过程工程学报
過程工程學報
과정공정학보
The Chinese Journal of Process Engineering
2007年
2期
360-365
,共6页
倪伟敏%吴忠标%官宝红%赵伟荣%郑平
倪偉敏%吳忠標%官寶紅%趙偉榮%鄭平
예위민%오충표%관보홍%조위영%정평
sedimentation%fractal geometry%Stokes' Law%dual-alkali FGD
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 aggregate 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 AμlD2. 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 process.