Characteristics of axial fans

In many areas of the national economy, especially in the petroleum, chemical, refrigeration, power, mining, and metallurgical industries, compressors are widely used in order to increase the pressure of process gases and transport gases. Among various compressors, axial flow compressors have the advantages of high efficiency, large flow, light weight, and small size. Therefore, in large petroleum refining enterprises, the regenerator of the catalytic cracking unit requires a large amount of air and low pressure for scorching. High, most use axial compressors.

Today we come to understand the characteristics of axial fans:

(1) The influence of the temperature and humidity changes of the inlet air of the axial flow fan on the flow is in accordance with the gas state equation. In actual production, the change value can also be compared and verified by referring to the calibration data of the unit surge line.

(2) Since the axial flow fan mainly relies on the pressure expansion of the cascade to increase the gas pressure, the air attack angle is very sensitive to the performance of the cascade. In practical applications, the angle of attack of the airflow is generally changed by changing the angle of the stationary blade cascade (the so-called angle of the stationary blade), so that the air volume of the unit is changed to adjust the air volume, so as to reduce the power consumption on the premise of meeting the technological requirements. .

(3) The blade shape of the moving and stationary blades of the axial flow wind determines the stage pressure ratio and efficiency of the cascade, and determines the overall performance of the fan. At present, most of the moving and static blades of axial flow fans are designed with ternary flow, and the efficiency of the whole machine is relatively high. However, due to the high accuracy, if external interference factors cause blade damage or blade fouling, that is, if the blade shape changes, the compression ratio and efficiency of the compressor will decrease, and the fouling of the blades will also cause the operating range of the axial fan Narrowing, in extreme cases, it will affect the dynamic balance of the shaft system and cause a shutdown accident.