Energy consumption of the flow in pulsed extraction columns with internals of discs and rings (doughnuts)

This paper deals with determination of energy consumption due to pressure drop in pulsed extraction columns with internals of discs and rings (doughnuts). While the common approach assumes equality of a pulsed flow with a given mean velocity to a permanent flow with the same velocity, here the periodical flow velocity pattern is taken into consideration. It is shown that the energy consumption in case of a pulsed flow is different and quite larger than that of an "equivalent" permanent flow, and should be accounted for the sake of a more precise column design. A correlation for determination of energy consumption in case of sinusoidal periodic pulsed flow is proposed, which reflects the influence of mean flow velocity and geometry parameters (plate free area and interplate distance). Its reliability is checked by comparison of calculated results and experimental data.