Travelling screen with travel pause for improved cleaning of screen and method of implementing same

Abstract

A travelling screen and screening method minimize reintroducing debris to liquid downstream of a screen while achieving the relatively high efficiency of fixed bar screens. A filter surface is defined by a pair of planar plates, each of the plates having openings through which the liquid but not the debris may flow. A connector between the plates positions the plates relative to each other at a selected fixed angle. The connector formed integrally with each of the plates has the planar plates and the connector formed from one sheet and the connector in the form of a bend. A guide mounts a first travelling screen element adjacent to a second such element at a screen element scraper path with one planar plate of the first screen element being oriented relative to one planar plate of the second screen element to define a linear scraper path. The guide also positions the first and second screen elements adjacent to each other along a debris separation path. One planar plate of each of the first and second screen elements is oriented generally horizontally to define a series of generally horizontal steps for debris collection. The guide positions the first and second screen elements with the respective planar plates extending out of and on one side of the debris separation path. A method positions the travelling screen elements for being scraped. A first screen element leads a second trailing screen element along the debris separation path, and one planar plate of the leading screen element and one planar plate of a trailing screen element are scraped at one time when the motion of the screen elements pauses.