Particle−Liquid Mass Transfer Coefficient in Two-/Three-Phase Stirred Tank Reactors

Knowledge of particle−liquid mass transfer coefficient ( k SL ) is important for a rational design of a solid−liquid/solid−liquid−gas stirred tank reactor (STR). Considerable efforts have been made by different investigators to study and correlate the behavior of k SL in STRs for a variety of geometric and operating conditions. This review attempts to put together and analyze the information available in the literature on k SL in STRs systematically. Different approaches used by researchers to correlate k SL are critically discussed. The effect of system configurations (type of the impeller, D / T, and C / T ), operating parameters (impeller speed/power input, particle loading, and gas flow rate), and physical properties ( d P, D m, μ, and Δρ) on k SL have been discussed elaborately. Some new data for six-bladed impellers have been generated to determine the optimum geometric configuration and operating conditions for particle−liquid mass transfer in three-phase STRs. It is concluded that k SL in two-/three-phase STRs can be correlated reliably over a wide range of system configurations and operating parameters by a relative particle suspension term, N / N S(G) . Scope and need for further studies have been suggested.