Fans can be classified into several types based on the materials used, such as iron shell fans (common fans), fiberglass reinforced plastic fans, plastic fans, aluminum fans, stainless steel fans, and so on.
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In the direction of gas flow
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Fans can be classified according to the direction of gas flow into types such as centrifugal, axial, oblique (mixed), and cross-flow.
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(1)
Centrifugal Fan After the airflow enters the fan impeller axially, it mainly flows radially. This type of fan is made based on the principle of centrifugal force. The products include centrifugal ventilators, centrifugal blowers and centrifugal compressors.
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(2)
Axial Flow Fan. The airflow enters the impeller of the fan axially and flows approximately along the axial direction on the cylindrical surface. This type of fan includes axial flow fans, axial flow blowers and axial flow compressors.
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(3) Rotary blower. The operation is carried out by changing the volume of the air chamber through the rotation of the rotor. Common types include Roots blowers and rotary compressors.
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Fans are classified according to the flow direction of the airflow after entering the impeller as: axial flow fans,
Centrifugal Fans and oblique flow (mixed flow) fans.
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Fans are classified by their application into forced draft local fans (hereinafter referred to as forced draft fans) and exhaust local fans (hereinafter referred to as exhaust fans), where the flameproof motor is placed outside or inside the flow channel and the flameproof motor is placed in an explosion-proof sealed cavity.
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Fans can also be classified into single-stage, double-stage or multi-stage pressurized fans according to the form of pressurization. For instance, 4-72 is a single-stage pressurized fan, while high-end fans are multi-stage pressurized fans.
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Fans can be classified by their applications into: axial flow fans, mixed flow fans, roof fans, air conditioning fans, etc.
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Fans can be classified by pressure into negative pressure fans, low-pressure fans, medium-pressure fans and high-pressure fans.
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According to the outlet pressure (pressure rise), they are classified as: ventilators (≤ 15,000 Pa), blowers (15,000-350,000 Pa), and compressors (≥ 350,000 Pa).
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Classify by layer type
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There are many classification methods for ventilators. Generally, they can be classified in the following layers:
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(1) According to the level of pressure generated, they can be classified as: volumetric type, reciprocating type and rotary type; Turbine type: centrifugal type, axial flow type, mixed flow type and cross-flow type, jet type.
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Ventilators generally refer to turbine types, including centrifugal, axial flow, mixed flow, cross-flow and other forms.
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Its main features are:
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Centrifugal fan: High pressure, but small air volume.
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Axial flow fan: Higher air volume, but lower pressure.
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Mixed-flow fan: Its air volume and pressure lie between those of centrifugal and axial flow fans.
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Cross-flow fan: It has a relatively high dynamic pressure and can achieve a flat airflow.
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(2) According to the different materials used, they can be classified as; Iron shell fans (ordinary fans), fiberglass reinforced plastic fans, plastic fans, aluminum fans, stainless steel fans, etc.
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(3) According to the direction of gas flow, it can be classified into types such as centrifugal, axial flow, oblique flow (mixed flow), and cross-flow.
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(4) According to the flow direction of the airflow after entering the impeller, they can be classified as: axial flow fans, centrifugal fans and oblique flow (mixed flow) fans.
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(5) According to their applications, they can be classified as: forced local fans and exhaust local fans with flameproof motors placed outside or inside the flow channel, and with flameproof motors placed in explosion-proof sealed cavities.
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(6) According to the form of pressurization, they can also be classified as: single-stage, double-stage or multi-stage pressurized fans.
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Fan performance parameters
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The performance parameters of a fan mainly include flow rate, pressure, power, efficiency and rotational speed.
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In addition, the magnitude of noise and vibration is also a major design indicator for fans. Flow rate, also known as air volume, is expressed as the volume of gas passing through the fan within a unit of time. Pressure, also known as wind pressure, refers to the increase in gas pressure within a fan, which can be classified into static pressure, dynamic pressure and total pressure. Power refers to the input power of the fan, that is, the shaft power. The ratio of the effective power of a fan to its shaft power is called efficiency. The total pressure efficiency of the fan can reach 90%.
