Mechanically agitated gas-liquid reactors

Abstract

The hydrodynamic, heat and mass transfer characteristics of mechanically agitated contactors have been critically reviewed. The mixing time (θ_mix) can be correlated well by a model based on circulation path and average circulation velocity. Flow patterns in mechanically agitated contactors (single phase) provided with disk turbine, pitched blade turbine and propeller can be characterised. The minimum impeller speed required for the gas induction (N_cr) in hollow shaft impellers can be predicted; the minimum impeller speed required for surface aeration (N_s) can also be predicted. Different strategies of operating mechanically agitated contactors have been examined. The advantages of multistage contactors over single contactors have been stressed. Recommendations have been made for correlations which can be used for design purpose; lacunae in the available literature have been delineated and recommendations for further work have been made.