Axial dispersion and dispersed phase hold-up characteristics of a reciprocating plate extraction column in which six different plate arrangement have been investigated.
The effects of plate shape in terms of various amplitude, frequency, dispersed and continuous phase velocities on axial dispersion coefficients and dispersed phase holdup have been determined.
In this experiments, 10.16 cm-ID QVF glass column was used as a main column. Reciprocation of plate stack was provided by a 1 HP D.C. motor which coupled to a speed controller and an adjustable yoke. The free opening area fractions of the perforated plate is 0.602 and that of fan plate is ranged from 0.285-0.796. Axial dispersion coefficient has been determined by the color change method and the flow patterns are observed visually.
Dispersed phase holdup has been determined by cutting off the inlet lines of continuous and dispersed phase as the average holdups in the column.
The axial dispersion coefficient were correlated in terms of $A^2f$ which has the same dimension of dispersion coefficient. The minimum value of $A^2f$ increased with increase in free opening area fraction of plate.
Dispersed phase holdup increased with the continuous phase velocity but it was relatively insensitive to changes in the dispersed phase velocity. Dispersed phase holdup decreased with an increase in free opening area fraction of plate.