摘要
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.
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 D2 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.
出处
《过程工程学报》
EI
CAS
CSCD
北大核心
2007年第2期360-365,共6页
The Chinese Journal of Process Engineering
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)
关键词
沉降
几何学
液态分离
过程工程
sedimentation
fractal geometry
Stokes' Law
dual-alkali FGD