US1954695A - Refrigerant circuit for refrigerating systems - Google Patents

Description

April 10, 1934. w GARLAND 1,954,695

REFRIGERANT CIRCUIT FOR REFRIGERATING SYSTEMS Filed Dec. 27, 1930 Q3 m Q m I N 1 k m m gvvuz'nto'o I H M g MiltonWG'arland s m M q ,7

Patented Apr. 10, 1934 UNITED STATES PATENT OFFICE REFRIGERANT CIRCUIT FOR REFRIGERAT- ING SYSTEMS Milton W. Garland, Waynesboro, Pa., assignor to Frick Company, Waynesboro, Pa., a corporation of Pennsylvania This invention relates to means for circulating refrigerant fluid through an evaporator of a refrigerating system.

The object of the invention is to provide means 5. for returning liquid or unevaporated refrigerant from an accumulator back to the evaporator and to utilize the force of gravity to overcome the pressure in the evaporator.

A further object is to provide means for con- E1 trolling the passage of liquid refrigerant to the evaporator in response to variations of the liquid level in the accumulator.

Referring to the accompanying drawing, which is made a part hereof and on which similar refer- 1'5 ence characters indicate similar parts.

Figure l is a side elevation of a system showing my invention embodied therein, and

Figure 2, a modified form of float control.

In the drawing reference numeral indicates a freezing tank having an evaporator therein, the evaporator comprising upper and lower headers 11 and 12 connected by riser tubes 13, only one of which is shown. The riser tubes 13 may be of any suitable shape, W tubes such as shown he- ;ing found one preferred form A line 14 connects one end of the upper header with an accumulator 15. A suction line 16 from the accumulator is connected to the suction of the compressors not shown. Liquid refrigerant is de- ;livered to the evaporator through a line 17 connected to one end of the lower header 12. An oil drain 18 may be connected at the other end of the lower header. Liquid refrigerant from a suitable source is supplied to the system through ';line 19 through a strainer 20, a float controlled valve 21, a line 22 and a line 23 to the line 17., The valve 21 is controlled by a float in a tank 24, the valve being opened when the liquid in the tank 24 reaches a predetermined low level. A booster line 25 controlled by valve 30 may be connected around the float control valve 21. The bottom of the accumulator is connected to the line 17 by means of a pipe 26. Equalizing pipes 2'7 and 28 connect the bottom of the tank 24 with o the line 26 and the top of the tank 24 with the accumulator 15. An oil drain valve 29 may be connected to the bottom of the accumulator.

In operation liquid refrigerant is first delivered to the system through the line 19 until 9 ;the evaporator is flooded. During operation gas drawn through the pipe 14 into the accumulator will carry over a certain amount of liquid along with it, depositing the liquid into the accumulator 15. This liquid refrigerant returns to the evapprator through the line 26 and pipe 17. The accumulator is positioned above the evaporator so that the liquid refrigerant which is carried over into the accumulator may freely flow by gravity to the evaporator against such pressure as is in the evaporator. Because of equalizing pipes 27 and 28 the level of liquid in tank 24 is the same as that in return pipe 26. The float controlled valve 21 is so arranged that as soon as the liquid in the tank 24 lowers the valve 21 will operate and supply additional liquid refrigerant to the evaporator coils. This system is particularly advantageous when applied to coil type evaporators where high evaporation causes entrained unevaporated liquid to be carried along with the suction gas into the accumulator where operating and temperature head in the evaporator do not permit the entrained liquid in the suction line to return to the evaporator without some pressure supplying means. In this instance the pressure is supplied by gravity so that the liquid from the accumulator will flow into the evaporator against such pressure head as may be therein.

In the modified form shown in Figure 2 the controlling float 31 is positioned in the accumulator 32 itself. This float controls a valve 33 in the liquid refrigerant supply line 34 so that as the liquid level in the accumulator falls additional liquid refrigerant will be delivered to the evaporator.

It will be obvious to those skilled in the art that various changes may be made in my device without departing from the spirit of the invention and therefore I do not limit myself to what is shown in the drawing and described in the specification, but only as indicated by the appended claims.

Having thus fully described my said invention, what'I claim as new and desire to secure by Letters Patent, is:

1. In a refrigerating system an evaporator, an accumulator positioned at a greater elevation than the evaporator whereby liquid may flow by gravity to the evaporator, a suction line from the evaporator to the accumulator and a liquid supply line from the accumulator to the evaporator, a float chamber connected to the accumulator and to the supply line to the evaporator to equalize the liquid level in the said supply line and in the said chamber, a liquid supply line to the evaporator, a valve for said line, a float in said chamber in control of the said valve, substantially as set forth.

2. In a refrigerating system an evaporator, an accumulator positioned at. a higher elevation than the evaporator, a suction line from the evaporator to the accumulator, a liquid supply line from the accumulator to the evaporator to return liquid refrigerant to the evaporator, a liquid refrigerant feed line for supplying additional liquid refrigerant to the evaporator, a float chamber communicating with the accumulator and with the liquid supply line from the accumulator to the evaporator to equalize the liquid level in the chamber and in the said liquid supply line, a valve in the feed line for supplying additional liquid and a float in the said chamber in control of said valve, substantially as set forth.

3. In a refrigerating system an evaporator, an accumulator positioned at .a higher elevation than the evaporator, a suction line from the evaporator to the accumulator, a liquid supply line from the accumulator to the evaporator to return liquid refrigerant to the evaporator, a liquid refrigerant feed line for supplying additional liquid refrigerant to the evaporator, a float chamber communicating with the accumulator and with the liquid supply line from the accumulator to the evaporator to equalize the liquid level in the chamber and in the said liquid supply line, a

valve in the feed line for supplying additional liquid and a float in the said chamber in control of said valve, said valve being opened upon a reduction of the liquid level in the chamber and closed upon a rise in the liquid level, substantial- IV as set forth.

4. In a refrigerating system an evaporator, an accumulator positioned with respect to the evaporator so as to cause liquid to flow by gravity from the accumulator to the evaporator, a suction line from the evaporator to the accumulator, a liquid return line from the accumulator to the evaporator, an auxiliary liquid supply line to the evaporator, a valve in said line, a float chamber communicating with the accumulator and a liquid line from the accumulator to the evaporator for equalizing liquid level in the chamber and in the return line, a float in said chamber in control of; the valve for supplying additional liquid to the evaporator, said float being responsive to variations in the flow of liquid from the accumulator to the evaporator, substantially as set forth.

MILTON W. GARLAND.

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