In this work the geometry of the sludge blanket clarifier was established based on BansinWater Treatment Plant, Taiwan. The meshes of the clarifier were constructed, and the boundary conditions were set, then the velocity field of the clarifier was calculated. Twomodels were computed individually: 1. the fluid in the whole clarifier is pure water a test for obtaining the flow pattern; 2. the flow field contains a homogeneous blanket of permeability k and pure water a test modeling the sludge blanket as a homogeneous porous medium.
The results showed that when the inlet velocity decreased from x = 0.3 m/s to 0.1 m/s, the effect of channel flow or break-through of blanket decreased. Decreasing of the rotation velocity of the impeller could decrease the effect of the reversed flow in the secondary reactor. In the case of a uniform blanket on the bottom of the clarifier, the high permeability of the blanket indicates the similar velocity field with those of pure water. While the clarifier with a low permeability blanket, the rebound of the blanket becomes seriously.
Relation:
淡江理工學刊=Tamkang journal of science and engineering 10(4)，頁317-322
