Method and apparatus for detection of orifice clogging in pressure-type flow rate controllers
US6302130A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jul 18, 2000 |
| Grant date | Oct 16, 2001 |
| Priority date | — |
| Expiry date | Jul 18, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/8326
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A method and apparatus for detection of clogging of an orifice by measuring the upstream side pressure without breaking up the piping system in a flow rate control unit using an orifice, so as to extend the life of the flow rate control unit and enhance its safety. The apparatus of detecting clogging of an orifice in a pressure-type flow rate controller has a control valve (CV), an orifice (2), a pressure detector (14) for measuring the upstream pressure P.sub.1 therebetween, and a flow rate setting circuit (32) wherein, with the upstream pressure P.sub.1 maintained about two or more times higher than the downstream pressure P.sub.2, the downstream flow rate Q.sub.C is calculated with the equation Q.sub.C =KP.sub.1 (K=constant) and wherein the control valve (CV) is controlled by the difference signal Q.sub.Y between the calculated flow rate Q.sub.C and the set flow rate Q.sub.S. The apparatus comprises: PA1 a storage memory M memorizing standard pressure attenuation data Y(t) of the upstream pressure P.sub.1 measured with the flow rate switched from the high set flow rate Q.sub.SH to the low set flow rate Q.sub.SL with the orifice (2) not clogged, PA1 a pressure detector (14) for d…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.