US1825664A - Refrigerating apparatus - Google Patents

Description

Oct. 6, 1931. H. B. HULL ET AL 1,825,664

REFRIGERATING APPARATUS Filed Feb. 29, 1928 s Sheets-Sheet 1 M (a M @0 71 INVENTORS BY M W 7AQATTokNEYs.

Oct. 6, 1931. H. B. HULL ET AL 1,825,664

REFRIGERATING APPARATUS Filed Feb. 29, 1928 3 Sheets-Sheet 2 a2 17 15 aa I 0 U Z2 INVETORS I BY v1 8, I 2 F 7 ATTORNEYS.

Oct. 6, 1931. v H. B. HULL ET AL 1,825,664

REFRIGERATING APPARATUS Filed Feb. 29. 1928 3 Sheets-Sheet 3 Patented Oct. 6, 1931 UNITED STATES" PATENT OFFICE HARRY B. HULL AND GEORGE E. HOFFERBEBTH, OF DAYTON, OHIO, ASSIGNORS TO FRIGIDAIRE CORPORATION, OF DAYTON, OHIO, A CORPORATION OF DELAWARE anrnream'rme Arranuus Application. filed February 29, 1928. Serial 170. 257,990.

This invention relates to refrigerating apparatus particularly to cabinets for storing small frozen confections such as those known as eskimo pies.

. One of the objects of the invention is to provide a compact and convenient self-con- I tained refrigerating cabinet which can be conveniently placed in stores and other places having a limited amount of space.

Another object of the invention is to provide an improved and simplified form of refrigerating apparatus for maintaining very low temperatures.

Another object of the invention is to provide an improved and simplified form of cabinet construction.

Still another object of the invention is to provide an improved evaporator which prevents flooding of the refrigerating machine.

Further objects and advantages of the present invention will be apparent from the following description, reference being had tothe accompanying drawings. wherein a preferred form of the present invention is 8 clearly shown. 1

Inthe drawings: 1 Fig. 1 is a perspective view partly broke away of a refrigerating apparatus constructed in accordance with the present in- 80 vention:

Fig. 2 is a vertical elevation partly in section through the refrigerating apparatus. the refrigerating machine being shown in elevation; and

Fig. 3 is a corresponding section taken at right angles to Fig. 2.

Referring to Fig. 1. 1O designates a cabinet having a refrigerating compartment 11, cooled by an evaporator 12; and a machine compartment 13 containing a condensing element generally denoted by 16 for circulating refrigerant through the evaporator. The refrigerating compartment is disposed above the machine compartment in order to reduce te floor space occupied by the apparatus and to place the articles which are to be stored within the compartment at a convenient height for dispensing. The cabinet has open- 50 ing 17 in its top'wall forv access to the cooling compartment, which may be closed by an insulating cover 18.

Referring to Figs. 2 and 3, the cooling compartment includes a metal chamber or container 20 having an opening inits top surrounded by a collar or flange 21, registering with the opening 17. The container is in intimate contact with the evaporator 12 and is enclosed with theevaporator by insulating side walls 22' and 23, top wall 24, bottom wall 25 and one end wall 26. The top wall has an opening registering with the opening 17. The insulating walls are preferably made of slabs of cork or similar material and are permanently secured in place. The end opposite the wall 26 is left open for a purpose to be described.

The cooling compartment, including the insulating walls, is supported within a cabinet frame having upright frame members 28, preferably of angle-iron held together by transverse brace plates 29 and 30. The plate 29 is preferably of metal and forms a support for the cooling compartment as well as serving as an impervious facing for the cork walls. The plate 30 is preferablyof wood and forms the top wall of the cabinet, having the opening 17, previously referred to, and being covered with a facing 31 of polished non-corroding metal such as monel. A facing sleeve 32. which may be of insulating material such as fiber. surrounds the opening in the cork top wall 24. This sleeve rests upon the top of the compartment 20 outside of the collar 21. the facing member 31 preferably having a flange or collar 33 which fits over the end of the sleeve. -The outer surface of the cabinet is formed by removable side facing members 35 which extend from top to bottom of the cabinet and also provide themachine compartment walls.

The evaporator which cools the container or compartment 20 is composed of a pair of coils 36 and 37 which are connected in series by a connection 38. Each coil may be described as generally helical,-that is, it consists of a series of c onvolutions which are not necessarily circular but which rather conform *to the shape of the compartment to be cooled, in this case a rectangle. Each coil is preferably formed by winding a length of tubing about the container 20 and soldering it to the container to insure intimate thermal contact. For purposes to be described below the coil 36 starts at a point--between the ends of the container and progresses upwardly to the top of the container, while the coil '37 begins at the bottom of the container and progresses upwardly to the point 40 nected by a conduit 44 to the liquid supply end of the condensing element, and the discharge end of the evaporator; that is the upper end of the lower coil, is connected to the vapor. receiving end of the condensing element.

The condensing element may be constructed as described in the application of Hull above referred to, and includes generally a compressor driven by a motor 51. for with; drawing gaseous refrigerant from the evaporator, a condenser 52 and a fan53 driven by the motor for liquefying the-refrigerant, a receiver 54 for storing the liquid refrigerant, and a switch contained in the casing-55 operated by a thermostat-56 for actuating the motor in response tothe refrigerating demand. The thermostat 56 is attached to 'a heat conducting support57 which is in intimate thermal contact with the evaporator; The expansion valve is provided with an air bulb 58 for regulating the amount of opening of the valve as is more fully disclosed in Hulls application referred to. This bulb is supported by a clip 59 on one of the frame members 28 as shown in Fig. 2 and in contact'with one of the facing members 35 so as to be exposed to the temperature of the atmosphere.

As mentioned above the'cork slab at one end of the'cooling compartment is omitted, and this provides sufficient space for the thermostat, the expansion valve, air bulb and the various conduits and connections between the evaporator and condensing element. After the apparatus has been assembled this space is filled with kapok or other suitableloose insulating material.

The motor and compressor of the condensmg unit are supported on a floatingbase 60 which is supported by springs 6L upon a rigid base member 62 as more fully described in the Hull'application previously referred to. The

rigid base member'62 is rigidly secured to cross braces 63 which extend between two of the corner upright members 28. The base thus serves as a brace or stretcher between the the greatest heat leakage into the cabinet oeours and consequently the point at which the reatest amount of refrigeration is required is at the top of the cooling compartment where the opening 17 is located. For this reason it is proposed to operate the apparatus so that the portion of the evaporator around the top of the cooling compartment is flooded with liquid refrigerant so as to provide the necessary intensity of refrigeration at this point. In order to be certain that the coil is flooded all the way to the top it is necessary to supply enough refrigerant so that there is a slight overflow of une-vaporated liquid into the lower coil. Since the lower end of the compartment requires less refrigeration than the upper end, the small amount of liquid overflowing into the lower coil will be sufiicient. If'the apparatus were operated at theoretical perfection all of this liquid would be evaporated in the lower' coil. However, there may be, a certain amount of liquid present in the lower coil of the evaporator when the compressor is stopped by the automatic switch. Since this occurs when the evaporator has become very. cold there will be very little boiling or evaporation ofthe liquid refrigerant and care must be taken to prevent this-liquid from flowing, by gravity to the compressor. Otherwise evaporation would subsequently occur in the compressor instead vention as herein disclosed, constitutes a pre- 1 ferred form, it is to be understood that other pansion type and including a single continuous conduit having an upper section wound about the container from a point between the ends of the container to a point near the top of the container and a lower section wound from a point near the bottom of the container to said point between the ends.

2. Refrigeratin apparatus comprising in combination, a ca inet having vertical side Walls and a. horizontal top wall enclosing a machine compartment and a cooling comincluding a pair of tortuous ex ansion chambers connected in series and disposed at different levels, the chambers being so arranged that refrigerant flows upward through the partrnent above the machine compartment, higher chamber and then upward through the an open-topped container within the cooling compartment, a refrigerating machine in the machine compartment, an evaporator surrounding the container and connected to the refrigerating machine for cooling the container, the evaporator being of the dry expansion type and including a single continuous conduit having an upper section wound about the container from a point between the ends of the container to a point near'the top, and a lower section wound from a point near the bottom of the container to said point between the ends, and a regulating device connected to the conduit at the lower end of the upper section for controlling the supply of refrigerant to the conduit.

8. Refrigerating apparatus comprising in combination, a condensing element and an evaporating element connected in closed circuit relation, the evaporating element being above the level of the condensing element and including a pair of expansion chambers connected in series and disposed at different levels, the chambers being so arranged that refrigerant flows upward through the higher chamber and then upward through the lower chamber.

4. Refrigerating apparatus comprising in combination, a condensing element and an evaporating element connected in closed circuit relation, the evaporating element being above the level of the condensing element and including a pair of generally helical coils disposed in vertical alignment, the lower end of the upper coil being connected to the liquid outlet of the condensing element, and the upper end of the upper coil being connected to the lower end of the lower coil.

5. Refrigerating apparatus comprising in combination, an evaporator including a pair of generally helical coils in vertical align ment, the lower end of the lower coil being connected to the upper end of the upper coil, and means for admitting refrigerant to the lower end of the upper coil.

6. Refrigerating apparatus comprising in combination, a condensing element and an evaporating element connected in closed circuit relation, the evaporating element being above the level of the condensing element and including a pair of coils of tubing connected in series and disposed at different levels, the coils being so arranged that refrigerant flows upward through the higher coil and then upward through the lower coil.

7. Refrigerating apparatus comprising in combination, a condensing element and an evaporating element connected in closed circuit relation, the evaporating element bein above the level of the condensing element ang lower chamber.

In testimony whereof we hereto aflix our signatures.

HARRY B. HULL. GEORGE F. HOFFERBERTH.

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