The KLASS spiral filter is used for the separation of suspensions, where solid components are thickened and dewatered. The patented KLASS Wendelﬁlter is used for solid-liquid separation, thickening and dehumidification of suspensions, especially for fine separation of very liquid media. It functions purely mechanically: The suspension is fed to the filter column by a worm pump. The filter unit consists of a spiral and a fine filter. The spiral transports the suspension upwards through the fine filter. A vacuum pump removes the liquid phase from the suspension through the fine filter. The dewatered solids are discharged via a solids chute at the top of the spiral. The drain pump pumps the filtrate away.
The low-noise, low-speed pump achieves a very high dry matter content (dry matter content) and separation efficiency with minimum energy costs and a very small space requirement. Due to the finest ﬁlter with 100 µm holes, the separation efficiency is higher than with filter presses. Suspensions with a very low input TS content can also be processed. The spiral is surrounded by a perforated filter tube, through which the filtrate can pass and is drawn off from the drain pump. With its pumping speed it supports the filtrate. The vacuum is decisive for the dry matter content of the solids; it can be adjusted by the speed of the discharge pump and read off on the manometer. The solids are thickened and dehumidified in the spiral on the way up. At the upper end, they are ejected via the solids chute and can be removed from there via a conveyor belt or a screw conveyor. Since the spiral is vertical, there is no start-up phase and no unseparated suspension can run out of the unit.