Gas-liquid mass transfer in the gas-liquid-solid mini fluidized beds

The gas-liquid-solid mini fluidized bed(GLSMFB)combines the advantages of fluidized bed and micro-reactor,and meets the requirements for safety and efficiency of green development of process industry.However,there are few studies on its flow performance and no studies on its mass and heat transfer performance.In this paper,the characteristics of gas-liquid mass transfer in a GLSMFB were studied in order to provide basic guidance for the study of GLSMFB reaction performance and application.Using CO_(2)absorption by NaOH as the model process,the gas-liquid mass transfer performance of GLSMFB was investigated.The results show that the liquid volumetric mass transfer coefficient and the gas-liquid interfacial area both increase with the increase of the superficial gas velocity within the experimental parameter range under the same given superficial liquid velocity.At the same ratio of superficial gas to liquid velocity,the liquid volumetric mass transfer coefficient increases with the increase of the super-ficial liquid velocity.Fluidized solid particles strengthen the liquid mass transfer process,and the liquid volumetric mass transfer coefficient is about 13%higher than that of gas-liquid mini bubble column.

New measurements on hydrodynamics in a gas-liquid-solid expanded bed

The solid holdup,in a 150 mm-ID×2460 mm-height gas-liquid-solid expanded bed with air,water and glass beads(the diameter of particles is 0.6-0.8 mm)was firstly investigated based on the immersion-type online multiphase measuring instrument,and bubble behavior was studied via the BVW-2 double electrical conductivity probe.The effect of the superficial gas velocity and liquid velocity on the expanded ratio,the transition ratio,the bubble rising velocity,the gas holdup and the solid holdup was studied.It is discovered that compared with the gas velocity,the liquid velocity has stronger impact on the expanded ratio,but it is opposite for the transition ratio.The average gas holdup and solid holdup increase linearly as the superficial gas velocity goes up.Among it,the gas holdup increases greater in the center,while the solid holdup increases greater near the wall.Compared with it,when the superficial liquid velocity rises,the average gas holdup hardly changes,but the average solid holdup keeps decreasing,especially the solid holdup distributes flatter with the increase of the superficial liquid velocity.