Correct Installation Of Centrifugal Fans Improves Work Efficiency
1. Check the outer dimensions of the foundation and the center dimensions of each reserved hole. The deviation of the outer dimensions of the foundation should be within the range of ±20mm, and the deviation of the center dimensions of each reserved hole should be between ±10mm. The foundation is marked with the main building base point or the vertical and horizontal center line of the boiler as the benchmark. The vertical and horizontal main center line deviation of the foundation should be ±10mm, the center line distance deviation should be ±3mm, and the foundation elevation should be between ±5mm.
2. Chisel the foundation, place the anchor bolts, and arrange the pads. The pad group generally consists of 2 flat and 1 oblique pads, and 3 pairs of pads. The thick ones are placed below, and the oblique pads should be used in pairs. And extend out of the frame by about 20mm. After alignment, it should be welded firmly and not loosened. The pads should be placed on the main load-bearing table of the equipment, the frame reinforcement, or on both sides of the anchor bolts, as close to the anchor bolt holes as possible without affecting the secondary grouting.
3. Rough positioning of the lower half of the casing: pay attention to the manufacturer's installation mark, usually "A" and "B" for each unit. Before positioning, pay attention to distinguish the relationship with the inlet and outlet air ducts, the rotation direction of the impeller, etc.
4. After inserting the bell mouth of the collector into the impeller and fixing it with wire, hoist the entire rotating group into the predetermined position. Install the anchor bolts. The curvature of the anchor bolts should be ≤L/100 (L is the length of the anchor bolts). The bottom of the anchor bolts should not touch the bottom of the hole or the wall of the hole. The anchor bolts should be evenly stressed and the bolts should be exposed for 2 to 3 buckles. Then loosen the wire and fix the lower part of the collector to the lower half of the casing with bolts to preliminarily adjust the gap between the impeller and the bell mouth.
5. Leveling and alignment of the fan rotating group: The verticality between the fan main shaft and the bearing seat is aligned by the following method: stick the magnetic seat on the main shaft, and point the dial indicator head to the outer ring of the bearing or the elastic end face of the bearing seat (i.e. the processing surface of the upper end cover). At this time, the needle reading of the main shaft should not exceed 0.15mm after rotating it for more than one circle. This reading value is the verticality of the bearing seat and the main shaft.
6. Leveling and alignment of the motor: adjust the coaxiality of the fan and the motor main shaft (i.e. leveling and alignment of the coupling). Use three dial indicators for alignment, two axial and one radial. Turn the moving shaft 90 degrees each time, record the data, measure the readings up, down, left and right, and adjust the coaxiality so that the error is ≤0.05mm. There should be a 10mm gap between the two backrest wheels. After alignment, check some data such as the shaft center height and keep records.
7. After the fan is aligned, the upper half of the casing is covered, the collector and the casing are installed in place, and asbestos rope should be padded between the two casings. Tighten the connecting bolts, and the bolts on the four sides should be evenly stressed. Using the impeller as a reference, adjust the gap between the impeller and the bell mouth again.
8. Install the air intake box, inlet adjustment damper door and other parts of the fan. The adjustment damper should be flexible. Otherwise, lubricating oil should be added to rotate until it is flexible before installation. The blade should be firmly fixed during installation, and there should be sufficient expansion gap with the shell. The adjustment operation device should be flexible and correct, the action should be consistent, and the opening indicator mark should be consistent with the actual situation. Pay attention to the opening direction, do not install it in reverse, and the air intake direction should be the same as the impeller rotation direction.
9. The layout of cooling water and lubricating oil pipelines should meet the requirements of the drawings, be correctly and beautifully arranged, and there should be no debris in the pipeline.
