PURPOSE: To supply corrosive gases without passing through a blower by disposing a blowing nozzle within a flange and providing an ejector for the flange to suck in secondary fluid.

CONSTITUTION: Air is blown through a nozzle 7 disposed within a flange 6 at a high velocity. Ambient air is sucked in through a flange 9 of an ejector 8 provided for the flange 6 when air is blown at a high velocity by the blower. Thus only normal air is sucked in and blown by the blower and corrosive gases or highly humid fluids are sucked in through the ejector 9 and indirectly blown by the blower.