CENTRIFUGAL TYPE MULTIBLADE BLOWER

摘要

PROBLEM TO BE SOLVED: To provide a centrifugal type multiblade blower capable of reducing an expansion angle of a scroll chamber in comparison with a conventional one for miniaturizing a casing and maintaining the approximately same air feeding efficiency and a noise level as those of the conventional one. SOLUTION: The multiblade blower 1 is provided with a first reverse flow preventing means 10 preventing the fed air flowing through the scroll chamber 4a from reversely flowing from an intake side gap G1 between an intake side case board 4d of the casing 4 and a multiblade fan 2 to an air intake port 4b and a second reverse flow preventing means 20 preventing the fed air from reversely flowing from a motor side gap G2 between the casing 4 motor side case board 4e and the multiblade fan 2 to the upstream side of the scroll chamber 4a. A length L1 in the motor shaft 3a axial direction of the scroll chamber 4a is set to be longer than a length L2 in the motor shaft 3a axial direction of the multiblade fan 2 and gradually increased toward the fed air discharge port 4c in the casing 4.