Change in the medium transported by the centrifugal pump
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When the medium transported by a centrifugal pump changes from methanol to water, what considerations should be taken to ensure that the motor is not damaged due to high power consumption? If the methanol flow rate when a pump is operating normally is 160 M3/H, with a designed maximum of 185 M3/H, what is the maximum water flow rate?
Water should be used when the pump is undergoing performance tests, with the manufacturer required to achieve the specified flow rate and head. I believe that when the medium is water, the flow rate and head can reach those achieved with methanol, and the motor will not be overloaded.
A centrifugal pump capable of handling methanol should have no problem pumping water; the molecular weight of methanol is much higher than that of water, so it is possible to pump a much larger volume of water with it compared to when using methanol.
That’s not the case; the specific gravity difference between the two mediums isn’t very large – water has a specific gravity of 1, while methanol has a specific gravity of 0.79； If it is changed to pumping water, both the pump flow rate and head will decrease
If the density of the medium changes, the flow rate and head will not change. It’s just the shaft power that changes; once it turns into water, the magnitude of the shaft power is calculated to determine whether the motor can handle it.
By converting the density, check whether the shaft power is excessive.