NUMERICAL INVESTIGATION OF INLET BAFFLE FEATURES EFFECTS ON THE HYDRAULIC PERFORMANCE OF PRIMARY SETTLING TANKS

Document Type : Article

Authors

Dept. of Mechnical Engineering Sharif University of Technology

Abstract

Cireulation is created in some parts of the settling tanks . It can increase the mi.-x.ing level, deerease the effective settling and ereate short circuiting from in­ let to outlet. All the above-mentioned phenomena act in such a way to deerease the tank's hydraulic ef­ ficiency, which quantitatively shows how flow within the tank is uniform and ealm . So, the main objee­ tive of the tank design process is to avoid form­ ing a circulation zone, which is known ar.;; the dead zone. Prediction of the flow field and size of the recireulation zone is the first step in the design of settling tanks. In this paper, while the FTC (Flow Through Curve) was introdueed, by using the Rl\G k -E turbulence model, the effects of inlet position on the hydraulic perfor mance of primary settling tanks were investigated . The ba.ffie presence effeet was also studied. Results show that the R.\.G k--t turbulence model ean predict the curvat ure of streamlines correctly. It is also shown that the inlet ba.ffie is not useful for the present ease-study rutd reduces its performance.

Keywords