摘要 |
Each of blades of a multi-blade centrifugal blower is provided with a taper portion, which is arranged at an inside periphery at least at the side of one rotation-shaft-direction end of the blade and tapers from the side of other rotation-shaft-direction end of the blade toward the side of the one rotation-shaft-direction end. The taper portion is positioned at a rotation-direction front side with respect to a back portion disposed at the side of the other rotation-shaft-direction end of the blade. Each of inlet angles throughout the taper portion is set in a range from 55° to 74°. Therefore, air flowing speed at an outlet of an impeller wheel is uniformed throughout the blade width. Work capacity and efficiency of the impeller wheel are increased, while noise is reduced.
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