Optimization of multi-stage velocity gradients in a cylindrical fluidized bed flocculator

作     者：Yamei Lu Jun Wang Dandan Zhou Zhengxue Xu Xiaotao T.Bi 

作者机构：Key Lab of Groundwater Resources and EnvironmentMinistry of EducationJilin University Changchun Urban Sciences Institute Department of Chemical and Biological EngineeringUniversity of British Columbia 

出 版 物：《Particuology》 (颗粒学报（英文版）)

年 卷 期：2015年第13卷第2期

页      面：118-123页

核心收录：

学科分类：080706[工学-化工过程机械] 08[工学] 0807[工学-动力工程及工程热物理] 

基　　金：the financial support from the Natural Sciences Foundation of China(50908096 50908097) 

主　　题：Abatement efficiency Floc protection Fluidized bed flocculator Multi-stage velocity gradient Optimization 

摘      要：Flocculation time is conventionally believed to be proportional to the fiocculation effciency of a cylindrical fluidized bed flocculator. However, in a single-stage velocity gradient situation, the flocculation efficiency decreases when the optimal flocculation time is exceeded. A multi-stage velocity gradient was established in a cylindrical fluidized bed flocculator, based on the hydraulic classification theory. This multi-stage velocity gradient fluidized bed flocculator （MGF） created a more suitable environment for floc growth and protection, which was confirmed by the size distribution of flocs along the bed height. Correspondingly, the abatement efficiencies for Kaolin slurry and dyed wastewater treatment in the MGF were enhanced by 5-10%, and by 7-20%, respectively, compared with those in the single-stage velocity gradient fluidized bed flocculators （SGFs）. The initial bed height distribution ratio along the velocity gradients was an important factor for MGF optimization.