parts of the pump.

Still another objective of the invention is to provide a ²⁵ simplified form of apparatus for refrigeration, wherein, a critical relationship is established between certain interacting parts, which arrangement will permit substantially automatic control of the operating characteristics of the improved refrigeration system.

³θ A further objective of this invention is to provide a simple arrangement for easy interchange of elements of the refrigerant circulating pump for resisting the passage of the working substance or high pressure volatile refrigerant from the high pressure side of the system to ^0t&gt; the low pressure side of the system whereby to enable the control and establishment of desired operating characteristics of the refrigeration unit.

Another feature of the invention is to provide a refrigeration system including a compressor, a condenser, ⁴⁰ an evaporator, a pressure chamber through which the refrigerant is circulated, a jet pump for circulating refrigerant through the evaporator, and an interchangeable fixed orifice arrangement in the pump, having a critical relaticnship to the capacity of the refrigerant compressor, for ⁰ controlling the effective pressure of the working high pressure refrigerant admitted into the jet pump whereby to control the performance characteristics of the refrigeration system when operating on a conventional cycle or on a vapor-gas principle.

Another feature of the invention resides in precooling the refrigerant supplied to the jet orifice of the jet pump to control the operation characteristics of the jet pump.

A still further objective of this invention is to maintain ₅- a substantially constant and predetermined input pressure on the working refrigerant delivered by the pressure and flow control orifice to the inspirator or jet nozzle of the jet pump, whereby, to electively establish and maintain predetermined operating characteristics of the jet _Gq pump in the pumping and delivery of refrigerant to the evaporator of the refrigeration system.

The foregoing and other objectives, important novel features and advantages of this invention will become more apparent and be more easily understood upon 65 examination of the following description thereof and upon the examination of the accompanying drawings and consideration of the appended claims. It should, however, be understood that, without desire of limitation, this invention will be described as improvements in a simple ⁱ⁰ refrigeration system. Certain changes and variations may suggest themselves to those skilled in the pertinent arts, which changes may not, however, depart from the

2,859,396

REFRIGERATION SYSTEM '

Dari L. Evans, Bloomsburg, Pa., assignor to Girton Manufacturing Company, Inc., Millville, Pa., a corporation of Pennsylvania

Application June 1; 1955, Serial No. 512,502

Claims. (Cl. 62—471)

This invention pertains to refrigeration apparatus. More specifically stated, this invention relates to improvements in refrigeration apparatus wherein refrigerant, which is not evaporated at the time of discharge from the evaporator, is recirculated directly through the evaporator.

Still more specifically stated, this invention relates to improvements in the arrangements for demountably supporting the refrigerant circulating jet type pump or injector and to the arrangements for securing and for maintaining the satisfactory operation of such pump.

The specific improvements in the herein described and illustrated jet type pump are more specifically described and are claimed in the co-pending companion application Serial No. 512,387, filed June 1, 1955, and entitled “Combined Jet Pump and Regulator.”

Many refrigeration devices consist basically of a compresser and a condenser and an evaporator connected in series in the order mentioned, having a return connection from the evaporator to the compressor and having a by-pass connection between the inlet and discharge connections of the evaporator, whereby, to permit a pump associated with such by-pass to immediately recirculate through the evaporator that portion of the volatile refrigerant which failed to evaporate in the evaporator on its initial passage therethrough. In such devices it is common practice to use jet type pumps, using the high pressure refrigerant as working fluid or working substance for recirculating the unevaporated refrigerant through the evaporator. Such jet type pumps are commonly located at the lower or discharge end of a separator tank or surge tank or accumulator through which all of the refrigerant discharged from the evaporator passes and in which the liquid refrigerant and entrained oil and scale and other foreign matter is separated from the gaseous refrigerant being returned from the evaporator to the compressor. In many instances the design of, and the location of, such recirculation pumps is such that the oil and scale separated from the refrigerant in the accumulator or similar tank enter into the recirculation pump and at least greatly interfere with the satisfactory and efficient operation of such pumps. In many instances such pumps are so constructed or are so arranged in the refrigeration system as to be relatively unaccessible and if accessible, difficult to disassemble and reassemble.

In many instances it becomes desirable to vary the refrigerating capacity of the refrigeration apparatus and such variation commonly involves the cumbersome task of completely replacing the jet pump which controls the flow into the evaporator of both the high pressure refrigerant and the recirculated refrigerant.

It is therefore one of the objectives of this invention to provide an improved refrigeration system of the type described, having a readily removable and readily adjustable jet type pump, for the recirculation of refrigerant, positioned in the lower portion of a surge tank or accumulator above a sump arranged for the collection of

2,859,596 spirit of this invention and may come within the scope of the appended claims.

In the accompanying drawings:

Figure 1 is a schematic view diagrammatically illustrating an embodiment of the improved refrigeration sys- 5 tern of this invention.

. Figure 2 is a vertical cross-sectional· view taken along line 2—2 of Figure 1 of the drawings, and

Figure 3 is a longitudinal vertical central sectional view taken through a slightly modified form of the jet ίθ type pump and the lower portion of the refrigerant surge tank assembly.

Referring to the drawings, wherein like elements are identified by like numerals, 1 represents generally any suitable refrigerant compressor, such as a conventional ¹⁵motor powered Unit, from the discharge end of which compressed volatile refrigerant is supplied through conduit 2 to a condenser 3. From the condenser 3 the refrigerant is in turn discharged through conduit 4 to an underlying receiver 5. From the receiver 5 the refrig- ²⁰erant flows through conduit 6 to and through the high pressure and hot side of a heat exchanger 7 in which the high pressure refrigerant is cooled by the low pressure refrigerant being returned to the compressor 1 as will be hereinafter described. The cooled, high pressure refrig- ²^ erant flows from the heat exchanger 7 through conduit '8 to and through a suitable refrigerant filtering or screening unit 9. From the filter 9 the filtered and precooled refrigerant flows through conduit 10 into the working fluid entrance port 11 of a jet type injector or refrigerant ³θ pump 12. Pump 12 includes a refrigerant pressure and flow control orifice 13 positioned in the pump 12 immediately ahead'of the refrigerant inspirator or jet nozzle 14 as shown in Figure 3 of the drawings. The function of the orifice 13 is to control the pressure of the refrigerant ³⁵supplied to the Jet nozzle 14. The pump 12 is housed in, and to one side of, the lower portion of a refrigerant surge tank or pressure vessel 15, and the capacity thereof, particularly the capacity of the orifice 13, has a critical relationship to the capacity of the compressor 1. ⁴³

The precooled high pressure refrigerant or working substance upon flowing through the injector or jet pump 12 draws accumulated refrigerant from the lower portion of the tank 15 into the pump 12 through the aspiration or suction ports 16. The refrigerant thus drawn into 45 pump 12 through port 16 is discharged from the pump 12 together with the high pressure refrigerant from the orifice or pressure and flow restrictor 13 through the cold refrigerant discharge passage 17 into conduit 18. The refrigerant flows through conduit 18 into the evaporator 50 19 under pressure in excess of that prevailing in the upper portion of the surge tank 15. The suction ports 16 of pump 12 are positioned to one side of the central portion of the tank 15.

The warmed, gaseous refrigerant, together with any 55 entrained unevaporated refrigerant, oil, scale, etc. is discharged from the evaporator 19 through conduit 20 into the upper portion of the surge tank 15. In the upper portion of the surge tank and separator 15, the refrigerant. oil. etc. im-inges against the convex surface of a 60 'ved baffle element 21 mounted in the upper portion of the surge tank 15 toward one side of the vertical central portion of that tank and opposite from the aspiration ports 16 in pump 12. The baffle 21 is interposed in the normal path of movement of the gaseous refrigerant 65 from pine 20 toward the suction outlet 22 located at the ’’’’ex the conical upper cover portion 23 of the tank 15.

^The im-ingement of the gaseous refrigerant and entrained liquid refrigerant, oil, scale, etc. against the baffle element 21 causes the separation of the gaseous refrig- 70 erant from the entrained materials some of which' latter materials accumulate first upon the baffle element 21 and then drop with other like material into the lower portion of tank 15 directly below the baffle 21 to accumulate in the dished, lower head or inverted conical bottom wall 75 of the tank 15. Such accumulated foreign material may be discharged from the downwardly directed central apex portion of the bottom wall 24 in a controlled manner hereinafter described. The accumulated refrigerant is recirculated to the evaporator 19 by the jet pump 12.

From the surge tank 15 the warmed or spent refrigerant gas is drawn by suction from connection 22 into and through conduit 25 to and through the hot side of the heat exchanger 7 and thence flows through conduit 26 to the suction inlet of the compressor 1, thereby completing the flow cycle of the refrigerant.

The general arrangement in a refrigeration system as illustrated in Figure 1 of the drawings, wherein the system includes a series connected compressor, condenser, receiver, and evaporator is of course old. Similarly the use of filters or .screens for filtering or screening the high pressure refrigerant before it enters a refrigerant circulating pump of the jet type is also old. The use of heat exchangers, whereby the partially warmed refrigerant gas being .returned to the refrigerant compressor is utilized to chill or· precool the high pressure compressed and condensed refrigerant, as well .as the use of oil and other foreign matter separating arrangements for separating Undesirable quantities of oil and other foreign matter from the refrigerant are also generally old. In like manner arrangements in refrigeration systems whereby a surge tank 'is connected in parallel with the evaporator for the accumulation of refrigerant to be circulated or recirculated .through the evaporator and to separate, from the.refrigerant being returned to the compressor, the unevaporated refrigerant entrained with the gaseous refrigerant discharged .from the evaporator, as well as the use of jet .type pumps for the recirculation of such returned refrigerant from the accumulator to the evaporator, is also, generally old. This invention, however, provides a new, novel and useful arrangement of an interchangeable arrangement of a jet type refrigerant recirculating pump or-injector , removably mounted in the lower portion of the refrigerant surge tank above an oil and scale accumulating portion of the tank and to one side of and below the entrained, unevaporated refrigerant oil and scale separating baffles whereby the satisfactory , and efficient operation of the, jet type pump is assured. The ready interchangeability of the improved jet pumps or essential parts of the .jet pumps, whereby to repair damage to. the pump or to adjust the. pumps to the desired operating characteristics is made readily possible by . this invention.

The foregoing desirable demountable and interchangeable features are made possible by the use of a cylindrical jet pump 12 which extends diametrically through the lower portion of the surge tank 15, slightly above the oil and scale accumulating station within the lower wall 24 of tank 15. Pump 12 is telescoped at its opposite ends into the axially aligned, cylindrical, diametrically oppositely positioned support elements .17 and 27 permanently fixed in the vertical wall of the tank 15 as by welding. The support element 17 also functions as the refrigerant discharge connection for the flow of refrigerant from the tank 15 to the evaporator 19.

The cylindrical casing or body or housing 28 of the pump 12 is telescoped snugly, at its opposite ends, into the associated but spaced and axially aligned supports or hangers 17 and 27, and, if desired, the discharge end of the pump 12 may be removably sealed to the support 17, as illustrated in Figure 3 of the drawings, by the use of an O ring type elastic seal element 29. Seal 29 is seated in groove 30 in the outer surface of the pump housing 28 and sealingly engages the housing 28 and the inner surface of the support'17. The spacing of the adjacent ends of the supports 17 and 27 is such as not to overlap the laterally opening, equally spaced, aspiration ports 16 in the casing 28 of the pump 12.

The pump 12 consists primarily , of the cylindrical housing 28 having an .integrally formed Venturi element, generally identified by the numeral 31, in the discharge

2,859,596 end thereof, and having, at the opposite end of the housing 28, a hollow cylindrical, plug-like, ported closure element 32 snugly telescoped thereunto until a peripheral shoulder 33 at the outer end of element 32, surrounding the entrance port 11, engages the adjacent end of the 5 casing 28. The inner end of the plug-like insert element or flow passage means 32 is spaced from the adjacent inner end of the Venturi element 31 to form thereby an aspiration chamber 34 within the casing 28 and between the inner ends of the plug-like closure element 32 and 1θ the Venturi element or discharge passage element 31. Access to the aspiration chamber through the wall of casing 28 for the material to be pumped or recirculated is provided by the three circumferentially equally spaced, circular aspiration or suction ports 16, one of which ports ¹⁵16 is preferably directed downwardly as clearly illustrated in Figure 2 of the drawings.

An annular gasket 35 is snugly telescoped over the casing 28 of pump 12 and is sealingly interposed between the adjacent opposed, parallel faces of the flange 33 and ²θ the support 27 and sealingly engages the outer surface of the adjacent end of the pump casing 28 for releasably sealing the plug or ported closure element 32 to the casing 28 and for sealing the outer end of the assembly of the pump 12 to the support 27. A single conventional type coupling nut 36, having an inwardly directed flange 37 which overlaps the shoulder 33 of the flow passage element or plug 32, is threaded onto the support 27 and is utilized to sealingly compress the flared end 38 of θθ refrigerant conduit 10 between the juxtaposed flanges 33 and 37 whereby to seal the end of pipe 10 to the entrance port 11 in plug 32, and is also utilized to compress the gasket 35 into sealing engagement with shoulder 33, casing 28 and support 27, and is also utilized to lock &lt;&gt;.the pump 12 to the hanger or support 27.

Projecting inwardly through the aspiration chamber 34 beyond the ports 16 toward the Venturi element 31, there is provided a cylindrical inspirator nozzle or jet nozzle 14 extending inwardly from the inner end of the plug 32. Jet nozzle 14 is integrally formed with the ported closure or plug 32 and is also coaxial with plug 32. The cylindrical jet nozzle passage 39 is coaxially arranged with the casing 28, the plug 32, the orifice 13, the nozzle 14, and the Venturi element 31. Passage 39 extends from tlie orifice 13, located inside of the plug 32, cen- ⁴⁵trally through the aspiration chamber 34 to the entrance end of the Venturi element 31.

In the operation of the improved device in the illustrated closed cycle refrigeration system, the high pressure precooled, refrigerant or working substance supplied by ⁵⁰the compressor 1 through the condenser 3 and receiver 5 and heat exchanger 7 and filter 9, is restricted in its flow to and through the jet nozzle passage 39 by the refrigerant pressure and flow regulating orifice 13, whereby to assure that the desired quantity of refrigerant at the ⁰desired pressure is supplied to the nozzle passage 39. The expansion of the refrigerant while flowing from the orifice 13 into the jet nozzle passage 39 prevents the flow of relatively warm compressed refrigerant into the Venturi element 31. The chilling effect of such initial expansion of the refrigerant upon entering the passage 39 is absorbed by the relatively heavy pump closure element 32 which is due to its snug fit into the pump casing 28 and the snug fit of the casing 28 into the hanger ele- θ₅ments 17 and 27 enables the closure element 32 to conduct sufficient heat from these elements and from the incoming compressed refrigerant so as to preclude the “freez-on” of condensate which may be present in the refrigerant onto the orifice 13 or nozzle 14. γθ

The rapid flow and expansion of the jet of refrigerant discharged from jet nozzle 14 into the Venturi element 31 produces the suction whereby to draw in through the ports 16 of pump 12 the refrigerant which has accumulated in the lower portion of the surge tank 15. The 75 β

pumped refrigerant is blended with the jet stream refrigerant supplied from nozzle 14, and the blended mixture is forced through pipe 18 to the evaporator 19 wherein the suction pressure is substantially the same as in the surge tank 15 which is connected in parallel to the evaporator 19 between the refrigerant supply and return pipes from compressor 1.

Entrained unevaporated refrigerant, oil and scale which is discharged from the evaporator 19 into the pressure surge tank 15, is separated, in the upper portion of tank 15, from the gaseous refrigerant as a result of the reduction in velocity of the flow of the refrigerant after leaving conduit 20 and entering surge tank 15, and as a result of the use of baffle 21, and as a result of precipitation of such materials to the lower portion of the tank 15 on the side thereof fartherest removed from the ports 16 of the jet pump 12. Such an arrangement prevents the objectionable entrance of such oil and scale into the pump 12. The accumulated oil may be drained from the tank 15 by opening the pet cock 40 positioned in the lower portion of the inverted, conical shaped, lower wall 24 of the tank 15. The accumulated oil together with any accumulated scale or other sediment may also be removed by removal of the clean out and drain plug 41, in which drain plug the pet cock 40 is mounted. Inspection of the interior of the surge tank 15 is made possible by the inspection glass 42 in the side wall of tank 15.

As has previously been mentioned, it is desirable, when using a jet type pump or injector 12 for the circulation of a volatile refrigerant into an evaporator to select a pump having the right size orifice 13 whereby to establish a desirable critical relationship between the pump 12 and the capacity of the compressor 1. To a somewhat lesser degree the relationship of the refrigeration load of the evaporator and the corresponding suction pressure in the evaporator 19 and in the surge tank 15 in which the pump 12 is housed, also has a similar bearing on the operating characteristics of the pump or injector 12. Consequently the advantages offered by this invention, whereby a simply constructed pump 12 may be easily and quickly interchanged as a unit in the refrigeration system to secure the desired pump capacity and operating characteristics, or whereby the closure element 32 wherein the orifice 13 is located, may be easily interchanged with a similar closure element 32 having a different size orifice 13 to secure the desired pump adjustment, become obvious.

The use of a jet type pump or injector 12 for the circulation and recirculation of refrigerant to an evaporator 19, which, may if desired, be located above the elevation of the pump 12 and above the normal “shut down” elevation of the refrigerant in the surge tank 15, has the further advantage that such an arrangement will permit the unevaporated refrigerant in the evaporator to drain back into the surge tank from the evaporator upon the discontinuance of the operation of the pump 12, thereby providing desirable control of the refrigeration procedure in the evaporator.

From the foregoing description of this invention and from the accompanying drawings, it will be apparent that this invention realizes the introductorily enumerated objectives respecting a refrigeration system, which refrigeration system possesses the hereinbefore listed advantages and provides a new, unique and useful arrangement in a readily adjustable refrigeration system including a demountable and interchangeable refrigerant recirculating pump in which interchange of certain essential and critical elements may be quickly and easily made to establish the desired operating characteristics of the pump by the disconnection of the liquid supply line leading to the jet pump and the interchange of pumps or the interchange of the orifice carrying closure element of the pump.