Characterizing the hydrodynamics of a fluidized bed flotation column is essential for understanding the behavior of this multiphase flow system.Bed pressure fluctuations and phase hold-ups are two of these key charact...Characterizing the hydrodynamics of a fluidized bed flotation column is essential for understanding the behavior of this multiphase flow system.Bed pressure fluctuations and phase hold-ups are two of these key characteristics.Static bed height effects on these two key characteristics were comprehensively studied using experimental and statistical analysis operating for different flow regimes.And three different bed height-to-diameter ratios(H/D=1.0,1.5,and 2.0)were investigated.The time series signals of pressure fluctuation were recorded via a pressure transducer,then analyzed through time and frequency domain methods.Cross-sectional and radial combined gas and solid hold-ups distribution were detected through the electrical resistance tomography under different H/D ratios.Results indicated that the key parameters of bed pressure fluctuation signals and gas-solid hold-up distributions are significantly affected by the change in static bed height,which can be explained by differences in bubble dynamics and particle movement behaviors.展开更多
The hydrodynamic characteristics in fluidized bed flotation column(FBFC)are critical for optimizing fluidized flotation processes,yet understanding the interactions between operating parameters remains a complex chall...The hydrodynamic characteristics in fluidized bed flotation column(FBFC)are critical for optimizing fluidized flotation processes,yet understanding the interactions between operating parameters remains a complex challenge.This study proposes a novel method to classify flow regimes and identify transition velocities in fluidized bed flotation columns.By analyzing gas-solid holdup variations(ε_(g,s))via electrical resistance tomography(ERT),we identified three distinct flow regimes and two transition velocities usingε_(g,s)-based criteria.Furthermore,we employed pressure transducer and ERT to analyze how gas velocity(U_(g)),water velocity(U_(w)),and particle size(D_(p))influence pressure fluctuations,minimum liquid fluidization velocity(U_(mf)),and gas and solid hold-ups distributions.Results showed that U_(w)and D_(p)significantly influenced pressure fluctuations,while U_(g)affected pressure fluctuations mainly for large particles.Umf increased with D_(p)but remained unaffected by U_(g).Higher U_(w)and D_(p)led to more uniform distributions of radial gas and solid hold-ups,with U_(g)influencing distribution only in the fixed bed regime.Finally,the using Box-Behnken design(BBD)and analysis of variance(ANOVA),significant in-teractions between U_(g)and D_(p)for the average differential pressure,and between U_(w)and D_(p)for ε_(g,s)were identified,with no significant interactions for normalized standard deviation of differential pressure fluctuation.Predictive models with high correlation coefficients were established for these interactions,offering guidance for FBFC optimization.展开更多
基金funded by Basic Research Program of Jiangsu(grant Nos.BK20240106 and BK20240014)National Natural Science Foundation of China(grant Nos.52174265,52425407,and 52274278).
文摘Characterizing the hydrodynamics of a fluidized bed flotation column is essential for understanding the behavior of this multiphase flow system.Bed pressure fluctuations and phase hold-ups are two of these key characteristics.Static bed height effects on these two key characteristics were comprehensively studied using experimental and statistical analysis operating for different flow regimes.And three different bed height-to-diameter ratios(H/D=1.0,1.5,and 2.0)were investigated.The time series signals of pressure fluctuation were recorded via a pressure transducer,then analyzed through time and frequency domain methods.Cross-sectional and radial combined gas and solid hold-ups distribution were detected through the electrical resistance tomography under different H/D ratios.Results indicated that the key parameters of bed pressure fluctuation signals and gas-solid hold-up distributions are significantly affected by the change in static bed height,which can be explained by differences in bubble dynamics and particle movement behaviors.
基金funded by Basic Research Program of Jiangsu(grant Nos.BK20240106,BK20240014)National Nature Science Foundation of China(grant Nos.52174265,52425407,52274278).
文摘The hydrodynamic characteristics in fluidized bed flotation column(FBFC)are critical for optimizing fluidized flotation processes,yet understanding the interactions between operating parameters remains a complex challenge.This study proposes a novel method to classify flow regimes and identify transition velocities in fluidized bed flotation columns.By analyzing gas-solid holdup variations(ε_(g,s))via electrical resistance tomography(ERT),we identified three distinct flow regimes and two transition velocities usingε_(g,s)-based criteria.Furthermore,we employed pressure transducer and ERT to analyze how gas velocity(U_(g)),water velocity(U_(w)),and particle size(D_(p))influence pressure fluctuations,minimum liquid fluidization velocity(U_(mf)),and gas and solid hold-ups distributions.Results showed that U_(w)and D_(p)significantly influenced pressure fluctuations,while U_(g)affected pressure fluctuations mainly for large particles.Umf increased with D_(p)but remained unaffected by U_(g).Higher U_(w)and D_(p)led to more uniform distributions of radial gas and solid hold-ups,with U_(g)influencing distribution only in the fixed bed regime.Finally,the using Box-Behnken design(BBD)and analysis of variance(ANOVA),significant in-teractions between U_(g)and D_(p)for the average differential pressure,and between U_(w)and D_(p)for ε_(g,s)were identified,with no significant interactions for normalized standard deviation of differential pressure fluctuation.Predictive models with high correlation coefficients were established for these interactions,offering guidance for FBFC optimization.
