How to avoid reverse flow of wear-resistant centrifugal pump?

In fact, the operation process of wear-resistant centrifugal pump is not very complicated, but it only needs to be used correctly. Even with the help of instructions or professionals, there will always be some problems that they cannot help. This requires us to constantly understand new content and solve new problems in the process of use, so as to better use the equipment.
The centrifugal pump can only discharge water when it is above 30-35Hz, because the higher head of the pump's performance curve must be greater than the net head of the pump, or the working head of the wear-resistant centrifugal pump running in parallel, and this frequency corresponds to the lower frequency of the variable frequency operation of the pump.
When the frequency is below very low frequency, the wear-resistant centrifugal pump does not produce water and has no effective power output. Its loss is only the no-load loss of the pump. Therefore, the current and power of the motor are very small. At this time, the efficiency of the pump drops to a lower value.
Once the operating frequency is higher than the lower frequency, the flow of the wear-resistant centrifugal pump after water discharge must overcome the resistance of the pipe network on the one hand and the net head on the other. Therefore, the pump power and motor current increase significantly, with a sudden jump, and then continue to increase with the increase of frequency.
Since the variable frequency pump always has a flow, there is no phenomenon that the flow of the power frequency pump flows back to the variable frequency pump. In the actual project, the pipeline is also equipped with a check valve. If the frequency of the frequency converter is lower than a lower frequency, the variable frequency pump does not discharge water, and the check valve automatically closes to prevent water from flowing back.

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