If you want to choose the right centrifugal fan and axial fan, we must first understand the difference between the centrifugal fan and the axial fan, and the matching relationship between the flow and pressure of the fan and the system, so as to accurately explain what type of fan is chosen in the condition of the centrifugal fan.
When the fan is selected, first of all, according to the two basic parameters of the fan's air volume and full pressure, the type and number of the fan can be determined by the factor table of the fan's factor. At this time, more than one product may meet the requirements. Then, the type and machine of the fan is selected, and the type and machine of the fan are selected. Type and structure material to meet the required working conditions, and strive to make the rated flow and pressure of the fan as close as possible to the flow and pressure required by the process, so that the operating point of the fan is close to the high efficiency area of the fan's characteristics.
The working principle of the fan is basically the same as that of the turbine compressor. Only because the gas flow velocity is low and the pressure changes little, it is generally not necessary to consider the change of the gas specific volume, that is, the gas is treated as an incompressible fluid.
Fans are widely used in factories, mines, tunnels, cooling towers, vehicles, ships and buildings, ventilation, exhaust and cooling; ventilation and ventilation of boilers and industrial furnaces; cooling and ventilation in the air conditioning equipment and household appliances; the drying and selection of grain; wind tunnel wind and air cushion ships inflating and propulsion.
The difference between the centrifugal fan and the axial fan: the centrifugal fan is the axial air inlet, the radial air outlet, the use of centrifugal force (depending on the speed and the outer diameter) to make work, so that the air increases the pressure. Therefore, under the same shape size (and speed), the pressure is greater than the mixed flow and axial fan; and the air volume is less than the mixed flow and axial fan. Axial flow fan is axial wind, axial wind, through the angle of the blade, using the thrust (Sheng Li) to do work, so in the same shape size (and speed), the pressure is far smaller than the centrifugal fan, and under the axial structure, the overflow area is far larger than the centrifugal fan, so the air volume is larger than the centrifugal fan;
2, in the selection, we should consider the structure and system resistance of the system and the internal characteristics of the fan (pressure, flow, speed). If the system resistance is large and the size of the structure is small, the centrifugal fan should be chosen, because the flow of the fan is first in the condition that the pressure is produced to overcome the resistance of the system. Air volume; for cooling, the air volume (flow rate) is enough, and the more air volume will make the fan consume the invalid energy; reduce the engine efficiency; if the system resistance is small and the structure is large, the axial flow fan should be selected; because the low pressure produced by the axial fan is enough to overcome system resistance, so A large amount of wind can be discharged; the last thing to pay attention is: when the fan is working, if the pressure of the fan can not overcome the system resistance, the wind volume is zero; in this condition, the fan is doing useless work.