During normal operation of roots blower, if the vibration value exceeds the specified technical requirements, specific analysis shall be carried out according to the vibration characteristics to determine the cause of vibration.
The working feature of Roots blower is that there is always a small gap between the impeller end face and the front and rear end covers of the fan, as well as between the fan impellers. Driven by the synchronous gear, the air is transported from the fan inlet to the exhaust side along the shell wall, causing intermittent and periodic changes in the suction and exhaust, and the gas in the pipe is pulsating. Gas parameters in the pipe, such as pressure, velocity and density, constantly change with the position and periodically change with time. This phenomenon is called gas pulsation.
When pulsating gas encounters elbow, reducer, control valve and other components, it will generate exciting force varying with time. Under the action of this exciting force, the pipeline will vibrate. The vibration source of pipeline vibration is mainly the pressure pulsation of the gas in the pipeline. Since the pressure pulsation always exists, it is normal for Roots blower to vibrate to some extent within the allowable range, but severe vibration should be avoided, otherwise the pipeline may be damaged.
1. Design reason: Roots blower is generally designed according to the use environment, temperature, air volume, air pressure, medium, etc. of the fan, while some enterprises that select Roots blower are not completely based on these factors, resulting in the following factors: improper fan design, poor dynamic characteristics, and vibration during operation; Unreasonable structure and stress concentration; The design working speed is close to or falls into the critical speed zone; Inaccurate calculation of thermal expansion leads to poor thermal alignment.
2. Manufacturing reason: the quality requirements of the manufacturer on the fan also affect the operation of the fan, such as poor processing and manufacturing of parts and insufficient precision; Poor material, insufficient strength and manufacturing defects of parts; The rotor dynamic balance does not meet the technical requirements.
3. Reason for installation and maintenance: The installation accuracy requirements of roots blower play a vital role in the operation of the blower. If the installation accuracy does not meet the installation requirements, it will play a destructive role in the operation of roots blower. In the process of fan installation, mechanical installation is improper, parts are misplaced, and preload is large; Poor shaft alignment; The fit clearance, interference amount and relative position of the machine are adjusted improperly; The rotor is improperly placed for a long time, which changes the dynamic balance accuracy; The original matching property and precision of the machine were damaged due to the failure to carry out maintenance according to regulations.
4. Operation reason: during the use of roots blower, the quality of fan maintenance plays a decisive role in the operation quality of roots blower. The process parameters deviate from the design values, and the operating conditions of the machine are abnormal; The operation of the machine at over speed and over load has changed the working characteristics of the machine; Poor lubrication or cooling; Partial damage or scaling of rotor; Inappropriate operation during startup and shutdown or speed increase and decrease, uneven thermal expansion or too long stay in critical area.
5. Reasons for machine deterioration: General equipment has a certain number of years in use, and the performance of equipment will deteriorate after reaching a certain number of years. The same is true for Roots blower. For long-term operation, rotor deflection increases or dynamic balance deteriorates; The rotor is partially damaged, fallen off or cracked; Wear, pitting or corrosion of parts; The force on the mating surface deteriorates, resulting in insufficient interference or looseness, which destroys the mating property and precision; The machine foundation settlement is uneven, and the machine shell is deformed.
I believe that after reading the above, you should also understand the reason for the vibration of Roots blower. I hope it will be helpful to you.
Text term label: Roots blower
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