Measurement of a gas characteristic
US5635626A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 1995 |
| Grant date | Jun 3, 1997 |
| Priority date | — |
| Expiry date | Nov 20, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/1963
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus to measure the calorific value and/or the Wobbe index of fuel gas supplied along a pipe. A control can operate two outlet valves and cause an inlet valve to be locked in a closed position or be unlocked to stay in a normally open state until the gas pressure in a chamber of predetermined volume reaches a preset pressure difference above the pressure in the pipe. Under direction of the control, a pump moves fuel gas from the pipe into the chamber whilst the outlet valves are closed. Once the pressure in the chamber attains the preset difference, the inlet valve closes automatically to be held locked closed by the control. Certain properties of the gas in the chamber, such as thermal conductivity, specific heat capacity and speed of sound, are measured and corrected to STP conditions. The pump moves two samples of gas into the chamber at two sequential times, each time until the gas pressure therein attains the preset value and the inlet valve again closes automatically in a locked position. Then 1 of 2 outlet valves is opened to allow gas from the chamber to discharge to the pipe through either an orifice place or a capillary passage. This discharge allows the control to m…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.