Authors

D. Egarr, M.G. Faram, T. O’Doherty, D. Phipps and N. Syred

Abstract

A Hydrodynamic Vortex Separator (HDVS) has been modelled using Computational Fluid Dynamics (CFD) in order to predict the residence time of the fluid at the overflow and underflow outlets. A technique which was developed for use in Heating, Ventilation and Air Conditioning (HVAC) was used to determine the residence time and the results have been compared with those determined experimentally. It is shown that in using CFD, it is possible to predict the mean residence time of the fluid and to study the response to a pulse injection of tracer. It is also shown that it is possible to apply these techniques to predict the mean survival rate of bacteria in a combined separation and disinfection process.

Authors

Darrell A. Egarr, Michael G. Faram, Timothy O’Doherty, David A. Phipps, Nicholas Syred

Abstract

A Hydrodynamic Vortex Separator (HDVS) has been modelled using Computational Fluid Dynamics (CFD) in order to predict the residence time of the fluid at the overflow and underflow outlets. A technique which was developed for use in Heating, Ventilation and Air Conditioning (HVAC) was used. The results have been compared to those determined experimentally. It is shown that in using CFD, it is possible to predict the mean residence time of the fluid and to study the response to a pulse injection of tracer. It is also shown that it is possible to apply these techniques to predict the mean survival rate of bacteria in a combined separation and disinfection process.

Authors

R.Y.G. Andoh, A.J. Stephenson and P. Collins

Abstract

The need for a more holistic approach in the development of solutions to wet-weather induced problems in urban drainage systems is advocated. A review of current approaches to resolving problems of premature overflows and flooding is presented outlining a case example of the successful application of non-conventional approaches, techniques and devices that assist in the better management and control of wet-weather flow sources. This involves the seeking of solutions within the upstream portions of drainage systems by intercepting, containing, controlling and treating excess wet-weather flows before they cause hydraulic and water quality problems in downstream areas (sections of the drainage system). These approaches have been found to be more cost-effective than conventional solutions and involve the implementation of distributed/decentralised schemes which in turn offer improved opportunities for wider community and other stakeholder involvement leading to the realisation of amenity and other non-structural benefits.