The exhaust volume of a centrifugal fan is usually related to its air volume. Many users will find that the air volume is insufficient when using the centrifugal fan, and some users’ centrifugal fans have a smaller air volume after a period of use, which is the reason for this situation. There are many aspects, what should I do if the air volume of the centrifugal fan is small?
1. The reason for the small air volume of the centrifugal fan
1. There is a problem with the piping system
The installation method of the duct system of the centrifugal fan will affect the air volume, and the sealing quality of the installation will also affect the air volume. If the actual value of the fan duct system is too different from the design value, or if there is damage and air leakage, the air volume will be reduced.
2. Fan failure
It is very common for centrifugal fans to reduce the air volume after long-term use. The main reason is related to the clearance of equipment parts and transmission belts. The gap between the parts in the centrifugal fan becomes larger, which will cause idle travel during the transmission process, or even air leakage, thereby reducing the air volume; another situation is that the air inlet of the fan is blocked, which will also lead to a reduction in the air volume. ; At the same time, when the use time of the centrifugal fan drive belt increases, there will be looseness, which will cause the belt to slip and reduce the air volume of the fan.
3. Inaccurate selection
When designing and selecting centrifugal fans, it generally needs to be carried out according to the actual use and demand. It is recommended to use the pre-sales technical service personnel of the centrifugal fan manufacturer to measure and calculate the parameters on site. Then proceed to the selection of the fan. In addition, because the piping system of the centrifugal fan will directly affect the wind pressure and flow at the inlet and outlet of the fan, if the design is unreasonable, the actual air volume will be smaller than the demand.
2.the solution for the small air volume of the centrifugal fan
1. Correct selection
The selection of centrifugal fans is particularly important, especially the parameters in the early stage, which will affect the subsequent use of the fan. Generally, users are required to provide accurate production air volume and air exchange volume, etc., and then set aside the excess amount of fan selection according to actual needs, so as to ensure that the air volume and air pressure can meet the requirements of use.
2. Reasonable design of piping system
The design of the centrifugal fan pipeline system should be carried out according to the manufacturer’s recommendations. Generally, non-straight pipelines need to have fluid guiding modules such as baffles, so as to prevent excessive pressure in the pipeline. In addition, the length of the duct should also be designed according to the size of the centrifugal fan outlet.
3. Regular maintenance and overhaul
The utilization rate of centrifugal fans in enterprise production and indoor ventilation is very high, and high-frequency use requires high-frequency maintenance and overhaul. Regularly cleaning the inside of the pipeline and the fan is an important method to prevent the centrifugal fan from being blocked. At the same time, regular adjustment and replacement of wearing parts are also an important means to ensure the normal operation of the centrifugal fan.
3.the adjustment method of increasing the air volume of the centrifugal fan
The air volume of some centrifugal fans is small and can be adjusted according to the actual situation. There are generally two adjustment methods: one is to increase the fan speed while keeping the characteristics of the fan piping system unchanged; the other is to directly adjust the piping system. . The principles of the two adjustment methods are as follows:
1. Centrifugal fan speed adjustment
Increasing the rotational speed of the centrifugal fan generally does not cause additional energy loss and is more economical. If a motor that cannot be changed in speed is used, it is only necessary to install a speed change device between the motor and the centrifugal fan. When the rotational speed of the centrifugal fan increases, its pressure, air volume, and power will change, and the direct performance is the increase in air volume, which can meet the air volume requirements of the piping system.
2. Adjust the centrifugal fan piping system
When the pipeline system is used for adjustment, a device such as a throttle valve or a plug board can be set in the centrifugal fan pipeline, and the opening degree of the throttle valve and the plug board can be adjusted according to the needs. When the opening degree is large, the air volume of the centrifugal fan will naturally increase, but At the same time, the pressure will be reduced, so it is necessary to determine whether to use this method according to the production demand.