CENTRIFUGAL BLOWER

PURPOSE: To prevent separating a flow in a negative pressure surface of a blade by vertically providing a straightening plate for intercepting a secondary flow of gas, flowing from a main plate side toward a side plate side, directed to a trailing edge of the blade in a pressure surface of the blade. CONSTITUTION: In a centrifugal blower formed by arranging an impeller 1 of fixing a plurality of sheets of blades 3 with an equal space apart along a circumferential direction between a disk-shaped main plate 5 fixed to a rotary shaft to be orthogonal to it and a tilted cone-shaped side plate 6 in a spiral scroll casing, a plurality of sheets of straightening plates 13 are vertically provided in both sides of a pressure surface 3b (when necessary negative pressure surface 3a) of each blade 3. A height of each straightening plate 13 is almost equal to a thickness of the blade 3, to form the total length in almost 1/2 a chord length of the blade 3, and the straightening plate is provided aside a leading edge of the blade 3. In this way, when the centrifugal blower is operated, a secondary flow B, generated on the pressure surface 3b of the blade 3 to flow from a side of the main plate 5 toward a side of the side plate 6, is interrupted by the straightening plate 13 and directed to outside a radial direction, to prevent separating the secondary flow B.