Experiments on bubble behaviors in three phase internal-loop airlift reactor using optical fiber probe measurements
Yongxiang Gao, Haoran Lu, Youwei Cheng*, Lijun Wang and Xi Li.
Department of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, PR China
The internal-loop airlift reactor has been gathered widely interests because of its simple structure, high efficiency of mass and heat transfer, good solid suspension and good mixing. A gas-liquid-solid three phase internal-loop airlift reactor combined with a conical bottom and a nozzle inlet was investigated deeply in term of its fluid dynamics in bubble-scale, besides in column-scale. The bubble behaviour was implemented by optical probe method. The image analysis was also carried out to validate the results. The data collected by the optical probe was processed in time and frequency domain analysis via MATLAB algorithms. The time domain analysis obtained dispersion parameters, such as the local gas holdup, the bubble rise velocity, and the bubble chord length distribution, and the frequency domain analysis revealed chaotic characteristics. The maximum entropy method was utilized to transfer the bubble chord length distribution (CLD) to bubble size distribution (BSD). The effect of the superficial gas velocity and solid concentration on the bubble behaviours in the riser and downcomer regions were discussed carefully. The reasonable agreement between the two measured methods certified and supplied a feasible method to predict the bubble behaviours in gas-liquid-solid three phase fluidized beds. The bubble behaviours in this work can be a benchmark for CFD simulation verifications for airlift reactor, and these in return can provide important guidance for reactor design and scale-up.
See more of this Group/Topical: Engineering Sciences and Fundamentals