| Gas-liquid mass transfer widely exists in the industrial field,and strengthening gas-liquid mass transfer can not only improve the mass transfer efficiency of the system and reduce the size of mass transfer equipment,but also reduce the energy consumption in the mass transfer process and achieve low energy consumption and high efficiency production.The method of strengthening the gas-liquid mass transfer by adding nano-particles into the base liquid has been confirmed from many macroscopic experiments,but the microcosmic characteristics of nanoparticles in the process of enhanced mass transfer have not been grasped accurately,which affects the in-depth study of gas-liquid mass transfer process.Therefore,it is necessary to observe the motion state of nanoparticles in the gas-liquid mass transfer process by visualization experiment,and to study its influence on the gas-liquid mass transfer process,so as to analyze the mechanism of strengthening gas-liquid mass transfer from the microscopic level.First of all,this paper gives a brief introduction to the construction of the total internal reflection fluorescence microscope experiment table used in the experiment and the principle of the evanescent wave,and emphatically analyzed the image processing program based on MATLAB algorithm for processing experimental image and the error in the experiment.Because the viscosity of the nanofluid has a great influence on the brownian motion of the nanoparticles and the effect on Brownian motion of nanoparticles can be analyzed by the change of the viscosity of the nanofluid,therefore the viscosity of the nanofluids under different experimental conditions was first measured by the rotary NDJ-8S viscometer in the experiment,and the influence of the solid content,the diameter,the temperature and the material property on the viscosity of the nanofluids was analyzed,then the microscopic motion of nanoparticles at the boundary of gas-liquid mass transfer near the wall surface in the process of nanoparticle-reinforced sodium sulfite absorbs oxygen under different experimental conditions was observed visually on TIRF experimental platform,and the experimental images were processed by image processing program.The relationship between the solid content,the diameter,the material property and Brownian motion of nanoparticles is analyzed combined with the change of viscosity.In order to further study the effect of Brownian motion of nanoparticles on gas-liquid mass transfer,the experiment of strengthening sodium sulfite to absorb oxygen by nanoparticles was carried out on TIRF experimental platform,and the effects of the solid content,the diameter,the material property on oxygen mass transfer coefficient were analyzed combined with the change of Brownian motion of nanoparticles in the process.The relationship between Brownian motion of nanoparticles and mass transfer coefficient was establishedm and the effect of Brownian motion of nanoparticles on gas-liquid mass transfer was analyzed from a microcosmic point of view. |
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