Effects of internal structures on mass transfer performance of jet bubbling reactor

In the cold-mold device of jet bubbling reactor, the effects of the liquid nozzle outlet diameter (dj), the diameter of annular gas distributor with a baffle (dg), and the distance between the liquid nozzle outlet and gas distributor (L) on the liquid volumetric mass transfer coefficient (kLa) are investigated through the dynamic dissolved oxygen method. The liquid jet flow field measured through the PIV shows that the radial jet is formed after the jet impacts the gas distributor, which prolongs the bubble residence time in the reactor. When the energy input to the reactor is constant, with the dj increasing, the L shortening, or the dg decreasing, the radial jet velocity and shear stress at gas outlet increases, causing the overall gas holdup increases and the bubble size decreases, so the kLa increases. An empirical correlation of the kLa is established. The relative error between the predicted values through the model and the experimental data is less than 20%. The research results can provide theoretical guidance for the optimization of the internals and scale-up of the jet bubbling reactor.

Automated summary

The effects of liquid and gas parameters on the liquid volumetric mass transfer coefficient in a cold-mold device were investigated. The results showed that increasing the liquid nozzle outlet diameter, shortening the distance between the liquid nozzle outlet and gas distributor, or decreasing the diameter of the gas distributor can enhance the mass transfer performance of the liquid.