Rotary displacement compressor with liquid circulation system

Rotary expansible chamber devices – Heat exchange or non-working fluid lubricating or sealing – With pump for non-working fluid

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

418 89, 418 97, 418 98, 418104, 418DIG1, 184 616, F04C 1816, F04C 2902

Patent

active

057279365

DESCRIPTION:

BRIEF SUMMARY
The present invention relates to a rotary displacement compressor having a simple and reliable dual liquid; circulation system.


BACKGROUND OF THE INVENTION

Injection of liquid, usually oil for lubrication, sealing and cooling purposes, into the working space of a compressor of this kind is widely used, in particular in screw compressors. The use of separate circuits for this oil injection and for the bearing lubrication system is advantageous when the compressor operates at high pressures and with a working medium that can dissolve in the oil. The higher the pressure of the oil is, the more the working medium can dissolve in the oil. The working medium dissolved in the oil will decrease the viscosity of the oil and therewith its lubricating ability. The provision of a separate circuit for the bearing lubrication makes it possible to use a lower pressure for the bearing lubrication, than when taking the oil from the oil separator, where compressor outlet pressure prevails. Therethrough the above mentioned problem is avoided. Such systems are earlier known e.g. from GB-A-2 008 684 and U.S. Pat. No. 4,394,113.
GB-A-2 008 684 discloses an oil injected rotary screw compressor in which a portion of the oil in the oil separator is throttled and conducted to a second oil separator at a lower pressure. From this second separator the oil is pumped to the bearings from where it is drained back to the pump. This arrangement requires an extra oil-separator and a recirculation circuit for the working medium in that separator, and therefore becomes somewhat circumstantial.
U.S. Pat. No. 4 394 113 discloses a rotary screw compressor having a main oil circulation circuit including an oil separator and a secondary oil circulation circuit including an oil tank, which secondary circuit operates at a lower pressure and provides lubrication of the bearings. Since oil might leak from one of the circuits to the other, means are provided for maintaining an appropriate amount of oil in the secondary circuit. These means include a conduit connecting the oil separator and the oil tank, which conduit is provided with a solenoid valve controlled by an oil level sensor in the oil tank. This sensor also controls another valve in a conduit through which excess oil in the tank is withdrawn to the compressor inlet. These control equipment makes the compressor complicated.


SUMMARY OF THE INVENTION

The object of the present invention is to attain a rotary displacement compressor having a simple and reliable dual liquid circulation system.
In order to achieve the above object, a rotary displacement compressor according to the present invention has an inlet channel for introducing low pressure gas, an outlet channel through which compressed gas escapes, and at least one rotor mounted in bearings and operating in a working space. The compressor includes a liquid injector for injecting liquid into the working space, a liquid separator provided in the outlet channel for separating liquid from the compressed gas, and a pressure liquid conduit connecting the liquid separator and the liquid injection port. A bearing lubrication circuit includes a tank, a pump, a supply conduit for supplying liquid from the pump to the bearings in which the rotor is mounted, a withdrawal conduit for withdrawing liquid from the bearings to the tank, and a pump inlet conduit for supplying liquid from the tank to the pump. The bearing lubrication circuit further includes a leakage path connecting the tank to a first cavity in the working space and a drainage connection connecting the tank to a second cavity in the working space, the first cavity having a higher pressure than the second cavity.
By connecting the tank through the drainage connection to the working space where a certain intermediate pressure prevails, the oil in the tank will be under that pressure. Through the leakage connection a small amount of oil will leak from the high pressure side of the compressor to the tank to secure a sufficient amount of oil in the bearing lubrication circuit, and through

REFERENCES:
patent: 4394113 (1983-07-01), Bammert

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Rotary displacement compressor with liquid circulation system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Rotary displacement compressor with liquid circulation system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rotary displacement compressor with liquid circulation system will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-952138

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.