| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a control system for a membrane air drier capable of decreasing gas volume lost as a sweeping gas from the membrane gas drier. SOLUTION: A control system comprises a purge valve 101 connected to a drain port 6 of a gas drier and a mechanism for controlling the purge valve 101. The purge valve 101 is provided with a pilot port to be closed in response to pressure for preventing a penetration sweeping gas from being emitted to the atmosphere through the drain port 6. When the control mechanism controls the purge valve 101 and a compressor is not in operation, the controller allows a dry gas flow from an air pressure instrument to pressurize the pilot port so as to close the purge valve 101 for the purpose of preventing the penetration sweeping gas from being emitted to the atmosphere, and when the compressor is in operation, the controller allows the pilot port to communicate with the atmosphere so as to open the purge valve 101 for the purpose of discharging the penetration sweeping gas from the drain port 6 of the membrane gas drier.</p> |
