Experimental research on free-surface vortices as transport mechanism in wastewater sumps
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Sumps of wastewater pumping station can experience problems due the formation of (solid) floating layers of fat and scum as a result of insufficient current guidelines for sump design with respect to transport of floating debris. To complimentary the guidelines, the use of free-surface vortices is defined as a potential transport mechanism for floating debris. The transport ability and capacity of vortices is investigated in an experimental set-up and experimental data will be used to design and validate a theoretical vortex transport model describing the transport ability and capacity of a free-surface vortex. Two theoretical vortex models describing the vortex flow field are used as a base for the transport model. Experimental results show that both models needs adaptation to match experimental results. Furthermore, the experiments show that the ability to transport buoyant material is highly sensitive on the flow field in the vortex (core) and on the particle density. Particles can either get stuck in the vortex core with no or less transport or either translated around the core with efficient transport. Before designing and validating the vortex transport model, extensive future research is needed to capture the observed phenomena’s.