MASS-TRANSFER IN HIGHLY VISCOUS-LIQUIDS IN A BUBBLE COLUMN WITH CONSTANT-FLOW NOZZLES

Bubble columns with constant-flow nozzles were used to obtain high values of gas holdup epsilon and volumetric mass transfer coefficient k(L)a for highly viscous liquids at relatively low gas-flow rates. Effects of various factors on epsilon, k(L)a, mass transfer coefficient k(L), bubble volume V(B) formed at constant-flow nozzle, and gas-liquid interfacial area a were investigated experimentally. Liquid viscosity, superficial gas velocity, number of constant-flow nozzles and pitch affected epsilon, k(L)a, k(L), V(B) and a. The experimental results were correlated by dimensionless equations, which were compared with previous works. For a given energy input, a in this bubble column was larger than that in conventional bubble columns with a perforated plate as gas distributor.