煤泥水絮凝沉降效果导向的旋流-扰流流场优化

Flocculating device has a significant impact on the flocculation process and effect by its inner flow field. According to the vortexflocculation dynamics theory, an integrated flocculation-sedimentation device with swirling-disturbed flow field was designed and used forthe continual flocculation and sedimentation of slime water. Firstly, the appropriate reagent addition conditions were determined by thesedimentation tube flocculation sedimentation experiment: the mass concentration of polyaluminum chloride is 5 mg/ L, and the mass concentration of polyacrylamide is 2 mg/ L. Then, under this fixed agents addition condition, the underflow concentration and overflow turbidity were used as indicators to investigate the influence of height, number of groups and installation angle of isosceles triangle spoilers on theflocculation and settlement of slime water in an nnnular flow channel between the inner and outer diameter of 50 and 100 mm, respectively. The results show that the height of the spoiler and the number of groups have a significant effect on the flocculation settlement effect:within the experimental range, the height of the spoiler is the best under the condition of 5 groups of spoilerswhen the height of the spoileris 15 mm, and the overflow turbidity is 142 NTU, which is better than 54 NTU that with none spoiler. When the number of spoiler groupsis in the range of 0-5, the case of 3 groups is the best, and the overflow turbidity is reduced to 112 NTU. Under the condition of 3 groupsof 15 mm spoilers, the change of the spoiler has little effect on the flocculation sedimentation effect, and the turbidity is between 107125 NTU, of which 30° is the most one. The analysis suggests that the spoiler height influences particle collision and breakage by controlling the characteristic scale of the vortex guided by it and the energy dissipation, while the number of spoiler groups mainly affects thelength of the coagulation zone, thereby changing the effective coagulation time of the particles.