function of feeding consistency and the continuous line the specific energy consumption oek of the rotor as a function of feeding consistency the pulp in question is oxygen delignified swsa softwood sulphate pulp lines 1 illustrate a screen with the novel rotor elements and lines 2 a prior art screen the device with the novel rotor elements operates at a significantly higher feeding consistency than the prior art device and still the energy consumption is lower also the thickening of the reject is lower in the device with the novel rotor elements although it is operated at the same or a higher feeding consistency as the device with the prior art screen the device with the novel rotor elements is further characterized in that lower rotor speeds can be used at the required feeding consistency which decreases energy consumption the screen with novel rotor elements disclosed herein may provide at least the following advantages b high feeding consistencies can be used e g in the apparatus disclosed herein had a feeding consistency of sw pulp of 1 5 higher than the prior art device as a result of this the number of water cycles in the mill is decreased need for pumping is decreased apparatuses such as containers are required in decreased numbers sizes of the apparatuses are decreased pipe lines become shorter the overall space requirement is decreased d better running security of the screen because cavitation is decreased and while the invention has been described in connection with what.