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 

机构地区：[1]Key Lab of Groundwater Resources and Environment,Ministry of Education,Jilin University [2]Changchun Urban Sciences Institute [3]Department of Chemical and Biological Engineering,University of British Columbia

出　　处：《Particuology》2015年第2期118-123,共6页颗粒学报（英文版）

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

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.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.

关 键 词：Abatement efficiency Floc protection Fluidized bed flocculator Multi-stage velocity gradient OPTIMIZATION 

分 类 号：TQ051.13[化学工程]