The operation mode in which two or more centrifugal fans inhale from the same intake pipe or intake chamber and supply gas to a common pipe at the same time is called parallel connection of centrifugal fan. In fact, in the process of using two fans to run in parallel, the influence of the same model on the parallel operation is different. Next, we analyze and discuss this problem.
Firstly, if the model of the two parallel centrifugal fan equipment is the same, the method can be obtained according to the parallel characteristic curve of the centrifugal pump when the parallel connection is carried out, The characteristic curve of the fan in parallel is obtained by the graphical method. It can be seen from the analysis that the air volume and the wind pressure in the system are increased after the parallel connection. However, after the parallel connection, the air supply of each machine is less than that of one fan.
However, when the two centrifugal fans of the same model are connected in parallel, the wind pressure of each fan is larger than that of the single fan. It can be seen that, after parallel connection of two fans of the same model, the total air volume is not twice that of the single fan when the single fan operates independently, but less than twice. After parallel connection, the air volume does not reach the air volume of one fan.
It is noted that, after the two models of centrifugal fans are connected in parallel, the increase in the actual air volume of the two models is often directly affected by the steepness of the characteristic curve of the fan pipeline system. In general, that steeper the characteristic curve of the pipeline system, i. e. the greater the impedance, the smaller the air volume increase after parallel. On the contrary, the larger the air volume is added. Therefore, in order to increase the air volume, the parallel connection is used, which is used in a system with less resistance to the pipeline, otherwise, the parallel connection can not be calculated.
There is another case, that is, two different types of centrifugal fan equipment in parallel, such as a large, one small two fans in parallel, although the small centrifugal fan is also in operation, but can not transport gas at all, in fact, the gas only in the fan internal rotation and heating, only the big fan in the system to transport gas.www.jnblower.com