| 摘要 |
<p>In a clean unit which has a dust filter with a blowing power source on the upper surface of a working room and which is capable of maintaining a clean environment, an external gas flow passage is directly connected or connected through a partition wall, through which dust particles can not pass but gas molecules can pass, to a feedback gas flow passage for connecting air-tightly a ventilation hole formed in the wall of the working room and the inlet of the dust filter to each other. On both sides of the partition wall, the flow velocity vector of a gas flowing in the feedback gas flow passage is made to be equal to the flow velocity vector of the gas flowing in an external gas flow passage.</p> |
