Longitudinal scrapers are mostly used with the purpose of grit and grease removal in pretreatment/ secondary plants, in basins with a rectangular section.
Similarly to circular scrapers, they can be classified with respect to various features. Power input can be realized by means of cable drum or cable trolley.
The disposal of the sludge settling at the bottom may be carried out by means of an air-lift system or a pump travelling on the bridge, or the sludge can be sucked away, or scraped continuously to the sludge funnel located at one end of the channel by means of scraper blades mounted on the bridge, depending on the application.