Centrifugal Blower

摘要

A centrifugal blower provided with a spiral shaped scroll chamber where a bottom part of the scroll chamber gradually expands downward in the axial direction of the fan well along with expansion of the spiral and where a flow area gradually expands toward an air outlet from a spiral start part of the casing, the centrifugal blower having an initial slant angle θ0 at the spiral start part of the bottom part of the scroll chamber of a range of angle of 5.2° to 27.5° or setting a backflow prevention rib at the fan outlet.

主权项

1. A centrifugal blower comprising:
a multi-blade fan having a plurality of blades arranged in a circumferential direction at fixed intervals to form a fan wheel and an air inlet provided upward in an axial direction of the fan wheel, the multi-blade fan having a fan outlet angle in the range of 20° to 75° and having a fan wheel diameter in the range of 0.05 to 0.15D when an outside diameter of the multi-blade fan is D, and a spiral shaped scroll chamber surrounding the multi-blade fan, the scroll chamber being defined by a spiral shaped casing which has an expansion angle of the spiral of 2° to 6° from a spiral start part as a starting point, the spiral shaped scroll chamber having a chamber bottom part which gradually expands downward in the axial direction together with the expansion of the spiral and having a flow area which gradually increases toward an air outlet from the spiral start part, an initial slant angle θ0 downward in the axial direction at the spiral start part of the chamber bottom part being a range of 5.2° to 27.5°.