Based on the multi-class bubble model and the assumption that bubbles rise in plug flow during dynamic gas disengagement, the function between gas holdup and time was obtained by using the pressure transducing technol...Based on the multi-class bubble model and the assumption that bubbles rise in plug flow during dynamic gas disengagement, the function between gas holdup and time was obtained by using the pressure transducing technology. The plot obtained by the model agreed with the plot obtained by experiment. The pressure transducing technology is shown to be a good method for the measurement of hydrodynamics in a bubble column. The changes of gas holdup, large bubble holdup and small bubble holdup, bubble rising velocity with superficial gas velocity and liquid viscosity were obtained by using dynamic gas disengagement.展开更多
The investigation of hydrodynamic behavior in three-phase external loop airlift reactors is important to their design and scale-up. Pressure difference was used to measure gas holdup and ultrasonic Doppler anemometry ...The investigation of hydrodynamic behavior in three-phase external loop airlift reactors is important to their design and scale-up. Pressure difference was used to measure gas holdup and ultrasonic Doppler anemometry was used to measure liquid velocity. Gas holdup, liquid velocity and expansion rate increased with increasing superficial gas velocity. Under the same superficial gas velocity, gas holdup increased with increasing static solid height, and decreased with increasing solid particle diameter.Adding large particles could increase interfacial area, increase gas residual time and intensify mass transfer. Liquid circulation velocity and expansion rate decreased with increasing solid particle diameter and static solid height.Liquid velocity could be controlled in a suitable range by adding particles to improve the performance in airlift loop reactors.展开更多
文摘Based on the multi-class bubble model and the assumption that bubbles rise in plug flow during dynamic gas disengagement, the function between gas holdup and time was obtained by using the pressure transducing technology. The plot obtained by the model agreed with the plot obtained by experiment. The pressure transducing technology is shown to be a good method for the measurement of hydrodynamics in a bubble column. The changes of gas holdup, large bubble holdup and small bubble holdup, bubble rising velocity with superficial gas velocity and liquid viscosity were obtained by using dynamic gas disengagement.
文摘The investigation of hydrodynamic behavior in three-phase external loop airlift reactors is important to their design and scale-up. Pressure difference was used to measure gas holdup and ultrasonic Doppler anemometry was used to measure liquid velocity. Gas holdup, liquid velocity and expansion rate increased with increasing superficial gas velocity. Under the same superficial gas velocity, gas holdup increased with increasing static solid height, and decreased with increasing solid particle diameter.Adding large particles could increase interfacial area, increase gas residual time and intensify mass transfer. Liquid circulation velocity and expansion rate decreased with increasing solid particle diameter and static solid height.Liquid velocity could be controlled in a suitable range by adding particles to improve the performance in airlift loop reactors.
