Oil cooling apparatus for refrigerators

Abstract

A refrigerator is connected to an oil separator through an exhaust gas conduit in which an atomizing section is provided and connected to a coolant supply source, whereby the coolant as atomized is easily evaporated by the exhaust gas to thereby cool the latter by latent heat upon the evaporation.

Description

BACKGROUND OF THE INVENTION

The present invention relates to an oil cooling apparatus for a refrigerator such as a screw type refrigerator in which a large quantity of oil is required for the operation.

In the hitherto known refrigerator of this type, oil is discharged from the refrigerator together with exhaust gas at high pressure and temperature and a large scale and capacity of oil cooler of a water cooling type is used for cooling the mixture of gas and oil. Accordingly, there arises a danger of the water cooler being subject to deposition of dirt and corrosion by the cooling medium or water.

AN IMPORTANT OBJECT OF THE INVENTION IS TO PROVIDE AN IMPROVED OIL COOLING APPARATUS FOR THE REFRIGERATOR IN WHICH THE DISADVANTAGES OF THE CONVENTIONAL OIL COOLERS SUCH AS ABOVE MENTIONED HAVE BEEN ELIMINATED.

To this end, according to the invention, high pressurized coolant liquid is atomized and introduced into an exhaust gas conduit from the refrigerator to thereby cool effectively the oil and gas mixture in a simple manner.

The above and other objects as well as novel features and advantages of the invention will become more apparent from the examination on the description of an embodiment of the invention. The description makes reference to the drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a circuit diagram of an oil cooling apparatus according to the invention; and

FIG. 2 is an enlarged sectional view of a liquid atomizer section of the apparatus shown in FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring to the accompanying drawing which shows a preferred embodiment of the invention, a screw type refrigerator 1 has an exhaust outlet or opening 5 from which an exhaust gas conduit 3 extends to an oil separator 2, which in turn is communicated with a condenser 7 through another gas conduit 6. The condenser 7 on the other hand is connected to a liquid receptacle or container 9 through a liquid conduit 8. The receptacle 9 has another liquid conduit 10 outgoing therefrom and connected to an evaporator 12 through an expansion valve 11. The screw refrigerator 1 has a suction inlet 14 to which a gas suction conduit 13 extending from the evaporator 12 is connected. A high pressure liquid conduit 4 which is led from the liquid receptacle 9 is connected to a liquid atomizing port 15 provided within the exhaust gas conduit 3. Alternatively, the high pressure liquid conduit 4 may be led from the condenser 7. The liquid atomization within the gas conduit 3 may be effected by utilizing the potential energy between the condenser 7 or receptacle 9 and the atomizing port 15 with the former positioned at a higher level than that of the latter. Otherwise, an ejector 16 may be arranged within the exhaust gas conduit 3 and connected to the high pressure liquid conduit 4. Furthermore, an electromagnetic valve 17 is provided in the high pressure liquid conduit 4 and opened or closed in synchronization with start or stop, respectively, of the operation of an electric motor 18 for driving the refrigerator 1. Additionally, an oil conduit 20 from an oil sump 19 of the oil separator 2 is connected to oil injection orifices 25 and other lubricating portions 24, 26 of the screw refrigerator 1 by way of filters 21, 22 and an oil pump 23.

In operation, gas discharged from the exhaust outlet 5 of the screw refrigerator 1 at a high temperature and pressure as mixed with oil in a mist form is cooled by evaporating latent heat of the liquid coolant derived from the receptacle 9 and atomized by the atomizing port 15 within the exhaust gas conduit 3, whereby oil component is cooled to the temperature of about 45.degree.C, while gas component is cooled to a temperature in the vicinity of the condensation temperature of the condenser 7, that is 30.degree.C to 35.degree.C. The cooled mixture of gas and oil is then introduced into the oil separator 2 in which gas is separated from oil. The gas from the separator 2 is then liquidized by the condenser 7 and collected at the receptacle 9. The gas condensation or liquid from the receptacle 9 is supplied to the expansion valve 11 through the liquid conduit 10 and, after having been expanded into gas at a low pressure, is introduced into an evaporator 12 where heat exchange takes place between the gas and heat load. Finally, the low pressure gas is sucked into the suction inlet 14 of the screw refrigerator 1 through the suction conduit 13. This process is repeated. Oil from the oil separator 2 is supplied to lubricating portions of the screw refrigerator 1 through the oil sump 19 and the oil conduit 20 and used for lubrication of bearings, cooling of gas and the sealing purpose.

As is apparent from the foregoing description, according to the present invention, the high pressure liquid conduit 4 is provided in the exhaust gas conduit 3 connecting the refrigerator 1 and the oil separator 2 to each other. As a result of that, coolant atomized in the exhaust gas conduit 3 is easily evaporated by the high temperature exhaust gas, whereby the exhaust gas as well as oil mixed therewith in a form of mist are cooled by latent heat upon the evaporation. Thus, gas supplied to the condenser 7 can be previously cooled, while oil component can be put in the state for easy separation from gas. In this manner, according to the invention, the apparatus or installations can be made or arranged in a compact form without requiring an additional separator of a large capacity as is in the case of the hitherto known apparatus. Furthermore, since a cooler of a water cooling type is not employed, the problem of dirt deposition on cooling water conduits as well as corrosion thereof will not arise.

While the invention has been described with reference to an illustrated embodiment, it should be appreciated that the invention will never be restricted thereto and one skilled in the art can make many changes and modifications in the form of the invention without departing from the scope and spirit of the invention.

Claims

What is claimed is:

1. Oil cooling apparatus for a refrigerator comprising a refrigerator, an oil separator, an exhaust gas conduit for connecting said refrigerator and oil separator to each other, an atomization means provided within said conduit, and a liquid coolant supply source connected to said atomization means.

2. Oil cooling apparatus as set forth in claim 1, wherein said liquid coolant supply source comprises a liquid receptacle.

3. Oil cooling apparatus as set forth in claim 1, wherein said liquid coolant supply source comprises a condenser.

4. Oil cooling apparatus as set forth in cliam 1, wherein said atomization means includes an ejector.

5. Oil cooling apparatus as set forth in claim 2, wherein said liquid receptacle is positioned at a higher level than that of the exhaust gas conduit in order to generate a potential energy between them.

6. Oil cooling apparatus as set forth in claim 1, wherein the oil cooled and separated from the gas in said oil separator is injected into said refrigerator and introduced for lubrication of bearings of said refrigerator without installing any oil cooler.