The effects of operating parameters on desulfurization efficiency of a dual-alkali FGD process in a rotating-stream-tray(RST)scrubber are investigated.A dimensionless factor,ε,is proposed in this study to predict des...The effects of operating parameters on desulfurization efficiency of a dual-alkali FGD process in a rotating-stream-tray(RST)scrubber are investigated.A dimensionless factor,ε,is proposed in this study to predict desulfurization efficiency of this dual-alkali FGD system.ε represents the desulfurization ability of a dual alkali FGD system,determined by five main operating parameters such as sodium ion concentration,ratio of absorbent flow rate to flue gas flow rate,pH value of absorbent solution,ratio of sulfate ion to total sulfur ion in absorbent solution,and sulfur dioxide concentration of inlet flue gas.The empirical expression for predicting desulfurization efficiency at different temperatures is obtained through the experimental study and theoretical calculation.It provides useful guide for engineering design.展开更多
The solid-liquid separation is an important operation for the regenerated slurry of dual-alkali FGD system,and calcium sulfite could predominate in particle aggregates of the slurry.The settling velocity of calcium su...The solid-liquid separation is an important operation for the regenerated slurry of dual-alkali FGD system,and calcium sulfite could predominate in particle aggregates of the slurry.The settling velocity of calcium sulfite particles is a key parameter for the solid-liquid separation design.However,the settling velocity predicted by Stokes' Law could be suitable only for a spherical aggregate, but not for the irregular one.In this work,fractal geometry was introduced in order to characterize highly irregular geometric shapes.The sizes of calcium sulfite particle aggregates were analyzed using a metallographic phase microscope and image analysis.The results showed that particle aggregates had fractal features.The fractal dimensions could reveal the characteristics of the aggregates' geometry and aggregation process.An exponential relation between the fractal dimension D_2 and the particle size l was determined as A∝l^(D2). According to fractal theory,a parameter can be used to modify Stokes settling velocity close to actual settling velocity.The results could be valuable for the design of solid-liquid separation processes.展开更多
基金Supported by the National Hi-tech Researchand Development Program(863program)of China(No.2001AA642030-1)Key Research Project of Zhejiang Province(No.2004C23028)New Century Excellent Scholar Program of Ministry of Education of the People's Republic of China(No.NCET-04-0549)
文摘The effects of operating parameters on desulfurization efficiency of a dual-alkali FGD process in a rotating-stream-tray(RST)scrubber are investigated.A dimensionless factor,ε,is proposed in this study to predict desulfurization efficiency of this dual-alkali FGD system.ε represents the desulfurization ability of a dual alkali FGD system,determined by five main operating parameters such as sodium ion concentration,ratio of absorbent flow rate to flue gas flow rate,pH value of absorbent solution,ratio of sulfate ion to total sulfur ion in absorbent solution,and sulfur dioxide concentration of inlet flue gas.The empirical expression for predicting desulfurization efficiency at different temperatures is obtained through the experimental study and theoretical calculation.It provides useful guide for engineering design.
基金Supported by the National Hi-tech Research and Development Program (863 Program) of China (No.2001AA642030-1)New Century Excellent Scholar Program of Ministry of Education of China (No.NCET-04-0549)The Key Research Project of Zhejiang Province (No.010007037)
文摘The solid-liquid separation is an important operation for the regenerated slurry of dual-alkali FGD system,and calcium sulfite could predominate in particle aggregates of the slurry.The settling velocity of calcium sulfite particles is a key parameter for the solid-liquid separation design.However,the settling velocity predicted by Stokes' Law could be suitable only for a spherical aggregate, but not for the irregular one.In this work,fractal geometry was introduced in order to characterize highly irregular geometric shapes.The sizes of calcium sulfite particle aggregates were analyzed using a metallographic phase microscope and image analysis.The results showed that particle aggregates had fractal features.The fractal dimensions could reveal the characteristics of the aggregates' geometry and aggregation process.An exponential relation between the fractal dimension D_2 and the particle size l was determined as A∝l^(D2). According to fractal theory,a parameter can be used to modify Stokes settling velocity close to actual settling velocity.The results could be valuable for the design of solid-liquid separation processes.
