[Circular Duct Fan]Circular Duct Fan Selection Circular Duct Fan Installation
As the key to ventilation system, logistics pipeline transportation, and gas pipeline circulation, the duct fan must follow certain principles in selection, and at the same time, it must meet the rationality and economy of use.
1. When selecting a duct fan, first select the type of fan (centrifugal fan, axial flow fan, etc.) according to the operating conditions and working conditions, and estimate the quantity used;
2. When selecting a duct fan, the maximum flow and pressure head must be calculated according to the distance of the pipeline and the layout requirements of the design, and then 10%-15% margin must be considered;
3 .If the pipeline distance is too long, when considering the joint operation of the duct fans, avoid the parallel or series working mode as much as possible;
4. When considering the installation location of the duct fan type selection, the rotation direction of the fan impeller must be ensured And the outlet position meets the requirements of the working conditions;
5. When the duct fan is selected for the working conditions with noise requirements, the fan with high efficiency and low peripheral speed of the impeller should be selected as much as possible;
6. When there are several types of duct fans for reference, it is necessary to compare the flow, pressure, noise, efficiency and other parameters at the rated point, and examine them through the performance curve;
How to ensure the duct fan What about the rationality and economy of the selection?
1. First of all, it is necessary to clarify the nature of the gas to be transported (whether the gas is clean, whether it is high temperature, whether it is flammable and explosive, etc.) and the required wind pressure and air volume range to determine the type of fan ;
2. After the selection calculation is completed, a certain margin can be added according to the requirements to determine the maximum air volume and air pressure, and refer to the selection table for selection;
3 .To determine the actual wind pressure, it needs to be converted into the wind pressure under the experimental conditions according to the pipeline conditions and Bernoulli equation;
4. According to the actual air volume and experimental wind pressure, determine the corresponding type of duct fan model, and select the fan in the high-efficiency area through the performance curve.
In addition to the above principles and requirements in the selection of duct fans, some applications of ventilation and dust removal have been added in the process of conveying or exhausting. Calculating the relevant air volume is a relatively complicated process. It also requires that the design of the pipeline must be reasonable. If the two are properly matched, it is possible to make the pipeline fan more reasonable and more economical.
Circular Duct Fan Installation
Circular Duct Fan Installation Step 1: Check the Foundation
First check the external dimensions of the foundation and the dimensions of each reserved cavity; the deviation of the external dimensions of the foundation should be within ±20mm and the size deviation of each reserved cavity should be within ±10mm; Based on the base point of the main powerhouse building or the vertical and horizontal lines of the boiler.
Installation step 2 of circular duct fan: chisel foundation and rough positioning
Place the anchor bolts and shims to be thick and put them below, shims It should be placed at the main stress-bearing platform of the equipment and the vertical reinforcement of the machine frame or on both sides of the anchor bolts. Of course, the anchor bolt holes should be made as far as possible without affecting the secondary grouting; note that the manufacturer’s installation marks are usually “A” and “B” ” No. 1, please pay attention to distinguish the relationship with the inlet and outlet air ducts and the rotation direction of the impeller before placing them in place.
Circular duct fan installation step 3: fix the anchor bolts
Insert the bell mouth of the collector into the impeller and fix it with iron wire, then turn the whole Hang the group into the predetermined position; install the anchor bolts, the bending degree of the anchor bolts should be ≤L/100 (L is the length of the anchor bolts), and the bottom end of the anchor bolts should not touch the bottom of the hole and 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 to fix the lower part of the current collector and the lower half of the casing with bolts to preliminarily adjust the gap between the impeller and the bell mouth.
Installation step 4 of the circular duct fan: fan rotating group
The perpendicularity between the main shaft of the fan and the bearing seat is corrected as follows: The seat is attached to the main shaft, and the dial indicator is pointed to the outer ring of the bearing or the end surface of the spring position of the bearing seat (that is, the processing surface of the upper end cover). The value is the vertical condition of the housing and the main shaft.
Adjust the coaxiality between the fan and the motor shaft (that is, the leveling of the coupling). Use three dial indicators for alignment, two in the axial direction and one in the radial direction; each disk moves at 90 degrees, record the data, measure the readings of its upper, lower, left, and right, and adjust the coaxiality to make the error ≤0.05mm; and the two backrests There should be a 10mm gap between the wheels. After alignment, review some data such as shaft height and make records.
Circular duct fan installation step five: install the air intake box
Install the air intake box and the inlet to adjust the damper door and the rest of the fan, adjust the damper The plate rotates flexibly, otherwise it should be rotated with lubricating oil until the rotation is flexible before installation; the blade plate should be fixed firmly during installation, and there should be sufficient expansion gap with the outer casing; the adjustment operating device should be flexible and correct, with consistent movements, and the opening indicator mark is consistent with the actual Consistent; pay attention to the opening direction, do not install it in reverse, and the intake direction is the same as the rotation direction of the impeller.
