Regarding the issue with starting the main fan?
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After the main fan starts up, there are significant fluctuations in its operation during the process of adjusting the air valves; the current levels fluctuate as well, and the sound produced seems to indicate that the airflow is not smooth. After inspection, the valve is fine. What could be causing this issue?
There must be a surge zone; the valve passes through this condition during its opening process. Quickly adjusting the valve should resolve the issue, just my opinion!
If it is indeed surge, then the bracket design is unreasonable. Fans are dynamic equipment that require dynamic analysis.
Hehe, it only occurs when the fan starts up, during the process of opening the damper. If the fan can operate normally after the damper is opened, it means there are no issues with the mechanical and electrical components; therefore, resonance must exist at a specific point, and it’s sufficient to get past that point quickly. Just my personal opinion!
The phenomenon you described does not occur even during the startup of the fan; if surge were to happen, this would indeed take place, but it would be accompanied by significant vibrations and a dull humming sound. You can conduct a single-unit test to see if this phenomenon occurs before proceeding with further analysis
This post was last edited by I Live by the Xiangjiang River on 2012-4-19 at 21:50. We encountered this situation; it happened when the system was started up after a major repair. After the main fan began to operate, it made an abnormal noise, similar to the sound of an ox, and that noise gradually disappeared by the next day. Later, we analyzed that during the major repair, the access hatches at the top and bottom of the fiber mist eliminator in the suction tower were opened. Due to the high temperatures, the acidic sludge on the fibers of the mist eliminator dried out, which reduced the size of the gas passages and caused poor airflow. However, once operations resumed, the acidic mist and high temperatures caused the fibers to expand, improving the airflow and eliminating the abnormal noises.
Thank you all for your kind responses. After analysis, it is believed that during startup (at line frequency), the valve opening was not adjusted properly, which led to poor flow of gas in the air duct.