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@Hussein Barakat • 09 Jan, 2010
effect of reversing the centrifugal pump impeller rotation ????

What will happen if we reverse rotation of the centrifugal pump impeller [c.w] <===> [c.c.w]?
And the effect on head [pressure] and discharge?
@Rohan_sK • 10 Jan, 2010 • 2 likes There is a big difference between the terms "Reverse Rotation" and "Reverse Flow" related to the Centrifugal Pump.

Reverse Rotation means that the direction of the rotation of the Impeller is reversed. This may be caused by the reversal of the direction of the driving motor by the reversing of the wiring connections.

In this case there will be no difference in the Operation of the Pump principally. That means the Pump would still continue to deliver the fluid from the low pressure suction side to the Higher Pressure Delivery side in the positive direction of flow.

But the fact is that the flow would not be generating the flow characteisitcs and parameters according to the original design. The flow would certainly be forward directed but there will be jamming in the flow and pressure heads would drastically change affecting the discharge.

This is actually happenig because of the original design of the Invollute Casing of the pump and the location of the Discharge tube. The Volute casing and Discharge tube are designed and located according to " the Direction Of Rotation Of the Pump" which is pre determined for a particular design.

The Impeller type used ( open flow, closed, mixed type) and the Volute Casing designed as per the original pump specifications will be responsible for the actual type of discrepancy in the pressure head and the flow characteristic observed and will vary from pump to pump.

But certainly the changed flow pattern ( though forward directed) will reduce the efficiency and cause bubbling etc. in the flow chamber eventually affecting the eficiency of the pump and reducing the discharge. There may be cavitation observed in the larger sections of the volute chamber and the pressure head will be affected accordingly.

But as far as the Basic Pumping action is considered the Pump would still continue to pump the fluid in the Positive Discharge Direction.
@Hussein Barakat • 10 Jan, 2010 Thanks [Rohan_sK], yes i meant "Reverse Rotation"
Thanks again ....... 😀
@vibhor_one • 16 Jan, 2010 nothing more required roshank nice explaination....
@paw1 • 27 Mar, 2010 Hi, (new here)

Just one question, why, while designing the impeller, was the direction of rotation (relative to the involute) chosen as it is? It obviously has to have some advantage over designing the pump for a reverse rotation.
@Mahesh Prakash Palav • 19 Aug, 2015 thank u so much sir.......

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