| 摘要 |
A main body casing (12) has an inlet provided on one side, a discharge port provided on the other side, and an air passage formed in the interior. A filter (18) for partitioning the air passage into the upstream side and the downstream side of the filter (12) is provided in the main body casing (12). An exhaust fan (28) for discharging the air on the downstream side of the air passage from the discharge port is provided on the downstream side of the air passage. A communicating means (26) for communicating between the exterior and the air passage between the exhaust fan (28) and the filter (18) is further provided. The communicating means (26) allows flow of air between the exterior and the air passage on the downstream side of the filter (18). |
