The velocity distribution in Rayleigh convection caused by acetone volatilization in acetone-ethyl acetate binary system was observed in a vertical cross section of an initially quiescent liquid layer by utilizing par...The velocity distribution in Rayleigh convection caused by acetone volatilization in acetone-ethyl acetate binary system was observed in a vertical cross section of an initially quiescent liquid layer by utilizing particle image velocimetry. Obvious turbulent vortexes that were induced by Rayleigh convection appeared in the bulk liquid,and its statistic features indicated that Rayleigh convection became more intense with the increase of Ra number and ReGnumber. Mass transfer coefficient was measured and the computed enhancement factor indicated that Rayleigh convection could promote the surface renewal of the liquid phase and intensify the interfacial mass transfer significantly. A method was proposed for the prediction of mass transfer coefficient based on the measured velocity vector, and the predicted mass transfer coefficients are in reasonable agreement with the experimental results.展开更多
By using a hybrid lattice-Boltzmann–finite-difference method(hybrid LBM–FDM method),three-dimensional simulations of solutal interfacial convection were conducted for the process of CO2absorption into ethanol.A self...By using a hybrid lattice-Boltzmann–finite-difference method(hybrid LBM–FDM method),three-dimensional simulations of solutal interfacial convection were conducted for the process of CO2absorption into ethanol.A self-renewal interface model is adopted as an interfacial perturbation model.The simulation results revealed some three-dimensional features of the induced interfacial convection,such as the development of diverging cellular flow and Rayleigh plume-like convection in liquid phase.The concentration distribution of the simulation result is validated and found to be in well agreement with the Schlieren visualization results qualitatively.Additionally,the mass transfer enhancements by interfacial convection were investigated via both simulation and experiment for the absorption process,and the mass transfer is shown to be enhanced by the interfacial convection by about two-fold comparing with that by diffusion.展开更多
A method of using laser induced fluorescence(LIF)technique was applied to two-dimensional measurement of the liquid concentration distribution in the 250 Y structured packing sheet. The experimental structured packing...A method of using laser induced fluorescence(LIF)technique was applied to two-dimensional measurement of the liquid concentration distribution in the 250 Y structured packing sheet. The experimental structured packing sheet was made of perspex so that the laser could pass through it. The visualization of the distribution of the liquid concentration in the structured packing sheet was realized. The calibration of the thickness and liquid concentration was carried out firstly and the regression formula I=kcd was acquired, in which concentration c and the liquid film thickness d were both considered. Then the liquid feed of uniform tracer(rhodamine)concentration entered the perspex structured packing from the top under different spraying densities. The corresponding thickness of liquid film on the packing was calculated. Finally, tracer(rhodamine)with a high concentration was injected only at one fixed point of the structured packing under different spraying densities of the liquid. With the known liquid film thickness, the concentration distribution of the tracer can be calculated inside the structured packing sheet.展开更多
基金Supported by the National Natural Science Foundation of China(20736005)
文摘The velocity distribution in Rayleigh convection caused by acetone volatilization in acetone-ethyl acetate binary system was observed in a vertical cross section of an initially quiescent liquid layer by utilizing particle image velocimetry. Obvious turbulent vortexes that were induced by Rayleigh convection appeared in the bulk liquid,and its statistic features indicated that Rayleigh convection became more intense with the increase of Ra number and ReGnumber. Mass transfer coefficient was measured and the computed enhancement factor indicated that Rayleigh convection could promote the surface renewal of the liquid phase and intensify the interfacial mass transfer significantly. A method was proposed for the prediction of mass transfer coefficient based on the measured velocity vector, and the predicted mass transfer coefficients are in reasonable agreement with the experimental results.
基金Supported by the National Natural Science Foundation of China(20736005)
文摘By using a hybrid lattice-Boltzmann–finite-difference method(hybrid LBM–FDM method),three-dimensional simulations of solutal interfacial convection were conducted for the process of CO2absorption into ethanol.A self-renewal interface model is adopted as an interfacial perturbation model.The simulation results revealed some three-dimensional features of the induced interfacial convection,such as the development of diverging cellular flow and Rayleigh plume-like convection in liquid phase.The concentration distribution of the simulation result is validated and found to be in well agreement with the Schlieren visualization results qualitatively.Additionally,the mass transfer enhancements by interfacial convection were investigated via both simulation and experiment for the absorption process,and the mass transfer is shown to be enhanced by the interfacial convection by about two-fold comparing with that by diffusion.
基金Supported by the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(No.2015BAC04B01)National Natural Science Foundation of China(No.21176171)
文摘A method of using laser induced fluorescence(LIF)technique was applied to two-dimensional measurement of the liquid concentration distribution in the 250 Y structured packing sheet. The experimental structured packing sheet was made of perspex so that the laser could pass through it. The visualization of the distribution of the liquid concentration in the structured packing sheet was realized. The calibration of the thickness and liquid concentration was carried out firstly and the regression formula I=kcd was acquired, in which concentration c and the liquid film thickness d were both considered. Then the liquid feed of uniform tracer(rhodamine)concentration entered the perspex structured packing from the top under different spraying densities. The corresponding thickness of liquid film on the packing was calculated. Finally, tracer(rhodamine)with a high concentration was injected only at one fixed point of the structured packing under different spraying densities of the liquid. With the known liquid film thickness, the concentration distribution of the tracer can be calculated inside the structured packing sheet.
