Boiler centrifugal draft fan is designed as a part of industrial boiler (1-20tons/hr) burning various coals and equipped with smoke prevention and dust control devices. It can be used for boilers of similar inlet condition and proper performances, but the temperature shall not exceed 250C, the medium of fan is flue gas.
Installation and use:
The centrifugal fan is equipped with an integral base, and the user does not need to make a self-installation foundation. When installing, the user only needs to place the fan on the ground as a whole, and after adjusting the level, fix it with anchor bolts. Users can also choose the special shock absorber of our factory, and put the whole fan on the horizontal ground through the shock absorber, without the need of anchor bolts, easy to install and adjust.
When the fan is used, the flow is too large and insufficient. This is mainly due to inaccurate calculation of pipe network resistance or changes in pipe network resistance. If the flow is gradually reduced over a long period of time during use, or suddenly decreases in a short time, it is mainly due to pipe network blockage.
After the new installation of the fan, the flow is too large or insufficient when the operation is officially performed. The main reasons are as follows:
1. The actual value of pipe network resistance is too different from the calculated value. According to the general pipe network characteristic equation: P=KQ2, if the actual value of the pipe network characteristic coefficient K is less than the calculated value, the flow rate increases: if the actual value of K is greater than the calculated value, the flow rate decreases.
2. When selecting, the influence of the total pressure deviation ΔP of the fan itself is not considered. When the actual full pressure of the fan is positive deviation, the flow rate increases: when the actual full pressure of the fan is negative deviation, the flow rate decreases.
When the flow rate of the centrifugal fan is deviated, it can be eliminated by the following methods:
1. Use a throttling device to regulate flow. Such as by adjusting the damper or adjusting the door.
2. Change the speed of the fan impeller to adjust the flow.
3. Replace the fan with higher or lower pressure to regulate the flow.
4. Change the pipe network resistance to adjust the flow.
It must be pointed out that throttling devices are generally used to regulate the flow of the fan. But when the actual flow is much larger than the required flow, this method wastes a lot of power and is uneconomical. Fans with reduced fan speed or low exchange pressure are usually used if conditions permit.
When the throttling device is fully open, the flow rate is still too small. At this time, the throttling device has lost its function. Therefore, the pipe network should be changed to reduce the resistance to increase the flow. It is also possible to increase the speed of the fan impeller or to change the pressure of the fan. However, the maximum speed of the fan must not exceed the maximum speed on the performance meter and the motor power must be accounted for.