US2303182A

US2303182A - Refrigeration apparatus

Info

Publication number: US2303182A
Application number: US347396A
Authority: US
Inventors: Raymond E Tobey
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1940-07-25
Filing date: 1940-07-25
Publication date: 1942-11-24
Anticipated expiration: 1959-11-24

Description

Nov. 24, 1942. R. E. TOBEY REFRIGERATION APPARATUS 3 Sheets-Sheet 1 Filed July 25, 1940 INVENTOR RAYMOND E.Toaz-/,

ATTOR Y Nov. 24, 1942. R. 5. TOBEY REFRIGERATION APPARATUS Filed July 25, 1940 s Sheets-Sheet 2 f INVENTOR RAYMOND E- v W lTNESSE S:

5 H Qg iz TOBEY ATI'ORN N -24,1 42 R. E. TOE-Ev "2,303,18

REFRIGERATION APPARATUS Filed Jul 25, 1940 s Shegts-Sheotfi wnuasszs: Q iNVENTOR RAYMOND E .TOBEY Patented Nov. 24, 1942 UNITED STATES 'PATJENTI OFFICE a oms: 7 I v p Raymond E. Tobey, Springfield,

to Westinghouse Electric &

Mass, assign."

Manufacturing ompany, East Pittsburgh, Pa... a corporation 7 Pennsylvania Application July 25, 1940, Serial No. 347,398

9 Claims.

This invention relates to refrigeration api the temperatures of both the cooling unit and the media ambient the refrigerator.

A further object is to provide a compensated Rcontrol of the type described which does not seriously affect the ice freezing capacity of the refrigeration apparatus it is controlling in low room temperatures.

These and other objectsare effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is a schematic drawing of the control apparatus of this invention applied to a refrigerator;

Fig. 2 is 'a detailed view showing the position of the elements of the control apparatus when the temperature of the media ambient the refrigerator is low; Fig. 3 is a view showing the position of the elements of the control apparatus when the temperature of the media ambient the refrigerator is high;

Fig. 4 illustrates a modification of the control apparatus of this invention applied to a refrigerator;

Fig. 5 is a detailed view of the modification shown in Fig. 4, showing the positions of the elements of the control apparatus when the temperature of the media ambient the refrigerator is low:

Fig. 6 is a detailed view of the modification shown in Fig; 4 showing the position of the elements of the control apparatus when the temperature of the mediaambient the refrigerator is high;

Fig. 7 is a schematic drawing of another modification of the invention; 1 I Fig. 8 is a detailed view showing the position I of the elements of the control apparatus when perature of' the media ambient the refrigerator I is high.

Referring specifically to the drawings for a detailed description of theinvention, reference numeral 8 designates a cabinet of a refrigerator having insulated walls 9 forming a food storage compartment Ill with an evaporator or cooling unit ll therein.- The evaporator H is supplied with liquid refrigerant through a capillary tube l2 which receives its supply from a condenser [3 into which compressed refrigerant is pumped through a conduit M by a compressor IS. The compressor i5 withdraws the vaporized refrigsnap-acting switch 2! placed in one of the lines erant from the evaporator ll through a conduit IS. The compressor i5 is driven by means of an electric motor l1 which receives electrical energy from lines l8. The condenserv l3 and the compressor I5 are cooled by a fan 20 which circulates air through thecondenser l3 and over the compressor I5.

A thermostatic device l9 controls the current supply to the electric motor ll by 'means of a I8. The switch 2| comprises a fixed contact 22 and a movable contact 23 carried on an arm 24 which is actuated by an overcenter linkage comprising a lever 25 and a spring 26. The lever 25 is actuated by a. Sylphon bellows 21, which in turn is actuated by thevapor pressure of a vola- .tile liquid 28 in a vessel 29 (see Figs. 2 and 3) adjacent the evaporator H. v A tube 30 connects the Sylphon bellows 2] with the vessel 29. The vapor pressure of the volatile liquid 28 at which the snap-acting switch 2! is actuated may be varied'by turning a threaded shaft ll which adjusts the pressure of a spring 35 on the lever 25.

Vessel 29 is an L'-shaped tube with the shorter leg 39 lying in contact with the cooling unit ll and the longer leg- 4| extending away from the cooling unit ll into the relatively warmer food storage chamber III. The vessel 29 accordingly the temperature of the media ambient the refrigi vessel 29, however, varyin response to varies in temperature, the colder portion beingthe portion 39 in contact with the cooling unit I l,

and the warmer portion being the portion. ll,- which portion varies in temperature and is progressively warmer depending on the distance of the various elements thereof from the cooling unit I l. The temperatures of all portions of the the temperature of the cooling unit ll. v

In accordance with the invention, a chamber 32 is located in the ambient air of the refrigerator. The chamber 32 is divided by an-elastic diaphragm 33, such as rubber, into two compart- "'

ments

34 and 38. The compartment 38 com-.

' and 38, the bellows 21, the tube 38, and the vessel 28 is exhausted prior to the introduction of .the liquids so that the only pressures in the chambers are the pressures of the vapors of the respective liquids.

The

liquids

28 and 38 are of such a nature that when the food storage compartment I8 is refrigerated, the vapor pressure of the liquid 38 exceeds that of the liquid 28 when the temperature of the air ambient the refrigerator is high and is below that of the liquid 28 when the temperature of the air ambient the refrigerator is low. Suitable liquids for this purpose are methyl chloride in the vessel 28 and methyl bromide in the compartment. Assuming a temperature of the cooling unit II such that the warmest portion of the methyl chloride is F., the vapor pressure of the methyl chloride'would be 13.8 pounds per square inch. The vapor pressure of the methyl bromide in a 60 F. room would be 8.7 pounds perature of the liquid line 48 as compared to the diiference between the temperature of cabinet air and the "cut-on temperature of the liquid line 48.

The control is preferably so proportioned that it decreases. the temperature of the cooling unit II, just sufliciently to offset the additional heat leakage through the refrigerator walls when the temperature of the ambient air rises. This maintains the average temperature of the air in the refrigerator substantially constant. The control -may also be adapted for over-compensation so that the refrigerator temperature drops when the temperature of the ambient air increases. This may be effected by lengthening the vessel 28 and decreasing its diameter.

per square inch and in a 90 F. room would be 26.7 pounds per square inch. The pressure of the methyl bromide is less, therefore, than that of the methyl chlqride in a cold room and greater than that of the methyl chloride in a hot room so that when the temperature of the ambient air is low, the position of the diaphragm 33 will be towards the right as indicated in Fig. 2, and when the temperature of the ambient air is high,

the diaphragm 33 will be moved to the left as shown in Fig. 3.

The'movement of the diaphragm 33 to the left forces the vapor of' the liquid 28 from the compartment 38, and the increased pressure causes the vapor to condense in the vessel 28. An increase in the quantity of the liquid 28 in the vessel 28 moves the dividing line 48 between the liquid 28 and its vapor farther away from the cooling unit. Thedividing line 48 will hereafter "be referred to as the liquid line 48 of the liquid When the temperature of the air ambient the refrigerator is low, the liquid line 48 is close to the cooling unit II as shown in Fig. 2 and closely follows the temperature thereof. Under these circumstances the volatile fluid 28 closes the switch 2| when the temperature of the cooling unit II rises to the cut-on temperature and opens the switch when the temperature of the cooling unit II drops to the cut-off temperature. However, when the temperature of the air ambient the refrigerator is high, the liquid line 48 of the volatile fluid 28 is moved away. from the cooling unit I I as shown in Fig. 3. The temperature of the cooling unit I I must now be much lower than formerly to cool the liquid at the liquid line 48 to the cut-oil temperature and similarly the liquid at the liquid line 48 reaches the cut-off" temperature only after the cooling unit II has been cooled to considerably below this temperature. It will be apparent from the above that the temperature of the cooling unit I I varies with the temperature of the ambient air and is decreased in temperature when. the temperature ambient the refrigerator increases and vice versa. The decrease in the cut-off temperature will also be found to be greater than the decrease in the cut-on temperature due to the greater temperature difference between the temperature of the air in the cabinet and the cut-off tem- 'Applicants device provides for the freezing of ice cubes andthe like by extending the portion 38 of the vessel 28 along the cooling unit. It will be apparent that even though the liquid line 48 drops below the level indicated in Fig. 2 in a very low ambient temperature,the temperature of the liquid at the liquid level 48 will not change relative to that of the cooling unit I I, and the switch will be opened and closed at substantially the same temperatures as for the conditions indicated in Fig. 2, at which a freezing temperature is maintained within the cooling unit I I.

The modification shown in Figs. 4, 5, and 6 produces a similar result as the modifications previously described and like parts are provided with the same reference numerals. In this modiflcation a receptacle 58 connects through a tube 5| with the tube 38. The receptacle 58 is located in the air ambient the refrigerator and contains a mineral oil 52 or other vapor-absorbing material. The volatile fluidin the vessel 28 of this modification comprises a fluid such as dichlorodifluoromethane 53 which is soluble in the mineral oil 52 inversely proportional to the temperature of the oil 52.

When the temperature of the ambient air is cool, a quantity of the dichlorodifiuoromethane vapor is absorbed by the mineral oil 52 and some of the dichlorodifluoromethaneliquid 53 in the vesesl 28 vaporizes to replace the absorbed vapor. The vaporization of the dichlorodifiuoromethane liquid 53 causes the liquid line 48 thereof to move closer to the evaporator II. When the temperature of the air ambient the refrigerator is high, a certain portion of the vapor absorbed by the mineral oil 52 is driven 011 and this vapor con-- denses'in the portion H of the vessel 28 in the same manner as in the first-described modification. The compensating action of the dichlorodifluoromethane liquid 53 at the liquid line 48 is the same as the volatile liquid 28 in the vessel 28 described in the first modification of the invention;

In the modification shown in Figs. 7, 8, and 9. somewhat similar apparatus is utilized as in the previous modification and like parts are provided with the same reference numerals. The liquid line 48 in this modification is moved back and forth by the expansion and contraction of a fluid, preferably a liquid 58, which is contained in a receptacle 58 secured to the metal of the outer shell 52 of the refrigerator. The receptacle 58 connects to the lower portion 38 of the vessel 28 through a tube 8|. The liquid 58 is subject to the temperature of the air ambient the refrigbient temperature.

shell 52 of the refrigerator to which the receptacle 59 is secured acts as a heat conducting fln for the receptacle 59 to maintain the temperature of the same in close relationship with the amy The liquid 28 in the vessel 29 in this modification may comprise methyl chloride, and theliquid 58, a solution of sodium chloride in which the methyl chloride is insoluble or nearly so. As shown in Figs. 8- and 9 the liquid 58 is arranged to lie below the volatile fluid 28 because the former is heavier than the latter.

- It will be aparent from the above ,that this v 2,803,182 in the previous modifications. The outer metal invention'provides a control for a mechanical refrigerator which compensates for room temperature and is responsive to both the temperature of the evaporator and to that of the room in which the refrigerator is operated. The control also provides for the proper evaporator temperature for forming ice even at low room temperatures. I

While I have shown my invention in several forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are specifically-set forth in the appended claims.

What I claim is:

1. In a mechanical refrigerator, the combination of an insulated cabinet containing a medium to be cooled, a cooling unit for eoolingthe medium means responsive to the ambient temperature of said cabinet'for moving the liquid portion ofthe fluid in said vessel from onev of said portions-of the vessel to another in a different heat exchange relationship to vary the mean temperature of the cooling unit.

4. In a mechanical refrigerator,'the combination of an insulated cabinet containing a medium to be cooled, a cooling unit for cooling the medium in said cabinet, apparatus for supplying refrigerant to the-cooling unit, a vessel having portions thereof in different degrees of heat exchange relationship with said cooling unit, a volatile fluidin said vessel, said volatile fluid having portions in the liquid and in'the vapor phase, means responsive to the pressure of said vapor for controlling said refrigerant-supplying apparatus, and means responsive to the ambient temperature of said cabinet for effecting the disposition of liquid portions of said volatile fluid in at least some of said various portions of said vessel to vary the mean temperature of the-cooling unit, the portion of said vessel in the most intimate heat exchange relationship with the cooling unit being of relatively large capacity to maintain the temperature of the cooling unit in said cabinet, apparatus for supplying refrigerant to said cooling-unit, a vessel having portions thereof in difierent degrees of heat exchange relationship with said cooling unit, a volatile fluid in said vessel, said volatile fluid having portions in the liquid and in the vapor phase, means responsive to the pressure of said vapor for controlling said refrigerant-supplying apparatus, and means responsive to the ambient temperature of said cabinet for effecting the disposition of volabelow a predetermined limit.

5. In a,mechanical refrigerator, the combination of an insulated cabinet, a cooling unit for said cabinet, apparatus for supplying refrigerant" to the cooling unit, and a vessel having a portion, thereof in intimate heat exchange relationship with the cooling unit and a'second portion thereof in heat exchange relationship with the cooling unit and with a medium warmer than said cooling unit to raise the temperature of said second portion above that of the cooling unit, a volatile fluid in said-vessel, said fluid having portions in the liquid and in the vapor phase, means responsive to' the pressure'of said vapor for controlling said refrigerant-supplying apparatus, and means responsive to an increase in the temperatureof the tile liquid in at least some of said portions of the vessel to vary the mean temperature of the cooling unit.

2. In a mechanical refrigerator, the combination of an insulated cabinet containing a medium to be cooled, a heat absorbing unit for cooling said medium, apparatus for supplying a heat absorbing material to said unit, a vessel having at least a part thereof lying in a'medium warmer than said heat absorbing unit, said part having-portions in different degrees of heat exchanging relationship with said heat absorbing unit to main.- tain said portions at difierent temperatures, a volatile fluid in at least the coldest portions of said vessel, means responsive to the vapor pressure of said volatile fluid for controlling said apparatu's, and means responsive to the temperature ambient said cabinet for effecting condensation of a portion of said vapor in the coldest available portion of said vessel as said temperature increasesto increase the vapor pressure of said volatile fluid.

3.-In a mechanical refrigerator, the combination of an insulated cabinet containing amedium to be cooled, a cooling unit for cooling the medium in said cabinet, apparatus for suppl ing refrigerant to the cooling unit, a vessel having portions thereof in different degrees of heat exchange relationship with said cooling unit, a volatile fluid in said vessel, said fluid having portions in the liquid and in the vapor phase, means reatmosphere ambient said cabinet for condensing quantities of the vapor -of said volatilefluid in said vessel to extend the liquid therein to the second portion of said vessel to lower the mean temperature of the cooling unit.

v 6. In a mechanical refrigerator, the combination ofan insulated cabinet, a cooling unit for said cabinet, apparatus for supplying refrigerant to the cooling unit, and a vessel having a portion thereof in heat exchange relationship with the cooling, unit and another portion thereof 'extending from the cooling unit into a zone of higher temperature, a chamber exterior of' said insulated cabinet, a movable partition in said chamber dividing the same into two compartments,-

one of said compartments communicating with said-vessel, a volatile liquid in the portion of said vessel in heat exchange relationship with the cooling unit and vapors of said liquid in the compartment communicating with said vessel, means responsive to the vapor pressure of said liquid for controlling the refrigerant-supplying apparatus, and a second volatile liquid in the other compartment of said chamber, said second volatile liquid being in heat exchange relationship 7 with the ambient air of said cabinet, the vapor pressures of the first-named and the secondnamed liquid being such that the differential between their vapor pressures-moves said partition to decrease the volume of the compartment communicating with the vessel when the temperature of the air ambient of said cabinet increases beyond predetermined limits thereby condensing the vapors in said first-named compartment in the portion of said vessel extending away from the cooling unit.

'I. In a control mechanism for a mechanical refrigerator comprising an insulated cabinet, a cooling unit therein, and refrigerant-supplying apparatus exterior of said cabinet, the combination of a vessel having a portion thereof in heat exchange relationship with the cooling unit and another portion thereof extending away from the cooling unit, a chamber, a movable partition therein dividing said chamber into two compartments, one of said compartments communicating with said vessel, a volatile liquid at least in the portion of said vessel in heat exchange with the cooling unit and vapors of said liquid in the compartment communicating with said vessel thus providing a liquid line in said vessel, a second volatile liquid in the other compartment of said chamber, said second volatile liquid being in heat exchange relationship with the ambient air of said cabinet, and means responsive to the vapor pressure of said first-named liquid for controlling the refrigerant-supplying apparatus, the vapor pressure of the first-named and the second liquid being such that-the differential between their vapor pressures moves said partition to decrease the volume of the compartment communicating with the vessel when the temperature of the air ambient of said cabinet increases, thereby condensing some of the vapor of the last-named compartment to supply additional liquid in the vessel to bring the liquid line therein farther away from the evaporator into a warmer area 'of the insulated chamber.

8. In a mechanical refrigerator, the combina- 4 tion of an insulated cabinet containing a medium to be cooled, a cooling unit for cooling the medium in said cabinet, apparatus for supplying refrigerant to the cooling unit, a vessel having portions thereof in varying degrees of heat exchange relationship with said cooling unit, a volatile fluid in said vessel, said fluid having portions in the liquid and in the vapor phase, means responsive to the pressure of said vapor for controlling said refrigerant-supplying apparatus, a vapor-absorbing material located exterior of said cabinet and in communication with said vapor, the vapor-absorbing quality of said material varying inversely with its temperature, said material absorbing some of said vapor when the material is at low temperatures and expellingsome of said vapor when at high temperatures, said expelled vapor condensing in the coldest portions of said vessel available to said vapor to eflect a variation of the average temperature of the cooling unit.

9. In a mechanical refrigerator, the combination of an insulated cabinet, a cooling unit for said cabinet providing a plurality of refrigerated zones of different temperatures thcrein, apparatus for supplying refrigerant to the cooling unit, a vessel having portions thereof in several of said zones, a volatile fluid insaid vessel, said fluid having portions in the liquid and in the vapor phase, means responsive to the pressure of said vapor for controlling said refrigerant-supplying apparatus, and a second fluid located exterior of said insulated cabinet communicating with a portion of said vessel located in one of the colder zones, said fluid expanding with increase in tem- RAY HOND E. TOBEY.