Effect of temperature on flow regimes and gas hold-up in a bubble column

The effect of temperature on the gas hold-up and flow regimes for air-water and air-electrolyte solutions (NaCl and CuCl2) was studied in a bubble column with a sintered glass disc distributor. For the air-water system, the gas hold-up was found to decrease with increase in temperature. For the air-electrolyte solutions, increase in temperature resulted in increased gas hold-up at lower gas velocity, while at higher gas velocity the gas hold-up was found to decrease with temperature. The gas velocity ugT for transition from bubble flow to churn turbulent flow was found to decrease with increase in temperature as a result of increased coalescence. In the presence of electrolytes, ugT was found to be higher than that for water