Selection principle of centrifugal fan:
1. Good adjustability
The ventilation and dust removal network requires the performance curve of centrifugal fan to be flat, but the pneumatic conveying network requires the performance curve to be steep. In the process of conveying materials in the pneumatic conveying system, when the conveying capacity changes, the network resistance will also change greatly. The centrifugal fan with a steep performance curve can make the air volume change little when the resistance changes. Therefore, it is necessary to select equipment with better adjustability in combination with its own production scenario requirements.
2. The working point should be in the high energy efficiency area
When selecting centrifugal fan, on the premise that the air volume and pressure of the fan meet the requirements of the air network, the working point should be set at a better efficiency or economic and practical range. Under normal circumstances, the efficiency of the working point should not be less than 90% of the higher limit.
3. Centrifugal fan shall be low noise and environmental friendly
When purchasing centrifugal fans, low-noise machinery shall be preferred on the premise of other conditions. Under normal conditions, the peak frequency of noise is proportional to the fan speed. Therefore, under the condition of meeting the network pressure and flow requirements, try to use the centrifugal fan with relatively low speed. Generally, the fan speed should not exceed 3000 R / min.
4. The motor shall not be overloaded
Since larger highways are located at the position of rated air volume, fans with backward blades will not be overloaded. For fans with forward and radial blades, the power will increase with the increase of air volume, with a straight-line upward trend and an increasing rate. Therefore, when the forward blade fan is selected for the pneumatic conveying network, it should be noted that the material pipe cannot be emptied when the damper is opened, so as to prevent overload risk of the motor.
5. Matching of centrifugal fan with the gas conveyed
There are various types of centrifugal fans on the market, and the application scenarios are also different. Therefore, it is necessary to select equipment with matching gas properties. For example, if the dust concentration in the air is high, it is necessary to choose a dust exhaust fan with anti-wear blades and not easy to accumulate dust. If the fan is matched with a dryer, a high-temperature resistant centrifugal fan is more suitable.
