Analysis of Different Structural Forms of Centrifugal Fans

Centrifugal fan

When conveying solid powder materials, we often choose screw conveyors. When conveying and transporting gas, we need to choose fans. There are different types of fans: centrifugal fans, axial fans, and Roots blowers.

There are various structural forms of centrifugal fans:

(1) Structural types with different rotation directions

Centrifugal fans can be made into right-handed or left-handed. Viewed from one end of the prime mover, if the impeller rotates in a clockwise direction, it is called right-handed, which is indicated by “right”; otherwise, it is left-handed, and is indicated by “left”.

(2) Structural types with different intake directions

There are two types of air intake for centrifugal fans: unilateral air intake (single suction) and bilateral air intake (double suction).

The single-suction fan is divided into two types: one-side single-stage impeller and one-side two-stage impeller. Under the same conditions, the wind pressure generated by the double-stage impeller is twice that of the single-stage impeller.

(3) Different structural types of transmission side

According to the different use conditions, there are many transmission modes of centrifugal fans. If the speed of the fan is the same as the speed of the motor, the large fan can use the coupling to directly connect the fan and the motor, and the small fan can directly install the impeller on the motor shaft; if the speed is different, the pulley can be used for variable speed transmission. There are also a variety of transmission methods.

Centrifugal fans can be divided into high, medium and low pressure centrifugal fans according to pressure; they can be divided into general, explosion-proof, anti-corrosion, suction, etc. according to their uses; according to materials, they can be divided into ordinary steel, stainless steel, plastic and FRP, etc. .

The full name of the centrifugal fan includes six parts: name, model, machine number, transmission mode, rotation direction and tuyere position.

Axial flow fans can be divided into cylinder type, simple cylinder type and fan type axial flow fan according to the structure type; according to the configuration direction of the shaft, they can be divided into vertical type and horizontal type axial flow fan.

At present, my country’s axial flow fans are divided into two categories according to the pressure level: low pressure and high pressure. The total pressure of the low-pressure axial fan is less than or equal to 490Pa; the total pressure of the high-pressure axial fan is greater than 490Pa and less than 4900Pa.

Among them, it can be divided into: general axial flow fan, mine axial flow fan, cooling axial flow fan, boiler axial flow fan, tunnel axial flow fan, textile axial flow fan, chemical gas discharge Axial flow fan. Axial flow fan for mine local axial flow ventilation, axial flow fan for cooling cool air and other purposes.

The full name of the axial flow fan includes six parts: name, model, machine number transmission mode, airflow direction and tuyere position.

When conveying solid powder materials, we often choose screw conveyors. When conveying and transporting gas, we need to choose fans. There are different types of fans: centrifugal fans, axial fans, and Roots blowers.

Roots blowers have various forms and structures according to the requirements of use.

(1) According to the structure type

L type (vertical type): The center line of the two rotors of the blower is in the same vertical plane, the air flow is horizontal, and the air inlet and outlet are on both sides of the blower.

W type (horizontal type): The center line of the two rotors of the blower is in the same horizontal plane, the air flow is vertical, the air inlet is on the side of the lower part of the casing, and the air outlet is on the top of the fan or the opposite. The intake and exhaust directions of the horizontal structure are considered from the strength. It is better to enter the top and bottom.

Roots blowers can be rotated either clockwise or counterclockwise as required.

(2) According to the cooling method

Air cooling: When the outlet pressure is less than 49.0kPa (5000mmH, 0), the air cooling structure is adopted, and the heat during the operation of the air-cooled blower is cooled by natural air, in order to increase the heat dissipation area. The surface of the casing is made of fins. structure.

Water cooling: when the outlet pressure is greater than or equal to 49.OkPa (5000mmH2O), a water-cooled structure is adopted, the heat of the water-cooled blower casing is forcedly cooled by cooling water, and a jacket layer is made on the casing surface to make the cooling water circulate in the jacket .

(3) According to the connection method

The blower uses a coupling to connect with the prime mover. That is, it can be directly driven or driven by a pulley. However, the transmission efficiency of the pulley is not high, and the bearing is easily damaged. Generally, it is rarely used.


Post time: Jul-09-2022