DETERMINATION OF LOCAL PHASE HOLDUPS IN AIRLIFT REACTORS BY MEANS OF TIME-DOMAIN-REFLECTOMETRY

Airlift loop reactors are useful in many chemical and biotechnological processes where three phase reaction systems are required. One exampl e is biological waste water treatment. In order to enhance biological reaction rates it is often useful to immobilize the bacteria on carrie r particles. Knowledge of solid distribution and local gas holdup in t hose systems is important for calculation of mass and energy transfer or reaction kinetics. For this reason a method has been developed whic h enables to measure such local phase holdups. The measuring system co nsists of a time-domain-reflectometry (TDR)-instrument in combination with a pressure difference meter. The method has successfully been app lied to determine local axial gas and solid distribution in internal a irlift loop reactors, filled with a three phase system consisting of w ater, air, and polymer particles.