Hydrodynamics and rupture of drops in a disc and crown pulse column

This work relates to the analysis of the operation of a pulse column with discs and crowns, a packing which is currently used; however, no information is available on the hydrodynamic mechanisms involved in this type of packing, so is the reason for this study. The main role of packing in a pulverized column is to create flow conditions such that the larger drops of the dispersed phase are broken. The coalescence mechanisms are thus thwarted so as to maintain a good distribution of the phase dispersed throughout the column. The study thus focused on the mechanism for breaking drops in a disc and crown pulse column, the first part of this memoir. To analyze the rupture mechanism, it was necessary to measure the power consumed to pulse the column. This aspect of the work is reported in an appendix. Secondly, the author tried to relate the drop breaking phenomenon to the hydrodynamic conditions prevailing in the column; this led to carry out a study of the instantaneous velocities in the column, using a laser anemometer. This work constitutes the second part of the memoir. It resulted in a model giving the instantaneous force exerted on the piston, during the pulsation. This model involves in particular pressure loss laws which have only been identified on a limited number of experiments; it would be interesting to extend the experimental domain, by studying the evolution of these laws. This model shows the role of the various constituent elements of the pulsation device and can be used to optimize this part of the installation. Finally, it allows to calculate in a precise way, the power consumed by the column.