Fluid supply apparatus
US6178995A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Aug 5, 1999 |
| Grant date | Jan 30, 2001 |
| Priority date | — |
| Expiry date | Aug 5, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/7761
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A fluid feeding apparatus includes parallel flow passages connected at their downstream side, each parallel passage including a pressure flow controller (C) for regulating the flow of fluid and a fluid changeover valve (D) for opening and closing the passage on the downstream side of the pressure flow controller. A fluid feeding control unit (B) controls the pressure flow controllers and changeover valves so that when a changeover valve is closed a control valve (1) upstream of the changeover valve is also closed to prevent a pressure buildup at the changeover valve. In addition to the control valve (1), each pressure flow controller includes an orifice (5) downstream from the control valve, a pressure detector (3) for sensing pressure (P.sub.1) in the passage at a point between the control valve and the orifice, and a calculation control unit (6) for producing a control signal Qy for controlling the drive (2) for the control valve. The calculation control unit first calculates a flow rate signal Qc=KP.sub.1, where K is a constant and P.sub.1 is the pressure sensed by the pressure detector. The calculation control unit then calculates Qy as the difference between a set point or flo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.