Vertical distributions of local void fraction and bubble size in air-water dispersion system were measured with a dual conductivity probe in a fully baffled dished base stirred vessel with the diameter T of 0.48 m, ho...Vertical distributions of local void fraction and bubble size in air-water dispersion system were measured with a dual conductivity probe in a fully baffled dished base stirred vessel with the diameter T of 0.48 m, holding 0.134 m3 liquid. The impeller combination with a six parabolic blade disk turbine below two down-pumping hy- drofoil propellers, identified as PDT ＋ 2CBY, was used in this study. The effects of the impeller diameter D, rang- ing from 0.30T to 0.40T （corresponding to D/T from 0.30 to 0.40）, on the local void fraction and bubble size were investigated by both experimental and CFD simulation methods. At low superficial gas velocity Vs of 0.0077 m· s-1, there is no obvious difference in the local void fraction distribution for all systems with different D/T. However, at high superficial gas velocity, the system with a D/TofO.30 leads to higher local void fraction than systems with other D/T. There is no significant variation in the axial distribution of the Sauter mean bubble size for all the systems with different D/T at the same gas superficial velocity. CFD simulation based on the two-fluid model along with the population balance model （PBM） was used to investigate the effect of the impeller diameter on the gas-liquid flows. The local void fraction predicted by the numerical simulation approach was in reasonable a^reement with the experimental data.展开更多
基金Supported by the National Natural Science Foundation of China(21121064,21206002,21376016)
文摘Vertical distributions of local void fraction and bubble size in air-water dispersion system were measured with a dual conductivity probe in a fully baffled dished base stirred vessel with the diameter T of 0.48 m, holding 0.134 m3 liquid. The impeller combination with a six parabolic blade disk turbine below two down-pumping hy- drofoil propellers, identified as PDT ＋ 2CBY, was used in this study. The effects of the impeller diameter D, rang- ing from 0.30T to 0.40T （corresponding to D/T from 0.30 to 0.40）, on the local void fraction and bubble size were investigated by both experimental and CFD simulation methods. At low superficial gas velocity Vs of 0.0077 m· s-1, there is no obvious difference in the local void fraction distribution for all systems with different D/T. However, at high superficial gas velocity, the system with a D/TofO.30 leads to higher local void fraction than systems with other D/T. There is no significant variation in the axial distribution of the Sauter mean bubble size for all the systems with different D/T at the same gas superficial velocity. CFD simulation based on the two-fluid model along with the population balance model （PBM） was used to investigate the effect of the impeller diameter on the gas-liquid flows. The local void fraction predicted by the numerical simulation approach was in reasonable a^reement with the experimental data.
