US2665558A

US2665558A - Two-temperature refrigeration system

Info

Publication number: US2665558A
Application number: US692438A
Authority: US
Inventors: Clara E Fiene
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1946-08-23
Filing date: 1946-08-23
Publication date: 1954-01-12
Anticipated expiration: 1971-01-12

Description

Jan. 12, 1954 M. E. FIENE 2,555,558

TWOLTEMPERATURE REFRIGERATION- SYSTEM Filed Aug. 25, 1946 2 Sheets-Sheet l Iverjtohg MaT`CL1S E. Fiehe, Deceased,

Clara E F'iene, Admnistratvix,

Attorh ey.

Jan. l2, 1954 M. E. FIENE v 2,665,558

TWO-TEMPERATURE REFRIGERTION SYSTEM Filed Aug. 23, 1946 2 Sheets-Sheet 2 Inventor:

Mavcus E. Fiene,Deceased, Clara E. Fienedmnstvatrix,

by y 1f. fm

Attorney.

Patented Jan. 12, 1954 Two-TEMPERATURE STE ceased, late ofscotia, N. Y.,

Marcus E. Fiene, de

REFRIGERATION M by Clara E. Fiene, administratrix, Scotia, N. Y., assignor to General Electric Company, a corporation of New York Application August 23, 1946, Serial No.692,438

Claims.

This invention relates to mechanical refrigerating apparatus and particularly to two-temperature refrigerating machines employing secondary refrigerant'systems.

In order to accommodate a suflicient amount of frozen foods many household refrigerators are now being made with two separate compartments. One of these compartments is maintained at a very low temperature, for example, 0 to 10 F., in order to provide for the storage of frozen foods and for the freezing of ice cubes. The second compartment, which is used for the storage of other types of food, is maintained at a temperature of about 35 to 4.0c F. To achieve the two widely separated temperatures required for the freezing compartment and for the general food storage compartment a primary refrigeration system may be provided for cooling the freezing compartment and a secondary refrigerating system for cooling the general food storage compartment. The secondary refrigerating system is dependent upon the primary system for its operation and it is necessary in order to maintain the desired temperature in the food storage compartment to provide some means of control within the secondary refrigerating system which will allow the maintenance-of a higher temperature by the secondary system Vdespite the continued operation of the primary refrigerating system at a much lower temperature. Accordingly, it is an object of this invention to provide an improved control apparatus for use with a secondary refrigerating system.

It is another object of this invention to provide improved apparatus for controlling the flow of refrigerant in a refrigerant circulating system.

Where the evaporator in a refrigerating system is not operated on `a defrosting cycle it is necessary that provision be made for the removal from time to time of the frost accumulating on such evaporator. Accordingly, it is another object of this invention to provide an improved defrosting arrangement for the evaporator of a refrigerating system.

Further objects and advantages of this invention will 'become apparent as the following description proceeds and the features of novelty which characterize this invention will bepointed out with particularity in the claims rannexed to and forming a part of this specification.Y

For a better understanding of this invention reference be had to `the'accompamzing drawings in which Fig. 1 is a side elevation, 'partly in section, of a household refrigerator incorporating one embodiment of this invention; Fig. ;2 is yan enlarged View, also partly vin section, showing `details of the ow controlling device which is `incorporated in the Vrefrigerator shown'in'Fig. 1*;

VturnsuctionA line IIJ.

and Fig. 3 is an illustration of a modified form of this flow controlling arrangement which incorporates apparatus for defrosting the secondary system.

Referring now yto the drawings, Fig. 1 shows a household refrigerator having a thermally insulated cabinet in which lare included a machinery cmopartment I, a food storage compartment 2, and a freezing compartment 3. The thermal insulating material is indicated generally by 4. Access to the food storage and freezing compartments is Vprovided bymeans of doorsI 5 and 6, respectively. y

The freezing compartment 3 is refrigerated by a primary refrigerating system which includes compressing and condensing apparatus (not shown) within the machinery compartment I, a primary evaporator- 'I and a liquid receiver 8. The liquid receiver 8 includes a float valveor other suitable device (not shown) for controlling the ilowrof refrigerant to the primary evaporator l. The liquid refrigerant from the condensing unit in the machinery compartment I is supplied lto the liquid receiver through a liquid line 9 which is shown in heat exchange relation with the re- 'I'he liquid refrigerant, under the control of the float valve, lis supplied from the receiver 8 to the lprimary evaporator v1 through a conduit I I. The `vaporized refrigerant from the primary evaporator is Withdrawn from the header I2 through the suction conduit IIB. As shown in Fig. 1, this suction conduit is preferably looped about the receiver -8 in vheat `exchange relationship to lcoo'l the noncondensable vgases in the liquid receiver.

The temperature of the primary evaporator may be controlled in any suitable manner. `In Fig. l'apparatus forcontrolling this ytemperature is illustrated as including a temperature responsive bulb i3 vconnected in the usual mannerl bya tube I4 to any suitable motor control switch arranged within the housing I5.

Turning now `to the secondary refrigei'a'ting system illustrated in Fig. l, this system includes a condensing portion or condenser I6, an evaporating portion or evaporator il and a new controlling apparatus, indicated generally as iii, for lcontrolling lthe flow of condensed refrigerant from the condenser 'it to the secondary evaporator i?. `As illustrated in Fig. i 'the condenser 'i6 is placedfin intimate heat exchange relation with the primary evaporator l'. This maybe accomplished, for example, by securing the ltube comrising the condenser in intimate contact with the primary evaporator 'i by several clamps, two of which are indicated at I9 and `.2t in Fig. 1.

The secondary evaporator I? is composed of severalturns disposed in serpentine arrangement about the food storage compartment 2 and secured to the exterior of the liner of this compartment to accomplish the refrigeration thereof. Although the secondary evaporator has been shown secured to the exterior' of the liner of the compartment 2 in a manner well known in the art, it will be apparent that this evaporator could, if desired, :be arranged within the compartment 2, just as the primary evaporator is arranged within the compartment 3. The flow controlling apparatus i8 includes a condensate flow control chamber 2i, a condensate reservoir 22, a conduit 23 which connects the condensate flow control chamber with the condenser It, a conduit 2d for transmitting liquid refrigerant from the condensate ilow con 1ol chamber 2i to the secondary evaporator il and a conduit 25 for transmitting liquid refrigerant from the condensate flow control chamber 2! to the condensate reservoir 22. The vaporized refrigerant from the secondary evaporator Il is returned to the condenser i6 through a conduit 2li. A bellows 27, which is connected to be actuated by a thermostatic bulb 28 placed within the -food storage compartment 2, is employed in connection with the condensate flow control chamber in a manner which will be described in greater detail in connection with Fig. l2. Although the bulb 28 is placed within the compartment 2 in the form illustrated, it will be apparent that it may, tact with the secondary evaporator Il and be directly responsive to the temperature of this evaporator, in the same manner as the bulb i3 is placed in contact with the primary evaporator l. For calibration purposes an opposing spring may be provided for the bellows in a manner wellknown in the art.

Referring now to Fig. 2, the condensate flow control chamber 2l is provided with an inlet 23 for the liquid refrigerant and two outlets 2li and 25 for the liquid refrigerant, leading to the secondary evaporator l? and the condensate reservoir 22 respectively. In order to direct the liquid refrigerant from the conduit 23 to the secondary evaporator l? or to the condensate reservoir 22, A

there is provided within the condensate flow control chamber 2l a vane or member 29 which is free to pivot on a shaft 3D. This member or bafile 29 is made of a magnetic material for reasons which will appear as this description proceeds. To control the position of the member 28 and hence to control the distribution of the liquid refrigerant as indicated above, a permanent magnet 3i is provided. In order that the magnet Si may control the position of the member 2S, the

chamber 2l or at least the lower portion thereof between the magnet 3i and member 2S is made of a nonmagnetic material. The magnet 3l is mounted on a supporting arm or member 32, which in turn is mounted on a shaft (not shown) which is generally in line with shaft 30. The position of the member 32 and hence the position of the member 29 is controlled by the expansible bellows 2'! which is connected by a link 33 to the member 32. Since the bellows 2'! is mounted by a bracket 3ft in fixed relationship to the condensate flow control chamber 2 i, the expansion and contraction of the bellows 2l in response to the thermostatic bulb 28 will result in a corresponding transmission of motion to the member 32 through the link 33. Movement of the member 32 will cause a corresponding motion of member 29 since, as stated previously, member 2S is comprised of magnetic material which will be influenced by the magnet 3 i. It will be apparent that if desired, be placed in conthe above-described apparatus will direct the liquid refrigerant to the conduits 2K5 and 25 in any proportions required, as indicated by the temperature responsive bulb 2t, or the dow may be cut off entirely from one or the other of the

conduits

24 and 25.

In order that the condensate directed to one side or the other of the condensate flow control chamber 2i will be conducted to the

proper conduit

24 or 25, there is provided barrier 35 which prevents passage of condensate from one side of the chamber 2l to the opposite side along the lower portion thereof. As can be seen by refer-- ence to Fig. 2, the top of this barrier is higher than the opening to conduits 2li and ..5 and hence, the level of the condensate in the bottom oi chamber 2| cannot rise above the top of the barrier. This prevents flow of condensate trom one side of the barrier to the other and insures that condensate directed to one side or the other by member 29 will be conducted to the proper conduit.

ln order to provide a relatively stable condition and to eliminate a frequent or continuous oscillation of the member 2%, arrangement is made for continuously supplying a small amount of refrigerant to the secondary evaporator. The amount of refrigerant so supplied is in the neigh- :borhood of ten per cent of the maximum refrigerant which could be supplied. directly from the chamber 2l to the conduit 2. This amount of refrigerant will compensate to some extent for the normal heat leakage into the storage compartment 2 and hence will prevent a rapid fluctuation of temperature which otherwise would require that the member 29 frequently vary the amount of refrigerant supplied to the secondary evaporator. This continuous supply of refrigerant to the secondary evaporator il is provided through a restricting tube or duct sometimes referred to as a capillary tube, connected between the condensate reservoir 22 and the conduit 2G. The diameter and length of this restrict ing tube is so chosen as to supply the desired amount of refrigerant to the conduit M and thence to the secondary evaporator i'i, even though the main supply of refrigerant thereto has been cut oi by the member 29. The condensate reservoir 22 is connected by a conduit Si to the conduit 2S in order to conduct refrigerant vaporized in the condensate reservoir directly to the condenser i6.

The operation or the refrigerating system illustrated in Figs. 1 and 2 is as follows. Liquid refrigerant is supplied from the condensing unit in machinery compartment l through the receiver 8 and iloat valve therein to the primary evaporator l, the now of refrigerant to the primary evaporator l being controlled by the float valve located in the receiver B. Heat is extracted from the freezing compartment resulting in a reduction in the temperature thereof, Refrigerant is supplied to the primary evaporator until the primary evaporator reaches some predetermined minimum temperature. When this minimum temperature is reached, the compressor will be stopped by operation of the motor control switch under control of thermostat i3. Conversely when a predetermined upper limit of temperature has been reached, the compressor will again be started through operation of the motor control switch.

Vaporizedrefrigerant in the closed secondary system' is condensed in the condenser I6 as a result of the extraction of heat therefrom by accette the. `primary evaporator 'l with which :the i condenser :1| 6 iszin fintimate i'heat exchange relationship. .Fig .2 :illustrates 'the position'of the member 2S Vat a time when rthe ltempera-turein-the food 'storage compartment has reached'its predeterminedzminimum, foreXample-So F. `Under this .condition the upper end of the ymember eis'positioned tothe right of theconduit 23 and .thence all of'rthe liquid refrigerant from the condenser Slt .is idirectedby the member F29 through .the conduit 25 Aand `thence intoV the condensate reservoir 22. A small .1arnount'1of liquid refrigerant `.from :the condensate reservoir 22 :is .supplied to the :secondary evaporator 'ifi during this periodthroughithe'frestrictingltube 36. The :amount :of refrigerant ksupplied :through 'this restricting .tube i3@ is su'fhcientto 'compensate for at least a portion of thenormal .heatleakage into the storage compartment 2. "Whenever v:the heat `load exceeds the r1amount'which.can ibe carried `this manner, .there l.will be an increase in .the '-.temperaturewithin the Vstorage `'compartment 2. As aresult of this .increase in temperature the thermostatic bulb 2.8*wil1cause anleitpansion of the bellows 2.7. 'Ihis causes .af-counterolockwise.movement-f .the member 32 and OfthemagnetSI. The memberEil 'Willlbe moved toa position somewhat to the `left -of Athe .righthand side of theconduit 2t and willtherefore cause a 'portion Tof thelliquid refrigerant nowing through conduit '23 to 'be directed 'through 'the conduit 24 to the ksecondary evaporator. If the amount of liquid refrigerant so directed through the 'conduit 2d is -not suicient'for Vthe requirements of the food storage compartment v"aand the temperature therein continues-to rise, -this temperature increase will be "reflected ina further expansion of the bellows 27.' This additional expansion -ofv the bellows 2-1 "will result, in the manner previously described, in `a"`further counterclocawise movement of the finember 32 andof the -member '29. II-his will result 'in a further increase .in ,the amount vof liquid 1refrigerant which is directed through the conduit 521i, and a corresponding reduction -in the amount Aof liquid refrigerant which is directed through the conduit to t'he condensate reservoi-rf'22. Any vfurther increase in the temperature `of food storage compartment 2 will .result -in fadditi'onal :counterclockwise movement fof "the member 29 until, should .the temperature fcon'dlitions necessitate, all ofthe liquid refrigerant flowing through the conduit 2t may be directed to the conduit 2li and thence to rthe secondary Ievaporator Il. As the temperature of the foodstorage compartment v2iis reduced, the bellows 121, kunder the control of the thermostatic `bulb 2e, will Lbegin to contract and -a clockwise movement `of the Imember 32, and a corresponding clockwise movement of the member 29, willlresult. As the temperature in foodk storage compartment 52 continues to decrease there will Vbe a turther clockwise Ymovement of the member 2d until, should vthe temperature reach the predetermined minimum, all ofthe liquid refrigerant from the conduit 23 will be directed-'through conduit 425 to Vthe condensate reservoir. Under Vthis condition the only liquid refrigerant which 'will be supplied to the secondary-evaporator -lfl will be that flowing 'from the condensate reservoir throughthe restricting tube 35,Y as has been/pre@ viously explained. I r

It is .contemplated that the secondary system shown inF'igs. land 2 will be operated von a defrosting cycle, that is,` the secondary 'evaporator will operate :for .a sufcient portion ofV eachV refrigerating cycle over-.a temperature range which will be'adequate to remove any frost 'which -ccllects during theremainder of the cycle. Since it may bevdesirablezto'operate on other than a clefrosting cycle, in the modification of this invention illustrated in Fig. 3, an arrangement isprovided for removing any1 frost which may accumulate on thesecondary evaporator. Referring now to Fig. 3, it will be seen that most of the elements are the lsame as those previously illustrated in Fig. 2. These include the thermostatic bulb h and bellows.-2l,'the condensateilow control chamber 2|, thecondensate reservoir 252, the restricting'tube `ijandthe conduits 2li, 25, 2E and 3l. The conduit 23 is connected slightly to the left of theposition shown in Fig. 2 in order that the upper end of member 2e will be just to the right of the conduit 2'3 when the member 23 is in the position freely assumed under the force of gravity. This isa factorlinthe accomplishment of the defrosting, as will be `explained below. In view `of the slight shifting of the position of conduit the link will be ofdifferent length or theposition of bellows 27 will be shifted relative to vthat used in Fig. 2in order to secure the same normal operation of the system. In the modification illustrated in Fig. 3 thepermanent'magnet ii! has been replaced by an electromagnet 38, in order that its control ofthemember 29 may be eliminated when necessary for defrosting. It will be recalled that in the embodiment illustrated in Fig. 2 a small amount of liquid refrigerant was suppliedto the secondary evaporator through the restricting tube 36, even though the main how of liquid refrigerant through the conduit 2e should be cut olf by the member 2S. In order to defrost the seco-ndary evaporator eiiectively it desirable that this flow of `refrigerant through the restricting tube be prevented, and .this is accomplished by providing apparatus for heating the restricting tube 35. This heating causes a vaporizaticn of refrigerant therein and thereby effectively blocks the flow of liquid refrigerant therethrough. The' specic apparatus forheating the restricting tube 35 illustrated in Fig. 3 isa resistance element 59.'

In order `to-con'trol the operation of the defrosting apparatus a .switch d, having two elements 'di and 42, is provided. In the embodiment shown in Fig. 3 there .is illustrated the switch as being operated by an automatic timing device 53, which operates the switch at any predetermined time to accomplish the defrosting. It will be apparent, however, that the switch dfi may be manually operated or may be controlled by any other suitable apparatus, for example by a device de' pendent on Vthe formation lof frost on the secondary evaporatorl'i. `Power for the electromagnet 3'8 and forfthe resistance element 39 is suppliedfrom lines et and'li. Line :it is connected directly toboth theelectromagnet and lthe resistance element Line G5 is connected to the electromagnet 38 through switch element di, and line 12.5 `is connected to the resistance element-39 through switch element d. The switch members di and rare so arranged that when one element closes the vcircuit through its cooperating contacts the ,other element will simultaneously open the circuit lthrough its cooperating contacts. f

The operation of'this apparatus shown in Fig. 3 during normal refrigeration isthe same as that previously "discussed in Vconnection with the embodiment yof my invention illustrated in 2.

During normal. operating of the system, Athe switch ill is positioned so that the element 4l closes the circuit to the electromagnet 38, and element 132 is spaced from its contacts so that the circuit through the resistance element t9 is open. Under these conditions the` electromagnet 38 will be energized and will control the member 29 in exactly the same manner as did the permanent magnet Si illustrated in Fig. 2.

To defrost the secondary evaporator, the switch 48 is operated to cause element si to open the circuit to the electromagnet 3B and to cause element 432 to close the circuit to the resistance element 39. The deenergization of the electromagnet 38 eliminates its control on the member 2G, and this member assumes its gravity-influenced position in which its upper end is to the right of conduit 23, as illustrated in Fig. 3. in this position, all of the liquid refrigerant through conduit 23 is directed by the member 29 to the conduit 25 and thence to the condensate reservoir 22, and no liquid refrigerant is allowed to pass through the condensate now control chamber 2l to the conduit 24. Because of the deenergization of electromagnet 38 it will be seen that even though the temperature in the iood storage compartment 2 should rise considerably above its normal range and there should be a continued expansion of the bellows 2, there would be no alteration in the above-indicated position of member 29. At the same time the current through the resistance element 39 causes a heating of the liquid refrigerant in the restricting tube Sii and a consequent vaporization of the refrigerant. This vapor eiiectively blocks the iiow of liquid rerigerant through the restricting tube 36, since this tube, as is wellknown in the art, will pass liquid refrigerant but Will be substantially blocked by gaseous refrigerant. Consequently, the supply of liquid refrigerant to the secondary evaporator is cut off and,

upon the resulting rise in temperature, deirosting of this evaporator is accomplished. When it is desired to terminate the deirosting, the switch it is operated to close the circuit to the elecromagnet 3S and simultaneously to break the circuit to the resistance element S), and normal operation of the system is resumed.

While this invention has been described in connection with two-temperature household refrigerators employing secondary refrigerating systems, other applications will be readily apparent to those skilled in the art. Therefore, this invention is not to be limited to the particular constructions shown and described and in the appended claims, all modifications are intended to be covered within the spirit and scope of this invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. Refrigerating apparatus comprising a primary evaporator, a secondary refrigerating system including an evaporating portion and a condensing portion, said condensing portion being in heat exchange relation with said primary evaporator, means providing a control chamber in said secondary refrigerating system between said condensing portion and said evaporating portion, a condensate reservoir in communication with said secondary reirigerating system, and a movable barile in said control chamber for selectively directing condensate from said condensing portion to said evaporating portion or to said condensate reservoir.

2. Refrigerating apparatus comprising a prmary evaporator, a secondary rerigerating system including an evaporating portion and a condensing portion, said condensing portion being in heat exchange relation with said primary evaporator, means providing a control chamber in said secondary refrigerating system between said condensing portion and said evaporating portion, a condensate reservoir in communication with said secondary refrigerating system, and a movable baiiie in said control chamber for varying the amount of condensate directed to said evaporating portion and oppositely varying the amount of condensate directed to said condensate reservoir.

3. Refrigerating apparatus comprising a primary evaporator, a secondary refrigerating system including an evaporating portion and a condensing portion said condensing portion being in heat exchange relation with said primary evaporator, means providing a control chamber in said secondary refrigerating system between said condensing portion and said evaporating portion, a condensate reservoir in communication with said secondary refrigerating system, a movable balile in said control chamber for selectively directing condensate from said condensing portion to said evaporating portion or to said condensate reservoir, and a restricting conduit for conducting condensate from said condensate reservoir directly to said evaporating portion at a predetermined limited rate.

4. Refrigerating apparatus comprising a primary evaporator, a secondary refrigerating system including an evaporating portion and a condensing portion, said condensing portion being in heat exchange relation with said primary evaporator, means providing a control chamber in said secondary refrigerating system between said condensing portion and said evaporating portion, a condensate reservoir in communication with said secondary refrigerating system, a movable baffle in said control chamber for selectively directing condensate from said condensing portion to said evaporating portion or to said condensate reservoir, and means dependent on a condition in said secondary refrigerating system for automatically controlling the position of said movable baiiie.

5. Refrigerating apparatus comprising a primary evaporator, a secondary refrigerating system including an evaporating portion and a condensing portion, said condensing portion being in heat exchange relation with said primary evaporator, means providing a control chamber in said secondary refrigerating system between said condensing portion and said evaporating portion, a condensate reservoir in communicaion with said secondary refrigerating system, a movable bailie in said control chamber for selectively directing condensate from said condensing portion to said evaporating portion or to said condensate reservoir, and thermostatically-controlled means for automatically controlling the position of said movable baiiie.

6. In a mechanical refrigerating apparatus for use with household refrigerators of the type which include a low temperature compartment and a higher temperature compartment, a primary evaporator for refrigerating the low temperature compartment, a secondary refrigerating system including an evaporating portion and a condensing portion, said evaporating portion being adapted to refrigerate the higher temperature compartment, said condensing portion being in heat exchange relation with said primary evaporator, means providing a control chamber' in said secondary refrigerating system between said condensing portion and said evaporating portion, a condensate reservoir in communication with said secondary refrigerating system, a movable baille in said control chamber for selectively directing the condensate from said condensing portion to said evaporating portion or to said condensate reservoir, and temperature responsive means for controlling the position of said movable bale. l

7. In a mechanical refrigerating apparatus for use with household refrigerators of the type which includes a low temperature compartment and a higher temperature compartment, a primary evaporator for refrigerating the low temperature compartment, a secondary refrigerating system including an evaporating portion and a condensing portion, said evaporating portion being adapted to refrigerate the 4higher temperature compartment, said condensing portion in heat exchange relation with said primary evaporator, means providing a control chamber in said secondary refrigerating system between said condensing portion and said evaporating portion, a condensate reservoir in communication with said secondary refrigerating system, a. movable member in said control chamber for selectively directing the condensate from said condensing portion to said evaporating portion or to said condensate reservoir, a restricting tube for conducting condensate from said condensate reservoir to said evaporating portion, and means for heating said restricting tube to prevent the now of refrigerant therethrough. .y

8. In a mechanical refrigerating apparatus for use with household refrigerators of the type which includes a low temperature compartment and a higher temperature compartment, a primary evaporator for refrigerating the low temperature compartment, a secondary refrigerating system including an evaporating portion and a condensing portion, said evaporating portion being adapted to refrigerate the higher temperature compartment, said condensing portion being in heat exchange relation with said primary evaporator, means providing a control chamber in said secondary refrigerating system between said condensing portion and said evaporating portion, a condensate reservoir in communication with said secondary -refrigerating system, a movable member in said control chamber for selectively directing the condensate from said condensing portion to said evaporating portion or to said condensate rsesrvoir, an electromagnet adjacent said movable member positioned in response to the temperature of the food storage compartment for controlling the position of said movable member, a restricting tube for conducting condensate fromlsaid condensate reservoir to said evaporating portion, means for heating said restricting tube to prevent the flow of refrigerant therethrough, and means for simultaneously deenergizing said electromagnet and energizing said heating means to defrost said evaporating portion.

9. In a refrigerating system, an evaporator and a condenser in a closed refrigerating circuit, a condensate reservoir outside said circuit but in communication therewith. a duct for conveying liquid refrigerant from said condensate reservoir to said evaporator, and means for heating said duct to control the ow of liquid refrigerant therethrough.

10. In a refrigerating system, a condensing portion, an evaporating portion, means providing a control chamber between said condensing portion f l0 and said evaporating portion, a condensate reservoir in communication with said chamber, a movable member in said chamber for directing refrigerant from said condensing portion selectively y to said evaporating portion or to said condensate reservoir, a duct for conducting refrigerant from said condensate reservoir -to said evaporating portion, and means` for heating' said duct to control the iloW Aof refrigerant therethrough.

1l. In a refrigerating system, a condensing portion, an evaporating portion, means providing a taneously deenergizing said electromagnet andk energizing said heating means to defrost said evaporating portion.

12. A secondary volatile refrigerating systemof the type having substantially the same pressure throughout, said system comprising, in combination, an evaporator adapted to vaporize refrigerant liquid by the absorption of heat, a vessel adapted to vaporize refrigerant liquid at a slower rate than said evaporator, a condenser adapted to condense the refrigerant vapor generated by said evaporator and said vessel, conduit means for conducting the refrigerant liquid condensed by said condenser to said evaporator, said conduit means including a vertical portion having a gap therein through which said liquid drops, and a bale adapted for movement into and out of `said gap, said baille being formed to deect the refrigerant liquid flowing from said condenser into said gap to said vessel when said bale is moved into said gap.

13.'The refrigerating system defined in claim 12 including a quantity of volatile liquid refrigerant in said system not in excess of the capacity of said vessel.

14. The refrigerating system defined in claim 12 including actuating means responsive to heat for effecting the movements of said baiTle. Y

15. The refrigerating system dened in claim 12 wherein said system includes a chamber enclosing said baiile, magnetic material associated with said baffle to move the same, said magnetic material being located within said chamber, magnetic material located outside of said chamber and adapted to move the magnetic material located within said chamber, and means responsive to heat for moving the magnetic material located outside said chamber.

CLARA E. FIENE,

Admnistratrz' of the estate of Marcus E. Fiene,

deceased.

References cited in the me of this patent UNITED sTATEs PATENTS Kalischer Dec. 23, 1947