The 4-72 centrifugal fan can be used for indoor ventilation in general factories and large buildings, conveying air and other unnatural, harmless, and non corrosive gases to steel. The B4-72 fan can be used for ventilation and exchange of flammable and volatile gases. There must be no viscous substances in the gas, and the content of dust and hard particles should not exceed 150mg/m3. The gas temperature shall not exceed 80 ℃. The 4-72 centrifugal fan is the earliest fan used in China, but it is also the most commonly used fan. From high-rise buildings to underground railways, from boiler blowing to factory ventilation, the 4-72 fan can be seen everywhere.

type
From one side of the motor, if the impeller rotates clockwise, it is called a right cyclone machine, represented by "right"; The counterclockwise rotation of the impeller is called a left cyclone, represented by "left".
The outlet position of the fan is represented by the angle of the air outlet of the casing. The 4-72 type fans N02.8~6 are all made into one type when they leave the factory, and the user unit installs them in the required position according to the requirements. There is no need to specify when ordering. The adjustment range of N02.8 air outlet position is 0 °~225 °, with an interval of 22.5 °; The adjustment range of N08~12 air outlet position is 0 °~225 °, with an interval of 45 °; N016、 The position of the 20 air outlets is fixed in three types: 0 °, 90 °, and 180 °, and cannot be adjusted. This should be noted when booking a loan.
There are four transmission modes for fans: A, B, C, and D. Among the 4-72 type fans, N02.8-6 use A-type transmission, N08-12 use C-type and D-type transmission, and N016-20 use B-type transmission.

structure
The N02.8~6 in the 4-72 type fan are mainly composed of impellers, casings, air inlets, motors, and other parts. In addition to the above-mentioned parts, N08~20 also has a transmission part.
Impeller: Composed of 10 aft tilting airfoil blades, curved front plate, and flat rear plate, made of steel plate cast aluminum alloy (steel plate for 4-72, cast aluminum for B4-72, stainless steel or fiberglass for F4-72, etc.), with radial and static balance correction, good air performance, high efficiency, and smooth operation.
Chassis: made into two different types. The N02.8~12 casing is made as a whole and cannot be disassembled, while the N016~20 casing is made as a three open type. In addition to being divided into two halves along the horizontal plane, the upper half is vertically divided into two halves along the centerline and connected with bolts.
Air inlet: made as a whole and installed on one side of the fan, with a curved cross-section parallel to the axial direction. Its function is to allow the airflow to enter the impeller smoothly with minimal loss.
Transmission: composed of main shaft, bearing box, rolling groove bearing, pulley or coupling.


Impurities in gas: There should be no viscous substances in the gas, and the dust and hard particles contained should not exceed 150 milligrams per cubic meter
Gas temperature: not exceeding 80oC