FILTER DOUBLING AS FLOTATION AND FILTERING METHOD DOUBLING AS FLOTATION

摘要

In a flotation basin a flotation zone and a pure liquid zone are formed which are separated by filter means. A liquid containing suspended matter is introduced into the flotation zone via an inlet and subjected to pressure release flotation by saturating pure liquid with pressurized gas under a pressure in the range of 3 to 8 bar and injecting the pressurized gas saturated liquid into the flotation zone in the region of the inlet. The flotated mud accumulating at the surface of the liquid is removed laterally by removal means coacting with the filter means or is removed by means of a combined filtering and removing device together with non-flotatable suspended matter on a filter web circulated or passed through the flotation basin. The mud is predried on the filter web and separated therefrom by redirecting its run, if desired, with assistance by a scraper. The mud falls into a collecting container separated from the flotation basin or its contents by a partition. The outlet is disposed in the pure liquid zone downstream from the filter web or between the runs thereof with respect to the direction of liquid flow. The pure liquid is discharged by a pump controlled in dependence on the inflow.