Axial blower furnished with bell mouth

TLDR: In this article, an impeller was used to make air capacity comparatively large in a large air capacity range, to make static pressure large in small air capacity ranges and to make a characteristic curve concave dropping to the right without lowering efficiency.

Abstract: PURPOSE:To make air capacity comparatively large in a large air capacity range, to make static pressure large in a small air capacity range and to make a characteristic curve concave dropping to the right without lowering efficiency. CONSTITUTION:On the inside of a casing 1, a bell mouth 2 having a curvature 2a the inside of which is smooth in the discharge direction is arranged. On the inside of the bell mouth 2, an impeller 3 is arranged, and air is blasted in the air blasting direction A. The bell mouth 2 is held free to slide in the axial direction against the casing 1 and energized in the discharge direction by springs 6a, 6b. As the bell mouth 2 is positioned in the discharge direction at low static pressure, it intakes air even from an outer diameter of a vane, and as its intake area is large, air capacity becomes large. Thereafter, when it is pushed by high static pressure P and comes to a position in the intake direction as a dashed line bell mouth 2h, without causing circulation of gas by centrifugal force on the intake side of the outer diameter of the vane, the centrigal force works to increase static pressure toward the discharge side.