Separation Performance of Vortex-Type Settling Tank

Abstract

A vortex-type settling tank is developed as a replacement of the rectangular grit separator traditionally in use in sewerage and other systems. The settling tank performance of the new separator is discussed in this paper.
The vortex-type settling tank is so designed that sewage containing grit flows tangentially into a circular water tank. While the sewage is whirling in the water tank, grit contained in it settles. Water free of grit drains from the outlet located in the side wall. Since this tank has a cone-shaped bottom, grit tends to settle at the center of its bottom.
The vortex-type settling tank is compared in performance with the conventional rectangular one..It is found that this settling tank exceeds its counterpart in grit separation and collection performance. The law of similarity concerning grit separation performance is defermined and the equation by which the performance is predicted is thus obtained.