What problems should we pay attention to when installing centrifugal fans? 

 What problems should we pay attention to when installing centrifugal fans? Centrifugal fans need to be installed and adjusted before use. If these two points are not well done, there may be no problem in a short time, once the running time is relatively long After a long time, the operation efficiency and service life of the equipment will be discounted to a certain extent, so the installation and commissioning of the centrifugal fan must be done well. Before installation, all parts of the fan should be checked first, and the impeller, spindle and bearing should be inspected carefully. If damage is found, it should be repaired, and then the inside of the bearing box should be cleaned with kerosene. However, After measuring whether the gap between the inner bearing is reasonable. If the span between two bearings is found to be large, it is necessary to shut down the equipment in time and deal with it. Problems to pay attention to during installation: 1, in the upper joint of the bolt, if there is a positioning pin, should first good pin, tighten, and then tighten the bolt. 2, in some joint surface, in order to prevent rust, reduce disassembly difficulties, should be coated with some grease or mechanical oil. 3. Check the inside of the casing and other shells. No tools or debris should be left behind. 4. The installation of the whole centrifugal fan unit should be placed directly on the foundation with a pair of diagonal pad iron leveling. 5. The cutting surface on the base of the centrifugal fan assembled on site should be properly protected and should not be corroded or operated. When the base is placed on the foundation, it should be levelled with diagonal cushion iron. 6, bearing seat and base should be closely engaged, longitudinal unlevelness should not exceed 0.2/1000, measured with a level on the spindle, transverse unlevelness bottom should not exceed 0.3/1000, with a level in the bearing seat level in the plane Up measurement. 7. Before scraping the bearing bush, the rotor axis line and the housing axis line should be corrected, and the clearance between the impeller and the air inlet and the clearance between the main shaft and the rear side plate of the housing should be adjusted to make it conform to the provisions of the equipment technical documents. 8, the spindle and bearing bush assembly, should be in accordance with the provisions of the equipment technical documents for inspection. The interference between the bearing cover and the bearing bush should be maintained by 0.03 ~ 0.04 mm (measuring the outer diameter of the bearing bush and the inner diameter of the bearing seat). 9. When assembling the fan housing, the position of the housing should be located on the basis of the rotor axis line, and the axial and radial clearance between the impeller air inlet and the housing air inlet should be reached to the range specified in the equipment technical documents at high speed, and the ground should be checked at the same time Whether the foot bolts are fastened. If the clearance value is not specified in the technical documents of the equipment, the axial clearance should be 1/100 of the outer diameter of the impeller in general, and the radial clearance should be evenly distributed, and its value should be 1.5/1000 ~ 3/100 of the outer diameter of the impeller 0(large value for small outside diameter). Adjust the gap value should be small, in order to improve the efficiency of the fan. 10, fan timing, fan shaft and motor shaft coaxiality: radial positioning should not exceed 0.05mm, tilt should not exceed 0.2/1000. 11. For the centrifugal fan assembled with rolling bearings, the different coaxiality of the bearing holes on the two bearing frames can be subject to flexible rotation after the rotor is installed. It is best to close the valve on the inlet or outlet pipe of the fan during the test run, and gradually open the valve after operation until the required working condition is reached, and pay attention to whether the running current of the fan exceeds the rated current.