US3276219A

US3276219A - Refrigeration system for cold vapor blast

Info

Publication number: US3276219A
Application number: US363461A
Authority: US
Inventors: Raymond M Leliaert
Original assignee: Wheelabrator Corp
Current assignee: Wheelabrator Corp
Priority date: 1964-04-29
Filing date: 1964-04-29
Publication date: 1966-10-04
Anticipated expiration: 1983-10-04
Also published as: SE324886B; AT259596B; CH429132A; DE1501169A1

Description

Oct. 4, 1966 v R. M. Lr-:LIAERT REFRIGERATION SYSTEM FOR COLD VAPOR BLAST med April 29, 1964 2 Sheets-Sheet l ENVSN '3 Nmrvam .sat1 9 INVENTOR. RAY/wam: M EL/4 ser BY 722o 47AM /KM`MM AYQOIILYQO ZOCKNOMZ. MoJ( 261m 44T roRNEYs Oct. 4, 1966 R. M. LELIAERT 3,276,219

REFRIGERATIN SYSTEM FOR COLD VAPOR BLAST Filed April 29, 1964 2 Sheets-Sheet 2 ELAST MACHINE DUzT COLLECTOR OTOR CONTROL IN1/MOR RAYMOND M. LEL/AERT TToR/vsrs United States Patent O 3,276,219 REFRIGERATION SYSTEM FOR COLD VAPOR BLAST Raymond M. Leliaert, South Bend, Ind., assignor to The Wheelabrator Corporation, Mishawaka, Ind., a corporation of Delaware Filed Apr. 29, 1964, Ser. No. 363,461 15 Claims. (Cl. 62-180) This invention relates to a system for the refrigeration of parts by means of a stream of cold air or other gas or fluid and it relates more particularly to a system of the type described having a flexibility to meet wide variations in demand for refrigeration, ranging from periods of no demand to periods of demand which greatly exceed the capacity of refrigeration engine, a reliqueer, recondenser or a cascade compressor-coil refrigeration system employed in the system thereby to shave olf the peaks and enable more efficient and effective utilization of refrigeration engine, a reliquefier, recondenser, or a cascade compressor-coil refrigeration system of intermediate capacity.

The invention will be described with reference to a system for the removal of flash or ns in the molding of parts of rubber or plastics, as described in U. S. Patent No. 2,996,846, wherein the parts to be deflashed are exposed to a blast of refrigerant such that the thin ns or flashing are reduced in temperature for embrittlement by the cold before the body portion making up the remainder of the parts. Engagement of the parts with a blast of particulate material operates to effect removal of the thin embrittled portions without undesirable effect on the remainder, therebyto produce nished parts Ifrom which the flash or tins are removed. The solids including the particles and removed plastic or rubber ilash are separated for recovery ofthe particles for re-use in the blast thrown against the refrigerated parts.

In the system of the aforementioned patent, use is made of a refrigerant liquid, such as liquid carbon dioxide, which is thrown directly onto the molded parts while in the blast machine to chill the parts whereby portions of small cross-section are reduced to embrittling temperature prior to the remainder for enabling removal of the embrittled portions by a centrifugal wheel blast of solid particles. The spent refrigerant gas is not re-usable in its spent state and as more refrigerant gas is added to the system the pressure within the system rises causing the cold gas and air to escape to the atmosphere outside the enclosed system by leakage, pressure relief valve or through doors during loading and unloading operations. This constitutes a material waste of refrigeration in that it exhausts a large amount of cold out into the atmosphere thereby to increase the cost of operation and to introduce other objections lto the described system.

The improvement of this invention is addressed to the use of a cold air blast or other blast of chilled gas or lluid for the refrigeration of the parts but wherein the air or gas or other iluid derives its refrigeration by indirect heat exchange with a refrigerant liquid maintained within a closed circuit whereby more eilicient use can be made of the refrigeration system and whereby the cold refrigerated air can be recovered for recycle in the refrigeration system thereby to reduce the amount and cost of refrigeration.

One of the principal problems arising in a system of the type described resides in the ability to meet the wide variations in demand from periods where no refrigeration of the parts is required during loading, unloading or non-use of the machine to periods when the demand for refrigeration varies between prefreeze periods and the mechanical abrasive blasting period subsequent to freezing of the flash on the parts and it varies depending upon the volume and nature of the parts being processed; the temperature required -for the selective embrittlement of the tins or flashings of the various parts varies depending somewhat upon the character and composition of the materials from which such parts are formed. The materials from which such parts are formed may range from rubbers and plastics capable of becoming embrittled at temperatures within the range of F. to +30 F. and organo silicon materials which are not embrittled until cooled to a temperature below F.

The design of a refrigeration system having a capacity sufiiciently to meet the demands for the refrigeration of parts formed of organo silicons can result in a unit having a capacity -far in excess of that needed for a great majority of the materials processed through the deflashing machine thereby generally to increase the cost not only from the standpoint of initial investment in equipment and installation, but also from the standpoint of space requirements, efciency of operation, and cost of operation, thereby to render the process less attractive.

It is an object of this invention to produce a refrigeration system of the type described which is simple in construction and easy in operation; which is effective to shave off the peaks in demand thereby to enable utilization of a refrigeration engine of intermediate capacity but which is capable of meeting the peak demands often required in use thereby to reduce the total cost of refrigeration; which is flexible in operation to meet the current demands for refrigeration from periods of low demand to periods of high demand thereby to adapt the single unit for multiple use in a refrigeration system; in which the refrigerant op-v erates in a closed cycle for savings in cost of refrigerant and refrigeration but in which the refrigeration is transmitted indirectly to a suitable carrier for supply of reyfrigeration in the desired amounts to the parts to be refrigerated; in which the amount of refrigeration taken up by the carrier can be varied to control the refrigeration conditions existing in the processing of parts for further flexibility in the control of the temperature to which the parts are refrigerated thereby to make most efcient use of refrigeration; and in which refrigeration can be recovered to save on the amount of refrigeration required thereby not only to increase the capacity of the machine but further to increase the savings in cost of refrigeration.

These and other objects and advantages of this invention will hereinafter appear and for purposes of illustration, but not of limitation, an embodiment of the invention is shown in the accompanying drawing, in which:

FIG. 1 is a flow diagram of the refrigeration system embodying the features of this invention; and

FIG. 2 is a schematic elevational view of a deilashing unit with which the refrigeration system of this invention is adapted to be utilized.

Referring now to the drawin'g, the system can be divided into a refrigerant circuit rshown in solid lines land a cold air refrigeration system shown in dotted lines and a signal or information circuitry in broken Ilines.

The yrefrigerant circuit includes a refrigeration engine, reliqueer, recondenser or lcascade system 10 dniven by a suitable power source and controlled by a low temperature safety switch 94 which shuts down the Irefrigenation engine when the temperature of the refrigerant liquid delivered through line 12 to a receiver 18 reaches a predetermined =low point. The refrigeration engine, for example, can be a standard piece of equipment, such as a Model B Cryogenerator, marketed by Cryogenerato'rs Division of North American Philips Co. Inc., of Ashton, Rhode Island. The refrigerant that is used in the system described in dichlorodiuo-romethane but other refrigerants, such as nitrogen, ethane, propane and the like, can

be used depending rupon the refrigeration temperature required to be developed in the system.

From the refrigeration engine 10, the cold liquid refrigerant flows through line 12 to the receiver 18 which is fitted with a safety valve 44 and a charging valve 36 through which additional refrigerant liquid may be introduce-d to make up refrigerant in the system. The receiver 18 is also provided with a level indicator 16 which shows when the right amount of refrigerant liquid has been added to the system or when 4the refrigerant has fallen below a predetermined operating level through leakage. The receiver is also fitted with a temperature indicator 126 for measurement of the temperature of the cold refrigerant liquid.

The receiver has an outlet at the bottom in communication with line 20 lhaving a pump 22 for movement of the cold refrigerant liquid from the receiver 18 through line 24 to the bottom side of one or a number of heat exchangers 26 and 26a, each of which is provided with coils 128 through which the refrigerant liquid flows in heat exchange with air or other gases or fluids of the refrigeration cycle. The warm-ed refrigerant leaves the heat exchangers 26 and 26EL at the top for return through

lines

30 and 34 to the refrigeration engine 10. Line 30 may be provided with a temperature indicator 118 for measurement of the temperature of the warmed refrigerant.

The cold air blast or refrigeration cycle includes a dust collector 82 which draws off spent cold 'air from the deflashing machine 122 and separates dust therefrom. Line 60 from the dust collector fan 84 and discharge T 86 communicates with a constant volume blower 54 which causes positive displacement of the spent filtered cold air through line 52 to one or more of the heat exchangers 26 and 26a depending on the open or shut positions of valves 50 and 50a. The air flows downwardly through the heat exchanger 26 :or 26a or both about the heat exchanger coils 128 for indirect heat exchange with the liquid refrigerant in countercurrent tlow upwardly through the coils to effect reduction in air temperature. The cold air issues from the outlet valves 130 and/or 130a at the bottom of one or both of the heat exchangers into line 66 for flow to line 88 and into the deflasher unit 122 where it flows over and through parts to be processed reducing the temperature of the thin sections of the flash or fins to the embrittlement state.

To provide temperature control of the cold air to the detlasher, a by-pass -line 64 is provided between

lines

60 and 66 whereby a portion of the air can be by-passed around the heat exchangers for rejoinder with the air cooled durin-g passage through the heat exchangers to enable adjustment of the temperature of the air to be `advanced through line 88 to the parts to a level between the temperature of the air recycled from the deashing machine and the temperature of the refrigenated air issuing from the heat exchangers whereby the temperature Of the blend `of the air in line 8S will correspond to the proportion of by-passed air to refrigerated air. The proportion by-passed for temperature control can be adjusted in Iresponse to the setting of the thermostat sensor 100.

For example, during the freezing of the ash on the parts, a lower than required temperature of the volume of cold air flowing to the deflashing machine for embrittlement of the flash ion the parts is desired for quick freezing. During this part of the cycle it is desirable to pass all of the air through the heat exchanger for maximum refrigeration land lowest temperature. As soon as the flash has been embrittled, it is desirable to reduce the temperature of the volume of air going to the deashing operation to a temperature more nearly that of the temperature required to maintain the flash `in a state of embrittlement during the mechanical abrasive blast part of the cycle for deflashing. This point is signaled when the thermostat sensor 100 shows that colder air is then flowing past the parts and through the deflashing machine. This thermostat sensor then operates the motor control valve 62 opening it partially to by-pass a portion of the total volume of air around the heat exchanger through line 64 to achieve the desired air temperature of air flowing onto the parts.

The blower 54 is preferably of the constant volume type. A by-pass loop 56 equipped with power operated valve 58 may be provided between the inlet and outlet of the blower 54 thereby to enable the blower to operate continuously at capacity while varying the volume of cold air recycled to the heat exchangers. This proportioning of the cold air depends upon the temperature and refrigeration requirements of the parts treated for embrittlement.

For example, during the freezing of the flash on the parts a lower than required embrittlement temperature and maximum rate of refrigeration is preferred. Therefore, valve 58 would be in the closed position with full volume of blower air flowing through the heat exchangers and to 'the deashing machine to freeze the flash on the parts. After the ash is frozen, only the required embrittlement temperature needs -to be maintained but since a lower rate of refrigeration can be tolerated to maintain the flash in a frozen condition, :a lower volume of -air can be refrigerated to meet these needs. To accomplish this lower volume of air, valve 58 would be opened sufticiently to give the desired air flow. Valve 58 operates in response to the thremost-at sensor 100 and control center 108.

This by-pass arrangement around the blower is a refinement which gives a greater degree of exibility to the rate of refrigeration in the system but it is not essential to maintaining the desired temperature of the cold air flowing to the parts to be refrigerated and therefore is not an essential element of the system.

An optional means of temperature control for deflashing rubber, plastic and similar parts having relatively warm embrittlement temperatures can be obtained through the use of by-pass Valve 80 which is mounted on cold -air line 8S which discharges into the deashing ma'chine 122. Such parts, for example, may be certain molded rubber parts of lacrylate polymers which may have embrittlement temperatures in the range of 0 F. to

When extremely cold air from the heat exchangers 26 and 26a is not required to embrittle parts, blower 54 can be shut down so that no cold air flows through line 88. In such case, `only cold, but somewhat warmer air is throttled or modulated through valve to achieve a more accurate temperature control wi-thin the deilashing machine and at less expense of Irefrigeration than when operating the refrigeration engine 10 and heat exchangers 26 and 26a. This :air coming from the insulated and enclosed room 132 is normally cooled to the range of 0 F. Ito 40 F. by an auxiliary refrigeration means 134 such .as a mechanical refrigerant compressor coil system.

In this case, temperature of fthe air flowing into the deflas'hing machine is controlled by thermostat sensor through the control center 108 which closes blower 54 land actuates motor control Valve 80 to control the volume of cold air entering the deflashing machine. Circulation of cold air into and out of the deflashing machine is by suction of the dust collector fan 84.

Another option-al means of temperature control of the cold air refrigeration system may Ibe obtained by the use of a motor type c-ontrol valve 32 in line 30, to throttle the flow of liquid refrigerant through coils 128 of heat exchangers 26 |and 26a by signal from the thermostat sensor 100 through the control center 108 which will be described in more detail hereafter. However, this is not a preferred method of temperature con-trol du-e to its lrelatively slow response to temperature change demands for the refrigerated air.

Still -another optional means of controlling the temperature of the air refrigeration system is through intermittent operation of 'the refrigeration engine 10. Although not a pref-erred means of temperature control due to its relatively slow response to temperature change demands for refrigerated fair, it is possible to vary the rate of refrigeration of the air at the heat exchangers 26 and 26a by controlling the temperature of liquid refrigerant 14 flowing through coils 128 in the heat exchangers by intermittent operation of refrigerati-on engine 10.

In such case, during periods of low demand for refrigeration, the refrigeration engine would shut down for certain periods and the liquid refrigerant 14 in receiver 18 would be circulated through the heat exchangers art relatively higher temperatures until such time as the liquid refrigerant became too warm for effective refrigeration of the air. The refrigeration engine 10 would then again start up to reduce the temperature of the liquid refrigerant to levels for effecitve refrigeration of the air.

From time to time it ywill be necessary to defrost or derime the coils 128 in heat exchangers 26 and 26a. This can be done on an intermittent operating basis or on a continuous operating basis by one of several means which are well known to those skilled in the art of heat transfer. For example, heat exchangers 26 yand 26Bv normally would operate with air flowing through both in parallel flow to be refrigerated. For such operation air line valves 50, 50a, 130 and 130ai would all be open. Valves 28 and 28a in the liquid refrigerant lines also would be open.

Defrost line valves

46, 46a, 48 and 48a would be closed.

Then if it is desired .to defrost heat exchanger 26, for example, while the other heat exchanger 26a remains on line on a continuous operating basis to refrigerate air,

valves

50, 130 and 28 would be closed and

valves

46 and 48 would be opened. Warm air would then be caused, by means not shown, to flow into heat exchanger 26 through valve 46 and exhaust from the heat exchanger through valve 48 thereby defrosting coils 128 in heat exchanger 26.

On the other hand, if it were desired to defrost on an intermittent basis, both heat exchangers 26 and 26' could be defrosted simultaneously. In

such case valves

50, 50a, 130, 130e, 28 and 28a all would lbe closed while

valves

46, 4S, 46a and 48a all would be opened. Warm air would then be caused to ow through both heat exchangers at the same time by passing in through valves 46 and 462l out through valves 48 and 48a.

The control center 108 has been referred to in previous paragraphs describing means of controlling the temperature of the 'cold air delivered to the deasher machine 122. The control center 108 is an integrated unit of timers, which may be of the mechanical, pneumatic or -solid state type by way of example; temperature sensortransmitter arrangements such as the Foxboro pneumatic arrangements which are well known in the industry land which can use gas lled sensor bulbs which compare and amplify signals to loperate pneumatic motor valves or electrically operated motor valves; or `temperature sensortransmitter arrangements using thermocouples (copperconstantan) by way of example which give an electrical signal which may be amplified and transmitted to operate pneumatic or electrically operated motor valves.

The control center can control the operations of thel deflasher machine on a temperature basis only such as by signal from thermostat sensor 100 to appropriate motor control valves or by timers which can be preset to signal various components of the deasher equipment as well as components of the refrigeration system or the control center can control the operations by a combination of temperature and time signals to the above mentioned cornponents.

When in operation, the temperature conditions in the deasher unit are normally met by the refrigeration capacity of the refrigeration engine whereby the temperature of refrigerant liquid withdrawn from the receiver 18 will just about correspond with the temperature of refrigerant liquid made available by the refrigeration engine so that the unit can operate steadily over an extended period of time Without interruptions.

On the other hand, when the temperature requirements demanded in the deflasher unit are such as to require less refrigeration than the capacity -of the refrigeration engine, temperature of refrigerant liquid will decrease to a point lower than desired for operation of the refrigeration machine and refrigeration system, Iat which time the safety low temperature switch 94 shuts olf the refrigeration engine. Under the extreme situation when the parts to be processed require very cold temperature for embrittlement, such as when processing parts of an organo silicon resinous material or elastomer which requires extremely low temperatures for embrittlement, the normal capacity of the refrigeration engine can be insufficient to maintain the desired low temperature of refrigerant liquid required to meet the demand for refrigeration,

. However, in the system described, the refrigeration means to be added to supplement that capable of being made available by normal operation of the refrigeration engine is supplied from the low temperature refrigerant liquid stored up in the receiver 18 whereby a -larger amount of low temperature liquid refrigerant can be made available over an extended period of time sucient to reduce the temperature of the refrigeration gas to a level low enough to process the silicone parts for embrittlement of the flash for removal. Since such high demand is intermittent by reason of the time required for loading and unloading of the parts and because of the possible intervening use of the machine with parts having lesser demand for refrigeration, the temperature of liquid refrigerant can be restored -to a -low level in the receiver to enable a unit of lower refrigeration capacity to be used in such situations -of high demand.

The demand for refrigeration which is placed on that available in the circulating liquid refrigerant is varied in the system described depending upon the temperature of cold air required and/or the volume of cold air to embri-ttle the ash on parts .and to maintain it in an embrittled state. This demand is capable of being balanced in the system described by the proportioning of the recycled cold air advanced `through line 52 to the heat exchangers for passage in heat exchange relationship with the refrigerant liquid and by the amount of Icold air by-passing the heat exchangers through line 64 whereby the desired temperature conditions can be maintained in the processing cold air while making most efficient utilization of the refrigerant.

For example, where intermediate temperatures on the order of 50 F. cold air, as measured by thermocouple 78 in line 88, is required for processing parts, such a temperature may be achieved by the recycle of the spent refrigerated cold air discharged from dust collector fan 84 and the insulated enclosure through T 86 and line 60 at a temperature of say about 20 F. to pass one portion of this total volume of air through the heat exchangers for reduction in temperature to about F. as measured by thermocouple 136 while the remainder of the volume of spent cold air is by-passed around the heat exchanges through line 64, as controlled by valve 62, for admixtu-re with the 180 F. air coming from the heat exch-angers to provide a blend of 50 F. air, as measured lat thermocouple 78, advanced through line 88 to the deflashing machine 122.

When instead of 50 F. air, the demand is for 110 F. air to be delivered through line 88, the percentage of air to be by-passed around the heat exchangers through line 64 is decreased and the percentage of total air passing through line 52 and through the heat exchangers is increased.

When instead of 50 F. or 110 F. air, the demand is for 180 F. to be delivered through line 88, all

of the recycled lair can be passed `in heat exchange relationship through the heat exchangers with little or no air passing through line 64 due to closing of valve 62. The refrigeration available in the refrigerant liquid 14 stored in receiver 18 is used to provide for removal of the larger amount of heat from the larger volume of lair passing through the heat exchangers,

If still lower air temperatures are required, this can be achieved by increasing the heat removal capacity of the heat exchangers either by putting more heat exchangers into the line or by increasing the volume of refrigerant liquid through coils 128 in heat exchange relationship with the air.

When higher temperature air is desired in line 88, for example, in the order of about v 10" F., then the heat exchanger system along with by-pass line 64 can be shut down completely by stopping blower 54 and air for embrittling parts and maintaining them at the desired temperature can be accomplished by drawing cold air from -the insulated enclosure 132 into the deflashing machine 122 through modulating valve 80 instead of refrigerated air from line S8. In this case, the air cooling is provided entirely by -auxiliary mechanical refrigeration means 134 and the more expensive extreme cold producing refrigeration engine need not be operated during this time period. However, the refrigeration engine 1t) can be operated during such time period to reduce the temperature of the liquid refrigerant stored in receiver 18 preparing for subsequent time periods when the demand for refrigeration at the heat exchangers may exceed the output of the engine.

Also, yas described earlier, optional or auxiliary means for temperature control can be used such as intermittent operation yof the refrigeration engine 10, varying the flow or volume of refrigerant liquid through the heat exchangers or altering the total volume of recycled spent cold air by by-passing a portion of it around blower 54.

It will be apparent from the foregoing that the system described provides f-or eicient utilization of a refrigeration engine or other cold producing means in a closed cycle for refrigerating refrigerant liquid whereby the amount of refrigeration made available in heat exchange relationship process to cool a gas may be adjusted to meet various demands of the equipment from demands which are less than the capacity -of the refrigeration engine to demands which are greatly in excess of the capacity of 'the refrigeration engine and wherein the cycle of the refrigerated cold gas passed in heat exchange relationship with the refrigerant liquid can be balanced with the refrigerant liquid to achieve a desired end result in the refrigeration capacity of the refrigerated cold gas thereby to provide great flexibility in the operation of the refrigeration system and to make refrigeration available at relatively low cost.

While the utilization of the refrigeration gas has been described with reference to the variations in demand for embrittlement of thin sections of parts molded of elasttorners or plastics to assist in the removal thereof, it will be understood that the described refrigeration system will have application to any other related and unrelated uses wherein variations will occur in the demand for the amount of refrigeration.

It will be further understood that changes may be made in the details of construction, arrangement and operation without departing from the spirit of the invention, especially as dened in the following claims.

I claim:

1. In a refrigeration system for making a large volume of cold uid available for the chilling of parts and media by direct contact of the parts and media with the refrigerated uid comprising the combination of a refrigerant liquid cycle and a refrigeration fluid cycle in which the refrigeration is transferred from the liquid refrigerant to the refrigeration fluid indirectly through a heat exchanger, the refrigerant liquid cycle comprising:

(a) a refrigerant machine for making available a refrigerant liquid,

(b) a receiver for the storage Iof refrigerant liquid delivered from the refrigerant machine,

(c) a heat exchanger having a refrigeration coil extending therethrough from an inlet at one end to an exit at the other end for the ow of refrigerant liquid therethrough,

(d) means communicating the machine with the receiver for the passage of refrigerant liquid from the machine to the receiver,

(e) means communicating the receiver with the inlet end of the heat exchanger coil,

(f) means communicating the outlet end of the heat exchanger coil with the machine,

(g) a pump means for displacement of refrigerant liquid from the receiver to the inlet of the heat exchanger said refrigeration fluid cycle comprising:

(l) a chamber int-o which 'the refrigerated fluid is introduced for passage into direct contact with the parts and media to be chilled,

(2) means communicating one end of the heat exchanger with the chamber for the passage of refrigerated fluid from the heat exchanger to the chamber,

(3) a pump means having an inlet and an outlet for positive displacement of fluid from the inlet to the outlet,

(4) means communie-ating the pump outlet with the other end of -the heat exchanger and means communicating the pump inlet with the chamber for positive displacement of spent refrigeration fluid from the chamber to the heat exchanger and through [the heat exchanger in heat exchange relationship with the heat exchange coils in the heat exchanger, and

(5) means interposed between the pump outlet and the heat exchanger communicating with the means communicating the heat exchanger outlet with the chamber for bypassing the heat exchanger with some of the fluid circulated by the pump means.

2. A refrigeration system as claimed in claim 1 which includes means for controlling the rate of flow of refrigerant liquid from the receiver to the heat exchanger coil -to control the amount of cold transmitted to the refrigeration fluid.

3. A refrigeration system as claimed in claim 1 which includes means for controlling ythe ratio between the amount of refrigeration fluid advanced through the heat exchanger and the amount bypassing the heat exchanger to c-ontrol the temperature of the uid mixture before introduction into the chamber.

l 4. A refrigeration system as claimed in claim 1 which includes switch means responsive to the temperature of the refrigerant liquid for controlling the operation of the refrigeration machine.

5. A refrigeration system as claimed in claim 1 which includes a level indicator for the receiver for controlling the operation of the refrigeration machine to shut off the machine responsive to the rise of the liquid to a predetermined level in the receiver and for initiating operation of the machine for the supply of refrigerant liquid responsive to the fall of the liquid in the receiver to a predetermined level.

6. A refrigeration system as claimed in claim 1 which includes a valve means for controlling the amount of refrigerant liquid circulated through the coil of the heat exchanger.

7. A refrigeration system as claimed in claim 1 which includes means for defrosting the coils of the heat exchanger.

8. A refrigeration system as claimed in claim 1 which includes a bypass communicating the pump means outlet with the pump means inlet for recirculating a portion of the Huid displaced by the pump, and means for controlling the ratio of fluid bypassed about the pump means to the amount of spent refrigeration uid circulated to the heat exchanger to permit the pump means to operate at capacity while a fractional amount of the spent refrigeration fluid is advanced towards the heat exchanger.

9. A refrigeration system as claimed in claim 8 in which said means comprises power operated valve means responsive to the temperature requirement of the chamber.

10. A refrigeration system as claimed in claim 1 which includes Valve means in the means communicating the heat exchanger with the chamber for controlling the amount of cold refrigeration fluid introduced into the chamber.

11. A dellashing system comprising a deflasher unit in which parts to be deashed are processed, a chamber enclosing the deflasher unit, and a refrigeration system for making a large volume of cold refrigeration fluid available for introduction into the deflasher unit for chilling the parts by direct contact with the refrigeration fluid in which the refrigeration system comprises the combination of a refrigerant liquid cycle and a refrigeration uid cycle, in which .the refrigeration is transferred from the refrigerant liquid to the refrigeration fiuid indirectly through a heat exchanger, the refrigerant liquid cycle comprising:

(a) a refrigerant machine for making available a refrigerant liquid,

(b) a receiver for the storage of refrigerant liquid delivered from the refrigerant machine,

(c) a heat exchanger having a refrigeration coil extending therethrough from an inlet at one end to an exit at the other end for the flow of refrigerant liquid therethrough,

(g) a pump means for displacement of refrigerant liquid from the receiver to the inlet of the heat exchanger coil for the flow of refrigerant liquid thereto;

the refrigeration cycle comprising:

( 1) means communicating one end of the heat exchanger with the deflasher unit for the passage of refrigeration uid from the heat exchanger to the deflasher unit,

(2) a pump means having an inlet and an outlet for positive displacement of fluid from the inlet to the outlet,

(3) means communicating the pump outlet with the other end of the heat exchanger and means communicating the pump inlet with the deflasher unit for positive displacement of spent refrigeration fluid from the deflasher unit to the heat exchanger and through the heat exchanger in heat exchange relationship With the refrigeration coil of the -heat exchanger, and

(4) means interposed between the pump outlet and the -heat exchanger and communicating with the means communicating the heat exchanger with the deflasher unit for bypassing the heat exchanger with some of the fluid recirculated by the pump means.

12. A deflashing system as claimed in claim 11 which includes means in the means communicating the heat exchanger with the deflasher unit for bleeding off some of the refrigeration fluid into the chamber.

13. A deflashing system as claimed in claim 12 which includes valve means for controlling the amount of refrigeration fluid bled into the chamber whereby uid withdrawn from lthe chamber into the deflasher unit during operation thereof has controlled refrigeration.

14. A deflashing system as claimed in claim 11 in which the fluid recirculated between the heat exchanger and the deflashing unit comprises air.

15. A deflashing system as claimed in claim 11 which includes a separator in communication with .the deashing unit for the separation of spent refrigeration fluid from the solid materials entrained therein and in which the pump means communicates with the separator for the recirculation of clean spent refrigeration fluid to the heat exchanger.

References Cited by the Examiner UNITED STATES PATENTS 1,978,382 10/1934 Jones 62-498 2,030,032 2/ 1936 Keyes 62-406 X 2,389,106 11/1945 Marshall 62-498 2,511,582 6/1950 Grindrod 62-180 X MEYER PERLIN, Primary Examiner.

Claims

1. IN A REFRIGERATION SYSTEM FOR MAKING A LARGE VOLUME OF COLD FLUID AVAILABLE FOR THE CHILLING OF PARTS AND MEDIA BY DIRECT CONTACT OF THE PARTS AND MEDIA WITH THE REFRIGERATED FLUID COMPRISING THE COMBINATION OF A REFRIGERANT LIQUID CYCLE AND A REFRIGERATION FLUID CYCLE IN WHICH THE REFRIGERATION IS TRANSFERRED FROM THE LIQUID REFRIGERANT TO THE REFRIGERATION FLUID INDIRECTLY THROUGH A HEAT EXCHANGER, THE REFRIGERANT LIQUID CYCLE COMPRISING: (A) A REFRIGERANT MACHINE FOR MAKING AVAILABLE A REFRIGERANT LIQUID, (B) A RECEIVER FOR THE STORAGE OF REFRIGERANT LIQUID DELIVERED FROM THE REFRIGERANT MACHINE, (C) A HEAT EXCHANGER HAVING A REFRIGERATION COIL EXTENDING THERETHROUGH FROM AN INLET AT ONE END TO AN EXIT AT THE OTHER END FOR THE FLOW OF REFRIGERANT LIQUID THERETHROUGH, (D) MEANS COMMUNICATING THE MACHINE WITH THE RECEIVER FOR THE PASSAGE OF REFRIGERANT LIQUID FROM THE MACHINE TO THE RECEIVER, (E) MEANS COMMUNICATING THE RECEIVER WITH THE INLET END OF THE HEAT EXCHANGER COIL, (F) MEANS COMMUNICATING THE OUTLET END OF THE HEAT EXCHANGER COIL WITH THE MACHINE, (G) A PUMP MEANS FOR DISPLACEMENT OF REFRIGERANT LIQUID FROM THE RECEIVER TO THE INLET OF THE HEAT EXCHANGER SAID REFRIGERATION FLUID CYCLE COMPRISING: (1) A CHAMBER INTO WHICH THE REFRIGERATED FLUID IS INTRODUCED FOR PASSAGE INTO DIRECT CONTACT WITH THE PARTS AND MEDIA TO BE CHILLED, (2) MEANS COMMUNICATING ONE END OF THE HEAT EXCHANGER WITH THE CHAMBER FOR THE PASSAGE OF REFRIGERATED FLUID FROM THE HEAT EXCHANGER TO THE CHAMBER, (3) A PUMP MEANS HAVING AN INLET AND AN OUTLET FOR POSITIVE DISPLACEMENT OF FLUID FROM THE INLET TO THE OUTLET, (4) MEANS COMMUNICATING THE PUMP OUTLET WITH THE OTHER END OF THE HEAT EXCHANGER AND MEANS COMMUNICATING THE PUMP INLET WITH THE CHAMBER FOR POSITIVE DISPLACEMENT OF SPENT REFRIGERATION FLUID FROM THE CHAMBER TO THE HEAT EXCHANGER AND THROUGH THE HEAT EXCHANGER IN HEAT EXCHANGE RELATIONSHIP WITH THE HEAT EXCHANGE COILS IN THE HEAT EXCHANGER, AND (5) MEANS INTERPOSED BETWEN THE PUMP OUTLET AND THE HEAT EXCHANGER COMMUNICATING WITHE THE MEANS COMMUNICATING THE HEAT EXCHANGER OUTLET WITH THE CHAMBER FOR BYPASSING THE HEAT EXCHANGER WITH SOME OF THE FLUID CIRCULATED BY THE PUMP MEANS.