Aeration Performance of Vortex Flow Insert Assemblies in Sewer Drop Structures

Sewer drops are localized points of flow energy release located throughout a conveyance system. As such, every sewer drop is a source of odor and infrastructure corrosion. Vortex Flow Insert (VFI) assemblies are prefabricated hydraulic devices designed to be installed in sewer drop structures for controlling odor and converting the ordinary drops into energy dissipaters and aerators of wastewater. The principle behind the operation of VFI assembly is creating a special flow trajectory – one that uses the flow's potential and kinetic energy to prevent H2S emissions, draw in ambient air, and mix the air into the wastewater.This article analyzes operation of the VFI's aeration effect and presents a model that can be useful for predicting the aeration performance for a given VFI installation. This model is then compared against actual measurements at two working installations.