Fan startup
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When the booster fan starts at power frequency, is it necessary to close the inlet damper door? Can it start under load? Are there any relevant regulations?
There is probably no specific rule for this, but as a general practice, one closes the inlet, starts the fan, and then opens the inlet again
It is generally not recommended to start the motor under load, as this can damage the motor.
Why is the outlet of the fan here closed? It should be opened after it starts up
Doing this may cause the motor to burn out.
Let me explain the situation here. The fan in our system is used to supply air to the boiler. I noticed that when the fan starts, the inlet damper is usually open, while the outlet is closed; it becomes open after the fan starts, just like with centrifugal pumps. I’m not sure if this refers to the same type of fan you’re talking about I took a look; this current increases as the outlet is opened wider
The booster fan I have is used to draw air from the coke oven and send it to the adsorption tower for desulfurization and denitrification. When purchasing the fan, it was specified that it would start at power frequency; can this power-frequency starting be understood as starting under load?
I’m not familiar with this term yet; as a beginner, I wouldn’t speak casually if I didn’t understand it. If you do understand it, please tell me. Thank you
Large centrifugal fans have extremely high starting torque, and the motors involved exhibit very high starting currents. In fans that do not have speed control, the air flow is regulated by closing the inlet dampers; starting such fans with the inlet dampers closed is equivalent to starting a pump with its outlet valve closed, in other words, operating it under no-load conditions.
Start the fan and close the inlet baffle. Starting with the inlet baffle open can easily cause the motor to overload and get damaged. Turning off the outlet damper to start the fan is a very energy-inefficient way of regulating. It also easily causes the fan to enter the surge zone.