* SWF-Ⅰ. Ⅱ.Ⅲ Series Mixed-flow Fan is a new type of ventilator between Axial fan and Centrifugal Fan. Its air pressure is higher than that of the same numbers of axial fan, while its flow rates Is higher than that of the same numbers of centrifugal fan. It has features as wider efficiency areas, higher efficiency, etc. It Is widely used for hotels, office blocks, and high lass buildings, refrigeration storage, textle industry, and other industrial and mineral plants to take place of low pressure centrifugal fan or high pressure axial fan so as to save a lot of silencers.