US2062827A - Refrigerating system - Google Patents

Description

Dec. 1, 1936.

S. RUPPRlCHT REFRIGERATING SYSTEM Filed Sept. 9, 1932 4 Sheets-Sheet l ATT O R N EY s. RUPPRICHT 2,062.827

REFRIGERATING SYSTEM Filed Sept. 9, 1952 4 Sheets-Sheet 2 INVENTOR ATTORN EY Dec. 1, 1936. 7 s. RUPPRICHT 2,062,827

REFRIGERATING SYSTEM Filed Sept. 9 1932 4 Sheets-Sheet 3 INVENTOR 50m Ima e/cm" BY m ATTORNEY ,1936. s. RUPPRICHTQ I v 2,062,827

BEFRIGERATING SYSTEM Filed Sept. 9, 1932 4 Sheets-Sheet 4 INVENTOR K956121517 Rl/PPRICHT BY ATTORNEY Patented Dec. 1, Q1936 Siegfried Ruppricht, New york, N. Y.

- Application September 9, 1932, Serial No. 632,344

20 Claims.

This invention relates to improvements in refrigerating systems and has for an object the provision of means for economically utilizing solid refrigerants, particularly solid CO2.

Heretofore, in using solid CO: for carbonat ing water it has been customary to place the ice into a pressure, chamber and as the chamber takes up heat the pressure builds up in the chamher and part of the solid 002 forms gas and part of it liquefles when the pressure becomes high enough. A pipe from the top of the pressure chamber leads CO2 gas through a coil of pipe and via a pressure reducing or regulating valve to a carbonator. The coil-ofpipe referred to is placed in a water boxand av gas-flame or other source of heat is applied below the water box to heat up the water therein toprevent the CO: gas from freezing up theregulating valve. This'results in a loss of energy int work that the-refrigerating 20 effect of the COzcould accomplish and the'loss of energy constituting theheat applied. Another object of the invention is to utilize this energy that has been. heretoforelost.

A further object of the invention is to utilize the liquefied CO: as a refrigerant in a series of steps, providing means whereby a part of the C0: may be utilized foncarbonating, and...finally discharging the spent gasinto the walls of a cabinet enclosing the apparatus thereby improv- 30 ing the insulating value of the walls. 1

Other objects and advantages ofthe improved refrigerating system will become apparent to those skilled in the artupon a perusal of this specification and the appended claims.

For describing and illustrating the invention 'a preferred embodiment is shown incorporated into a soda fountain, although it has many other applications. A

Referring to the drawings: Figure I is a diagrammatic sketch showing a well known arrangement for using solid CO2 for making carbonated water wherein heat is applied to the coil to preventthe regulating valve from freezing up; I

Figure 2 is a diagrammatic sketch along the lines of that shown in Figure 1, showing the invention in simple form utilizing the liquid CO2 for refrigerating purposes before using it-otheg;

o-"WiSe; I

Figure '3 is a view, partly in section, showing v a horizontal type of cooler constitutingv part of the invention and suitable for use in the embodi ment thereof herein shown;

sure reducing restrictions used in the improved refrigerating system; 1 I

Figure 5 is a front elevation, partly in section, incorporating a preferred embodiment of. the invention; 7 i

Figure 6 is. an end elevation, of the left end of the fountain shown in Figure 5, partly broken away to 'show the arrangement of some of the elements of the system; I

Figure '7 is an end elevation,- partly broken 10 away, of the right end of the fountain shownin Figure i Figure.8 is a view showing the relation of the syrup jars to the cooler; p

Figure 9- is a cross sectional view, similar to 1| Figure 8,-taken along the line.9-8 of Figure 3;

ating system;

13 is a sectional plan ..of the devic shown in Figure 12 along the line l3l 3;

Figure 14 is a detailed view partly in section of an improved thermostatically controlled regulating valve suitabie forusein the improved refrigerating system.

The diagrammatic "'tch Figure 1 is shown in order to give abetter-understanding of the invention. 'This-dlagram showsdiagrammatically an arrangement commonly used where dry ice. or solidICO; is utilized for carbonating water. The solid. refrigerant is placed in the pressure chamber 20 and the chamber is sealed up. As the dry ice takes up heat,the pressure thereinrises and after a time the solid refrigerant beglnsto. liquefy, the liquid collecting in the bottom of the chambenand the gaseous CO: occupying the remainder of the space inlthe chamber not occupied by liquid or solid 00:. A pipe 2| leadsfrom the top of thechamber ill via a coil Manda pipe 23 to the pressure-reducing valve 24. The 'presv sure-reducing valve is provided for-reducing the pressure of the gas "fronf the liquefying pres-- sure inthe chamber 20 to the most favorable pressure for use in carbonating water; The gas. J at a reduced pressure, isled via the;.pipe ,2! to the carbonator I. water enters'the carbonator via the pipe 21, Asthe method f carbonating wateris well known'to those skilledin the art it u will not hereinbe described. The carbonated water is led out from the carbonator via the pipe 28.

. gram shown in Figure 1, so that the invention may be more readily understood.

A pressure chamber 204 is provided so that: solid CO2 maybe placedtherein and sealed up.

When the temperature of the vessel 20a'rises and pressure builds up, liquefy'ing some of the this liquid settles into a receiver 32. The liquid from the receiver passes via the pipe 33 and the coil 22a to the reducing valve 24a. Th coil 22a submerged in the closed tank 29a. containing liquid which will presently .be described. The

refrigerant passing. from the valve 240 at a reduced pressure passes: through a coil of pipe- 94, which is also submerged in the-liquid in the tank 29a. A pipe 35 leads the refrigerant frpm the cooling coil 34 tothe T 3i'and a pipe 31 leads the CO: to the carbonator 26a; Part of the C0: is

9 led from the T via the pipe- 39-to a. thermostati- 'cally-controlled reducing valve 39, which is controlled by a thermo-bulb 49. This valve will presently be described more in detail in connection with Figure 14. (30: passing from-the valve 39 at a further reduced pressure is led viaa pipe 4i into an annular space 42 around the tank 2911, which is formed betweenv the wall thereof, the wall 43 and the annular heads 44 and 45-. The CO: passing from the annular space 42 may be ledvia the pipe 46 to the outside air or to the space between theinsulated walls.of the device, which wilhpresently be described in connection with Figures 5, 6, '7 and 11.

rile-am];v 29a, with the coils m and therein,

and the annular space 42. formed thereabout may be termed cooler and carbonated water from the carbonator 26a passes via the: pipe 41 into thespace 48-within the-cooler 29a and may be withdrawn via the pipe 49. 7

A. suitable shut-oi! valve 50 is provided between thepressui'e chamber 20a and the receiver 32, and a similar shut-oi! valve i is provided between the receiver 32 and the pipe 33. A short. length of pipe 52. leads down'to the bottom of the.

receiver so that as long as there is. any liquid;

therein it will pass out byway of this pipe. a

1 Liqutd refrigerant,. at very low temperature, passes through the pipe 33- to the coil 22a, where it absorbs heat from the water in the cooler 29a.

The refrigerant, after having'its temperature raised-by the carbonated water, passes. through the reducing valve" 24, and is again passed. through the cooler via the coil where more.

heat is absorbed from the carbonated water. The refrigerant passes out of the. coil 34 through the pipe 35 to the. T 35. Part of the refrigerant is utilized in the carbonator 26a and. part, of it passes through the thermostatically-controlled:

reducing valve 39 into the annular space 42,.where the temperaturesof the cooler is still further reduced and the spent 00: passes through the pipe 49 and on out into the open air, or into spaces In order. to prevent the pressure-reducing between the insulations in a cabinet in which the device is installed.

From this, it can readily be seen that in existing arrangements, such as that shown in Figure 1, no advantage is taken of the refrigerating effect of the C02, as this is allowed to go to waste, and there is a further loss of energy in that heat is applied to the tank 29 so that if any liquid refrigerant gets to the coil= 22 it will be immediately ,evaporated, into gas.

In the arrangement shown in Figure 2, which diagrammatically illustrates the invention, the carbonated water is cooled by means of the refrigerating effect of the C02. The air in a cabinet in which the cooler 29a is placed is also refrigerated, part of the gas is used to carbonate the water and part of the gas is used to improve the insulating. qualities of the cabinet in which the apparatus is housed.

Figure 3 shows a horizontal type of cooler which is a modification of the one shown at 29a in 318- ure 2. This cooler is designated generally by thev numeral 53. The cold liquid CO: is led'via pipe 54 with a coil 55 and via the pipe 56 to a pressure-reducing valve like- ,the one shown at 2411, in Figure 2, where the pressure of the refrigerant is reduced. The refrigerant again passes into the cooler via the pipe 51 through thef coil 581thereln and out via the pipe 59. A novel expansion means is introduced-in the coil 58 at the point indicated'by the numeral. 69. This will presently be explained. in connection with Figui'e 4.

Refrigerant passing out of the coil 59 via the pipe 59 branches and some of the CO2 may be utilized to charge the water inthe carbonator and some of the CG: passes via the thermostaticallycontrolled reducing valve 39 into the annular space (it formed between the walls 62 and 33 of the cooler 53. The CO: from the reducing valve 39 passes into the space 6| via the pipe, a portion of which is indicated by the-.nnmeral s4.

The "space it 'is-bnokenup into a connected series-of passages by means of a heavy copper ribbon 65 and it has been found preferable to have these spiral. spaces gradually diminish as the end of the. cooler is approached, so that gaseous refrigerant therein has its velocity gradually accelerated. The gaseous refrigerant passes out of the series of passages 6i via the, pipe 64a.

When this type of cooler is applied to a soda fountain a suitable receptacle Gii is provided to hold the syrup jars 61 (Figures 8, 9 and This receptacle is in heat exchange relation to the outer wall 63 of the cooler, 53 and the pipe 64a may have one or more loops formed therein and in contact with the receptacle 68. t

To facilitate the heat exchange between th cooler 53 and the syrup jars 61 a suitable liquid iB may be placed in the receptacle 96.. The CO: gas

passing out via the pipe 64, and any loops thereof in contact with the receptacle 86, is then led via the pipe 11 to one or more distributing pipes,

which will'presentlyzbe described.

A cooling coil 10 is provided in the interior 69 "of the cooler 53 through which the carbonated water is passed to be cooled. The carbonated water enters the coil I9 via the pipe H and leaves the cooler via the pipe I2 from which-it may be led to a suitable draft-arm 13. The interior space 69. in the cooler 53 also serves for cooling plain water. This water is led into the space 69 via the pipe 14 and'th'e cooled water passes out of the cooler via the pipe 15, from which it may be led to a suitable water spigot 16. s

One of the expansion devices placed in the coils and 58 at the union indicated by the numeral 88 is shown more in detail in Figure 4. The union 8!! has a stationary member 18 which is secured to the end of the coil 58. A wire 18 has a long sharp point 88 formed on one end thereof. The other end of the wire I8 is formed into a circular loop 8|. This wire is inserted into an end of the coil 58 and the pointed end extends well into the coil in an area thereof which is surrounded by water. The looped end 8| of the wire is secured, along with suitable packing 82, between the face of the stationary member I8 and the interior face of the union 88, being held therein in gastight relation to the outside air and stationary preferably concentric with the pipe forming the coil 58. Refrigerant passing thereto via the pipe 51 passes through the restricted area between the pipe 58 and the wire with a resultant reduction in pressure. Due to the fact that the point 88 is well within the pipe, which in turn is surrounded by water, it is impossible for the restriction to freeze up because a large body of water is available for the pipe to absorb heat from. This eliminates a great deal of trouble heretofore encountered with expansion valves freezing up and instead of having the reduction of pressure at one small point it is given gradient by the presence of the wire within the pipe and this gradient may be increased by lengthening the wire or decreased by shortening the wire, but the'important feature is the presence of the water about the pipe serving to give up heat to the pipe and thereby remove all possibility of the same becoming frozen up.

The new and improved refrigerating system is shown in Figures 5, 6 and 7 as applied to a soda fountain. The soda fountain designated generally by the numeral 88 is shown having the insulated portions of the walls thereof containing corused. The insulation 84 may be of cork or any other material having similar qualities. Although cork may also be used in place of the foil insulation 85 the foil is used for two reasons, first, because it is many times lighter than .cork, and secondly, CO: gas may occupy the space between the layers of foil and thereby improve the insulating qualities thereof. This foil insulation may consist of so-called crumpled foil or'it may be "preformed" sheets of foil assembled into the space of the cabinet. 7

A pressure chamber 86 is mounted within the cabinet 88 preferably in a horizontal position. This chamber is provided with a pressure-tight removable door 81 and the same may be made tight in any suitable manner. In one preferred form of construction the pressure chamber 88 has an inwardly extending flange 88 formed therewith. This flange has an eccentric opening and its interior face is provided with suitable packing (not both the cover and the rim enough of the surfaces thereof are in contact with the gasket 'to hold the pressure in the chamber. This pressure builds up as the outside surface thereof absorbs heat from the cabinet and air circulating in the cabinet due to the presence of the baffle board 88 therein may be traced as follows: Air in contact with the pressure chamber 88 becomes cooled, falls to the bottom of the cabinet and passes under- A neath the baflie plate 88 into the compartment 88 of the cabinet, becomes warmer and rises, and passing over the top of the baflle 88 it again returns to the pressure chamber to be re-cooled.

As the pressure in the chamber 88 builds up, the CO2 gas therein liquefies and this liquid passes from the pressure chamber via the pipe 8| to the receiver 82. The portion of the pipe 8| inside the receiver is bent upwardly to a point near the upper surface thereof so that the receiver can be almost filled with liquid. Liquid refrigerant passes from the receiver 82 via the pipe 88. The portion of the pipe 88 within the receiver is bent down to a point near the bottom thereof so that substantially all of the liquid can be drawn therefrom. The pipe 88 delivers refrigerant to the coil 55 via the pipe 54. The refrigerant upon passing into the coil 55 passes through a restricted portion ,of the pipe similar to that shown and described in Figure 4, where areduction in pressure is effected. This liquid is very cold and upon passing through the coil 55 absorbs heat from the water in the cooler and passes out via the pipe 58 to the reducing valve 84. Refrigerant from the reducing valve 84 passes via the pipe 51 into the cooling coil 58. There is, as was previously described, a reduction in pressure between the Pipe 51 and the coil 58 which is accomplished by the novel arrangement described'in Figure 4.

Refrigerant leaves the coil 58 via the pipe 58,

passes via the. thermostatically-controlled reducing valve 88 and the pipe 84 into the spiral space 8| between the walls 82, 88 of the cooler 58 and out via the pipe 84a through coils formed therein which are in heat exchange relation to the receptacle 88 and via the pipe 11 to theinsulated wall 85 of the cabinet 88. Suitable slits 85 may be provided in the end of the pipe 11 to distribute the gas between the various layers of foil 85. A T 88 may be provided in the pipe 58 so that some of the CO: gas may pass to a carbonater *(not shown).

An auxiliary cooler 88 is provided in the compartment 88 to pre-cool the'water and the carbonated water before they enter the cooler 58. This cooler may consist of a double casing having a coil of pipe 88 mounted therein. The pipe 81 leading into the auxiliary cooler '88 may be connected to a suitable source of plain water and water passing therein surrounds the coil 88. This water passes out of the auxiliary coo1er'88 via the pipe 14 into the interior space 88 of the cooler 58. A pipe 88 connected to a suitable carbonator leads carbonated water through the coils 88 in the auxiliary cooler 88 and via the pipe II to the coil 18 in the cooler 58. Carbonated water passing through the coil 18 via the pipe 12 may be led to a suitable draft-arm 18 on the fountain. The pre-cooler not only serves for cooling the water but it also has a regulating'effectupon the system as a'whole. between the cooler 88 and the pre-cooler 88.

When the pressure chamber 88 is first filled with solid 00:, the pre-cooler 88 is cooled by and gives up heat to the pressure chamber 88. The heat from the water in the pre-cooler 88 is given up to the pressure chamber 88, thereby building up There is 'a co-relation pressure therein and liquefying some of the CO2.

the liquid passing into the receiver 82 as previous- 1y described.

obtained from the pressure chamber 86 which cools and circulates the air inthe cabinet as previously described. Up .to this point there is no refrigeration produced in the cooler 53 by evaporation of liquid refrigerant. The cooler 53, however, is cooled both by carbonated water and by plain water passing therethrough. This also cools the receptacle 66 and the syrup jars therein.

The refrigerating effect is conserved in the following manner: The cooler which is at first cooled by the water from the pre-cooler passing therethrough, is of low enough temperature to cause the thermo-bulb 40 to close the expansion valve 39 and allow no liquid refrigerant from the receiver 92 to pass into the cooler.

When all of the solid-C02v has become liquefied the liquid refrigerant produces the. maximum refrigerating effect in the cooler 53 ,at which time most of the air circulation in the compartment 90 is effected as follows: Air in contact with the cooler 53 becomes cold andfalls to the bottom of the compartment 90, spreading out on the floor thereof, whereupon it risesandpasses over to again come in contact with cooler 53 and the process is continued.

when the pressure chamber 06 is first charged up with solid CO2, it (the pressure chamber 86) produces the maximum refrigeration and when all of the CO2 therein is liquefied the liquid produces the maximum refrigeration in the cooler 53, and between these two extremes there is a gradual gradient in temperature and also agradient be-' tween the circulation of air in the compartment and its cooperation with the pressure chamber 86 and with the cooler 53.

One of the most important features of this system is the conservation effect by.means of the pre-cooler 96 as described above. This pre-cooler, by giving up heat from the water to the pressure chamber 86, insures the building up of pressure inthe chamber and the liquefaction of refrigerant therein A suitable tray or receptacle I00 maybe' provided in heat exchange relation to the pressure chamber 86 for freezing ice or ice cubes.

A suitable ice cream compartmentmay be built into the fountain or a separate ice cream cabinet may be used in an arrangement such as shown in Figures 12 and 13. 1 I

To provide refrigeration for the ice cream com-' partment, the liquid line 54 (Figure '5) may have a T (not shown) placed therein and a branch line therefrom is led via the pipe I M to the coil I02. Liquid refrigerant passing through the coil I02 absorbs heat from the ice cream compartment I05. The liquid refrigerant, after having its temperature raised in'the coil I02, passes through the expansion valve 30a and into the coil I03 in the compartment I05, producing refrigeration therein. The spent gases are discharged at the point indicated bynumeral I06 into the walls I0'I of the cabinet. Suitable covers I08 are provided in the top of the cabinet for getting accessto the ice cream cans I08. 7

' The expansion valve 39 or 30a is shown more in detail in Figure 14. This valve is not only controlled by temperature by having a thermostatic bulb in contact with the evaporator or chamber in which the same is located, but it also controls determined pressure the valve automatically closes regardless of what the temperature is.

Therefore, this expansion valve may be termed a combined expansion and safety valve.

The valve consists of a main body casting IIO having a chamber III therein which, by virtue of the opening II2 leading to the evaporator, has a pressure maintained therein substantially the same as that in any evaporator to which the valve is connected. A closure plate I I3 is provided for the body casting I I0, sealed thereto by a suitable gasket Ill and held in this relation by suitable screws II5. A -sylphon or other flexible diaphragm H6 is mounted in the chamber III and may be securely held therein by a flanged portion between the body I I0 and the closure plate II3. A member I I1 is in contact with thesylphon at the point indicated by the numeral" H8 and the arm thereof in contact with the sylphon I6 at the point H8, and the other arm of the bell crank controls the motion of the needle I22. A closure nut I24 serves to seal the chamber III against the outside air and also serves as a guide for the needle I 22 and for the spring I23.

All parts of the valve described above may be constructed to stand normally low pressures, for example pressures that would be encountered in using methyl chloride as a refrigerant, but as this valve is to be used in connection with CO: pressures of a thousand pounds or over are encountered.

A nozzle member I25 of the valve is preferably constructed of stainless steel having a high tensile strength. This nozzle has suitable threads I26 for connecting the same to the liquid CO2 line. A suitable passage I21 is provided in the nozzle I25 for the liquid refrigerant and a smaller passage I28 of substantial length is provided therein between the passage I21 and the valve seat Y Refrigerant passes through the valve in the following manner; via the passage I2l,.the reduced 45 passage I28 and thevalveseat l29'into the cham- 'sylphon II6 by means of the capillary tube II! and the member I" being: reduced byvirtue of the low temperature allows the pressure of the spring I23 via the bell crank I20 to move the sylphon II6 upward and theneedle I22 to the left, as viewed in Figure 14, I whereupon the needle seats in they valve seat I20-and allows no more refrigerant to enterv the evaporator. When the temperature in theevaporator rises the pressure in the thermo-bulb rises and this pressure communicated to the sylphon by the means previously described, overcomes the pressure of the spring I22 via the bell crank I20 and allows the valve to open so that more refrigerant can pass to the evaporator.

In case the connection between the opening I22 and the evaporator becomes frozen up or clogged, the pressure in the chamber III could become as high as that in thepassage I21 which may be a thousand pounds tojthe square inch or more, were it not for thefollowing action.

If t e pas as r pipe between the opening in of the chamber III and the'evaporator becomes frozen up or clogged the pressure in the cham- 7 her I I I immediately begins to bulid up and this pressure against the sylphon bellows 6 overcomes the pressure imparted to the sylphon in the opposite direction by the thermo-bulb 40, whereupon needle I22 is seated upon the valve seat I29 and no more refrigerant is allowed to enter. Therefore it is impossible to build up an excessive pressure in the chamber III although pressures capable of liquefying C: are encountered in the system.

Although but one specific embodiment of this invention has been herein shown and described, it will be understood that numerous details of the construction shown may be altered or omitsorb heat and liquefy, expanding the liquid CO2 in stages to obtain the maximum refrigerating effect therefrom, and by-passing a portion of 'the COz between two of said stages for use in the production of carbonated water.

2. In a refrigerating system, a cabinet, a pressure chamber within the cabinet, a liquid receiver connected to the chamber, a refrigerating coil the liquefied refrigerant, a pressure reducing means and an evaporator connected to said receiver, said evaporator also adapted to absorb heat from the cabinet, and means within said evaporator for cooling water.

\ 4. In a refrigerating system, a cabinet, a pressure chamber within and arranged to refrigerate the cabinet, a solid refrigerant in the chamber adapted to cool the cabinet and to liquefy upon the absorption of heat therefrom, and a liquid cooler in the cabinet including a series of expansion chambers adapted to utilize the liquefied refrigerant in stages for cooling drinking water and for further cooling the cabinet.

5. In a refrigerating system, an insulated cabinet having the insulation thereof in layers, a

pressure chamber and an evaporator in the cabinet, solid CO2 in said chamberadapted to refrigerate the cabinet while changing from a solid to a liquid state, means for also refrigerating the cabinet via the evaporator while changing the CO2 in stages from liquid to a gaseous state, means for bypassing between stages a portion of the refrigerant for use in makmg carbonated water, and means for discharging gaseous -refrigerant between the layers of insulation to improve the insulating value of the a cabinet.

6. In a refrigerating system of the character described, a, cooling unit comprising a cylindrical casing closed at each end andhaving a plurality of; paths therethrough, and means for expanding refrigerant in stages therein, each of said paths constituting one of said stages.

7. In a refrigerating system of the character has liquefied.

described, a cooling unit comprising in combination, a casing forming a liquid cooler, a plurality of refrigerating members in heat exchange rela? tion with the liquid in said cooler, said members being serially included in a circuit through which refrigerant is passed, and means in each of the members for efiecting expansion. therein, said means also being in heat exchange relation with said liquid.

8. In a refrigerating'system of the character described, a cooling unit comprising in combination, a casing forming a liquid cooler, a plurality of refrigerating members within said liquid cool-' er in contact with liquid therein, said members being serially included in a circuit through which refrigerant may be passed, and-pressure reducing means in each of said members so positioned therein that the heat of the liquid in the cooler prevents the formation of snow within the members.

9. In a refrigerating system of the character described, a cooling unit comprising in combination,.a casingforming a liquid cooler, a plurality of refrigerating'members within said liquid cooler in contact with liquid therein, said members being serially included in a circuit through which refrigerant may be passed, and pressure reducing means including restricting wires in each of said members so positioned therein that the heat of the liquid in the cooler prevents the formation of snow within the members.

10. In a refrigerating system of the character described, a cooling unit comprising in combination, a casing forming a liquid cooler, a plurality of refrigerating members within said liquid cooler in contact with liquid therein, said members being serially included in a circuit through which refrigerant may be passed, pressure reducing means in each of said members so positioned therein that the heat of the liquid in the cooler prevents the formation of snow within'the members, and a coil within the cooler for carbonated water. y

11. In a refrigerating system, a cooler comprising in combination in a unitary structure, a casing through which a liquid to be cooled passes, an evaporator within said casing, a receptacle in heat exchange relation with said evaporator and said casing, syrup containers in said receptacle, and liquid in the receptacle in contact with said containers.

12. In a refrigerating system of the character described, a cooler comprising in combination, a casing through which a liquid to be cooledpasses, an evaporator in contact with liquid in 'said casing, a receptacle in metallic contact with said casadapted to pre-cool'water before the same enters said cooling unit, said water serving to cool the cooling unit before any of the solid refrigerant "14. In a system of the character described, a' cabinet a pressure chamber, a water cooler in heat exchange relation with'an evaporator I and a water pre-cooler therein, and a solid refrigerant in said chamber adapted to refrigerate the cabinet and the pre-cooler via the pressure chamber while changing from a solid to a liquid state and adapted to refrigerate the cabinet and the pre-cooler via the evaporator while changing from the liquid to a gaseous state.

15. In a thermostatically controlled expansion valve, a body casing adapted to withstand low pressures, a conduit secured to said body capable of withstanding excessively high pressures, a valve seat in said conduit, a valve in said body cooperating with said seat, and a metallic bellows adapted under control' of a thermo-bulb to open or close said valve and also adapted to close I receiver connected to said chamber for receiving the liquefied refrigerant, a pressure reducing means and an evaporator connected to said receiver, said evaporator being adapted to absorb heat from a second cabinet, and a wall between said cabinets having ports formed therein whereby air may circulate therebetween.

17. In a refrigerating system, a cabinet having a plurality of compartments, 8. pressure chamber within one of said compartments, 2. solid refrigerant within the chamber adapted to liquefy upon the absorption of heat from said compartment, an evaporator and a pressure reducing device in another of said compartments and connected to the pressure chamber, said evaporator adapted to absorb heat from said second compartment and contents, and a partition between said compartments having ports formed therein communicating with both compartments to allow air to circulate therebetween.

18. In a. refrigerating system, a cabinet, a pressure chamber within and in heat exchange relation to the cabinet, a solid refrigerant in the chamber adapted to absorb heat directly from the cabinet and io liquefy, a water coil, and means including anbeyaporator in heat exchange relation to said coil and the interior of the cabinet utilizing said liquid for further absorbing heat from both the cabinet and water in said coil.

19. In a refrigerating system, a cooler comprising in combination a casing including a conduit through which liquid to be cooled may pass, an evaporator. in heat exchange relation with liquid in said conduit, a receptacle in metallic contact with said casing, and a plurality of syrup jars positioned in said receptacle.

20. In a pressure system, a source of fluid medium under high pressure, means adapted to receive said medium at a lower pressure,'means defining a passage between said source and said first means, and pressure reducing means in said passage comprising a restricting member, having

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