Clogging in Waste Water Pumps

When designing wastewater pumps, a major challenge is to minimize the risk of clogging and jamming in the hydraulic part. Cost of system maintenance, and downtime caused by clogging and jamming in pumps, underlines the importance of minimizing the occurance of these failures.
To prevent clogging and jamming, the number of vanes in the pump impeller can be reduced or the impeller shroud width can be increased. However, these changes will often reduce the hydraulic performance of the pump significantly. Another possibility is to improve design features of the pump. Basing the design of pumps on practical experience is expensive and time consuming. By identifying changes in design features in the design stage, before production of the pump, the cost of developing wastewater pumps can be significantly reduced.
By accurately simulating the flow in a pump, several designs can be tested before pump production. The use of CFD to model fluid flow in pumps is common. However, wastewater often contains high fractions of solid particles, which is very challenging to model in a CFD context. Therefore, clogging effects has not previously been modelled using this method.
This project will couple CFD with DEM using the commercial software Fluent and EDEM. This enables simulation of the flow of water and fibrous material through a wastewater pump, including effects of clogging and jamming. The simulations will be validated through tests. The goal is to use the simulations to identify design features and general principles making wastewater pumps more resilient to clogging and jamming, and maintaining a high pump efficiency.