US2190138A - Oil separator for refrigeration systems - Google Patents

Description

v 7. FeB. l3, 1940. G. W. SMI TH ET-AL OIL SEPARATOR FOR- REFRIGERATION SYSTEMS Filed Mar a; 9Q 1959 George WJIm/fi A ATTORNEY Patented Feb. 13, 1940 on. SEPARATOR FOB REFRIGERATION srs'mms George W. Smith and James A. Smith, Lyons,

N. Y., assignors to Kenmore Machine Products, Inc., Lyons, N. '1.

Application March 9, 1939, Serial No. 260,711

5 Claims.

This invention relates to an oil separating device which is adapted for use in refrigeration systems.

In large refrigeration systems it has been pro-- posed to cause the separation of oil from the compressed gas while the refrigerant is still in the vapor phase, that is before it is subjected to condensation, the objective being to eliminate all oil from the evaporative portions of the system and thus to obtain an increased efiectiveness. The practical solution of this problem has proved troublesome, not only from a mechanical viewpoint, but also for thermal reasons, since sec-' ondary condensation of refrigerant in the separator induces the. risk of the return of liquid refrigerant to the compressor.

In the present invention there is provided a simple and effective separating device which con-- tains a novel regenerative heating arrangement, by which means the accumulation of liquid refrigerant is entirely prevented. The operation of this separator is wholly automatic in its oil return and heating functions, and it performs theseduties without imposing any discernible additional load on the system.

The more specific aspects of the invention will be more apparent from a study of the accompanying specification and drawing, wherein:

Fig. 1 is a vertical section through the sepaconnecting the compressor l8 and the condenser II. The separator includes a cylindrical housing I l3 capped by upper and lower heads [4 and I 5 respectively, the former head carrying inlet and outlet fittings l6 and I1 connected to the outlet of the compressor and to the condenser respectively by pipes l8 and I9. An oil return fitting 28 is carried low in thewall of the housing l3, and a pipe 2| which is connected thereto carries separated oil volumes back to a crankcase fitting 23 on the compressor l0. Studs 24 are secured to the lower head I 5 and they serve to mount the unit on a suitable'base B, as indicated in dotted lines in Fig. 1.

A slotted sleeve 25 is secured to the inner end Ito of the fitting l6, and the sleeve carries a filter through lever and needle to provide a pivotal asneedle, and the corresponding eflluence of oil 45 mass 26 which is retained therein by a cotter pin 21. A perforate washer 21a may be interposed between the pin and filter mass 26. The outlet fitting I1 is formed with a comparatively longer end or barrel lla', which end contains a bore 32 5 adapted to receive slidably one terminal 28a of a heating coil 28. The coil is formed with a circular section 29 which rests on the lower head\ l5, and the remainingterminal 28b of the coil extends verticallyalong the wall of the housing l3 10 to a high point adjacent the upper head i 4.

The oil return fitting 28 is a two-part structure (Fig. 2) consisting of a valve body 30 and a shouldered pipe bushing 3|, which bushing enters through a hole 33 in the housing and is pressed 15 into a bore 34 in the body 38. The body 30 contains a vertical passage 36 havin atightlyfltted seat insert 31 at its upper e; A n n l of the passageserving as valve needle 38. A transverse the body establishes commu" a valve seat and the pipe bushing 3|, while a second hole 4| connects the valve passage 36 to the interior of the housing.

The valve needle 38 is operated by a fioat-- controlled mechanism including a float lever 43, one end of which is received within the bifurcated lower extremity 44 of the valve body. A pivot pin 45 extends transversely through suitable holes in the bifurcations and lever, and it is retained 30 against displacement by a spring clip 46, whose beaded sides 41 anchor over theprojecting ends of the pin (Fig; 3). A vertical hole 48 in the lever receives loosely the projecting lower end of the valve needle 38. A pin 43 extends transversely 35 sembly. A hollow float 58 is-provided with a depending-stud 5| which enters a vertical clearance hole 52 in the free end of the lever. A transverse pin 53 provides'an assembly similar to that of 40 the valve needle connection.

It will now be apparent that oil accumulating in the lower end of the separator will cause the float-controlled opening movement of the valve through the seat 31 and thence through the pipe 2| back to the crankcase of the compressor. In its raised or open position, the-extreme left hand portion of the lever 43 engages a stop pin 55to limit further movement.

It is preferred that the housing l3 and upper head l4, together with the fittings thereon, be united by hydrogen welding toiorm a substantially integral structure, into which the float mechanism, heating coil, and filter pack are late;/

.plied with a ring 51 of a fusible alloy, as shown in Fig. 4, which ring is inserted in the bore 34 of the body 30. When suitable heat is applied, the

ring 51 melts, and, by capillary flow action. seals not only the pipe bushing 3| to the body 30, but

flows about the edges of the housing holev 33 and .thus firmly secures both parts of the fitting to the housing.'

In the operation of the separator, the relatively hot compressed gas delivered by the compressor through the pipe l8 impingesdirectly during theesubeequent cycle, receives the entire upon the filter mass 26 before escaping into the upper portions of the housing l3. Such impingexnentencourages the coalescence of oil particles which have .been entrained with the refrigerant gasesin the compressor l0, and accordingly the oil drips through the perforate washer 21a. and gathers in a liquid body in the bottom of the housing. The separated gas, in the meantime,

, enters the terminal 281; of the heating coil and finally is directed to the condenser through the, outlet 'fitting l1 and pipe l9.

It will-be appreciated, since the compressor I0 is only intermittently operated in response to load demands of the system, that the compressed refrigerant gas within the separator will be subject to condensation during the periods in which the compressor is inactive. As a result, small quantities of liquid refrigerant gather in the oil body 0, and such bodies if returned with the 011 during subsequent cycles, create a serious hazard o was of the compressor, as is well I in g -jjagt, This possibility is avoided eflect of the heating coil 28, which,

hot gas discharge of the compressor. The immersed portions of the coil thus immediately affect the temperature of thenow relatively cold oil body, and the included liquid refrigerant volumes are rapidly evaporated and driven ofi. It will be understood that the liquid refrigerant will sink in the oil, and thus any oil return action occurring prior to heating will not create a. serious problem, since the valve outlet hole 4| is at a relatively high level.

While the invention has been described with respect to a single embodiment, it will of course be understood that it is susceptible of modifications and variations such as are encompassed by the scope of the following claims.

We claim:

1. An oil return device comprising a housin having a refrigerant gas inlet and outlet, a passage within said housing having one terminal communicating with a high point within said housing, a body portion extending to the bottom of the housing, and its remaining terminal communicating with said .outlet', a float controlled valve mechanism including a valve seat disposed within the housing adjacent the bottom thereof, and'an 011 return conduit communicating with said valve seat.

2. An oil return device comprising a housing having a refrigerant gas inlet and outlet, a tubular heating coil disposed within said housing and having one terminal communicating with a high point within the housing, a bent body portion extending to the bottom of the housing, and its remaining terminal communicating with said outlet, a float controlled valve mechanism including a valve seat disposed within the housing adjacent the bottom thereof, and an 011 return conduit communicating with the valve seat.

3. An oil return device comprising a housing having a refrigerant gas inletand outlet, said inlet being located adjacent the top of the housing and having an extension within said housing containing a foraminous mass to provide an oil and gas dividing means, said outlet having atubular extension depending to the bottom of the housing and having a terminal extending vertically to a high point in the housing, a float controlled valve mechanism including a valve seat oil return'conduit secured to the exterior of the housing and communicating with said seat, a. valve in said guide passage, a lever pivotally carried on the fitting and having an opening therein for loosely receiving the end of said valve, a pin extending through the lever and valve to provide a. pivotal mounting for the valve, and a float connected to said lever.

5. An oil returndevice comprising a cylindrical housing having securing means at one extremity for mounting the housing on a vertical axis, inlet and outlet fittings disposed in the opposite extremity of the housing, a tubular heating coil disposed within the housing and having one terminal communicating with a high point within the housing, a body portion extending to the bottom of the housing, and its remaining terminal slidably entered in said outlet fitting, afloat controlled valve mechanism including a valve seat disposed within the housing adjacent the bottom thereof, and an oil return conduit communicating with the valve seat.

GEORGE W. SMITH. JAMES A. SMITH.

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