Study of the optimal mode of sludge agitation in the receiving tank of a wastewater pumping station

Summary

Sludge agitation in the receiving tank of a wastewater pumping station is a rather serious problem due to the high risks of the pumping equipment failure, sludge caking and decay inside the tank. As a rule, sludge settling control methods provide for emptying only the area close to the suction nozzles of the pumps. In the rest of the tank, the caked sludge is periodically washed out by hand during maintenance or minimum filling. A comparison is made between two methods of sludge agitation in the receiving tank of a wastewater pumping station. In the first case, sludge is agitated hydraulically, i. e., using pipelines located along the perimeter of the tank. In the second, conical mixers of improved geometry are used, that is, sludge is agitated mechanically. A comparison of mixing efficiency was made using CFD-modeling. According to the results of modeling the hydrodynamics of mixing, during the operation of conical mixers, no stagnant zones is actually formed in the near-bottom mixing area.

Key words

treatment facilities , pumping station , mathematic modelling , conical mixers , sludge agitation