Thermal Power Generation Fan 4-68

Describe

The 4-68 boiler centrifugal fan is a series of products jointly designed by the fan industry in 1982. It is mainly suitable for the ventilation and induction system of steam boilers with an evaporation capacity below 230t/h in thermal power plants. When the performance is similar and there is no special requirement, 4-68 can also be used for mine ventilation and general ventilation. Both types of fans have the advantages of high efficiency, low noise and high strength.

The medium conveyed by the ventilator is air, and the maximum temperature shall not exceed 80°C. The medium conveyed by the induced draft fan is flue gas, and the maximum temperature shall not exceed 250°C.

Before the induced draft fan, a dust removal device with a dust removal efficiency of not less than 85% must be installed to reduce the dust content of the flue gas entering the fan. Improve the service life of the fan.

Type and structure

Both the ventilator and the induced draft fan are single-suction, with seven machine numbers: №8, №9, №10, №11.2, N12.5, №14, №16. Each type of fan can be made into two types of right-handed or left-handed. When looking at the fan from one end of the motor, any impeller that rotates in a clockwise direction is called a right-handed fan, which is represented by “right”, otherwise it is a left-handed fan. “Left” means.

The outlet position of the fan is represented by the outlet angle of the casing, and the “right” and “left” fans can be made at 0°, 45°, and 90°. , 135°, 180°, 225°, a total of six angles. Please contact our factory when you require a special machine number or a special angle.

The transmission mode of the fan is D type, and the connection between the motor and the fan is directly driven by an elastic coupling.

The fan is mainly composed of impeller, casing, air inlet, regulating door and transmission group.

Impeller: It is made of 12 backward inclined airfoil blades welded between the arc cone wheel cover and the flat wheel disc. The impeller of the induced draft fan is generally 16Mn, and the joint between the blade and the wheel cover is lined with a wear-resistant guard plate. The head of the blade is made of a solid body, and wear-resistant materials are added to the wear-resistant part to increase the service life of the blade. Ventilators are different. The impellers have passed the static and dynamic balance correction and overspeed operation test, so the operation is stable and reliable.

Chassis: volute body welded by ordinary steel plate. The casing of the single-suction fan is made into two different types of №8~№12.5 casings to form an integral structure, and a quarter of the casings of №14 and №16 can be dismantled. For the induced draft fan, the volute plate has a dust removal door and is properly thickened to prevent soot from being worn.

Air inlet: Convergent streamlined overall structure, fixed on the inlet side of the casing with bolts.

Regulating door: used to adjust the size of the fan flow. №8 and №12.5 are composed of 11 petal-type blades, and Na14 and Ng16 are composed of 13 petal-type blades, all of which are axially installed in front of the air inlet. Due to the external transmission structure, the rotation is flexible and convenient, and the adjustment range is from 90°( fully closed) to 0° (fully open). Adjust the position of the door handle, it is on the right side when viewed from the direction of the air inlet. For right-handed fans, push the lever from bottom to top from fully closed to fully open; for left-handed fans, pull the lever from top to fully closed to fully open. In order to make all parts of the regulating door work normally, lubrication must be paid attention to. For the regulating door of the fan, it is lubricated with calcium-sodium-based grease; for the induced draft fan, due to the high temperature of the gas, it must be lubricated with molybdenum disulfide high-temperature (260°C) grease.

Transmission group: the transmission mode is D type. It is composed of main shaft, bearing box, coupling and so on. The main shaft is made of high-quality steel with rolling bearings and a water-cooled integral bearing box.