Effect of Agitation on Oxygen Transfer in Paenibacillus Polymyxa HY96-2 Culture Broth and CFD Simulation

Effects of impeller combination, system′s viscosity, gasflux, space of impellers and gas sparger on the oxygen transfer with CMC as liquid phase and air as gas phase were investigated in this paper. The results indicated that slope blade Rushton turbinehydrofoil impeller (SRT-HI) was favorable to oxygen transfer in CMC system. When the power consumption per volume (P/V) was not less than 1.5 kW/m3, the transfer coefficient (kLa) of SRT-HI was 10% higher than that of the double Rushton turbine combined(RT-RT),and even better with increase of the ratio of height to diameter.The distributing profile of velocity, gas and oxygen transfer coefficient in the gas-liquid two phases were obtained through CFX 11.0 simulation. The effect of SRT-HI and RT-RT to dissolved oxygen was studied through paenibacillus polymyxa HY96-2 fermentation in 50 L agitated reactor, and the results indicated that the dissolved oxygen of SRT-HI was higher than that of RT-RT when P/V was 1.6 kW/m3.