US1822918A - Refrigerating apparatus - Google Patents

Description

Sept. 15, 1931. E BARNES 1,822,918

REFRIGERATING AP PARATUS Filed Feb. 1, 1928 2 Sheets-Sheet l Sept. 15, 1931. I BARNES 1,822,918

REFRIGERATING APPARATUS I Filed Feb. 1, 1928 2 Sheets-Sheet 2 Patented Sept. 15, 1931 UNITED- STATES PATENT. OFFICE EUGENE L. BARNES, OF BUFFALO, NEW YORK REFRIGERATING APPARATUS Application filed February 1, 1928. Serial No. 250,977.

is capable of utilizing a refrigerant which is soluble in, and which in the liquid form dissolves, lubricating oil.

Another object of the invention is the provision of improved means for shutting down the apparatus either temporarily or for an extended period of time.

A still further object-0f the invention is the provision of means for freeing the lubricant from any refrigerant dissolved therein.

These and other objects will be'more clearly understood and may be better pointed out in the following detailed description of the apparatus with reference to the accompanying drawings, in which:

-Fig. 1 is a diagrammatic elevation of the refrigerating apparatus partly in section; Fig. 2 is a plan View of the oil separator and the upper header of the con-denser; 4 Fig. 3 is a side elevationof the compressor unit; and

Fig. 4 is a sectional view showingdetails of the heater. I

Heretofore whenethyl chloride has been used as refrigerant, glycerine has been used as a lubricant because of the substantial insolubility of ethyl chloride in glycerino. It is desirable, however, to use ordinary petroleum lubricating oil rather than glycerine but difficulties of operation arise due to the solubility of ethyl chloride in lubricating oil. As was stated above, one of the objects of the present invention is to utilize a refrigerant which is soluble in the lubricant used, and although the description will be made with reference to the use of ethyl chloride and petroleum "oil, it will be understood that the features of he apparatus rendering such use possible also make the apparatus capable of using other mutually soluble refrigerants and lubricants.

The complete apparatus consists of a compressor unit and a boiler or cooling unit. The various parts of the former unit are mounted on a'frame 2 which carries an electric motor tbelt connected to a pulley 6 mounted on the shaft of a rotary compressor 8 which may be of any ordinary construction. The ethyl m chloride vapors are compressed by the compressor and delivered through exit tube 10 to a suitable separator 12 which, as shown,

consists of a tank provided with a filling plug 14 and an outlet tube 16, opening near the top of the tank. The ethyl chloride vapors carry lubricant into the separator and the lubricant settles into the bottom of the separator, While the ethyl chloride vapors pass down through the open end of tube 16 into the upper header 7o 18 of a condenser. The upper header 18 is connected by a large number of tubes 20, cooled by a fan, which may be mounted on the compressor shaft, to a lower header 22. A valve 24 is interposed between the lower header of the condenser and a pipe 26, which constitutes a pressure line from the compressor unit to the vaporizer 28.

The liquid ethyl chloride passes into the vaporizer 28, the flow being controlled by any 0 suitable means, and evaporates therein, pass ing back to the compressor unit through a vapor 'tube30. During the evaporation of the refrigerant in the vaporizer, heat is absorbed, and the vaporizer is, as customary, 35 located in a refrigerator. Adjacent the vaporizer, a valve 32, which will be hereinafter referred to as a defrosting valve, is placed in tube 30 and may be closed or opened at will to either prevent or allow the passage ofao vaporized refrigerant back to the compressor unit. 7

. interposed in the vapor line adjacent the compressor unit is a sump 34, the inlet tube of which extends across the chamber forming the sump, while the exit tube 36 extends in overlapping relation therewith, so that any liquid passing through the vapor line will flow into the sump and will be prevented from passing in the liquid form to the compressor. The vapors leaving the sump pass into-a casing 38, which is connected to the compressor proper and provided with a check valve 40 adjacent thereto, this check valve being of anysuitable construction and operating to permit the flow of vapors into the compressor and to prevent a backward flow therefrom. Suitable gauges may be provided to indicate the pressures existing respectively on the high andlow sides of the compressor.

Communicating with the vapor line between check valve'40 andthe boiler is a tube' 42 opening at its other end into a pressure controlled switch 44, provided with a diaphragm and plunger and adapted to actuate switch 46 which controls the flow of current to motor 4. The connections are so made that upon a fall in pressure in the vapor line the diaphragm and plunger are moved to open the circuit through the motor-audaccordingly stop the compressor. 7

The lubricant in separator 12 which forms a reservoir,'runs to the compressor through a heater 48 which consists of an outer shell 50 communicatingwith the bottom of the separator and in which is suitably secured,

ration takes place, causing a lowering of tem perature in the refrigerator. As the temperature drops, the vapor pressure of the ethyl chloride in the vaporizer becomes corre-v spondingly lower until a vacuum is formed in the vaporizer and vapor line, causing an inward movement of the diaphragm 44 of the pressure controlled switch 46, which results in the stopping of motor 4. The motor,

4 and compressor will then remain inactive until the vaporizer heats up sufliciently to raise the vapor pressure of'the ethyl chloride to a pointat which the diaphragm 44 will be moved outwardly, causing a closure of switch 46 and a renewal of the operation of the coinpressor. Heretofore it has been customary to close down either for short or longer periods of time by cutting off the current through the motor driving the compressor. In the present apparatus, however, the apparatus.

may be most readily shut down by merely closing the defrosting valve 32, when-a vacuum will be produced in vapor line 30 by the compressor and stopping of the compressor will result, check valve 40 servingto prevent leakage of ethyl chloride back- Shells 50 and 52v have wardly through the compressor, which leakage might result in a starting of the motor.

The defrosting valve is so called because it is convenient to close down the apparatus temporarily to permit a slight heating of the refrigerator, necessary to remove frost from the vaporizer and its connections.

Sincemineral oil dissolves ethyl chloride to a very considerable extent, and the ethyl chloride will so dilute the oil that it will render it ineiiective either aslubricantor seal for the compressor, there is provided a heater 48, which not only serves to warm the lubricant to maintain its fluidity but also serves to heat the lubricant to a suflicient degree to drive ofi ethyl chloride before-the lu brica'nt in which it is dissolved returns'to the compressor. The heater further acts to reduce the solubility of the ethyl chloride in the oil, since the ethyl chloride is less soluble in warm oil than in cold ,oil. Further, since rvlvuring the operation of the apparatus the hole of the apparatus is cooled to a considerable extent and hence the lubricating oil tends to become viscous, it is desirable that heater 48 be kept in operation even though motor-4 be inoperative, hence the heater is connected directly to the line independently of switch 46.

Sump 34 .is especially advantageous when a refrigerant is used which is soluble in the lubricant, since if liquid refrigerant were permitted to enter the compressor, it would dissolve the lubricant and the mixture would be carried into separator 12. The level ofliquid in the separator might thus rise to such a height that liquid would overflow into tube 16 and into the condenser and vaporizer, from which the lubricant would fail to return to the compressor. -In this way, lubricant might accumulate in 'the' vaporizer and would necessarily have to be periodically drained therefrom. The sump, preventing the entrance of liquid ethyl ch oride into the compressor, prevents such occurrence.

Although the vaporizerin the system is shown as a boiler, it will be understood that any suitable vaporizer, for example, an expansion valve, may be used to produce an expansion or evaporation of the refrigerant.

Having now fully described my invention, I

what I claim and desire to protect by Letters Patent is: Y l

1. A lubricant reservoir comprising a chamber, a shell-having an open end communicating with said chamber, and a second shell enclosin a heating element and located within said first mentioned shell, whereby the walls of the shells form an annular liquid receiving space about the-heating. element,

said liquid receiving space having an exit" whereb liquid ma flow from the chamber throng said liqui receiving space.

2. In a refrigerating system, a refrigerant compressor, a vaporlzer, a pressure line lsu through which refrigerant passes from the compressor to the vaporizer, a vapor line through which refrigerant passes from the vaporizer to the compressor, an electric motor for driving the compressor, a pressure re-' sponsive device communicating with the vapor line and operative when the pressure in the vapor line drops below a predetermined point to stop the operation of the motor, a lubricant separator in the pressure line, a conduit for leading separated lubricant from the separator to the compressor,

and electrically heated means for heating the lubricant prior to its return to the compressor, said heating means being operative independently of the operation of the compressor.

3. In a refrigerating system, a refrigerant compressor, a vaporizer, a pressure linethrough which refrigerant passes from the compressor to the vaporizer, a vapor line through which refrigerant passes from the vaporizer to the compressor, a lubricant separator in the pressure line, a conduit for leading separated lubricant from the separator to the compressor, and means arranged to heat the lubricant while the lubricant flows in a thin layer prior to its return to the compressor.

In testimony of which invention, I have hereunto set my hand, at Bufialo, N. Y., on

this twentieth day of January, 1928.

EUGENE L. BARNES.

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