Oil free screw compressor operating at variable speeds and control method therefor
US6739841B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 2003 |
| Grant date | May 25, 2004 |
| Priority date | — |
| Expiry date | Mar 18, 2023 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04C2240/403
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An oil free screw compressor having a low-pressure stage compressor body and a high-pressure stage compressor body. Power of a motor driven by an inverter is transmitted to the compressor bodies through gears. A low-pressure stage blow-off two-way valve is provided in a pipe branching off midway an air pipe connecting between the high-pressure stage compressor body and the low-pressure stage compressor body, and a high-pressure stage blow-off two-way valve is provided in a pipe branching off from a discharge air pipe provided on a discharge side of the high-pressure stage compressor body. During no-load operation, a controller gives a command to the inverter to make the rotational speed of the motor a set lower limit rotational speed, and also gives an open command to the low-pressure stage blow-off two-way valve.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.