A level measuring device, installed upstream of the spiral screen, monitors the respective level of the liquid. When the preset maximum level is reached or exceeded, the drive of the spiral screen is automatically activated. The deposits of solids retained in the sieve basket are then conveyed by the spiral into the pressing zone and dewatered. A rotating scraper in the discharge area ensures that the dewatered solids are automatically discharged. During the discharge procedure, the sieve basket surface is cleaned by means of a spiral brush mounted on the spiral. As a result of the cleaning and discharging processes, the level of the liquid upstream of the sieve basket drops. When this level reaches or falls below the set level, the spiral drive switches off automatically. The Noggerath Spiral Sieve suits for numerous different applications and is adaptable due to several variations or add-on modules.
Noggerath® Spiral Sieve NSI is ranked among the best machines of their kind in the world. The liquid flows into the sieve basket, which is open on the inlet side. Solids with a larger diameter than the hole/gap width are retained. A continuous layer of solids is therefore formed on the surface of the screen, reducing free passage through it and causing the level of the liquid upstream of the screen casing to rise.