A new correlation for the prediction of gas hold up in bubble columns was proposed based on an extensive experimental database set up from the literature published over last 30 years. The updated estimation method rel...A new correlation for the prediction of gas hold up in bubble columns was proposed based on an extensive experimental database set up from the literature published over last 30 years. The updated estimation method relying on artificial neural network, dimensional analysis and phenomenological approaches was used and the model prediction agreed with the experimental data with average relative error less than 10%.展开更多
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(No.20076036)and Education Department of Hubei Province.
文摘A new correlation for the prediction of gas hold up in bubble columns was proposed based on an extensive experimental database set up from the literature published over last 30 years. The updated estimation method relying on artificial neural network, dimensional analysis and phenomenological approaches was used and the model prediction agreed with the experimental data with average relative error less than 10%.
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.
