|
G4-73、Y4-73Boiler centrifugal fan and induced draft fan
1. Purpose
G4-73 and Y4-73 boiler ventilation and induced draft fans are suitable for ventilation and induced draft fan systems of steam boilers below 670t/h in thermal power plants. G4-73 can also be used for mine ventilation and general ventilation unless otherwise specified.
The medium conveyed by the ventilation fan is air, and the maximum temperature shall not exceed 80 ℃; The medium conveyed by the induced draft fan is flue gas, and the maximum temperature shall not exceed 250 ℃.
Before the induced draft fan, a dust removal device must be installed to minimize the dust content of the flue gas entering the fan as much as possible. According to the general usage of power plants, the dust removal efficiency shall not be lower than 85%.
2. Form
(1) The ventilation fan and induced draft mechanism are single suction, each with 12 machine numbers from No.8-28.
(2) The fan is made in two directions of rotation, left and right. When viewed from one end of the motor and the impeller rotates clockwise, it is called a right cyclone fan, represented by "right"; The counterclockwise rotation of the impeller is called a left cyclone, represented by "left".
(3) The outlet position of the fan is represented by the angle of the air outlet of the casing.
(4) The transmission mode of the fan is D-type, all of which use elastic couplings for transmission.
3. Structural characteristics
The fan is mainly composed of an impeller, a casing, an air inlet, a regulating door, and a transmission part.
(1) The impeller consists of 12 inclined blades with oblique angles welded between a conical front plate and a flat rear plate. Due to the adoption
The use of wing shaped blades ensures the high efficiency, low noise, and high strength of the fan. The impeller has undergone static and dynamic balance correction, ensuring smooth operation. The impeller structure of the ventilation and induced draft fans with the same machine number is the same.
(2) The casing is a snail shaped body welded from ordinary steel plates. The casing of a single suction fan is made in three different forms (No.8-12)
The casing is made as a whole structure and cannot be disassembled. Cabinets 14-16 are made as two open types, while casings 18-28 are made as three open types. The induced draft fan and volute plate have been appropriately thickened to prevent wear.
(3) The converging and streamlined air inlet is made into a whole structure and fixed on the inlet side of the fan with bolts.
(4) The device used to adjust the flow rate of the fan is installed axially in front of the air inlet. The adjustment range is from 0 ° (fully open) to 90 ° (fully closed). Adjust the position of the door lever, looking on the right side from the air inlet direction. Push the lever of the right cyclone machine from bottom to top in the direction from fully closed to fully open; For the left cyclone machine, the direction of pulling the lever from up to down is from fully closed to fully open.
(5) The main shaft of the transmission part is made of high-quality barium, and this fan uses rolling bearings. There are two forms of bearing housings: No.8-16 use integral cylindrical bearing housings, and No.8-28 use two independent pillow bearing housings. The bearing box is equipped with a thermometer and an oil level indicator (only for the induced draft fan). The lubricating oil used is full loss system oil L-AN46, and the amount of oil added is according to the requirements of the oil level mark. When lubricating grease is used for the No.8-16 integral cylindrical bearing box, an oil baffle should be added on one side of the ball in the bearing box, and its fixing groove has been prefabricated. The induced draft fan is equipped with a water cooling device, therefore, a water supply pipe must be installed. The water consumption varies with the temperature, generally considered at 0.5-1m3/h.
|
