Micro-processor control of compression ratio at full load in a helical screw rotary compressor responsive to compressor drive motor current
US4519748A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 1984 |
| Grant date | May 28, 1985 |
| Priority date | — |
| Expiry date | Oct 10, 2004 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04C2270/60
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An axial flow helical screw type compressor has a slide valve member and slide stop member mounted end to end beneath the intermeshing rotors such that the slide valve member controls communication between the work chamber defined by the rotors and the casing to the outlet port and the slide stop member and the valve member together control the working fluid inlet to the bores of the rotors, the slide valve member and the slide stop being independently movable. Control means for the slide valve member and slide stop include position sensing means for these two members, inlet and outlet pressure sensing means, and means for feeding these inputs into programmable circuitry to control the positions of the slide member and slide stop. Additional control means senses the occurrence of full load operation and then causes the slide valve member and slide stop member to move as a closed unit in a given direction, or the reverse, as the compressor drive motor current is sensed, continuously seeking the position at which such current is at a minimum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.