Fremgangsmåde og apparat til opdeling af en höstmaterialeström

The crop flow separation method involves separating the flow into useful material and waste material in at least two stages with first and second selectivity values and controlling the first selectivity value for the first stage according to the detected proportion of useful material in the waste flow irrespective of the throughput. The method involves separating the flow into useful and waste material in at least two stages by separating the flow in a first step with a first selectivity into a pre-cleaned flow with mainly useful and residual material and a first waste flow with mainly waste and residual useful material, separating the pre-cleaned flow again with a second selectivity and controlling the first selectivity according to the detected proportion of useful material in the waste flow irrespective of the throughput. An independent claim is also included for the following: (a) an arrangement for separating a crop flow containing useful and waste material.