Peripheral knowledge of PPH equipment: common sense of fan (1)

First. Classification of fans:
1. Classification according to the airflow direction:
Centrifugal fan: the airflow enters the impeller axially and flows in the radial direction through the rotation of the impeller.
Axial fan: After the air enters the impeller axially, it flows along the axial direction on the cylindrical surface.
Mixed (oblique) flow fan: Meridian acceleration type, the airflow direction is between the centrifugal type and the axial flow type, and it flows approximately along a cone.
2. Classification according to the leaf form:
A) Lean forward (single suction and double suction, applicable pressure below 1000Pa)
B) Backward tilting (single piece, wing-cut type, single suction and double suction, applicable pressure above 1000Pa)
C) Axial flow (iron fan blade, propeller type)
D) Diagonal flow, mixed flow
3. Classification according to pressure form: low pressure, medium pressure, high pressure
4. According to the transmission form:
Transmission mode: A, direct (inner rotor, outer rotor, direct motor, coupling)
B. Belt type (ordinary, continuous bearing, water-cooled, oil-cooled)
According to the place of use and purpose, the fans can be divided into:
Boiler, cooling, explosion-proof, anti-corrosion, ships, textiles, tunnels, dust exhaust, general industrial ventilation, air-conditioning fans, etc.
Second. Classification of centrifugal fans:
Centrifugal fans include medium and high pressure centrifugal fans and medium and low pressure centrifugal fans. According to their different blade types, they are divided into forward, radial and backward tilt.