| 摘要 |
1,267,295. Sampling valves. ENTREPRISEDE RECHERCHES ET D'ACTIVITES PET ROLIERES (ELF). 3 April, 1970 [10 April, 1969], No. 15864/70. Heading B1X. [Also in Divisions B8 and F2] Samples for introduction into analytical apparatus particularly gas chromatographs, are taken from a fluid stream flowing from inlet 18 to outlet 20 by unscrewing spindle 10 so as to lift cone 8, thereby allowing the stream to flow through sample passage 26, then screwing down spindle 10 so that cone 8 forces trap 24 down against spring 28 until passage 26 containing the required sample is closed at the lower end by cone 6. In this position, the stream continues to flow through the valve by means of ducts 30 which open when trap 24 is moved away from abutment against shoulder 22. With the sample in passage 26, the valve is flushed, dried with compressed air, weighed if desired, heated to the required operating temperature, and connected to a stream of carrier gas passing to the analytical apparatus. Spindle 10 is fully unscrewed and the sample is swept from channel 26 by the carrier gas. The system is of particular application in the gas chromatographic determination of heavy hydrocarbons. |
