EDDY-DIFFUSION COEFFICIENT IN VALVE TRAY DISTILLATION COLUMNS.

For determining the number of trays required for tray distillation towers, tray efficiency must be known. There is a correlation between Murphree point efficiency and tray efficiency, depending on the material system and the extent of liquid mixing involved in the process. For establishing the extent of liquid mixing, the eddy-diffusion coefficient must be known. Since there is some weeping in valve tray columns of a rate depending on tray design, the correlation proposed for static trays does not apply to valve trays. A correlation has been elaborated for calculating the eddy-diffusion coefficient. Evaluation of the test results was made on a model allowing for weeping. This correlation has proved to be suitable for determining the effective number of trays required for tray distillation columns with a fair accuracy.