What are the general failures of the fan

Update:14-11-2020
Summary:

With the development of science and technology, it has […]

With the development of science and technology, it has become more widely used in various industries, and it is inevitable that the fan will vibrate during use, and a series of problems will follow. Generally speaking, there are the following:
1. Design reason: The design of the fan is generally based on the use environment, temperature, air volume, wind pressure, medium, etc. of the dedicated fan. Some companies do not select the centrifugal fan based on these factors, resulting in the existence of The following factors: improper fan design, poor dynamic characteristics, vibration during operation; unreasonable structure, stress concentration; design working speed close to or falling into the critical speed zone; inaccurate calculation of thermal expansion, resulting in poor thermal alignment.
2. Manufacturing reasons: The quality requirements of the fan manufacturers also affect the operation of the fan, such as: poor parts processing and manufacturing, insufficient precision; poor parts material, insufficient strength, manufacturing defects; rotor dynamic balance does not meet technical requirements, etc.
3. Reasons for installing and repairing the fan: The installation accuracy requirements of the fan play a vital role in the operation of the fan. If the installation accuracy does not meet the installation requirements, the operation of the new fan will be damaged. During the installation of the fan, there are the following influencing factors, such as: improper mechanical installation, misalignment of parts, large preload; poor shaft alignment; improper adjustment of machine geometric parameters (such as fit clearance, interference, and relative position); The improper placement of the rotor for a long time has changed the accuracy of dynamic balance; failure to check and repair according to the regulations has destroyed the original matching properties and accuracy of the machine.
4. Reasons for operation and operation: During the use of the ventilation cooling fan, the maintenance and maintenance of the fan plays a decisive role in the operation quality of the fan. Such as: process parameters (such as medium temperature, pressure, flow, load, etc.) deviate from the design value, the machine operating conditions are abnormal; the machine runs at excessive speed or overload, which changes the working characteristics of the machine; poor lubrication or cooling; Partial damage or fouling of the rotor; improper operation during start-up and shutdown or speed-up/down, uneven thermal expansion, or staying in the critical zone for too long, etc.
5. Reasons for machine deterioration: General centrifugal fans and axial fans have a certain number of years in use, and the performance of equipment will deteriorate when they reach a certain number of years. The same is true for fans, such as: long-term operation, the rotor deflection increases or the dynamic balance deteriorates; the rotor is partially damaged, peeled off or cracked; parts are worn, pitted or corroded, etc.; the mating surface is stressed and the interference is insufficient Or loosening, etc., destroying the matching properties and accuracy; the machine foundation has uneven settlement and the machine shell is deformed.

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