1. The selected control parameters of the ducted fan are air volume, total pressure, efficiency, noise, motor power, etc.
2. According to the physical and chemical properties of the conveyed gas, choose the ventilator for different purposes. If you are transporting clean air, you should choose a general ventilator; for transporting flammable and explosive gases, you should choose an explosion-proof ventilator; for transporting corrosive gases, you should choose a corrosion-resistant fan.
3. When selecting the fan type, the air leakage loss of the piping system, calculation errors, and the negative deviation of the actual air volume and air pressure of the fan should be considered. Generally, the air volume is 1.05~1.1, and the air pressure is 1.10~1.15. But it is not too large to prevent the fan from running in the low efficiency area for a long time.
4. Pay attention to the matching relationship between the pipe network resistance characteristics and the fan characteristics. In order to make the ventilator operate stably, the ventilator should be operated near its highest efficiency point. The working point of the ventilator is located on the right side of the peak point of the total pressure in the performance curve (that is, the large air volume side, and generally located at 80% of the peak value of the total pressure) ).
5. For ventilation systems that require noise reduction, first select a fan with high efficiency and low impeller circumferential speed, and make it work near the highest efficiency point. Corresponding noise reduction and vibration reduction measures should also be taken according to the propagation mode of noise and vibration generated by the ventilation system.
6. The duct fan changes the shape of the blades, so that after the air enters the fan, it has part of the axial flow and part of the centrifugal effect, so its performance is between the axial flow fan and the centrifugal fan.
7. The duct fan can provide medium wind pressure and medium air volume, and it is more suitable for the ventilation system in high-rise civil buildings.
1. The fan mounting base (foundation, hanger) should have sufficient strength, stability and durability, and the vibration of the base should meet the following requirements:
(1) The natural vibration frequency of the basic device shall not be greater than 1/3 of the speed of the motor and fan;
(2) The difference between the vibration speed when the fan is running and the vibration speed when the fan is stationary must be more than 3 times.
(2. Flexible joints should be provided between the inlet and outlet of the ventilator and the air pipe. The air inlet pipe, the air outlet pipe and other devices should be independently supported and firmly supported by the foundation or other components of the building. The casing should not bear The weight of other parts.
3. Vibration isolation measures should be taken when the fan is installed on building components.
4. The installation of the fan can refer to the following national building standard design drawings.
5. The duct fan can be installed on the straight air pipe, which has the advantages of convenient connection and small space occupation.
