摘要 |
A centrifugal blower (10) has an impeller (14) which draws air through a central inlet, an annular envelope (16) positioned around the impeller (14) to receive airflow from the impeller and direct airflow out of a discharge, the envelope having an axially forward inlet section (16A) and a flow directing envelope section (16B) bounded by an inner envelope surface (21) and an outer envelope surface (20), with the flow directing envelope section (16B) located behind the inlet section (16A) and extending rearwardly to an annular outlet (22), the flow directing section (16B) having two stages of airfoil vanes (24, 26) positioned in the annular envelope (16) to turn and diffuse airflow in the envelope, with the inner envelope surface (21) having a convex rearward terminal section (28) curving gradually from a general axial segment (27) to a rear wall (30) that is transverse to a rotating axis of the impeller (14).
|