Flow investigation in an innovating dynamic filtration module using tracing methods

Abstract Residence Time Distribution (RTD) experiments were carried out under laminar and turbulent regime in a complex dynamic filtration module, named Rotating and Vibrating Filtration (RVF). This filtration module dedicated to biological down steam process consists of two filtration cells in series in which a three-blade impeller rotates between two membranes. The global objective of this study is to improve filtration and overall industrial bioprocess performances: (i) to better understand the flow behavior through residence time distribution and (ii) to model and describe the RTD curves by a systemic analysis. Analytical study of distribution functions was conducted. Statistical moments were calculated and discussed. The influence of operating parameters (stirring speed N and flow rate Q f ) on the mean residence time t s was investigated. A systemic analysis led to the comparison of three models. Finally, a simple model allowing the description of the evolution of the RTD of the studied filtration module was proposed. This study is susceptible to provide useful recommendations, guidelines with the aim to identify efficient volume (functioning area), dead zone volume (dysfuntioning area), evolution of the dispersion in function of the operating conditions.