| 摘要 |
PROBLEM TO BE SOLVED: To reduce noise in outside air lead-in operation of a selective gas enriching device. SOLUTION: The selective gas enriching device is provided with a permeation membrane allowing specific gas to pass through; a pump for sucking air and allowing gas to pass through the permeation membrane; a tube extending from the permeation membrane to a gas exhaust port; an optionally adjustable variable valve provided between the permeation membrane and the pump; and the like. To prevent freezing by discharging dew condensate generated in the tube particularly at a low temperature during selective gas enriching operation, control using the variable valve is performed in outside air lead-in operation according to an atmospheric temperature, the operating time of the pump, or the length of the tube, thus reducing noise. COPYRIGHT: (C)2006,JPO&NCIPI
|
