The main function of centrifugal fan is ventilation, dust removal and cooling, it is a driven fluid machine.
1)Introduction of centrifugal fan
1. What is a centrifugal fan
In general, during the operation of the fan, the air flow enters the blade space from the extension shaft and rotates with the impeller under the drive of the impeller. On the other hand, the energy can be increased under the action of inertia, and it leaves the impeller along the radial direction, mainly by the centrifugal force generated. The fan that is doing the work is the centrifugal fan. It has a simple structure, high wind pressure, reliable operation, and an efficiency of up to 94% at rated load, so it is widely used.
2. Classification of centrifugal fans
(1) According to the wind pressure: According to the size of the wind pressure, it can be mainly divided into fans, the wind pressure is mainly below 10000Pa; the wind pressure of the blower is 10000～300000Pa; Wait for three.
(2) According to the blade: Centrifugal fans can be divided into three types according to the shape of the blades: flat type, curved type, and airfoil type.
(3) According to the blade installation angle: The blade installation angle of the centrifugal fan has three types: radial, forward and backward.
(4) According to the structure: According to the structure of the centrifugal fan, it can be divided into single-stage single-suction or single-stage double-suction impeller, and the unit is arranged horizontally.
a. Single suction type: The single suction type is welded by the front disc, rear disc, blade, hub, etc., and has only one air inlet and air outlet.
b. Double suction type: The double suction type has two front discs and one middle disc. Impeller blades are welded between the front and middle discs. There are two air inlets and one air outlet.
2)Working principle of centrifugal fan
The working principle of the centrifuge is basically the same as that of the centrifugal water pump. When the motor drives the fan impeller to rotate at a high speed, the gas between the blades on the impeller obtains centrifugal force, so that the gas is thrown out from the opening between the blades, and the thrown out gas touches the air. The casing, thereby increasing the kinetic energy of the gas in the casing. The casing is mainly in the shape of a spiral, and the cross-section of the air flow increases gradually, and the kinetic energy will be converted into static pressure energy and reach a larger value at the air outlet of the fan, so that the gas is pressed out of the outlet of the fan, and the central part of the impeller is pressed out. The pressure is reduced and the gas is sucked into the fan, so the impeller rotates continuously, so that the air can flow continuously in the pipe under the action of the fan.
The above is the answer to the question of what is a centrifugal fan. After the above introduction, it can be seen that centrifugal fans can be divided into different types according to wind pressure, blade shape, blade installation angle, structure, etc.
