Pressure-type flow rate control apparatus
US6152168A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | May 24, 1999 |
| Grant date | Nov 28, 2000 |
| Priority date | — |
| Expiry date | May 24, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/7761
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A pressure-type flow rate control apparatus for use especially in the gas supply system in semiconductor manufacturing facilities. The flow control apparatus is provided with a bore-variable orifice, which permits easy switching of the fluid flow rate control range as well as size reduction of the pressure-type flow control apparatus, and offers other advantages including improved gas replaceability, prevention of dust formation, and reduced manufacturing costs of the flow control system. The apparatus comprises an orifice, a control valve provided on the upstream side of the orifice, a pressure detector provided between the control valve and the orifice, and a control unit to calculate a fluid flow rate Q on the basis of a pressure P1 detected by the pressure detector with the equation Q=KP1 (K=constant) and to output in a drive for the control valve the difference between the set flow rate signal Qs and the calculated flow rate signal Q as control signal Qy, wherein the pressure P1 on the upstream side of the orifice is regulated by actuating the control valve for controlling the flow rate of the fluid downstream of the orifice with the ratio P2/P1 between the pressure P1 on the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.