Bubble column with internals: Effects on hydrodynamics and local heat transfer

• Internals structure significantly affect local heat transfer and hydrodynamics in bubble column.
• Fast response heat transfer probe used in the study proved useful to elucidate internals effects on hydrodynamics.
• Internals design has significant effect on gas holdup structure.
• Desirable improvements possible with proper internals configurations and combinations.

Local heat transfer and column hydrodynamics are investigated in a bubble column in presence of internals of different configurations. The liquid phase used is tap water and the gas phase is oil-free compressed air. The gas velocity is varied over a wide range of 0.03–0.35 m/s. The heat transfer variations are measured with a fast response probe capable of capturing bubble dynamics as well as detect local flow direction and deduce local liquid velocity. Measurements obtained in presence of internals are compared with those without internals to elucidate the effects of different internals design. Comparisons are based on average values and temporal variations obtained with the fast response probe. The average gas holdup, local liquid velocity and bubble fractions holdups obtained with and without internals are also compared to further point out the differences. The observed differences are discussed based on the insights provided by these comparisons. The results obtained show influence of internals design on column hydrodynamics which need to be considered for their proper design and modeling.