Patent ID: 6817832
Filing Date: 2004-11-16
Classification: F01D,F04D,F05D

Abstract:
A centrifugal blower, comprising a multiblade impeller with a plurality of blades arranged around a rotor, and a scroll casing surrounding said multiblade impeller, with a spiral passage defined between the scroll casing and the impeller to guide air radially accelerated in the impeller to an air outlet port of said scroll casing, thus discharging the air from the scroll casing through said air outlet port, further comprising:an eddy blade installed in said spiral passage at a position around the air outlet port to generate a uniform current velocity distribution of air, thus preventing generation of an eddy at variance with a main current in a stream of air, wherein said eddy blade is placed in said spiral passage such that leading and trailing edges thereof are directed toward an interior and the air outlet port of the scroll casing, respectively, and the eddy blade is inclined downward from the leading edge to the trailing edge at a predetermined angle of inclination relative to a horizontal axis, wherein said leading and trailing edges of said eddy blade are rounded forward and rearward in vertical directions at predetermined radiuses of curvature (R1, R2), wherein the radius of curvature (R1) of said leading edge, the radius of curvature (R2) of said trailing edge, and a distance (C) between centers of curvature of said leading and trailing edges are expressed as follows: R1=(0.08Ëœ0.1)Ã—(D2âˆ’D1)/4 R2=(0.03Ëœ0.05)Ã—(D2âˆ’D1)/4 C=(0.95Ëœ1.01)Ã—(D2âˆ’D1)/2 where D1 is an inner diameter of said impeller equal to a diameter of said rotor, and D2 is an outer diameter of said impeller including the blades.