Need to determine whether the fan is used for ordinary normal temperature clean gas exhaust, process exhaust, or fire exhaust, explosion-proof exhaust, anti-corrosion exhaust, kitchen exhaust, etc.

1. Ordinary exhaust:

There are no special requirements for the fan, as long as the design conditions and customer requirements are met. However, the speed of the fan should generally be controlled below 1500rpm. Because the speed is too high, the fan and its components are easily damaged, such as bearings and shafts, belts and pulleys that wear out in advance, resulting in frequent replacement of components and increasing maintenance costs.

2. Process exhaust:

There are many types, and some may contain welding slag, paint, explosive gas, and sometimes require high temperature resistance, oil fume exhaust, etc.; different components have different treatment methods, and different requirements for fans.

1) Welding slag contained in the gas: The exhaust of welding workshop or blanking workshop usually takes into account the metal shavings and welding slag contained in the exhaust gas; a filter should be added, and the motor cannot be built-in. If these impurities enter the fan, they may scratch and wear bearing belts and other accessories, and more seriously damage the motor and cause the motor to be scrapped. Therefore, it is required to add a primary effect filter aluminum screen (filter particles with a diameter greater than one millimeter), and an external motor (to prevent metal chips from entering the motor) 2) The gas contains paint: most of them need to add a filter, an explosion-proof fan, and an explosion-proof motor. Shaft seal and external motor; paints contain volatile organic solvents, which are flammable and explosive gases. If exposed to open flames, such as electric sparks, they may cause an explosion. Therefore, explosion-proof fans are required;

3) Exhaust gas contains explosive gas or explosive dust: explosion-proof fan and explosion-proof motor must be equipped;

4) The exhaust gas contains corrosive gas: first of all, it is necessary to know what corrosive gas and what kind of composition, if it is acid-base, use FRP (glass reinforced plastic) or plastic material; if it is medium corrosive, select stainless steel; if When it is weak acid-base exhaust or when the content of corrosive gas in the air is relatively low, the purpose can be achieved by applying anti-corrosion coating on the impeller. The single-layer coating can reach 10 microns, and the double-layer coating can reach 20 microns. about.

3. Fire exhaust:

The fan that has passed the national fire protection certification should be selected.

4. Fume exhaust:

You should choose a fan type that has an impeller with a non-stick coating and can collect oil droplets for easy cleaning.