US2548608A - Flow-controlling device for refrigerators - Google Patents

Description

April! 16, 1951 JANOS 2,548,608

FLOW-CONTROLLING DEVICE FOR REFRIGERATORS Filed Dec. 18, 1946 2 Sheets-Sheet 1 Inventor: Ah red G. Janos His Attorney.

April 10, 1951 A, JANQS 2,548,608

v FLOW-CONTROLLING DEVICE FOR REFRIGERATORS Filed Dec. 18, 1946 2 Sheets-Sheet 2 Inventor: I Ahr-ed G. Janos,

His Attorney.

Patented Apr. 10, 1951 FLOlW-CONTROLLING DEVICE FOR REFRIGERATORS Alfred G. Janos, Erie, Pa., assignor to General Electric Company, a corporation of New York Application December 18, 1946, Serial No. 716,933

13 Claims. 1

My invention relates to flow-controlling devices and more particularly to flow-controlling devices for use with refrigerating apparatus.

In certain types of refrigerating apparatus it is sometimes desirable to control the flow of fluid througha conduit or passage in accordance with the temperature prevailing at the point in the passage where the control device is located. For example, a refrigerator compartment may be provided with a drain conduit for the removal of water resulting from defrosting of the cooling unit; however, it is desirable to prevent the circulation of air through the drain during normal operation of the cooling unit at low temperature, and a valve responsive to the temperature within the drain may be employed for this purpose. Another example is the control of the flow of refrigerant in a so-called secondary refrigerat ing system which comprises a sealed conduit partially filled with a quantity of liquid refrigerant, an upper portion of the conduit constituting: the condenser of the secondary system and being cooled by a primary evaporator and the lower portion containing the liquid and serving as the evaporator of the secondary. Vaporized refrigerant flows from the evaporator portion to the condensing portion, and, after condensation, the liquid refrigerant flows back to the evaporator portion. It may be desirable to control the temperature of the evaporator portion and this may be accomplished by controlling either the fiow of vaporized refrigerant or the return of liquid refrigerant in response to the temperature prevailing in a portion of the conduit. In these and other systems, particularly where there is little pressure difference tending to produce the flow of fluid, it is desirable to provide a simple control device with few moving parts. Accordingly it is an object of myinvention to provide an improved fluid flow-controlling device which is of simple construction and which is actuated in accordance with its temperature. I

It is another object of my invention to provide a device which will control the flow of fluid in response to changes in state of a freezable substance.

It is a further object of my invention to provide an improved fiow-controlling'device, the operation of which is dependent on the expansion of a substance in changing from the liquid state to the frozenstate.

It is still another object of my invention to provide a device which will effectively block communication through a conduit during normal oppassage-between a low temperature zone and a higher temperature zone during defrosting of the low temperature zone and which automatically closes the passage when defrosting is terminated.

It is another object of my invention to provide an improved arrangement for controlling the flow of refrigerant in accordance with temperature wherein all the control elements are disposed within a closed refrigerating system.

Further objects and advantages of my invention will become apparent as the following description proceeds and the features of novelty which characterize my invention will be pointed out with particularity in. the claims annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to the accompanying drawings in which Fig. 1 is a sectional view of a portion of a refrigerator cabinet incorporating an embodiment of my invention; Fig. 2 is an enlarged sectional view of a device used to control communication between the low temperature and the higher temperature zones of a refrigerator cabinet; Fig. 3 is a view of this device in its ex.- panded condition; Fig. 4 is a sectional view of a modified form of the controlling device; Fig. 5 is a view showing another embodiment of my invention; Fig. 6 is a sectional view of the controlling device of Fig. 5 shown in its contracted form; and Fig. 7 shows the controlling device in its expanded form.

Referring to Fig. 1, I have shown a two-temperature refrigerator cabinet I which includes a low temperature or freezing compartment 2 and a higher temperature or cooling compartment 3. Doors 4 and 5 are provided for closing the freezing compartment and the cooling compartment respectively. Suitable heat insulating material 5 is incorporated in the cabinet.

The freezing compartment 2 is formed by ametal shell or wall 1, and a breaker strip 8 of suitable heat-insulating material is provided at the front of the freezing compartment to close and a breaker strip I2 of suitable heat-insulating material closes the space between the liner II and the outer wall 9 of the cabinet. A substantial portion of the top surface of the liner I l slopes toward the rear of the cabinet in order to direct moisture collecting thereon toward the rear of the cabinet.

In order to collect the water resulting from the defrosting of the exterior walls of the freezing compartment 2 there is provided beneath the shell 1 a receptacle or water-collecting member I3. An opening I4 is provided in the receptacle i3 and the receptacle is so constructed that the bottom thereof slopes toward the opening I in order to direct toward the aforementioned opening any water collecting in the receptacle. The receptacle I3 is spaced from the freezing cornpartment and defines therewith a low temperature zone.

A passage i5 is provided between the cooling compartment 3 and the low temperature zone adjacent the shell I in order that the Water resulting from the defrostin of the freezing compartment may be directed from the receptacle I3 to thecooling compartment. In order to prevent the water flowing through the passage i5 from dropping upon the food in the cooling compartment, and to direct the water toward the rear of the refrigerator and down the back wall of the cooling compartment, the liner I I is provided with an upwardly-extending sloping portion I6. In order to minimize direct conduction of heat from the metal of the liner II to the metal of the receptacle I3 and to minimize the leakage of moisture into the heat-insulating material 6, a tube I! of suitable heat-insulating, moisture-impervious material, such as rubber, is provided. This tube is connected in sealin relationship to the edge of the upwardly extending portion I6 of the liner I I and fits closely about a downwardly extending portion of a cup-shaped member I8. The upper portion of the member I8 is secured to the receptacle I3 in any suitable manner, as by welding, and this member completes the passage I5 between the low temperature zone adjacent the freezing compartment and the higher temperature zone existing in the cooling compartment.

It is desirable that transfer of air between the cooling compartment and the low temperature zone be prevented in order to facilitate the control of the refrigerating system to maintain the substantial temperature difference which must exist between these two zones. However, it is necessary that provision be made for the'opening of the passage between the two zones when the freezing compartment is to be defrosted in order that the water resulting from such defrosting may be removed readily from the area adjacent the freezing compartment. In order to afford free passage of water between these zones and to prevent free circulation of air therebetween, a controlling device or element I 9 is placed within the cup-shaped member I8.

Referring now to Fig. 2, this element I9 is in the form of a closed container whichi filled with a suitable freezable substance 20, which has the characteristic of changing in size on freezing. In the form shown in Fig. 2, the substance used is water, which expands on freezing. The

element I9 includes two rigid metal disks or the device, a rigid post or member 23 is provided, and the disks 2I and 22 are fixed to the post 23. The post 23 and the disks 2I and 22 mounted thereon provide a rigid frame. The disks 2I and 22 are provided with flanges 24 and 25 respectively, which extend toward but are spaced from each other. The element I9 is provided with a flexible portion which is adapted to change its shape in accordance with the expansion and contraction of fluid 20 during its changes of state.

- In the form shown in Fig. 2, this portion consists of a band of flexible material 26, such as rubber, which is vulcanized or otherwise suitably bonded to the flanges 24 and 25 and closes the gap between these flanges to form a closed container. In Fig. 2, the freezable substance is shown in the liquid or contracted state. Under this condition the flexible band 26 which forms the side wall of the element I9 is spaced from a concentric vertical wall 21 of cup-shaped member III to provide a passage for water resulting from defrosting of the freezing compartment. In order to provide space for the flow of this water between the disk 22 and the bottom of the V cup-shaped member I8, a plurality of raised portions 28 are provided on the bottom of the cupshaped member.

In Fig. 3, the element I9 is shown in the condition which it assumes when the water 20 has frozen and undergone the resulting expansion. It can be seen that the expansion of the water upon freezing forces the flexible band 26 outwardly into contact with the vertical wall 21 of the cup-shaped member I8. The flexible band 26 is maintained in contact with the wall 2! throughout its circumference and limits communication between the low temperature zone adjacent the freezing compartment 2 and the higher temperature zone of the cooling compartment 3. The post 23 is made of metal or other material having good heat conductivity, and thereby causes freezing of fluid to begin at the central portion of the element I9 and to proceed outwardly. This results in a more even expansion of the flexible band 26, since unfrozen fluid is forced outwardly against it by the frozen mass forming in the center of the element I 9.

The temperature of the low temperature zone during normal operating conditions will be well below the freezing point of water and, since the element I9 is located adjacent the low temperature zone, the temperature of the water contained therein will be maintained well below its freezing point. Accordingly, during normal operation of the refrigerator, the water will be frozen to ice and the flexible band 26 will be forced outwardy against the Wall 2'! of the cup-shaped member I8. The expansion of the water is concentrated in a lateral direction to force the flexible band 26 outwardly against the wall 21, since the post 23 limits expansion of element IS in the direction of the axis of the post 23. This limits communication between the low temperature zone and the higher temperature zone through the passage I5, and facilitates the maintenance of a substantial difference in temperature between the freezing compartment and the cooling coinpartment during the normal operation of the refrigerator. Should defrosting of the freezing compartment be initiated, the temperature in the low temperature zone adjacent the freezing compartment will increase and, as the defrosting operation proceeds, the temperature of this zone will rise above the freezing point of water. Accordingly, the ice contained in the element I9 5. will melt,'and there will be a resultant contraction. The flexible band 26 will thereupon resume the shape shown in Fig. 2, and a space will be provided between the band 26 and the wall 21. This provides a passage from the low temperature zone past the element 19 through the passage to the cooling compartment 3. Therefore, as the defrosting operation proceeds and the water from the melting frost on the exterior Walls of the freezing compartment collects in the receptacle l3, it will be directed by the sloping bottom of the receptacle through the opening l4 and through the passage l5 around the contracted element [9. The water ultimately passes along the sloping portion l6 toward the rear of the liner I l of the cooling compartment and flows down the back of this liner for ultimate disposition in any suitable manner. Thus the element l9 automatically expands during normal operation of the refrigerator to prevent free circulation of air between the low temperature zone and the higher temperature zone through the passage l5, and it automatical-' ly contracts during the defrosting of the freezing compartment to allow water to be freely discharge through the passage [5.

In Fig. 4, there is shown a modified form of the element for controlling the communication between the low temperature zone and the higher temperature zone. This element, which has been indicated by the numeral 29, includes a metal disk or member 2! and a post or member 23, which correspond to the parts bearing the same numerals in Fig. 2. A flat metal disk or member 36 is secured to the opposite end of the post 23 and the disks 2! and 30 are maintained in a predeter-' mined spaced relationship by the post 23. A metal ring or member 3! is secured to the flange 24 of the disk 2| to complete the rigid frame of the element IS. The element 29 is provided with a flexible portion which is adapted to expand and contract in accordance with the changes of state of a freezable substance 32, which has the characteristic of changing in size on freezing. In

the form shown in Fig, 4, water, which has the i characteristic of expanding upon freezing, is employed, and the flexible portion consists of a band or member 33 of L-shaped cross-section, which is composed of rubber or other suitable flexible material, and which is secured between the disk 30 and the ring 3i to close the gap therebetween.

The band 33 is provided with lips 34 and 35 which furnish a broad area of contact with the ring 3| and the disk 36 respectively, and facilitate the effective bonding of the flexible material to the metal members 30 and 3|. In order to provide a further connection between the disk 30 and the flexible band 33, a circumferential groove 36 is provided in the interior of the flexible band 33, and the edge of disk 30 is arranged to fit within this circumferential groove.

The operation of the form of controlling device shown in Fig. 4 is the same as that previously'described in connection with the modification shown in Fig. 2. During normal operating conditions of the refrigerator, the temperature in the area surrounding the element 29 will be below the freezing point of water. Accordingly, the water within the element 29 will be frozen to ice. This will cause an outward bulging of the flexible band 33, as shown by the dotted lines in Fig. 4. When so expanded, the flexible band 33 will be pressed against the wall 21 of the cup-shaped member 18 and will limit communication between the low temperature zone and the higher temperature zone. through. the passage 15. Under 6 defrosting conditions, the element 29 will con tract due to the melting of the ice, and the flexible band 33 will be allowed to assume its normal shape. Under this condition, the band will be spaced from the surrounding wall 21 of the cupshaped member IE to afford communication between the two zones for the discharge of the defrosting water in the same manner as-previously described in connection with Figs. 2 and 3. 7

Referring now to-Fig. 5, there is shown another embodiment of my invention in which a controlling device or element is'used for governing the flow of refrigerant. device is used to controlthe flow of refrigerant in a closed secondary system but it will be apparent from the ensuing description that it can be applied equally well to other types of refrigerating systems. shown, liquid refrigerant is supplied to a primary evaporator 31 through a conduit 38, and vaporized refrigerant is withdrawn from this evaporator through a suitable conduit 39. Any suitable apparatus well known in the art maybe used for supplying refrigerant to, and withdrawing refrigerant from, the primary evaporator.

The closed secondary system includes a secondary condenser 46 and a secondary evaporator 41. The condenser is maintained in heat exchange relation with the primary evaporator by clamps,

42 or by any other suitable securing arrangement. The secondary evaporator is secured in heat exchange relationship with a heat transfer surface 43, which may form, for example, a wall of a food storage compartment-of a household refrigerator. A device for controlling the flow of refrigerant is enclosed within a housing 44; The secondary evaporator is connected to the housing by a conduit 45 and the secondary condenser is connected to the housing by a' conduit 46. The housing 44 is mounted on the heat transfer surface 43 by a clamp 41, or by any other suitable mounting arrangement.

Referring now to Fig. 6, the housing 44 includes a cup-shaped member 48, which is connected in any suitable manner, as by brazing, to the conduit 4'5. manner to the conduit 46, is arranged to fit over the top of the cup-shaped member 48, and is sealed to the member 48. The controlling device or element 56 is mounted within the housing 44. The controlling device is held in spaced relationship with the bottom surface of the member 48 by suitable projections 5i in order to permit flow of refrigerant between the member 48 and the controlling device 50, and is spaced from the cap 49 by corresponding projections 52.

The controlling device 56 includes an upper metal disk 53 and a lower metal disk 54, which are mounted in fixed spaced relationship by a center post or member 55 to form a rigid frame. The gap between the disks 53 and 54 is closed by a band 56 of flexible material, such as rubber, which is sealed to flanges 51 and 5B of the disks 53 and 54, respectively.

Theconstruction described forms a closed tainer.v and the space within this container is filled with a suitable freezable substance 59 which has the characteristic of changing in size on freezing. In the form shown in Fig. 6, water, which has the characteristic of freezing within the general temperature range to be maintained by the secondary evaporator 4| and which has the further characteristic of expanding upon freezing, is employed. Where the secondary evaporator M is used to maintain the proper In this embodiment, the.

In the particular construction A cap 49, Which is connected in a similar COH- temperature within a food storage compartment, water is a satisfactory fluid for the control element since a temperature range extending somewhat above and below 32 F. will provide satisfactory refrigeration. In the form ShOWn in Fi 6, the controlling device 58 is represented in its contracted position. In this position the flexible band, which forms the side wall of the device 50, assumes its normal shape, wherein the flexible band is spaced from a concentric wall of the cupshaped member 48. Thisaifords a path for the flow of vaporized refrigerant from the secondary evaporator to the secondary condenser. In Fig. 7, the controlling device 50 is shown in the position it assumes when the Water therein has frozen to ice. Since water expands on freezing, the flexible band 56 has been forced outwardly into contact with the concentric wall of the cupshaped member 48, and flow of vaporized refrigerant from the secondary evaporator to the secondary condenser is limited. It can be seen from the preceding description that when the temperature of the surface to be cooled by the secondary evaporator rises sufficiently above 32 F. to melt the ice within the controlling element 48, there will be a resultant contraction, and the flexible band 56 will be withdrawn from contact with the concentric wall of the cup-shaped member 48. This permits vaporized refrigerant to flow between the controlling device 50 and the housing 44, and refrigeration takes place in the secondary evaporator 41. When the temperature has been lowered to a predetermined minimum, the temperature in the area of the controlling device will be below 32 F., and the water 59 will freeze. The resultant expansion will force the flexible band 56 firmly against the concentric wall of the cupshaped member 48, limiting the flow of vaporized refrigerant and discontinuing refrigeration by the secondary evaporator. Moreover, since the flexible band 56 gradually expands as the water freezes upon the lowering of the temperature and, similarly, gradually contracts as the ice melts upon increase in temperature, a modulating effect can be achieved whereby the amount of refrigerant flowing, and hence the amount of refrigeration, is varied directly in accordance with changes in temperature.

Therefore, by my invention, a controlling device is provided which will maintain the temperature of a surface or compartment to be cooled within a predetermined temperature range, and which can be included entirely within the refrigerating system. No parts extending from the refrigeration system such, for example, as a tube extending to a thermostatic bulb are necessary, and the necessity for making additional provisions for scaling in the area of such parts is eliminated.

While I have shown particular embodiments of my invention, I do not desire m invention to be limited to the particular constructions shown, and

I intend in the appended claims to cover all moditemperature zone and said higher temperature 8. compartment, and a freezable element positioned within said passage, said element having the characteristic of changing in size on freezing to control communication through said passage.

2. Apparatus for controlling the flow of fluid comprising means providing a passage for the flow of fluid, a closed container disposed within said passage, said container having a laterally expansible portion normally spaced from the wall of a said passage, and a liquid Within said container, said liquid having the characteristic of expanding on freezing to move said portion laterally for varying the size of said container whereby the spacin between said container and the wall of said passage is varied to control the flow of fluid through said passage, said container including a central axial member of heat-conducting material for facilitating heat transfer from the central portion of said container whereby freezing of said liquid begins at said central portion and an even lateral expansion of said laterally expansible portion is secured.

3. A control device comprising a closed container, said container including a rigid frame having a gap peripheral therein and a flexible portion closing said gap, a freezable substance within said container, said substance having the characteristic of changing in size on freezing whereby the position of said flexible portion is changed to vary the size of said container, and a heat-conducting member centrally disposed Within said container for facilitating initial freezing of said freezable substance at the center of said container whereby an even expansion of said flexible portion is secured.

4. A control device comprising a plurality of rigid members, means including a member of heat-conducting material for maintaining said rigid members in predetermined spaced relationship, a flexible band for closing the space between said members to form a closed container, and a liquid within said container having the characteristic of expanding on freezing for forcing said flexible band outwardly whereby the size of said container may be varied with change in temperature above and below the freezing point of said liquid, said member of heat-conducting material'being centrally disposed within said container for facilitating freezing of said liquid from said central portion outwardly whereby an even expansion from said flexible band is secured.

5. In a refrigeratin system, means providing a passage for the flow of refrigerant, a hollow element associated with said passage for controlling the flow of refrigerant through said passage, said element containing a flexible wall and normally providing a predetermined spacing between said fiexible wall and the wall of said passage, said element containing a liquid having the characteristic of expanding on freezing whereby said spacing may be varied in response to temperature to vary the flow of refrigerant, and a heat-conducting member centrally disposed within said hollow element for causing freezin to begin at the central portion of said hollow element and to proceed outwardly whereby an even movement of said flexible wall of said hollow element is secured.

6. In 'a refrigerating system, means providing a passage forthe flow of refrigerant, an element associated with said passage for controlling the flow of refrigerant therethrough, said element including a frame having a circumferential gap therein, a flexible band for closing said gap, said flexible band being normally spaced from the wall of said passageyand a liquid within. said element.

having the characteristic of expanding on freezing whereby the spacing between said flexible band and the wall of said passage may be varied in response to temperature to control the flow of refrigerant, said frame including a post of heatconducting material centrally disposed within said container for causing freezing of said liquid to begin at the central portion of said container and to proceed outwardly whereby an even movement of said flexible band is secured.

7. A cabinet for refrigerators and the like comprising means defining a compartment maintained at a low temperature, means defining a compartment maintained at a higher temperature, a low temperature zone adjacent said low temperature compartment, a passage providing communication between said low temperature zone and said higher temperature compartment, and a closed container disposed within said passage, the sides of said container being normally spaced from the wall of said passage, said container being filled with a liquid which expands on freezing whereby the sides of said container are urged toward the wall of said passage to limit communication between said zones when the temperature is below the freezing point of said liquid.

8. A cabinet for refrigerators and the like com prising a low temperature zone, a higher temperature zone, a passage providing communication between said zones, a closed container within said passage, said container including a frame having a circumferential gap therein and a flexible material covering said gap, said flexible material being normally spaced from the wall of said passage, and a liquid within said container, said liquid having the characteristic of expanding on freezing whereby said flexible material will be urged toward the wall of said passage to limit communication between said low temperature zone and said higher temperature zone through said passage when the temperature is below the freezing point of said liquid.

9. A cabinet for refrigerators and the like comprising means defining a compartment maintained at a low temperature, means defining a second compartment maintained at a higher temperature, a low temperature zone adjacent said low temperature compartment, a passage providing communication between said low temperature zone and said high temperature compartment, and a closed container within said passage adjacent said low temperature zone, said container being filled with a liquid which freezes within the temperature range of said low temperature zone and which expands on freezing, said container being of such size as to provide a predetermined spacing between said container and the wall of said passage when the temperature is above the freezing point of said liquid and being adapted to be expanded against the wall of said passage to seal said passage when said liquid expands on freezing whereby said container limits communication between said zones during normal operation of the refrigerator and affords communication during defrosting of said low temperature zone.

10. A cabinet for refrigerators and the like comprising a low temperature zone, a higher temperature zone, a passage providing communication between said zones, and means for controlling communication between said zones throu hsfild passage, said means including a liquid-filled element within said passage having a rigid frame 10 and a flexible portion normally spaced from the wall of said passage, said liquid having the characteristic of expanding on freezing for urging said flexible portion toward said wall to limit communication through said passage.

11. A cabinet for refrigerators and the like comprising a low temperature zone, a higher temperature zone, a passage providing communication between said Zones, and means including a liquid-filled element associated with said passage for controlling communication between said zones, said element including a plurality of rigid members in predetermined spaced relationship, a flexible band for closing the space between said members, said band bein normally spaced from the wall of said passage, and a rigid member centrally disposed within said element for maintaining said first-mentioned members in said predetermined spaced relationship, said liquid having the characteristic of expanding on freezing for urging said band toward said wall to limit communication through said passage, said centrally-disposed member being composed of a material of high heat conductivity to facilitate freezing of liquid about said centrally-disposed member.

12. In a refrigerator cabinet of the type having a low temperature zone and a higher temperature zone, an arrangement for disposing of the water forming in the low temperature zone during the defrosting thereof comprising a passage providing communication between said low temperature zone and said higher temperature zone, and means associated with said passage for controlling communication between said zones through said passage, said means including an element within said passage adjacent said low temperature zone, said element being filled with a liquid which expands on freezing whereby said element will contract under defrosting conditions in said low temperature zone to afford passage of water from said low temperature zone to said higher temperature zone but will expand to limit communication between said zones through said passage during normal operating conditions.

13. A control device comprising a plurality of rigid disks having flanged portions, a central post of heat-conducting material for maintaining said disks in predetermined spaced relationship, a flexible rubber band for closing the space between said disks to form a closed container, said band being bonded to the flanged portions of said disks, and a liquid within said container having the characteristic of expanding on freezing for forcing said flexible band outwardly whereby the size of said container may be varied With change in temperature above and below the freezing point of said liquid, said post being centrally disposed within said container for facilitating freezing of said liquid from said central portion outwardly whereby an even expansion of said flexible band is secured.

ALFRED G. JANOS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 20,388 Hoard May 25, 1858 1,990,663 Mufliy Feb. 12, 1935 2,133,958 Kalischer Oct. 25, 1938 2,442,204 Janos May 25. 1948

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