Modelagem hidráulica de floculador de placas de orifícios

Abstract

The hystory of the behaviour of water flowing through orifices has been very useful to describe function and design of important hydraulic structures, like reservoirs and Water Treatment Plants. This work presents the development of a hydraulic model that allows determination of two hydraulic parameters essential to dimensioning plate flocculators: the discharge coefficient (Cd) and the relation X/S. As a result of this research, it was possible to present an equation that correlates the Reynolds number (between 4000 and 18000) with the discharge coefficient, this equation is still unpublished in today’s literature. Another important point found was that the population average of Cd in many hydraulic conditions was 0.758, different of what had been previously published (0.61) and close to the value published at the current literature. It was also found a correlation and an equation correlating the X/S parameter with the Reynolds number. The range of Reynolds numbers in this new method matches partially the range obtained by the only model currently existing Di Bernardo and Giorgetti (1980, p. 528– 533). The differences between the values of X/S obtained by both models result in a significant difference between the range of the jets and, consequently, the dimensioning of the flocculator. Finally, it were used the models developed to dimension a plates flocculator composed of three chambers, with 100 m³.h⁻¹ of capacity, integrant part of a flocs-flotation system.