Fans are generally centrifugal fans and axial fans. The analysis laboratory is mainly used for the exhaust hood of the laboratory fume hood and other ventilation and air exchange.

(1) Centrifugal fans There are many types of centrifugal fans, which are commonly used in analysis laboratories. Fans are divided into hq≤0.98kpa, medium pressure 0.98kpa≤hq≤2.94kpa, high pressure hq>2.94kpa, When selecting a fan, pay attention to its performance and characteristics, and require the following characteristics: 1. Smooth operation and low noise; 2. Large air volume and high efficiency; 3. Complete structure and easy maintenance; 4. Easy disassembly and assembly. The laboratory is often used for the ventilation and discharge of corrosive and poisonous gases, so the material of the fan should be considered when selecting the fan. Plastic fans and FRP fans are commonly used fan models in modern laboratories. The glass fiber reinforced plastic fan has the characteristics of corrosion resistance, high temperature resistance, sun and rain resistance.

(2) Axial flow fan Axial flow fan also has low pressure hq＜490pa and high pressure hq≥490pa. The fan is characterized by simple and compact structure, low noise, stable air volume and pressure, stable operation and safe use at specified speed Reliable and easy to install, the axial flow fan consists of three parts: a wind wheel, a wind casing, and an air collector. The fan is directly driven. The impeller is composed of blades, a disc and a hub; the casing is composed of a wind tube, a base and a supporting plate, and the hub is directly mounted on the motor shaft.