US2540343A - Refrigerating mechanism - Google Patents

Description

Feb. 6, 1951 G. MUFFLY 2,540,343

` REFRIGERATING MECHANISM Filed Oct. 9, 1945 2 Sheets-Sheet 1 ATTORNEYS.

Feb. 6, 1951 G. MUFFLY 2,540,343

REFRIGERATING MECHANISM Filed Oct. 9, 1945 2 Sheets-Sheet 2 IN VEN TOR ATTORNEY@ Patented Feb. 6,' 1951 UNITED STATES PATENT OFFICE `This invention relates to refrigerating mechanism and particularly to the use of latent heat hold-over means inconnection with systems including two or move evaporators. The applica-- tion relates to the same subject matter as my application, Serial No. 237,629, led October 29 i938, whichmatured into U. S. Patent No. 2,359,- 780, October 10, 1944. Reference is made to this issued patent for additional details of the herein disclosed mechanisms and their uses.

An object of the present invention is to provide means for maintaining one zone of a refrigerator at a sub-freezing temperature during an extended idle period of the refrigerating sys tem.

Another object is to provide an improved arrangement of the freezing solution tank and the evaporator associated therewith so that the initial operation of the refrigerating system at the beginning of a running period acts to cool the air of a frozen food compartment and then to cool and freeze the hold-over solution.

A further object of this invention is to provide for ready heat transfer from the air of a frozen food compartment to the frozen solution within the hold-over tank.

Other objects of the invention will become apparent from the following specification, the drawings relating thereto, and the claims hereinafter set forth.

In the drawings in which like numerals are used to designate like parts:

Figurel is a front elevation, partly in section and partly diagrammatic, showing a refrigeras ator and refrigerating system including a freezing hold-over tank, an evaporator and an inner insulated compartment for frozen food storage.

Fig. 2 is a sectional view in side elevation showing a slightly modified arrangement of the parts.

in Fig. 1 with further details.

In both gures there is enclosed within an outer refrigerator cabinet an inner compartment H9 which is provided with additional insulation 98 and is cooled to a lower temperature.

The refrigerant path may be followed in Fig. 1 as follows: High pressure gas from compressor 10 passes through tube 1| to condenser 12, where it is liqueiied and the liquid enters the cabinet through tube 59, going to expansion valves 80 and 60 which are here shown connected in par allel though they might be connected in series.

That part of the liquid passing through expansion valve 60 iiows into one of the evaporators 23 or 241 according to which has its outlet open `tube 1| to the condenser.

2 at the valve |43 and the vaporized refrigerant returns through tube 69 to the higher pressure suction port of the compressor 10, here shown as a port in the side of the cylinder to be uncovered by the piston near the bottom of its stroke.

Another portion of the liquid refrigerant passes through the expansion valve 60 to the* sharp freezer evaporator 95 and returns through tube |00 to the lower pressure suction port of compressor 10, here indicated as a valve in the cylinder head. On the suction stroke (or portion of rotation in the case of a rotary compressor) the compressordraws in nearly a cylinder full of low pressure vapor from the colder evaporator 95, after which a further movement of the compressor uncovers the high pressure suction port and takes in a volume of higher pressure vapor from the warmer evaporator associated with the ice-maker and/or an evaporator which serves to cool the air in the main food compartment.

Since there is, in accordance with common practice, a check valve where gas from tube |00 enters the cylinder, gas from the higher pressure suction line 69 cannot pass into the lower pressure suction line |00.- Gas from both suction lines is compressed and discharged through The expansion valve 60 is of the thermostatic type, having its bulb 58 clamped against suction tubesy 66 and 61. Expansion valve 60' is likewise of the thermostatic type. but is designed to stop refrigerant flow Y Land to prevent excessive refrigeration of the 40* warmer (main) food storage space.

The space II9 is enclosed by insulated walls and is fitted with an insulated door 205, shown broken away in Fig. 1 and in section in Fig. 2. The eutectic freezing solution 96 is preferably of the jelly type with a freezing point ofl about zero F. to 10 degrees above, thus keeping the space I I 9 well below the freezing for several hours with the system idle and providing refrigerating effect that is normally stored up for instant use in freezing foods more quickly than they could be frozen by the evaporator 95 lacking this hold-over.

The tank 2|0 contains the freezing solutionpreviously described and in Fig. 2 it also contains the sections 2I6 and 2 I1 oi the colder evaporator 95. This tank is shown in Fig. 2 as being held assasse 3 in place by the angle 2| i attached to the rear lining of the freezer 9d and by the clamping strip 2li which is removably secured by screws 2te. By removing the clamping strip 212 and disconnecting the unions 2id at the inlet and outlet of the expansion coil 95 (comprising sections .Zl, 2i6 and 2|?) the tank 2 lil may be removed from the freezer assembly and from the cabinet. This facilitates repairs or substitution of a new tank assembly 2|!! in which there may be a freezing solution 9B of different characteristic as to freezing temperature, or tanks of different sizes may be interchanged. The bottom of tank 2|B is fitted with fins 2|8 for increasing heat transfer rate between the air of freezer compartment H9 and the coil 2|5 on the outside bottom of tank 2in or the mixture 96 within it. a

When a load is placed in the compartment li and the control has caused the system to start, the first expansion of refrigerant within the freezer occurs in the section 2 I5 of the evaporator 95. This section is exposed to air within the space H9, which it will cool more rapidly than if all of evaporator were within the tank. In addition to exposing this part of the evaporator coil to air, I provide the fins 2 I8, soldered to the bottom of tank 2|0 between the legs of coil 2|5 or directly to the coil 2|5. These fins and the coil section 2|5 assist in cooling the air of compartment H9 both when the system is in operation and between runs when the heat absorbing capacity of the material 96 is called upon todo this cooling.

Liquid refrigerant from expansion valve 60 which may be located inside of the freezing space H9, as-in Fig. 1 or outside of it as in Fig. 2, enters loops 2 l5, then goes to the crosswise loops 2 6 on the inside of tank bottom and finally to the` upper loops 2 I 1, which extend from front to back like loops 2|5. This arrangement of expansion coil on and in a tank of freezing solution causes the solution to freeze from the bottom upwardly and avoid expansion strains on the tank. I'he arrangement here shown represents an improvement over my disclosure in Patent No. 1,827,097 issued October 13, 1931, wherein the method of freezing from the bottom upward is shown.

The freezer assembly 9| and evaporator 22| are supported from the top of the cabinet or top and side wall by means of the straps 220. These `straps are not attached to the tank I0 which merely rests upon the evaporator 22| and may be withdrawn from the cabinet without disconand in part inside of said tank, and means for cooling said evaporator progressively, rst in said outside part and then in said inside part.V

2. In a refrigerator, insulated walls completely enclosing a space for the storage oif a frozen product, a tank having its bottom wall exped to contact with the air of said space and con taining a freezable material for storing refrigerating effect, and a refrigerating system including an evaporator located within said storage space externally of 'said tank in thermal contact with the bottom thereof and also in direct contact with the air of said storage space, said evaporator serving to cool the entire body of air enclosed within said space to a sub-freezing temperature and thereafter to complete the freezing of said material from the lower portion of said tank upwardly until substantially all of the material is frozen, said evaporator also serving while not refrigerated by operation of said system to absorb heat from the air in said space and transfer it to said freezable material which has previously been frozen and thereby to utilize the stored refrigerating eect.

3. In a refrigerating system, means forming a storage space, a tankhaving its bottom wall exposed to said space, a material sealed within said tank having a freezing temperature well below 32 F., and an evaporator located within said storage space externally of said tank in thermal contact with the bottom thereof and in direct contact with the air of said space, said evaporator serving to cool said air and to freeze said mate? 4. In a refrigerating system, means forming an enclosed and insulated sub-freezing space for the storage of frozen foods, a tank having its bottom wall exposed to said space, a freezable liquid filling a major portion of the interior of said tank, and an evaporator located within said storage space externally of said tank and in thermal contact with a bottom wall thereof and in direct contact with the air of said space, said evaporator necting anything. Evaporator 22| is provided `refrigerating system including an evaporator located in part on an outside wall of said tank serving to freeze said liquid and to cool the air within said space by direct 'contact therewith.

while the evaporator is active and also serving to cool said air by aiding in heat transfer from the air to the frozen liquid within said tank when the system is inactive.

' GLENN MUFFLY.

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

UNITED STATES PATENTS Number Name Date 1,998,693 Voorhees Apr. 23, 1935 2,005,860 Huntington June 25, 1935 2,063,646 Whitesel Dec. 8, 1936 2,073,123 Smith Mar. 9, 1937 2,261,681` Ullstrand Nov. 4, 1941 2,359,780 Muiiiy Oct. 10, 1944 2,375,319 Mufiiy May 8, 1945 2,428,312 Herbener Sept. 30, 1947

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