Patent ID: 7807060

Claim:
A method for extracting solids from a suspension containing the solids and suspension liquid in a continuously or virtually continuously operating drum filter device, the filter volume of the drum filter being separated into chambers which receive the suspension to be filtered, using a two-sided filtering material, on the one side of which, the high-pressure side, a higher pressure prevails than on its other side, the low-pressure side, and which passes successively through a plurality of working zones of the filter device in a working direction, the method comprising the steps of: supplying the suspension to the filtering material on its high-pressure side in a first working zone; filtering the suspension wherein the suspension liquid flows through the filtering material on account of the difference in pressure between the high-pressure side and the low-pressure side while at least some of the solids are deposited on the filtering material forming a filter cake; resuspending the solids which are deposited on the filtering material by injection of the washing liquid into the filter cake in chambers of a second working zone, which zone is arranged downstream of the first working zone in the working direction; and filtering the resuspension via a conveying system in chambers of a third working zone, which zone is arranged downstream of the second working zone in the working direction.