Patent ID: 7967557

Claim:
A multiblade centrifugal blower, comprising: a centrifugal fan that includes: a hub that is rotated by a motor; and a plurality of curved rectangular blades that are arranged at predetermined intervals in a circumferential direction of the hub to form a cylindrical basket with an opening on a front side of the hub; and a scroll casing that includes an air inlet and an air outlet, and that houses the centrifugal fan inside such that the centrifugal fan faces the air inlet, wherein rotation of the centrifugal fan causes suction of air from the opening and the air inlet toward a direction of a rotating shaft of the motor, and causes discharge of the air through a space between the blades in a centrifugal direction so that the air is blown out from the air outlet, a length B 2 from a rear end to a front end of an outer edge of the blade is shorter than a length B 1 from a rear end to a front end of an inner edge of the blade, a bell mouth is located at the air inlet such that a distance from a tip part of the inner edge of the blade to an inner wall of the scroll casing is minimum at an inner tip part of the bell mouth, and wherein a ratio B 2 /B 1 satisfies 0.75≦B 2 /B 1 ≦0.95.