Three-tier Modular Agitator Gas-liquid Mixing Characteristics

Gas-liquid stirred fermenter is one of the most important equipment in biochemical fermentation industry. Gas-liquid operation involves gas dispersion, liquid mixing, solid-liquid suspension and heat transmission, etc. The big height-radial scale tank and multiple impellers are always used. Since the shortcoming of vertical hosepipe as heat transfer and the radial flow turbine impeller used in big tank, the disc hosepipe and six different impeller combinations include both radial flow impeller and axial flow impeller are investigated.In this paper the experimental data of six impeller combinations, such as power number of gas and non-gas conditions, gas hold-up(O) and coefficient of mass transfer are analyzed and correlated. The result has shown that, for two impeller combinations LA315+ITB+6ADT and LA310+PTB+6ADT, they are apparent than others in power consumption, they are equal to others in gas hold-up, and they are less than others in the coefficient of mass transfer.Taking power number, gas hold-up and coefficient of mass transfer comprehensively into consideration, the impeller combination 6ADT+6DPTU+6PTU is well enough. So the impeller combination 6ADT+6DPTU+6PTU is preferred in the condition of disc hosepipe as heat transfer and three-lay impellers fermenter. The data and rules of six impeller combinations are described in this paper can be useful for the scales-up, design and application of gas-liquid stirred fermenters.Final the measurement system of mixing experiment is also improved at this paper. The rotational speed, the torque and the derived data can be computed and recorded automatically by the self-designed software.