The company has a centrifugal fan; every time it is turned on, the outlet is opened while the inlet remains closed. Why is that?
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The company’s fans are used in the drying system; why does the shift leader ask us to turn on the outlet first and then the inlet every time it’s started?
Centrifugal fans operate with variable flow and constant pressure. It is best to start and test them without any load, that is, with the inlet and outlet dampers closed; these dampers should be gradually opened after starting, while paying attention to changes in current.
Since gas is compressible, when the inlet is opened, the outlet is closed and the fan is started, the fan compresses the gas to do work, resulting in a high starting current； This is the difference between centrifugal fans, centrifugal compressors, and centrifugal pumps.
“The team leader said that things like this are merely a transition, and this transition should not last too long. It is necessary to understand the operating principles early on to prevent violations, especially passive violations.