What are the adjustment methods of centrifugal fan for air volume? There are air inlet and outlet opening air valve size adjustment, volute line adjustment, wind wheel blade size adjustment, wind wheel angle adjustment, C-belt drive speed adjustment, or drive motor power pole number adjustment. Fans of the same model can be adjusted in multiple ways. Now many mechanical matching fans and equipment matching fans use belt-driven fans. For different types of fans, due to the different adjustment methods, the energy-saving effects obtained are very different. Big.
Inlet and outlet valve adjustment: centrifugal fan outlet valve adjustment is to change the characteristics of the pipe network, not the characteristics of the fan. The air volume adjustment range is usually in all working conditions below the fan's rated performance curve. Due to the artificial increase in the resistance of the pipe network to change the characteristics of the pipe network, the pressure drop is consumed by the additional resistance generated when the small air valve is closed. For such an adjustment, the economy is poor. Inlet air valve adjustment: When the exhaust pipe is set on the suction side of the fan, its adjustment principle is the same as that of the air valve; it changes the performance curve of the fan by changing the inlet pressure of the fan, and this adjustment is economical;
The adjustment of the volute line type: It is to change the area of the fan to change the characteristics of the fan. Compared with the reduction of the air volume, the power change is small and the energy saving is not significant. This kind of adjustment method can be used in all working conditions under the rated curve in principle, and it can shift the surge point to the direction of small flow. Therefore, it is widely used in fans with fixed speeds, and it is also suitable for those that have been purchased. The user of the fan is more troublesome, so it is not recommended to adjust the air volume through this change method.
The adjustment of the size of the impeller blade: by changing the size of the blade, the direction of the airflow sucked into the impeller is changed, and the performance curve of the fan is changed. The positive spiral adjustment of the inlet airflow of the fan can realize all the working conditions below the performance curve when the angle of the inlet guide vane is zero degrees; and the adjustment of the size of the inlet airflow can increase the total pressure and air volume of the fan, but the adjustment range value has a certain limit . Because the blade adjustment of the wind wheel has a wider adjustment range and higher economy, it is widely used by wind turbines. (Change the size and angle of the impeller blades to the same type)
C. Speed adjustment of belt drive: Some fans with direct motor connection can be transformed into bearing seat link and belt drive when the impeller strength is satisfied. By adjusting the speed, the fan's work efficiency can be increased. This method is generally Mechanical matching fans and equipment matching are widely used, because every project, construction site, pipeline length, size, site environment, there are many restrictions, and the adjustment of mechanical equipment filtration methods, for belt-driven fans, The audience range is wider, and the speed of the fan can be adjusted according to the situation on the spot, so as to achieve the desired effect.
Adjustment of the number of poles of the drive motor: If the motor of the same power is installed because the effect is not obvious or the effect exceeds the budget range value, if the fan uses a 4-pole motor (1450 speed), and the strength of the impeller has been analyzed, you can Adjust to 2 poles: 2800 speed. To increase, increase the fan's air flow rate and fan static pressure. When it is adjusted to 6 poles (speed 960), reduce the fan static pressure and fan flow.