| 摘要 |
PROBLEM TO BE SOLVED: To fix a main body to a ceiling through a round hole bored in the ceiling without deteriorating air capacity characteristics and noise characteristics of a centrifugal fan which has no casing owing to an attachment part of metal fittings for fixing the main body.SOLUTION: An ion generation device is configured by providing an outer surface recessed part 12 to an outer surface of a main body 1, providing attachment metal fittings for fixing the main body 1 to a ceiling 100 while moving the outer surface recessed part 12, using an inner surface projection part 30 formed by the outer surface recessed part 12 as a tongue part of a centrifugal fan, and providing a pressure raising part between the inner surface projection part 30 and a discharge port of the centrifugal fan. Consequently, air capacity characteristics are not made worse by using the inner surface projection part 30 as the tongue part as a part of a casing of the centrifugal fan, so the ion generation device can have the main body 1 fixed through a round hole bored in the ceiling 100 without deteriorating the air capacity characteristics and noise characteristics of the centrifugal fan which has no casing owing to the attachment part of metal fittings for fixing the main body 1. |
