The Efficiency Coefficient of Vertical Gravitational Separators

Consider the separation of liquid from gas in a vertical gravitational separator where the flow is directed against the force of gravity. Obviously, the drops that reach the exit of the separator will be the ones that satisfy the inequality Uj U , where Uj is the sedimentation velocity of a drop with the radius R, and is the flow velocity, which is assumed to be constant. The minimum size of drops is determined from the condition Uj = U . Let us invoke the expression (18.28) for velocity Ug. Then in order to determine the minimum drop radius, one should solve the following equation  

A comparison of equations (18.31) and (18.42) for the rninimum drop radius in horizontal and vertical separators shows that if the equality U /Uj(. = D/,/D holds (here the bottom indexes v and h correspond to the parameters of horizontal and vertical separators), then, all other things being equal, the minimum radii of drops in both separators coincide. But this certainly does not mean that their CE s should be the same, because the ratio of liquid phase volume concentrations at the exit of the two separators is 

If we take (14.1) as the initial distribution and consider it to be uniform at the entrance, the CE of a vertical separator can be represented as 

The growth of drops in the flow can also occur due to condensation, but this can only happen in the absence of phase equilibrium. It was shown earlier that phase equilibrium develops much faster than dynamic equilibrium. Therefore, condensation-driven growth of drops in the separator is only possible if the DPC is located in the immediate vicinity of the separator, for instance, directly at the entrance. 

Later on we shall be estimating the effect of drop coagulation and condensation on the value of CE. 

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