Air Volume Centrifugal Fan Accessories Guide Vane Adjust Door

Guide Vane Adjust Door For Air Volume Centrifugal Exhaust Fan

Sometimes, due to the special needs of the work, the air volume of the centrifugal fan needs to be adjusted to meet the air volume requirements.

At present, there are two methods to adjust the fan air volume:

One is the valve adjustment, and the other is the inlet blade adjustment. Each adjustment method has a different adjustment effect, such as air valve adjustment and outlet valve adjustment: changing the characteristics of the pipe network, rather than the characteristics of the centrifugal fan. The air volume adjustment range is usually in all conditions of the fan rating performance curve. Due to the method of manually increasing the resistance of the pipe network to change the characteristics of the pipe network, the additional resistance caused by closing the small air valve consumes the pressure drop and the economic difference.

Inlet valve adjustment: when the pipe is set on the suction side of the fan, the adjustment principle is the same as the outlet valve; When the pipe is set on the exhaust side of the fan, the performance curve of the fan is changed by changing the fan inlet pressure. Fan, so the tuning is economical. The adjustment of the spiral air valve changes the characteristics of the fan by changing the outlet area of the fan. Compared with the reduction of air volume, the power change is small, and the energy-saving effect is not obvious.

These two adjustment methods can be used under all conditions under the rated curve to move the surge point in the direction of small flow. Therefore, it is widely used in constant speed centrifugal fans.

Inlet blade adjustment is to adjust the blade, change the flow direction of the suction impeller and the performance curve of the fan. When the inlet blade Angle is zero, the positive volume regulation of the inlet flow of the centrifugal fan can achieve all conditions below the performance curve. The negative winding adjustment of the intake volume can increase the pressure and flow of the fan, but the adjustment range is limited.

Therefore, when it is necessary to adjust the air volume of the centrifugal fan, a more suitable method can be selected according to the structure and use requirements of the fan, so that the fan is in a good running state without damaging the fan body. Increase the air volume to meet the requirements of its working conditions.

The corrosion and wear of fan impeller is mainly caused by corrosion and stress corrosion caused by corrosive gas in the fan conveying medium. The types of corrosion caused by different transport media are also different. In order to prevent corrosion and impeller corrosion and wear, the following measures are usually adopted: stainless steel with strong corrosion resistance is used as impeller material; Coating or spraying anti-corrosion layer on the surface of the impeller and improving the surface quality of the impeller to solve the corrosion and wear problem.
Fan impeller corrosion resistance spraying has surface thermal spraying and plasma spraying, etc. Spraying materials are nickel and nickel alloy wire, powder; Stainless steel wire, powder, etc. Nickel and nickel alloy spray coating to hydrogen sulfuric acid, phosphoric acid, hydrogen cyanide acid, hydrofluoric acid, acetic acid, ferrous sulfate solution and dry gas and other media, corrosion resistance is better, but to hydrochloric acid, nitric acid, potassium acetate, sulfite and other media, corrosion resistance is not good.
Austenitic stainless steel in stainless steel is used for thermal spraying more, such as 1Cr18Ni9Ti, has good processability, and has good corrosion resistance in most oxidizing media and some reducing media.
There are other methods of fan impeller corrosion resistance, such as rubber anti-corrosion coating, epoxy resin coating and so on. There are many wear resistance and anticorrosion methods of fan impeller. Due to the different working conditions of the fan operation system and the different manufacturing process methods of the impeller, the wear resistance and anticorrosion methods of the fan impeller are also different among enterprises.
Austenitic stainless steel (such as 1Cr18Ni9Ti) has low yield strength and is not suitable for the manufacture of high speed impeller, which is suitable for general low-speed fan anti-corrosion impeller material. In the medium containing CO2 and other corrosive gases and smoke, Cr13 stainless steel is mainly used, but attention should be paid to stress corrosion, and fan impellers requiring strong corrosion resistance and high speed are widely used martensite precipitation stainless steel, such as 0Cr17Ni4Cu4Nb and FV520B.

Key Features 

• Product as drawing.
• Customized
• Diameter :400-3500mm. 
• Material:Carton steel Q345, Staliness steel, Aluminium.Cast iron, bronze, stainless steel, manganese bronze, Monel, INCONEL, and non-metallic materials.Non-metallic material composition: PPS plastic, phenolic resin and so on
• Special Treatment: Wear-resisting processing, Surfacing welding processing.