Micro Fan Factory Introduces The Characteristics And Types Of Fans For You

A wind turbine is a machine that utilizes electricity to operate and transmit wind power. Fans have gained many job positions in industrial production due to their versatility. There are different types of fans, and different types of fans also have different characteristics. The following is an introduction and recommendation from the micro fan factory for this feature.
According to the different gas flow directions, fans are mainly divided into centrifugal, axial, oblique, and cross flow types.
(1) Centrifugal fan
Centrifugal fan is a type of modern society that uses a power machine (mainly an electric motor) to drive the impeller to rotate within a volute casing. Air is sucked in from the center of the impeller through the intake port. Due to the dynamic action of the blades on the gas, the pressure and speed of the gas are increased, and under the centrifugal force, the gas is thrown along the blade path towards the casing and discharged from the exhaust port. Because the flow of gas in the impeller is mainly in the radial plane, it is also known as a radial flow fan.
The centrifugal fan mainly consists of an impeller and a casing. The impeller of a small fan is directly installed on the motor. Medium and large fans are connected to the motor through a coupling or pulley. Centrifugal fans generally have a single side intake and use a single stage impeller; Large flow can be dual intake, using two back to back impellers, also known as double suction centrifugal fan.
The impeller is the main component of a fan, and its geometric shape, size, number of blades, and manufacturing accuracy have a significant impact on its performance. The impeller can only rotate smoothly after static and dynamic balance correction. According to the different outlet directions of the blades, the impellers are divided into three types: forward, radial, and backward. The top of the blade of the forward facing impeller is inclined towards the rotation direction of the impeller; The top of the blade of the radial impeller is radially oriented, and is divided into straight blade type and curved blade type; The tip of the blade of the backward facing impeller is tilted in the opposite direction of impeller rotation.
The pressure generated by the forward impeller is the largest, and when the flow rate and rotation number are fixed, the required impeller diameter is the smallest, but the efficiency is generally low; On the contrary, backward impellers produce the smallest pressure, require the largest impeller diameter, and generally have higher efficiency; The radial impeller is between the two. The blade profile is the simplest for straight blades and the most complex for airfoil blades.
In order to obtain a suitable velocity distribution on the blade surface, curved blades, such as equal thickness circular arc blades, are generally used. Impellers usually have a cover plate to increase the strength of the impeller and reduce gas leakage between the blade and the casing. The connection between the blade and the cover plate is welded or riveted. The welded impeller has a light weight and smooth flow path. The impellers of low and medium pressure small centrifugal fans are also cast with aluminum alloy.
(2) Axial flow fan
When an axial flow fan operates, the power machine drives the impeller to rotate within the cylindrical casing, and gas enters from the collector. Energy is obtained through the impeller, increasing pressure and speed, and then discharged axially. Axial flow fans can be arranged in three types: vertical, horizontal, and inclined. Small impellers have a diameter of only about 100 millimeters, while large ones can reach over 20 meters.
Small low-pressure axial flow fans are composed of components such as impellers, casings, and current collectors, and are usually installed on the walls or ceilings of buildings; A large high-pressure axial flow fan consists of a current collector, an impeller, a streamline body, a casing, a diffuser, and transmission components. The blades are uniformly arranged on the hub, and the number is generally 2 to 24. The more blades, the higher the wind pressure; The blade installation angle is generally 10 ° to 45 °. The larger the installation angle, the greater the air volume and pressure. The main parts of axial flow fans are mostly welded or riveted from steel plates. [2]
(3) Oblique flow fan
Diagonal flow fans are also known as mixed flow fans. In this type of fan, gas enters the impeller at an angle to the axis, obtains energy in the blade passage, and flows out in the inclined direction. The impeller and casing of the fan are conical in shape. This type of fan has both centrifugal and axial flow characteristics, with a flow range and efficiency between the two.
(4) Cross flow fan
Cross flow fan is a small high pressure centrifugal fan with forward multi blade impeller. The gas enters the impeller from one side of the outer edge of the rotor, and then exits from the other side through the inside of the impeller. The gas is subjected to the force of the blade twice within the impeller. Under the same performance conditions, it has a small size and low rotational speed.
Compared with other types of low speed fans, cross flow fans have higher efficiency. Its axial width can be arbitrarily selected without affecting the flow state of the gas, and the gas still maintains a uniform flow across the entire rotor width. Its narrow and long outlet section is suitable for installation in various flat equipment for cooling or ventilation.
The performance parameters of a ventilator mainly include flow, pressure, power, efficiency, and rotational speed. In addition, the size of noise and vibration are also the main technical indicators of the ventilator. Flow, also known as air volume, is expressed as the volume of gas flowing through the ventilator per unit time; Pressure, also known as wind pressure, refers to the pressure rise of gas in the ventilator, which can be divided into static pressure, dynamic pressure, and total pressure; Power refers to the input power of the ventilator, namely, shaft power. The ratio of the effective power of a fan to the shaft power is called efficiency. The total pressure efficiency of the ventilator can reach 90%.
The future development of ventilators will further improve their aerodynamic efficiency, device efficiency, and usage efficiency to reduce electrical energy consumption; Replacing large centrifugal fans with axial-flow fans with adjustable moving blades; Reduce fan noise; Improve the wear resistance of the impeller and casing of smoke and dust exhaust fans; Realize variable speed regulation and automatic regulation.
To sum up, there are different types of fans, so operating in different environments will have different performances. When selecting fans, we must pay attention to selecting fans that can adapt to actual conditions and operate. It is incorrect to blindly pursue certain indicators. If you have any questions, you can contact the micro fan factory.