System for and method of providing a wide-range flow controller
US7874208B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 2008 |
| Grant date | Jan 25, 2011 |
| Priority date | — |
| Expiry date | Dec 12, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D7/0635
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved flow measuring device, such as a mass flow meter or mass flow controller, providing a high turn-down ratio as compared to prior art devices. In accordance with various embodiments of the invention, a flow sensor includes a sensor flow path that includes one or more restrictions configured to provide the sensor flow path with a non-linear relationship between a pressure drop across the sensor flow path and the flow of fluid through the flow sensor conduit. Such a flow sensor preferably achieves a high turn-down ratio by way of a variable bypass ratio that is directly proportional to the sensor tube mass flow rate so that the turn-down ratio of the mass flow controller will be ideally proportional to the square of the turndown achievable by the flow sensor conduit fluid sensing portion alone. In some embodiments, the restriction can be employed as a part of a fluid seal having an orifice and disposed between a flow sensor portion of a flow meter and a bypass portion of the flow meter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.