Schematic of the batch centrifuge separating two immiscible fluids

Schematic of the batch centrifuge separating two immiscible fluids 

A force balance equation for a fluid in the rotating bowl rotating at angular velocity, w leads to pressure gradient equation given below 

Integrating this equation provides an equation for pressure P exerted by the liquid on the walls of the bowl of radius R when the radius of the inner surface of the liquid is ro as 

The retention time, C for the mixture with feed rate equal to Q is given by 

In practice the relative values of rt and r, are adjusted to modify the relative residence times of the individual phases to give extra separating time for the more difficult phase. 

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