Injection cooling of screw compressors
USRE30499E · kind E · reissue
Assignee
Inventors
Key dates
| Filing date | Nov 19, 1974 |
| Grant date | Feb 3, 1981 |
| Priority date | — |
| Expiry date | Nov 19, 1994 |
Classification
- Technology area (CPC —)General
Abstract
A liquid injection expansion valve permits liquid refrigerant at high pressure, bled from the condenser, to be injected into the working chamber between the screws and intermediate of the suction and discharge sides of a helical rotary screw compressor for cooling the refrigerant working fluid and the captured oil. A solenoid valve limits bleeding of liquid refrigerant from the condenser at high compressor loads. A thermostat sensing the temperature of the screw compressor discharge, modulates the liquid injection expansion valve downstream of the liquid injection solenoid valve. A compressor unloader slide valve may port oil and the liquid refrigerant into the working chamber. The condenser may be positioned at a height considerably above that of the screw compressor to increase the head of the bled liquid refrigerant to a pressure higher than the screw compressor discharge pressure. System oil pressure may be supplied to a fluid pressure operated, direct acting, on-off control valve upstream of the liquid injection expansion valve and within the bleed line, under control of a solenoid valve which is responsive to the temperature of the oil leaving the oil pump, where such tempera…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.