US1954543A

US1954543A - Refrigerator plant and process

Info

Publication number: US1954543A
Application number: US601262A
Authority: US
Inventors: Schwarz August
Original assignee: Individual
Current assignee: Individual
Priority date: 1932-03-25
Filing date: 1932-03-25
Publication date: 1934-04-10
Anticipated expiration: 1951-04-10

Description

April 10, 1934. A, SCHWARZ 1,954,543

REFRIGERATOR PLANT AND PROCESS Filed March 25, 1952 2 Sheets-Sheet l FROM COOL ING Room 4-72 5 47 rFfifigr E 42 1L 6 F Q .93. 140 1 O O 5.9 I 42 ll 46 .46 1 FROM COOL/N6 I 70 J ROOM 23 14 Q I O LET J I? l 76 6 5 2 FRESH-1432,7252 6 6 3PM) L/qugasi Hchwarz,

April 10, 1934. l A. SCHWARZ REFRIGERATOR PLANT AND PROCESS Filed March 25, 1932 2 Sheets-Sheet 2 3 wu e/wbo c vfiu gusl Bchwarz,

Patented Apr. 10, 1934 UNITED STATES PATENT OFFICE REFRIGERATOR PLANT AND PROCESS August Schwarz, Chicago, Ill.

Application March 25, 1932, Serial No. 601,262

' 41 Claims. (01. 62-415) The invention relates to refrigerator plants. The subject matter of this application is a part of the rejected application Serial No. 429,176 filed February 17, 1930.

An object of the invention is to provide a two stage refrigerator plant.

The main object of the invention is to provide a two stage refrigerator plant for liquefying and gasifying CO2 to produce lower temperatures by lower suction pressure than was possible heretofore.

Another object of the invention is to provide a two stage refrigerator plant, the first stage of which comprises a fresh water cooled condenser, the cooling water whereof is aircooled, and the second stage of which is equipped with a brine cooled condenser. I

A still further object of the invention is to provide a two stage refrigerator plant, in which the refrigerant flows continuously through the refrigerator and the two condensers, wherein the fresh water and the brine solution flow in counter directions.

Another object of the invention is to provide a two stage refrigerator plant comprising a two part refrigerator, the smaller part of which may be operated alone, when the plant is started up, the larger part being started, when the temperature in the smaller one has reached a predeterminate low degree.

A still further object of the invention is to provide bypaths and valves in the pipe lines for the refrigerant so that one or both of the condensers may be used as desired. I

Still another object of the invention is to provide a refrigerator plant with two stages of refrigerationhavingbypaths in the pipe line conducting the brine solution, and also valves, so that either, all or only a predeterminated part of the said solution may be conducted to the cooling room. In the second case the part of the brine not conducted to said room fiows directly to the brine cooled condenser, while the part conducted to the cooling room flows directly back to the brine pump. In the first case the brine flows from the cooling room to the condenser and from there to the pump.

Another object of the invention is to provide a two stage refrigerator plant having a fresh water cooled condenser and a brine cooled condenser said condensers being adapted to be used together with the two part refrigerator or the brine cooled condenser being cut out, so that the refrigerator works only with the fresh water cooled condenser although the brine may be circulated at will through the refrigerator and the brine cooled condenser.

Other objects not specifically mentioned may be easily ascertained and understood from the following description in connection with the accompanying drawings forming a part thereof. It is however to be understood, that the invention is not to be limited or restricted to the exact construction or formation shown in the drawings and described in the specification, but that said invention is only to be limited by the scope of the claims appended hereto.

In the drawings illustrating a preferred embodiment of the invention Fig. 1 is a diagrammatical view of a refrigerator plant according to the present invention.

Fig. 2 is a sectional view-taken through the two part refrigerator used in connection with the refrigerator plant according to the present invention.

Fig. 3 is a sectional view taken on line 3-3 in Fig. 2, and l Fig. 4 is a sectional view showing the brine cooled condenser used in connection with the present invention.

A fresh water pump 5 is connected with its intake to a source of fresh water (not shown) and with its outlet through a pipe line 6 to an air cooler '7. In this cooler, the fresh water is cooled by atmospheric air. If desired, a fan 8 or the like may be provided to force the air through the cooler, and more particularly in contact withsuitable coils through which the water is conducted. The air cooled fresh water is then conducted through a pipe line 9 into a water cooled condenser 9a. As shown in the drawings the cooling water enters the upper end of the condenser, and after flowing through the condenser is withdrawn from the bottom through a drain pipe 10.

A compressor 11 forces the refrigerant used in the refrigerator plant through the fresh. water cooled condenser 9a by means of a pipe line 12. This pipe line is provided with valves 13 and 14 respectively to-make it possible' to shut off the entire or a part of the pipe line for purpose of repairing the same. In addition to these valves, a check valve 15 is arranged. in the pipe line 12, to prevent a reverse flow of the refrigerant therethrough. The pipe line 12 leads to the lower end of the condenser, so that the refrigerant and the cooling water will fiow through the condenser in opposite directions. From the upper end of the fresh water cooled condenser 9a a pipe line 16 leads to the lower end of a brine cooled condenser 17 and conducts the refrigerant cooled in the first stage with fresh water into the corn denser 17, where it will be cooled by brine, as described later on. The pipe line 16 is provided with valves 18 and 19 to close the pipe line either entirely or partly. The refrigerant pipe line 16 is also equipped with a check valve 20 to prevent backward pressure in said pipe line.

From the brine cooled condenser 17 the refrigerant is conducted through a pipe line 21 to a refrigerator 22 with a cooling coil having pipes extending vertically as shown in the Figs. 2 and 3. In the refrigerant line 21 a plurality of valves 23 are arranged, tomake it possible to shut off said pipe line eitherentirely or partly in case of leakage. An expansion valve 23a is located in the pipe line adjacent the refrigerator 22, and a pressure gauge 24 is also arranged in this pipe line.

From the refrigerator 22 the refrigerant is conducted back to the compressor 11 through a pipe line 25, closing the circuit for the refrigerant, which flows through the two stage refrigerator plant as follows: From the pump 11 through the pipe line 12, the first stage condenser 9a, which is cooled with fresh water, the pipe line 16, the brine cooled condenser 17, the pipe line 21, the refrigerator 22 and the pipe line 25 back to the compressor 11.

In the pipe line 25 one or more valves 26 may be arranged to close this pipe line.

A second refrigerator 27 is provided which is preferably arranged with its cooling coils or tubes located adjacent the cooling coils or tubes of the refrigerator 22. In the drawings Figs. 2 and 3 the coils or tubes of the second refrigerator are shown as extending at right angles to the coils or tubes of the first refrigerator and the pipes forming this coil are arranged between the pipes forming the coils of the first refrigerator 22. The reason for this preferred arrangement will be described later on.

A bypath or pipe line 28 connects the refrigerant conducting pipe line 21 with the second refrigerator 27. The outlet of the second refrigerator 27 is connected through a pipe line 29 with the pipe line 25, which leads back to the compressor 11. A valve 30 is provided in the pipe line 28 to interrupt, if desired, the connection between the refrigerant conducting pipe line 21 and the second refrigerator 27. Adjacent the entrance.end of the second refrigerator 27 an expansion valve 31 is provided in the pipe line 28 leading refrigerant from the pipe line 21 into the second refrigerator. One or more valves 32 I are inserted in the pipe line 29 conducting rethe valves 35. in the bypath 34 are closed (as they generally are in normal operation of the plant) and the valves 13 and 14 in pipe line 12 remain open. A shut-off valve 38 provided in the pipe line 16 before the connection with the upper end of the bypath 34 will be closed, so that -the refrigerant will be forced into a bypath 36 connected to the pipe line 16 between the valves 18 and 38. This bypath conducts then the refrigerant to the lower end of the bypath 28 communicating therewith between the shut-off valve imwhichisclosedinthiacm and the expandrawings Fig. 1 will be closed. Then a part of the refrigerant will flow into the first refrigerator 22 and the other part into refrigerator 27.

It may be mentioned here, that pressure gauges may be arranged in the pipe line 16 adjacent the upper end, that is the outlet end for the refrigerant, of the fresh water cooled condenser 9a, and in the

pipe lines

25 and 29 adjacent the outlet end for the refrigerant in the

refrigerators

22 and 27 respectively.

The circuit for the brine solution forming the cooling fluid in the second stage of the present refrigerating plant is as follows: A brine solution pump 39 forces said solution through a pipe line 40 into the refrigerator 22, where the solution will surround the pipes of the two refrigerators 22- and 27. From there the brine flows through the pipe 41 into the condenser 17, and then through the pipe line 42 back to the brine pump 39. Throughout the entire circuit the brine solution flows in the direction opposite to that in which the refrigerant flows.

A pipe line43 is connected with the brine conducting pipe 41 and leads the brine to the cool ing room (not shown). In the brine pipe 41 a valve 44 is provided and in the pipe line 43 a valve 44a. By means of these two valves it is possible to direct a predeterminate part of the brine solution through the pipe line 43 to the cooling room and the rest of the brine into the condenser 17. It is also possible by closing the valve 44 in the pipe 41 and by opening entirely the valve 44a in the pipe line 43 to conduct all the brine solution to the cooling room. If a part only of the brine is directed to the cooling room, this brine is returned to the brine pump through the pipe 45 in which a valve 46 is inserted. If all the brine is led to the cooling room the brine is conducted from there through the pipe 47 into the condenser 17 and from there through the pipe 42 back to the pump 39. In the last case valves 44 and 46 are closed.

By adjusting the valves 13 and 14 in the pipe line 12 and the valves 35 partly a predeterminate part of the refrigerant coming from the pump 11 may be directed to the fresh water cooled condenser 9a and the rest of the refrigerant through the pipe line 34 and the upper part of the pipe line 16 directly to the brine cooled condenser 17.

The refrigerator plant described above is operated as follows:

The fresh Water pump 5 is started and thereby fresh water is forcedthrough the fresh water cooler 7. The Water is cooled by means of atmospheric air. In case this air is comparatively warm, air may be forced through the cooler by vmeans of an air fan 8. The cooled water flows then through the pipe 9 into condenser 9a, and leaves said condenser through the drain pipe- 10.

The pressor 11 urges a refrigerant through a pipe line 12 into the condenser 9a, through which it flows in the direction opposite to the one in which the air cooled water flows. The refrigerant flows from the condenser 9a through the pipe line 16 into the brine cooled condenser 17, from where it flows' through the pipe line 21 into the refrigerator 22. The pipe line 25 conducts the refrigerant from this refrigerator back to the compressor 11.

The brine pump 39 forces the brine solution through the pipe line 40 into the refrigerator 22 and from there through the pipe line 41 into the condenser 17 and from there through the pipe line 42 back to the brine pump 39.

The brine for the cooling room (not shown) is returned by the. pipe line 4'7 which leads the brine to the condenser 1'7. The brine is' then returned to the pump through the pipe 42. It can be seen, that the direction in which the brine flows is opposite that in which the refrigerant flows.

- If only a part of the solution is to be used for cooling the cooling room, the valve 44 in the pipe 41 and the valve 44a in the pipe line 43 are partly closed. The brine solution directly flowing through the condenser 17 is then returned through the pipe 42 to the brine pump 39, while the part of the brine solution flowing first through the cooling room returns to the pipe 42 through the pipe line 45. I

To start the refrigerator plant according to the present invention the liquefied refrigerant present in the refrigerator 22 is sucked out of this refrigerator by means-of the compressor 11. The valve 38 in the pipe line 16 is closed, so that the refrigerant is conducted through the pipe line 36 into the smaller refrigerator 27. The by-path connecting the two condensers 9a and 17 must be open to let a part of the refrigerant fiowinto the condenser 17 to prevent an excessive pressure in the condenser 9a. In this case the valve 30 is closed so that the refrigerant can not flow into the pipe line 21 and from there into the refrigerator 22. When the refrigerant is expanded in the refrigerator 27 the brine pump 39 is started so that the brine solution will be forced into and through the refrigerator 22. The

brine solution flows from the refrigerator 22, where it is cooled by the refrigerant in the refrigerator 27, into the condenser 17 and back through the pipe 42 and the brine pump 39 and again through refrigerator 22, where it is cooled I frigerant must be still high enough in the two condensers, that the fresh water in the condenser 9a will have the same cooling effect as in a refrigerator equipped only with a common fresh water condenser. When for instance the cooling water has a temperature of about degrees Fahrenheit and CO2 is used as refrigerant, a pressure of about 900 lbs. must be present. When the cooling freshwater will have the above mentioned temperature of 75 degrees Fahrenheit, the refrigerant will leave the fresh water condenser 9a at a temperature of about '78 degrees Fahrenheit and will enter the condenser 17 at about this temperature.

The brine solution is cooled down more and more by the refrigerant in the refrigerator27 as described above until it obtains the predeterminate degree, for instance 10 degrees above zero Fahrenheit. Thereby the temperature of the refrigerant is also decreased, and the suction pressure in the refrigerator is lowered, so that with the refrigerating plant according to'the present invention lower temperatures can be obtained with lower suction pressures than with plants known and used heretofore. The valve 38 in the pipe line 16 is opened so that the refrigerant will be adapted to fiow through the condenser 17, the pipe 21 and the refrigerator 22. When the brine solution will have been cooled down to the'desired degree, for instance 10 degrees above zero Fahrenheit, and the brine will enter the brine cooled condenser 17 at this temperature, then the refrigerant will be cooled down to about 15 degrees above zero Fahrenheit and will enter the two

refrigerators

22 and 27 at approximately this temperature. Under this condition the refrigerant can create lower temperatures than if it entered the refrigerators directly from the fresh water cooled condenser 9a.

If the plant is to be shut down the brine solution will be kept circulating for a while so that the pressure in the two condensers and the refrigerator 22 will be equalized. Said pressure would increase excessively in the brine cooled condenser 1'7, if the refrigerant could not flow over into the refrigerator 22, because the brine solution and the refrigerant will return to the atmospheric temperature, when the plant is shut down. The gases flowing over from the condenser 17 to the refrigerator 22 after the outlet of said refrigerator is closed will be condensed in the tubes of said refrigerator and said tubes will serve as condenser tubes. To keep the brine solution cool refrigerator 27 may be also operated for a while.

It will be evident that the refrigerator plant is adapted to be operated at a normallyhigh pressure or at a relatively lower pressure depending on the amount of refrigerant that is used. If the plant is operated at a high pressure, the primary condenser 9a will condense the refrigerantand the brine cooled condenser 17 will further cool the liquid refrigerant, thereby increasinglthe efficiency of the refrigerator 22 and making possible the attainment of unusually low temperatures. In shutting'down the plant, the valves 19 and 26 are closed, and the refrigerant in the tubes 22 is condensed so as to equalize the pressure in the tubes and the condenser -17 and thereby prevent the building up of an excessive pressure in the condenser. Subsequently, the refrigerant will return to atmospheric temperature. a

As an alternative, in shutting down, the

valves

13, 38, 30 and 32 may be closed, and the valves 35 may be-opened to isolate the fresh water condenser 9a and the tubes 2'7, and allow the refrigerant to flow from the condenser 1'7 into the refrigerator 22.

If the plant is operated at a relatively low pressure, the pressure in the condenser 9a, before the condenser 17 is connected, will be relatively high and the refrigerant will be condensed therein for expansion into the tubes 2'? to cool the brine. After connecting the condenser 1'7 in series with the condenser 9a the pressure of the refrigerant in the pressure side of the system will'drop to a relatively low point, and hence the condenser 9a will 'preocol or de-superheat the compressed gaseous refrigerant and the condenser 17 will liquefy the refrigerant for expansion into the tubes 22.

Having described my invention andhow the same is to be used I claim as new and desireto secure by Letters Patent:

1. In a refrigerator plant, in combination, a compressor, a fresh water cooled condenser, a conduit connecting said compressor to said condenser, a regulating valve in said conduit, a brine cooled liquid cooler, a second conduit connecting said condenser. and said cooler in series, a bypass conduit connecting said first mentioned conduit between said compressor and said valve to said second conduit, a regulating valve in said by-pass conduit, a regulating valve in said second conduit between said first mentioned condenser and said by-pass conduit, a discharge conduit connected to said second conduit between said first mentioned condenser and said last mentioned valve, a regulating valve in said discharge conduit, a discharge conduit opening from said liquid cooler, and a regulating valvein said last mentioned discharge conduit. i

2. In a refrigerator plant, in combination, a compressor, a primary condenser, a conduit connecting said compressor to said condenser, a regulating valve in said conduit, a secondary condenser, a second conduit connecting said condensers in series, a by-pass conduit connecting said first mentioned conduit between said compressor and said valve to said second conduit, a regulating valve in said by-pass conduit, a regulating valve in said second conduit between said primary condenser and said by-pass conduit, a discharge conduit connected to said second conduit between said primary condenser and said last mentioned valve, a regulating valve in said discharge conduit, a discharge conduit opening from said secondary condenser, and a regulating valve in said last mentioned discharge conduit.

3. In a refrigerator plant, in combination, a compressor, a fresh water cooled condenser, means for circulating fresh water through said condenser, a conduit connecting said compressor to said condenser, a brine cooled closed type condenser, means for circulating brine through said last mentioned condenser, a second conduit connecting said condensers in series, a regulating valve in said second conduit, a discharge conduit connected to said second conduit between said first mentioned condenser and said valve, a regulating valve in said discharge conduit, a discharge conduit opening from said brine cooled condenser, and a regulating valve in said last mentioned discharge conduit.

4. In a refrigerator plant, in combination, a compressor, a fresh water cooled condenser, a low temperature closed type brine cooled condenser and liquid cooler, an expansion, valve, 'a refrigerator, and a system of conduits and valves for connecting said units in series in the order named to form a closed circuit for a refrigerant and whereby the condensers may be singly or jointly connected in said circuit.

5; In a refrigerator plant, in combination, a compressor, means for. condensing the compressed refrigerant, a refrigerator, means for expanding liquid refrigerant from said first mentionedmeans into said refrigerator, and a system of conduits and valves for connecting said units in series in the order named to form a closed circuit, said first mentioned means comprising a primary condenser and a secondary condenser, said valves being adjustable to connect said condensers in series or singly in said circuit.

6. In a refrigerator plant, in combination, a compressor, a primary condenser, a conduit connecting said compressor to said condenser, a secondary condenser, a second conduit connecting said condensers in series, a regulating valve in said second conduit, a discharge conduit connected to said second conduit between said first mentioned condenser and said valve, a regulating valve in said discharge conduit, a discharge conduit opening from said last mentioned condenser,

ret rees and a regulating valve in said last mentioned discharge conduit.

7. In a refrigerator plant, in combination, a compressor, a primary condenser, a conduit connecting said compressor to said condenser, a secondary condenser, a second conduit connecting said condensers in series, a regulating valve in said second conduit, a discharge conduit connected to said second conduit between said first mentioned condenser and said valve, a regulating valve in said discharge conduit, a discharge conduit opening from said last mentioned condenser, a regulating valve in said last mentioned discharge conduit, two refrigerator elements connected respectively to said discharge conduits, two expansion valves interposed respectively at the inlets of said elements, and a common return conduit for connecting the outlets of said elements to said compressor.

8. In a refrigerator plant, in combination, a compressor, a primary condenser, a conduit connecting said compressor to said condenser, a secondary condenser, a second conduit connecting said condensers in series, a regulating valve in said second conduit, a discharge conduit connected to said second conduit between said first mentioned condenser and said valve, a regulating valve in said discharge conduit, a discharge conduit opening from said last mentioned condenser, a regulating valve in said last mentioned discharge conduit, a secondary refrigerator element having an expansion valve at its inlet connected to said first mentioned discharge conduit, a primary refrigerator element having an expansion valve at its inlet connected to said last mentioned discharge conduit, a by-pass conduit connecting said discharge conduits at the outlet sides of the two last mentioned regulating valves, and a regulating valve in said by-pass conduit.

9. In a refrigerator plant, in combination, a compressor, a fresh water cooled condenser, means for circulating fresh water through said condenser, a conduit connecting said compressor to said condenser, a brine cooled condenser and liquid cooler, means for circulating brine through said last mentioned condenser and cooler, a second conduit connecting said condensers in series, a regulating valve in said second conduit, a discharge conduit connected to said second conduit between said first mentioned condenser and said valve, a regulating valve in said discharge conduit, a discharge conduit opening from said brine cooled condenser and cooler, a regulating valve in said last mentioned discharge conduit, a relatively small refrigerator element having an expansion valve at its inlet connected to said first mentioned discharge conduit, a relatively large refrigerator element having an expansion valve at its inlet connected to said last mentioned discharge conduit, and an exhaust conduit for connecting the outlets of said elements to said compressor. 7

10. In a refrigerator plant, in combination,

compressor means, a fresh water cooled condenser, a conduit connecting said compressor means to said condenser, a brine cooled condenser, a second conduit connecting said condensers in series, a liquid discharge conduit opening from said brine cooled condenser, said discharge conduit having two branches, two regulating valves one in each branch, two refrigerator elements connected respectively to said branches, two expansion valves one at the inlet of each element, and conduit means for connecting the outlets of said elements to said compressor means.

11. In a refrigerator plant, in combination, compressor means, a primary condenser. a conduit connecting said compressor means to said condenser, a secondary condenser, a second conduit connecting ,said condensers in series, a discharge conduit opening from said secondary condenser, a regulating valve in said last mentioned discharge conduit, a relatively large refrigerator element having an expansion valve at its inlet connected to said discharge conduit, a branch conduit connected to said discharge conduit, a regulating valve in said branch conduit, and a relatively small refrigerator element having an expansion valve at its inlet end connected to said branch conduit, the refrigerator elements being juxtaposed and incorporated in a closed housing.

12. In-a refrigerator plant, a refrigerator comprising, in combination, a chamber having inlet and outlet headers, a plurality of spaced cooling tubes connecting saidheaders, said tubes constituting a relatively large refrigerating element, means including an expansion valve for admitting refrigerant to the inlet header, means for withdrawing refrigerant from the outlet header, said chamber having two additional headers respectively at opposite sides and adjacent said inlet header, a plurality of transverse cooling tubes extending between said first mentioned tubes and connecting said side headers, said transverse tubes constituting a relatively small refrigerator element, means including an expansion valve for admitting refrigerant to one of said side headers, means for withdrawing refrigerant from the other of said side headers, and means for circulating brine through said chamber about said vertical and horizontal tubes.

13. In a refrigerator plant, a refrigerator comprising, in combination, a chamber, a relatively large refrigerator element having a series of spaced heat exchange surfaces disposed in said chamber, a relatively small refrigerator element having a series of spaced heat exchange'surfaces disposed in said chamber, said surfaces of said respective elements being arranged in closely spaced relation, means for circulating refrigerant through said elements, and means for circulating brine through said chamber.

, 14. In a refrigerator plant, in combination, a

' compressor, closed type condenser means, re-

- cuit. I

'frigerant expansion means and a refrigerator con nected inthe order named in a closed circuit,

. means'for circulating brine through said refrigerator and part of said condenser means, and valve controlled means whereby said brine may be diverted from the refrigerator for outside use and whereby the brine may be returned to said refrigerator.

15. In a refrigerator plant, in combination, a compressor, two condensers, one of said condensers comprising a brine chamber 'and a condenser element, a refrigerator comprising a brine chamber and a refrigerator element in said last mentioned chamber, an expansion valve at the inlet of the refrigerator element, a system of conduits connecting said compressor, said condenser element, the other condenser and said refrigerator element in a closed circuit, a brine pump, and a system of conduits connecting said chambers and said pump in a closed brine cir- 16. In a refrigeratorplant, in combination, a compressor, two condensers, one of said condensers comprising a brine chamber and a condenser element, a refrigerator comprising a brine chamber and a, refrigerator element in said last mentioned chamber, a system of conduits connecting said compressor, said condenser element, the other condenser and said refrigerator element in a closed circuit, an expansion valve at the inlet of the refrigerator element, a brine pump, a system of conduits connecting said chambers and said pump in a closed brine circuit, and a closed branch circuit connected to said brine circuit in parallel to said last mentioned chamber.

17. In a refrigerator plant, in combination, a compressor, a gas cooler, a condenser, refrigerant expansion means, and a refrigerator connected in series in the order named to form a closed refrigerant circuit, a brine pump,- a system of conduits connecting said refrigerator, said condens er and said pump in a closed brine circuit, a regulating valve in said brine circuit between said refrigerator and the brine inlet of said condenser, said brine circuit including branch conduits connected respectively to said brine circuit between the refrigerator and said regulating valve and between said condenser andsaid brine pump, and two regulating valves one interposed in each of said branch conduits. 18. In a refrigerator plant, in combination. a refrigerator comprising a brine passage and two refrigerant passages separated from said brine passage by heat exchanging surfaces, a compressor connected to the outlet ends of said refrigerant passages, a condenser connected to the discharge of said compressor, a discharge conduit opening from said condenser and having two branch conduits connected respectively to the inlets of said refrigerant passages, two expansion valves interposed respectively in said branch conduits, two regulating valves interposed respectively in said branch conduits, and means for circulating brine through said brine passage.

19. In a refrigerator plant, in combination, a refrigerator comprising two separate elements, expansion means for said elements, means for circulating brine through said refrigerator, compressor means connected to the outlet ends of said elements, a condenser connected to said compressor means, means available at will for connecting said condenser to the inlet of one of said elements to complete a closed preliminary cooling circuit, a brine cooled condenser, means for connecting said brine cooled condenser to said compressor means, means available at will for connecting said brine cooled condenser to the inlet of the other of said elements to complete a closed main cooling circuit, and means for circulating brine from said refrigerator through said brine cooled condenser.

20. The process of refrigeration which comprises circulating brine through a closed path,

circulating a refrigerant of low boiling point in a closed refrigerant path and in the course of circulation compressing the refrigerant, abstracting heat from the compressed refrigerant 'by means of fresh water to condense the refrigerant, and expanding the liquid refrigerant to abstract heat from the circulating brine until the latter attains a predetermined low temperature, then circulating the refrigerant at an increased rate in a second closed refrigerant path and in the course thereof compressing the refrigerant,

abstracting heat from the refrigerant first by means of fresh water and then by. means of a part of said circulating brine to condense and cool the refrigerant and expanding the liquid refrigerant to abstract heat from the circulating brine.

21. Fornse in a refrigerator plant comprising a refrigerator having a brine passage and two separate refrigerator passages separated from said brine passage by heat exchange surfaces, expansion means for said refrigerator passages, compression means, a fresh water cooled condenser and a brine cooled condenser, the process of refrigeration which comprises circulating brine in a closed path including said brine passage and said brine cooled condenser, initially circulating a refrigerant in a closed preliminary refrigerating path including one of said refrigerator passages and said water cooled condenser and in the course of circulation compressing the gaseous refrigerant, condensing the refrigerant in said water cooled condenser, and expanding the liquid refrigerant in said one refrigerator passage to abstract heat from the circulating,

brine until the latter attains a predetermined low temperature, then during normal operation circulating the refrigerant in a closed main refrigerant path including said water cooled condenser, said brine cooled condenser and the other i of said refrigerator passages and in the course of circulation compressing the gaseous refrigerant, abstracting heat from the compressed refrigerant in said water cooled condenser, abstracting heat from the refrigerant in said brine cooled condenser, and expanding the liquid refrigerant in said other refrigerator passage to abstract heat from the circulating brine.

22. For use in a refrigerator plant comprising, in combination, a brine circulating path and two separate refrigerant circulating paths in each of which refrigerant paths the refrigerant is compressed, condensed and expanded in a recurrent cycle, the process of refrigeration which comprises initially utilizing one refrigerant path to cool the circulating brine down to a predetermined low temperature, then utilizing the second refrigerant path to continue abstracting heat from the circulating brine, and in the course of said last mentioned step utilizing the cold brine as a condensing medium for the re- I frigerant.

23. The process of refrigeration which comprises compressing the refrigerant, abstracting heat from the compressed refrigerant by means of a coolant to condense the refrigerant, and expanding the liquid refrigerant to abstract heat from brine until the latter attains a predetermined low temperature, and then utilizing said coolant and a portion of the cold brine to condense said refrigerant.

24. For use in a refrigerator plant comprising a refrigerator having a brine passage and two separate refrigerator passages separated from said brine passage by heat exchange surfaces, compressor means, a fresh water cooled condenser and a brine cooled condenser and cooler, the process of refrigeration which comprises cir-' culating .brine in a closed path including said brine passage and said brine cooled condenser and cooler, initially circulating a refrigerant in a closed preliminary refrigerating path including one of said refrigerator passages and said water cooled condenser and in the course of circulation compressing the gaseous refrigerant, condensing'the refrigerant in said water cooled condenser, and expanding the liquid refrigerant in said one refrigerator passage to abstract heat from the circulating brine until the latter attains a predetermined low temperature, then during normal operation circulating the refrigerant in a closed main refrigerant path including said water cooled condenser, said brine cooled esa condenser and cooler and the other of said refrigerator passages and in the course of circulation compressing the gaseous refrigerant, abstracting heat from the compressed refrigerant in said water cooled condenser, abstracting heat from the refrigerant in said brine cooled condenser and cooler, and expanding the liquid refrigerant in said other refrigerator passage to abstract heat from the circulating brine, and upon shutting down again circulating the refrigerant through said first mentioned refrigerant path and in the course of said circulation expanding the liquid refrigerant in said one refrigerant passage to cool or condense any refrigerant trapped in said other refrigerant passage to prevent high pressure in said brine cooled condenser.

25. For use in a refrigerator plant comprising an expansion type of refrigerator having a brine passage and two separate refrigerator passages separated from said brine passage by heat exchange surfaces, compressor means, a fresh water cooled condenser and a brine cooled condenser, the process of refrigeration which comprises circulating brine in a closed path including said brine passage and said brine cooled condenser, initially circulating a portion of the refrigerant in a closed preliminary path including one of said refrigerator passages and said water cooled condenser and'in the course of cir'- culation compressing the gaseous refrigerant, condensing the refrigerant in said water cooled condenser and expanding the refrigerant in said one refrigerator passage to abstract heat from the brine and the remaining portion of said refrigerant until they have attained a predetermined low' temperature, then during normal op eration circulating the refrigerant in a closed main path including said water cooled condensof said refrigerator passages and in the course of circulation compressing the refrigerant, ab-

stracting superheat from the compressed gaseous refrigerant in said water cooled condenser which functions as a water cooled gas cooler, condensing the refrigerant in said brine cooled condenser, and expanding the liquid refrigerant in said other refrigerator passage to abstract heat from the brine.

26. For use in a refrigerator plant comprising a refrigerator having a brine passage and two separate refrigerator passages separatedfrom said brine passage by heat exchange surfaces, expansion means for said refrigerator compressor means, a fresh water cooled condenser and a brine cooled condenser, the process of refrigeration which comprises circulating brine in a closed path including said brine passage and said brine cooled condenser, initially circulating a portion of the refrigerant in the closed prelim- 'ihary path including one of ;said refrigerator passages and said water cooled condenser and in the course of circulation compressing the gaseous refrigerant, condensing the refrigerant in said water cooled condenser and expanding the refrigerant in said one refrigerator passage to abstract heat from the brine and the remaining portion of said refrigerant until they have attained a predetermined low temperature, then during normal operation circulating the refrigerant in a closed main path including said water cooled condenser, said brine cooled condenser and the other of said refrigerator passages and in the course of circulation compressing the refrigerant, abstracting superheat from the compassage and said brine cooled condenser and cooling or condensing gaseous refrigerant in said other refrigerator passage to equalize the pressure in said passage and said brine cooled condenser.

27. For use in a refrigerator plant comprising an expansion type of refrigerator having a brine passage and two separate refrigerator passages separated from said brinepassage by heat exchange surfaces, compressor means, a fresh water cooled condenser and a brine cooled condenser, the process of refrigeration which comprises circulating brine in a closed path including said brine passage and said brine cooled condenser, initially circulating refrigerant in a preliminary closed path including one of said refrigerator passages and said Water cooled condenser and in the course of circulation compressing the refrigerant, condensing the refrigerant at a relatively high pressure in said water cooled condenser and expanding the liquidrefrigerant in said one refrigerator passage to abstract heat from the brine until the latter has attained a predetermined low temperature, then during nor mal operation circulating the refrigerant in a closed main path including said water cooled condenser, said brine cooled condenser and the other of said refrigerator passages and in the course of circulation compressing the refrigerant, abstracting superheat from the gaseous refrigerant in said water cooled condenser at a relatively low pressure, condensing therefrigerant in said brine cooled condenser by utilizing a portion or all of the circulating brine as the condensing medium, and expanding the liquid refrigerant in said other refrigerator passage to abstract heat from the brine.

28. In a refrigerator plant, in combination, a compressor, a condenser connected to said compressor and operable to liquefy the refrigerant gas therein, a, combined low temperature gas and liquid cooler connected to the discharge of said condenser, a by-pass line in parallel with said condenser and connecting the inlet of said cooler to said compressor, said liquid cooler serving to condense the gas from said by-pass line and to further cool the liquid from said condenser, a refrigerator connected to said cooler, expansion valves interposed between said cooler and said refrigerator, and valve controlled means for connecting the outlets of said refrigerator to the inlet of said compressor.

29. In a refrigerator plant, in combination, a compressor, a fresh water cooled condenser, means for circulating fresh water through said condenser, a conduit connecting said compressor to said condenser, a brine cooled condenser, means for circulating brine through said last mentioned condenser, a second conduit connecting said condensers in series, a regulating valve in said second con'duit, a check valve in said second conduit at the inlet of said brine cooled condenser to prevent back-flow of the cold refrigerant into said water cooled condenser for the purpose of preventing freezing, a discharge conduit connected to said second conduit between said first mentioned condenser and said valve, a

regulating valve in said discharge conduit, a discharge conduit opening from said brine cooled condenser, a regulating valve in said last mentioned discharge conduit, a relatively small refrigerator element having an expansion valve at its inlet connected to said first mentioned discharge conduit, a relatively large refrigerator element having an expansion valve at its inlet connected to said last mentioned discharge conduit, an exhaust conduit for connecting the outlets of said elements to said compressor, and a check valve between the outlet of said small refrigorator element and said exhaust conduit to prevent the fiow of the higher temperature spent refrigerant from said large refrigerator element into said relatively lower temperature small refrigerator element.

30. In a refrigerator plant, in combination, a compressor, a water cooled condenser connected to the discharge of said compressor, said condenser acting either as a gas cooler at relatively low pressures or as a condenser to liquefy the gas at relatively high pressures, a closed type brine cooled condenser connected in series with said water cooled condenser, said brine cooled condenser serving to liquefy pre-cooled gas from said water cooled condenser at said low pressures or to super-cool the condensate from said water cooled condenser at said high pressures, the pressures being determined by the amount of refrigerant in the plant and the temperature maintained in said brine cooled condenser, a refrigerator, a valve controlled conduit connecting said refrigerator to the discharge of said brine cooled condenser, an expansion valve in said conduit, a valve controlled brine conveying connection between the refrigerator and the brine cooled condenser, means for circulating brine through the refrigerator and through the brine cooled condenser; a valve'controlled branch line leading from said brine connection to con-v vey brine for outside use, means for returning said brine'to the brine circulating means, and a conduit connecting the outlet of said refrigerator to said compressor.

31. A refrigerator comprising, in combination, a housing defining a chamber adapted to contain a fiuid medium and having means-for admitting and withdrawing said medium, and two independent heat exchange elements defining closed passages opening through said-chamber, said elements being adapted for external contact with said medium, one of said elements being adapted to expand and evaporate a refrigerant therein to refrigerate said chamber, the other of said elements being adapted selectively either to expand and evaporate a refrigerant therein to refrigerate said chamber or to act as a condenser for the vaporized refrigerant therein through exposure to the temperature of said first mentioned element or said medium,

32. In a refrigerator, a closed housing defining a chamber adapted to contain a fluid medium and having means for admitting and withdrawing said medium, two opposite walls of said housing being formed respectively with inlet and outlet manifolds, a plurality of tubes connecting said manifolds and extending through said chamber, two other opposite walls being formed respectively with inlet and outlet manifolds, and a plurality of tubes connecting said last mentioned manifolds and extending transversely of said first mentioned tubes through said chamber, said elements being adapted to act as refrigerating elements to cool said medium.

33. In a refrigerator plant, in combination, a compressor, a condenser, an expansion valve and a refrigerator connected in a closed circuit in the order named, said refrigerator being adapted to cool brine to a.low temperature, a brine passage through said refrigerator, a low temperature condenser unit, means for leading a vapor to be condensed or a liquid to be cooled through said last mentioned condenser unit, and means for circulating the brine between said refrigerator and said last mentioned condenser unit to abstract heat therefrom and then returning it to said refrigerator to be re-cooled.

34. The process of refrigeration which comprises compressing, condensing and expanding a volatile refrigerant in a continuous cycle to obtain a low refrigerating temperature, utilizing said expanded refrigerant at said temperature to cool brine, and circulating said cold brine along the path of the expanded refrigerant and along the path of a fluid medium to be cooled to condense said fluid medium at a very low temperature and then returning said brine to be recooled by said refrigerant.

35. The process of refrigeration which comprises compressing, condensing and expanding a volatile refrigerant in a continuous cycle involving two paths arranged in the same closed chamher to obtain a low refrigerating temperature to cool brine in said chamber, and circulating said low temperature brine along the path of the expanded refrigerant and along the path of a fluid medium to be cooled to condense the fluid medium to a very low temperature and then returning said brine to said closed chamber to be re-cooled therein.

36. In a refrigerator plant, a refrigerator comprising, in combination, a chamber having inlet and outlet headers, a plurality of spaced cooling tubes connecting said headers, said tubes constituting a relatively large refrigerating element, means including an expansion valve for admitting refrigerant to the inlet header, means for withdrawing refrigerant from the outlet header, said chamber having two additional headers respectively at opposite sides, a plurality. of transverse cooling tubes extending between said first mentioned tubes and connecting said side headers, "said transverse tubes constituting a relatively small refrigerator element, means including an expansion valve for admitting refrigerant to one of said last mentioned headers, means for withdrawing refrigerant from the other of said headers, means whereby said elements may be singly or jointly operated, and means for circulating brine through said chamber about said elements.

37. In a refrigerator system, a closed circuit which involves a primary condenser, and a primary refrigerator, a second circuit involving a secondary condenser and a secondary refrigerator; said primary refrigerator and said secondary refrigerator being enclosed in a closed housing; and means whereby the refrigerant from the primary condenser and the refrigerant from the secondary condenser are commingled and the temperatures equalized before expanding the refrigerant in a portion of the refrigerator means.

38. In a refrigerating plant a refrigerator unit having two independent refrigerating elements arranged therein for high and low temperatures, a compressor common to both elements, a condenser, two expansion valves at the inlets of said refrigerating elements and means for circulating brine through said refrigerator unit so as to first contact with one of the refrigerating elements and then to contact with both of said elements, whereby the brine is first brought into contact with the high temperature refrigerator element and then while passing through said refrigerator unit made to contact with the low temperature refrigerator element.

39. The process of refrigeration which consists in circulating a refrigerant of low boiling point in closed refrigerant paths, and in the course of circulation compressing, condensing a part of the refrigerant, pre-cooling but not condensing a part of the refrigerant, commingling the parts to liquefy all of the refrigerant and vaporizing the liquid refrigerant to obtain a low refrigerating temperature.

40. The process of refrigeration which consists in circulating a refrigerant in closed paths, and in the course of circulation compressing, precooling the compressed gas, liquefying a portion of the gas by means of a low temperature condensing medium, commingling the portion of precooled gas with the low temperature liquid portion of the refrigerant whereby the gas' portion will also be liquefied, and expanding the liquid refrigerant into a vapor and then recompressing the refrigerant.

41. In a refrigeration plant, the combination of a compressor, a low temperature closed type brine cooled condenser, an expansion valve, a refrigerator, a system of conduits for connecting said elements in series in the order named to form a closed circuit for a refrigerant with means whereby brine may be circulated between the refrigerator and the condenser, and means whereby additional cold brine from an outside source may be circulated through and away from said condenser, said means being controllable to permit interruption of the circulation of brine between the refrigerator-and the condenser.

AUGUST SCHWARZ.