摘要
To improve the mixing efficiency in water purification or wastewater treatment process and understand the mechanism of mass transfer,and a suitable evaluation factor is introduced to evaluate the efficiency of mixing process.The diffusion mass transfer under turbulent condition is investigated based on dynamic and mathematical analysis.The results indicate that submicroscopic diffusion is the rate-limiting step in mass transfer,and the inertia effect of micro vortex causes the phase mixing.An excellent efficiency can be obtained by controlling the scale of micro vortex within millimeter.Furthermore,a new indicator named mixing factor(IH)is proposed to evaluate the efficiency of mixing processes,which is more feasible than conventional evaluation methods,because of its connection of mixing extent with energy consumption.
To improve the mixing efficiency in water purification or wastewater treatment process and understand the mechanism of mass transfer, and a suitable evaluation factor is introduced to evaluate the efficiency of mixing process. The diffusion mass transfer under turbulent condition is investigated based on dynamic and mathematical analysis. The results indicate that submicroscopic diffusion is the rate-limiting step in mass transfer, and the inertia effect of micro vortex causes the phase mixing. An excellent efficiency can be obtained by controlling the scale of micro vortex within millimeter. Furthermore, a new indicator named mixing factor (IH) is proposed to evaluate the efficiency of mixing processes, which is more feasible than conventional evaluation methods, because of its connection of mixing extent with energy consumption.
基金
Sponsored by the National Eleventh Five-year Special Item of Water Pollution (Grant No.2008ZX07207-005-02)
the National Eleventh Five-year Supporting Plan of Science and Technology(Grant No.2006BAJ03A05 -01)
the Excellent Younger Teacher Awards Project of Harbin Institute of Technology(Grant No.NACZ98504851)