亚微涡旋的混凝作用研究

Coagulation effects of submicroscopic vortices

以粒子图像速度场仪(PIV)测得了Taylor-Couette反应器旋转内筒和固定外筒间的环隙流场图像.所得图像表明环隙间存在亚微尺度的涡旋.同时实验研究了在Taylor-Couette反应器环隙间不同涡旋形态下聚合氯化铝(PAC)对高岭土悬浊液的混凝效能.结果表明,在波涡流(WVF)形态范围内混凝效能达到了最大(50%以上),这可归因于涡的闭合特性及其随时间的膨胀和收缩.但在波涡流形态范围以外得到的混凝效能相对较低,可归因于相互连通的非闭合涡特性.

Velocity field data were acquired for Taylor-Couette flow in the annulus gap between a rotating inner cylinder and a fixed concentric outer cylinder by using particle image velocimetry （PIV）.The vortices of submicroscopic size were produced in the annulus gap according to the velocity vector map. The flocculation efficiencies were also obtained in the same Taylor-Couette flow under the conditions corresponding to the different vortices. The flocculation efficiencies reached the maximum values （above 50%） in the wavy vortex flow（WVF）range due to the closed vortices and their contractions and expansions with time, but out of WVF range, the comparatively low flocculation efficiencies were obtained due to the no-closed vortices connected with each other.