Travelling waste water screen sizing and performance, UK

Travelling screens have been used in the UK waste water industry for several decades and are widely renowned for their high solids capture ratio, robust design, reliable cleansing and relatively low operating and maintenance cost. However, achieving optimal performance of these screens is subject to their adequate sizing and control, combined with regular monitoring of their performance and proactive maintenance. Analysis of the photographic evidence and data gathered during a 3 months’ screen trial carried out in the UK by United Utilities at an operational waste water site revealed some key factors that could adversely affect the screen performance. It also prompted further critical analysis of the current design guidance and practices, which allowed making recommendations for improving the methods of sizing, control and maintenance of this type of screens. This resulted in some generalised conclusions being drawn which could be applied to other similar types of screens.