According to the principle that kinetic energy is converted into potential energy, centrifugal fan uses high-speed rotating impeller to accelerate the gas, then decelerates and changes the flow direction, so that kinetic energy is converted into potential energy (pressure). In a single-stage centrifugal fan, the gas enters the impeller from the axial direction, changes to the radial direction when passing through the impeller, and then enters the diffuser. In the diffuser, the movement direction of the gas is changed and the cross-section area of the pipe is increased to slow down the gas flow.

　　这种减速作用将动能转换成压力能。压力增高主要发作在叶轮中，其次发作在扩压过程。在多级离心风机中，用回流器使气流进入下一叶轮，产生更高压力。离心风机本质是一种变流量恒压安装。当转速一定时，离心风机的压力-流量理论曲线应是一条直线。由于内部损失，实践特性曲线是弯曲的。离心风机中所产生的压力遭到进气温度或密度变化的较大影响。

　　This deceleration converts kinetic energy into pressure energy. The increase of pressure mainly occurred in the impeller, followed by the expansion process. In the multistage centrifugal fan, the air flow is sent into the next impeller with a reflux device to produce higher pressure. Centrifugal fan is essentially a variable flow and constant pressure installation. When the rotating speed is fixed, the theoretical curve of pressure flow of centrifugal fan should be a straight line. Due to internal losses, the practical characteristic curve is curved. The pressure produced in the centrifugal fan is greatly affected by the change of inlet air temperature or density.

　　对一个给定的进气量，进气温度（空气密度）时产生的压力。关于一条给定的压力与流量特性曲线，就有一条功率与流量特性曲线。当鼓风机以恒速运转时，关于一个给定的流量，所需的功率随进气温度的降低而升高。

　　For a given intake volume, the highest intake temperature (lowest air density) produces the lowest pressure. For a given pressure and flow characteristic curve, there is a power and flow characteristic curve. When the blower is running at a constant speed, the required power increases with the decrease of inlet air temperature for a given flow.

　　磨损问题离心风机传动部位磨损是常呈现的设备问题，其中包括抽风机轴承位、轴承室磨损、鼓风机轴轴承位磨损等。针对离心风机上述毛病，传统维修办法有堆焊、热喷涂、电刷渡等，但均存在一定弊端：补焊高温产生的热应力无法完整消弭，易形成材质损伤，招致部件呈现弯曲或断裂；而电刷镀受涂层厚度限制，容易剥落。

　　The wear problem of the transmission part of the centrifugal fan is a common equipment problem, including the wear of the bearing position of the suction fan, the bearing chamber, and the bearing position of the blower shaft. In view of the above problems of centrifugal fan, the traditional maintenance methods include overlay welding, thermal spraying, brush crossing, etc., but all of them have some disadvantages: the thermal stress generated by high temperature of repair welding can not be completely eliminated, and it is easy to form material damage, resulting in bending or fracture of parts; while brush plating is subject to the limitation of coating thickness, which is easy to peel off.