JPH04342894A - Oil separating device - Google Patents

Abstract

PURPOSE:To prevent the invasion of oil, which is caused by bubbling action at the time of stopping the operation of a compressor, into a separating element by providing a preventing net between the periphery of the separating element to separate the oil in compressed air and an oil tank inside which the above element is set. CONSTITUTION:Air enters a compressor 1 and is compressed there, and oil is jetted during the above process for sealing and lubricating the compressor 1, and discharged to an oil separator 3 with a compressed air. The oil stays partially in an oil tank 6, and the other part of the oil flows together with the compressed air to a separating element 10. Oil content further passes through a recovering piping 9 and is recovered on the suction side of the compressor 1, and the compressed air passes through a pressure regulating valve 7 and is cooled by a after-cooler 5 and then discharged. On the other hand, during the cessation of the operation of the compressor 1, an air discharging valve 8 is opened to discharge the compressed air in the oil separator 3 to the atmosphere. In this case, the compressed air having mixed into the oil expands to generate bubbles 12, which is made to adhere to a preventing net 11 provided on the periphery of the separating element 10 as an oil film.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separation element for separating oil from compressed air of an oil-cooled screw compressor, and more particularly to a device for preventing bubbles from entering the separation element when miniaturized.

0002

[Prior Art] Conventionally, as disclosed in Japanese Utility Model Application No. 53-95419, a foam suppressing plate was provided to prevent foam from entering when the compressor was stopped, but the air passage when the compressor was in operation was In some cases, particles may enter the separation element through the When the compressor is restarted in this state, the oil remaining in the separation element (the oil that has disappeared from the bubbles) cannot be completely recovered and is mixed into the compressed air and discharged.

[0003] In addition, in an oil separator that does not have the structure as in the above-mentioned publication but only has a built-in separation element,
The distance between the separation element and the oil level at the bottom of the oil separator is increased.

0004

Conventionally, when the compressor is stopped and the compressed air in the oil tank is released to the atmosphere, the compressed air mixed in the oil expands, causing a bubbling phenomenon. If the amount of oil is large or if the oil has become dirty due to long-term use, this foaming will become severe and will enter the separation element and remain there. If the engine is restarted in such a state, the oil in the separation element cannot be smoothly collected, but instead is mixed into the discharged air and carried away.

An object of the present invention is to prevent bubbles from entering the separation element in order to prevent such a phenomenon.

[0006]

[Means for Solving the Problems] A cylinder made of a net-like material that prevents the intrusion of bubbles is attached to the outer periphery of a separation element for oil separation so that a space is created between the cylinder and the outer periphery of the separation element. This cylinder is smaller than the total height of the separation element and is open at the top so that no pressure difference occurs between the inside and the outside of the cylinder.

[0007]

[Operation] When bubbles reach the cylinder made of a mesh provided on the outer periphery of the separation element, a film of bubbles is formed on the surface of the mesh due to the surface tension of the oil. Since the cylinder is manufactured so that the pressure is the same on the inside and outside of the cylinder, bubbles that rise later during air release cannot pass through the oil film on the surface of this cylinder, and are inside the separation element. The objective is to be achieved by not being able to invade the area.

[0008]

[Embodiment] Hereinafter, an embodiment of the present invention will be explained with reference to FIGS. 1 and 2.

FIG. 1 is an overall flow diagram of an oil-cooled screw compressor. Air enters the compressor 1 through this suction throttle valve and is compressed to a predetermined pressure. During the process, oil is injected for sealing and lubrication, and the air is discharged to the oil separator 3 together with the compressed air. Some of the oil enters the oil separator 3 and accumulates in the oil tank section 6 at the bottom.
The remainder flows to the separation element 10 together with the compressed air. Here, the oil is collected and accumulated in the lower part of the separation element 10, and is recovered to the suction side of the compressor 1 through the recovery pipe 9. On the other hand, the compressed air passes through the pressure regulating valve 7, is cooled by the aftercooler 5, and then is discharged.

The oil in the oil tank 6 below the oil separator 3 is cooled by the oil cooler 4 and supplied to the compressor again.

When the compressor is stopped, the air release valve 8 opens to release the compressed air in the oil separator to the atmosphere. At this time, the compressed air mixed in the oil expands and bubbles are generated. The bubbles grow as shown in FIG. 2 and reach the prevention net 11 provided around the outer periphery of the separation element 10. This prevention net 11 has a mesh shape, and when bubbles come, an oil film is formed on the surface of the mesh. The inside of the prevention net 11 is open at the top and there is no pressure difference between the inside and the outside, so the bubbles that rise later will be unable to go any further due to the oil film created by the bubbles that came first, and the prevention net will close. Do not invade inside. Therefore, only the compressed air does not enter the separation element, and only the compressed air passes through the upper part of the separation element 10 (the part without the prevention net) and is released into the atmosphere.

0012

According to the present invention, it is possible to prevent oil from entering the separation element due to foaming when the compressor is stopped, and it is also possible to prevent oil from being mixed into the compressed air when the compressor is restarted. It is economical because it is smaller and has a simpler structure than conventional bubble intrusion prevention measures. Further, in order to prevent the intrusion of bubbles without providing a prevention net as in the present invention, it is necessary to provide a large distance between the oil level at the bottom of the oil separator and the separation element, and the oil separator itself becomes a large container. Therefore, the present invention leads to miniaturization of the oil separator.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an oil-cooled screw compressor.

FIG. 2 is an explanatory diagram showing the state of bubbling within an oil separator.

[Explanation of symbols]

3...Oil separator, 10...Separation element, 11...
Prevention net, 12...foam.

Claims (1)

[Claims] Claim 1: An oil tank with a built-in separation element that separates oil from compressed air, and a prevention net or perforated prevention plate with a certain space attached to the outer periphery of the separation element to prevent bubbles from entering. An oil-cooled compressor characterized by being equipped with a separation element.