Study of a new sludge unloading station at a sewage treatment plant : Analysis of flow losses and a sludge pump

A sewage treatment plant is going to get a station in their plant reconstructed. It is the station where the water is separated from the sludge and then transported out of the plant. This new station is the main area for this project. The project holds two parts, one where the flow losses are examined and the second is where the system curve and pump configurations are explored. The flow losses can be divided into two parts, major and minor losses. Both will be examined in this project and further the distribution between major and minor losses will be studied. Furthermore, to study the station and the pump configuration, a system curve and a pump curve will be established. Depending on the percentage of dry matter in the sludge (3%, 4% and 5%) the viscosity of the sludge will vary. Therefore, different system curves will be obtained depending on the dry matter. At a given pressure increase, the pump curve will tell what power output is needed depending on the flow rate. The result shows that the flow losses will be the highest for the lowest dry matter rate, 3%. The lower the dry matter rate is, higher velocity on the flow can be used in the station. Due to the higher velocity the losses will increase. The system curves for 3% and 4% are similar. But the curve for 5% differs in where the transition from laminar flow to turbulent flow occurs at a higher flow rate