What happens when the frequency of Roots blower is changed?

What happens when the frequency of the boiler return Roots blower changes?

The boiler return fan, also called boiler fluidization fan, is mainly used for fluidizing furnace ash and transporting ash back to the furnace for secondary incineration. What will happen if we change the motor frequency of Roots blower due to working conditions? Will the air volume increase or decrease? Does the pressure increase or decrease?

1. Air volume change

If the frequency of Roots blower motor changes, the air volume of the fan will become larger. In unit time, the speed of the fan will increase, and the air delivered will increase, which should be well understood.

2. Pressure change

Knowing the children's shoes of Roots blower, we should all know that Roots blower is a positive displacement fan, and the change of pressure depends on the back pressure, that is, the pressure of the front pipe. If the pressure of the front pipe changes, the pressure gauge display of Roots blower will change.

Note: The main function of the pressure gauge of roots blower is to present the current pressure. If the rated pressure of roots blower is 16kpa, the pointer of the pressure gauge will be 16kpa. If we find that the pointer number of the pressure gauge is 20kpa because of some actions, this does not mean that the pressure bearing capacity of roots blower has reached 20kpa, nor does it mean that the pressure of roots blower has increased by 20kpa, It means that Roots blower has overpressure! The difference between boiler combustion supporting roots blower and boiler centrifugal induced draft fan!

3. Change frequency, change pressure

Some friends found that the fluidization amount increased and the pressure also increased when changing the frequency of the boiler return fan? What's going on here? It is necessary to check the problems of the boiler, such as whether there is ash deposition. If the frequency changes, the boiler has ash deposition, the more ash deposition in a unit time, the more obvious the pressure change of roots blower, which is equivalent to the blockage of roots blower pipeline. Operating principle of the return Roots blower on the boiler!

The above picture is a picture sent by a friend in the boiler industry. We can see that the fluidization fan in the above three pictures has obvious dust, and it can be seen that it has not been cleaned for a long time. What problems will occur in this case?

First of all, the inlet silencer is blocked. If the blockage is serious, you should be able to feel the obvious air volume drop of the fan;

Secondly, there should be some wear inside the fan. The internal leakage of the fan will increase and the air volume will decrease to a certain extent, which is one of the reasons why the friend needs to adjust the frequency.

Finally, the service life of the fan will be greatly shortened. The fan that could have been used for 10 years may be repaired in less than 5 years. Why use more Roots fans and less centrifugal fans for boiler air supply?

If you have any questions about the purchase of Roots blower, you can contact our official customer service hotline. Luo