US2469086A

US2469086A - Reciprocating compressor having means for separating gaseous refrigerant from foam

Info

Publication number: US2469086A
Application number: US714581A
Authority: US
Inventors: Daniel F Shepherd
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 1946-12-06
Filing date: 1946-12-06
Publication date: 1949-05-03
Anticipated expiration: 1966-05-03

Description

May 3, 1949. D. F. SHEPHERD 2,469,086

RECIFROCATING COMPRESSOR HAVING MEANS FOR SEPARATING GASEOUS REFRIGERANT FROM FOAM Filed Dec. 6, 1946 2 Sheets-Sheet 1 FlG.l

INVENTOR.

y 3, 194% D. F. SHEPHERD 2,

RECIPROCATING COMPRESSOR HAVING MEANS FOR SEPARATING GASEOUS REFRIGERANT FROM FOAM Fil ed Dec. 6, 1946 2 She'ets-Sheet 2 FBG.2

IN VEN TOR.

Patented May 3, 1949 RECIPROCATING COMPRESSOR HAVING MEANS FOR SEPARATING GASEOUS REFRIGERAN T FROM FOAM Daniel F. Shepherd, Syracuse, N. Y., assignor to Carrier Corporation, Syracuse, N. Y., a comration of Delaware Application December 8. 1946, Serial No. 714,581

11 Claims. (Cl. 230-206) This invention relates to reciprocatin compressors and more particularly to a reciprocating compressor provided with means for separating gaseous refrigerant from foam created in the crankcase during start-up of the compressor.

Considerable difliculty is experienced by the foaming of oil in the crankcase of a compressor during start-up. The preferred refrigerant, dichlorodifluoromethane, commonly known as F-12, is miscible with the lubricating oil in all proportions. Thus, oil in the crankcase of the compressor normally contains a large amount of gaseous refrigerant. shut down over night, for example, and is started the next day, the pressure in the crankcase is considerably greater than pressure in the suction manifold. Accordingly, upon start-up, the oil in the crankcase foams, and such foaming is encountered for perhaps the first ten minutes of the operation. During this time the foam is drawn into the compressor and is distributed throughout the refrigeration system. Occasionally, insufficient oil remains in the crankcase to lubricate satisfactorily various elements of the compressor, with the result that damage or faulty operation may occur.

The chief object of the present invention is to provide a device adapted to separate gaseous refrigerant from foam thereby retaining the oil in the foam in the crankcase upon start-up of a compressor.

from the following description.

This invention relates to a refrigerant compressor which includes a cylinder, a crankcase, a crankshaft in said crankcase adapted to actuate the cylinder piston, an oil sump in said crankcase, and means in the crankcase for separating gaseous refrigerant from oil in foam created at stratup of the compressor; the separated gaseous refrigerant passin to the suction manifold of the compressor and the separated oil returnin to the sump. Preferably, such means comprises a fan disposed in the crankcase adapted to separate When the compressor is by centrifugal action the gaseous refrigerant from the oil in the foam; the centrifugal fan may be actuated by the crankshaft. After foaming has substantially subsided, the fan serves to draw oil collected in the suction manifold into the crankcase.

The attached drawing illustrates a preferred embodiment of my invention, in which:

Figure 1 is a diagrammatic view illustrating a. compressor provided with the separating fan of the present invention; and

Figure 2 is a sectional view through the crankcase of the compressor.

Referring to the drawing, there is shown a reciprocating compressor 2 including, preferably, a plurality of cylinders 3. Thecompressor 2 is actuated by any suitable power element; for example, a motor 2' connected to any suitable source of current. Each cylinder 3 contains a piston 4 connected by connecting rod 5 to the crankshaft 6 of the compressor disposed in the crankcase I. An oil sump 8 is formed in the crankcase I adapted to contain oil for lubricating various elements of the compressor. Ports 9 are provided connecting the crankcase l and the suction manifold M of the compressor. Ports 5 are adapted to be closed by flapper valves 6 I, depending upon the difference in pressures existing in the suction manifold and the crankcase.

A fan 82 is disposed at any suitable position in crankcase 'i to separate gaseous refrigerant from oil in foam created at start-up of the compressor. Fan i2 may be actuated by crankshaft t and serves primarily to break down foam created at start-up by centrifugal action and by elimination or removal of the gaseous refrigerant therefrom.

Fan it includes a ring or washer member it which may be secured by any suitable means to the counterweight of the crankshaft or to the crankshaft. Mounted on member 93 and preferably riveted thereto is an impeller member provided with a plurality of impellers IS. A shroud i'l including a ring i8 and a vertically extending member 69 having a flange 20 at a right angle to the body of member i9 is disposed adjacent impeller member 55. Flange 20 partially extends over adjacent impellers IS in order to reduce leakage. Shroud I1 is pinned in nonrotating position. An opening 2| extends through member I9 to the inlet 22 of lines 23 leading to the suction manifold III, as hereinafter described.

Considering the operation of the device, at start-up it will be appreciated that pressure in the crankcase I is considerably greater than asoaoso pressure in the suction manifold It of the coinpressor.

erant from the oil, to break the foam, passing the separated gaseous refrigerant through opening 2|, inlet 22, and lines 23 to the suction manifold I0, while permitting the'separated oil to return to sump 8 in crankcase '1. Such action can-*- tinues until foaming has substantialiy subsided, thus preventing possibility of damage or injury to the compressor due to the presence of insufflcient oil in the crankcase to effect satisfactory lubrication. I

It will be appreciated this problem of foaming in the crankcase exists for a short period of time only. After pressures in the crankcase and. the

suction manifold have been substantially equalized, the check valves open providing additional openings for equalization which in turn permits fan I: to reverse the gas flow thereby drawing oil collected in the suction manifold, as shown in Figure 2, into the crankcase. Fan 12 thus serves in effect toeliminate the dangers created by foaming during start-up of the compressor and to assist in the return of .oil in the refrigeration system to the crankcase during the remaining period of operation of the compressor.

My invention provides a simple and inexpensive device to eliminate the difficulties involved in foaming during start-up of a reciprocating cgmpressor. While the device does not eliminate the formation of foam, it serves to break any foam created easily and readily, thus assuring the maintenance of an adequate supply of oil in the crankcase for lubrication purposes to prevent damage or faulty operation due to failure to lubricate satisfactorily various elements of the compressor. The device so provided may be disposed in any desired position in the crankcase for ease of assembly and operation. 1

While I have described and illustrated a preferred embodiment of my invention, it will be understood my invention is not limitedthereto since it may be otherwise embodied within the scope of the following claims. 1 I claim: I

1. In apparatus of the character described, the combination of a compressor, a suction line connected to the compressor, an oil sump serving as a source of lubricant for various elements of the compressor, and a separator fan for separating gaseous refrigerant from oil in foam created at start-up of the compressor, the separated gaseous refrigerant passing to the suction line of the compressor and the separated oil passing to the sump. 1 2. Apparatus according to claim 1 in which said fan serves to withdraw oil collected in the created at start-up of the compressor, the

separated gaseous refrigerant passing to the suction manifold of the compressor and the separated oil returning to the sump.

4. A compressor according to claim 3 in which said separator fan is actuated by the crankshaft.

5. A compressor according to claim 3 in which said separator fan serves to withdraw oil trapped in the suction manifold andto return such oil to the sump after the foam created at start-up of the compressor has substantially subsided.

6. In a compressor, the combination of a cylinder, a piston in said cylinder, a crankcase, a crankshaft in said crankcase adapted to actuate the cylinder piston, an oil sump in said crankcase. and a separator fan in said crankcase actuated by said crankshaft, said fan serving to separate gaseous refrigerant from oil in foam created at start-up of the compressor, a suction manifold connected to the cylinder, and a line connecting said fan with the suction manifold to forward the separated gaseous refrigerant to the suction manifold, the separated oil being returned to the sump, said fan serving to drawbil trapped in the suction manifold into the crankcase after foam created at start-up of the compressor has substantially subsided.

suction line and to return the oil to the sump after the foam created at start-up of the com 7. In a compressor, the combination of a cylinder, a piston in said cylinder, a. crankcase, a crankshaft in said' crankcaseadapted to acuate the cylinder piston, an oil sump in said crankcase, a suction manifold connected to the cylinder, pressure in said crankcase being greater at start-up of the compressor than the pressure in the suction manifold, a port connecting the suction manifold and the crankcase, means for clos-' ing said port when pressure in Saidcrankcase reaches a predetermined oint greater than pressure in the suctipn manifold, a fan mounted on said crankshaft and actuated thereby, a line con necting thg fan with the suction manifold, said fan servin to break up foam created at start-up of the compressor due to the difference in pressure in the crankcase and the suction manifold and to forward the separated gaseous refrigerant through said line to the suction manifold while permitting the separated oil to return to the sump, and after operation of the compressor has continued fora period of time sufficient to equalize substantially the pressures in the crankcase and the suction manifold, thereby permitting said means to open said port, serving to draw oil collected in the suction manifold into the crankcase.

8. .A compressor according to claim 7 in which the fan comprises a ring member adapted to be attached to the crankshaft, an impeller member attached to said ring member, and a shroud member having an vopening therein leading to said line, said fan servingto separate gaseous re-v frigerant from oil in the foam by centrifugal action and to pass the separated gaseous refrigerant through the shroud opening and said line to the suction manifold, the separated oil returning to the sump. I

9. A device for substantially eliminating thedeleterious effects of foaming at start-up of a compressor including a suction manifold and acrankcase which comprises 7 a fan adapted to separate gaseousrefrigerant in the foam by centrifugal action and to pass the separated gaseous refrigerant to the suction of the compressor, said fan including a ring member, an impeller member attached to the ring member and a shroud mem-" ber connected to the suction of the compressor, and means for actuating said fan upon startup of the compressor.

10. A device according to claim 9 in which the fan serves to withdraw trapped oil from the suction manifold of the compressor after foaming has substantially subsided due to substantial equalization of pressures in the crankcase and the suction manifold.

11. A device for substantially eliminating the deleterious eflects of foaming at start-up of a compressor including a suction manifold, a crankcase and a crankshaft which comprises a fan disposed in the crankcase of the compressor, said fan separating gaseous refrigerant from foam in the crankcase by centrifugal action, passing the separated gaseous refrigerant to the suction manifold of the compressor and returning separated oil to a; sump in the crankcase, said fan including a ring member mounted on the crankshaft of the compressor and adapted to rotate therewith, an impeller member attached to said ring member, a shroud member disposed adjacent.

the impeller member, and a line connecting the shroud member and the suction manifold of the compressor.

DANIEL F. SHEPHERD.

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

UNITED STATES PATENTS