Visualization of the Motion of Textiles through a Waste Water Pump at Different Operating Points

In this paper, the motion of textiles through a waste water pump is studied by aid of vision technologies. The steel volute of a commercial pump is replaced with a similar volute made in acrylic glass, which allows recording the motion of textiles inside the pump. Recordings are made at four different operating points to investigate the influence of rotational speed of the impeller and flow rate on the passage of textiles through the pump. The experiments show that the textiles flow rapidly through the pump when the pump is operated near the best efficient point for both high and low impeller speed. The textiles tend to stay inside the pump when the pump is operated at part load for both low and high impeller speed. At low impeller speed, the textiles often stick to the tongue in the pump casing. At higher impeller speed, the textiles flow multiple rounds in the volute. For fail-safe operation, it is recommended not to operate waste water pumps far away from the best efficiency point.