To a certain extent, the centrifugal fan of boiler is a constant pressure device with variable flow rate. When the rotational speed is fixed, the pressure and flow curve of the equipment should be a straight line, and for a given pressure and flow characteristic curve, There is a curve of power and flow characteristics. When the blower is running at constant speed, the required power increases with the decrease of inlet temperature for a given flow rate.
Installation of centrifugal Fan for Boiler
1. The installation of the integral unit of the boiler centrifugal fan should be directly placed on the basis of a pair of inclined cushion iron in the course of operation.
2. The cutting surface on the base of the boiler centrifugal fan assembled in the field should be protected effectively and properly, and no corrosion or operation base should be applied to leveling the inclined cushion iron when it is placed on the foundation.
3. The bearing seat and the base of the equipment should be effectively closely combined, the longitudinal unevenness should not exceed 0.2 / 1000, the horizontal meter should be measured on the main shaft, the transverse non-horizontal bottom should not exceed 0.3 / 1000, and the horizontal instrument should be used to measure the horizontal surface of the housing.
4. In order to adjust the rotor axis line and the housing axis line, the clearance between the impeller and the inlet and the clearance between the spindle and the shaft hole of the rear side plate of the shell can be adjusted effectively during the operation before the bearing bush of the centrifugal fan of the boiler is scraped. This enables it to conform to the requirements of the equipment technical documentation.
5. when the axle bush and main shaft of the boiler centrifugal fan are assembled, it should be checked effectively according to the provisions of the equipment technical documents. The bearing cover and the axle bush should be kept in the interference of 0.03 to 0.04 millimeters (measuring the outer diameter of the axle bush and the inner diameter of the bearing seat).
6. when the fan shell of the boiler centrifugal fan is assembled, the position of the positive shell should be found effectively with the rotor axis line as the main reference, and the axial and radial clearance between the inlet of the impeller and the air inlet of the engine shell is at high speed to the specified range of the equipment technical documents, and the fastening bolts are checked at the same time. If the clearance value is not specified in the equipment technical documents, the axial clearance should be 1 / 100 of the outer diameter of the impeller, the radial clearance should be uniformly distributed, and the value should be 1.5 / 1000 / 3 / 1000 of the outer diameter of the impeller. Adjust to strive for a small clearance value to improve fan efficiency.
7. Fan timing, the axis of the fan and motor axis of the different axis: radial positioning should not exceed 0.05 mm, tilt should not exceed 0.2 / 1000.
8. The centrifugal fan assembled by rolling bearing and the different axial degree of bearing hole on the two bearing frame can be rotated flexibly after the rotor is installed.