Abstract: A classifier for classifying granular feedstock has a rotary cage rotating about a rotor axis and an air-guiding system arranged around the rotary cage, wherein a classifying zone is formed between the rotary cage and the air-guiding system. In the classifying zone one or more baffles are arranged such that the torque acting on the rotary cage is increased—for the same rotational speed—by at least 20% with respect to an embodiment without baffles and/or the separation between the air-guiding system and the rotary cage is chosen such that the torque acting on the rotary cage is increased—for the same rotational speed—by at least 20% with respect to an embodiment wherein the separation of the air-guiding system is without influence on the torque of the rotary cage.

Abstract: Disclosed herein, a classifier for classifying granular feedstock has a rotary cage rotating about a rotor axis and an air-guiding system arranged around the rotary cage, wherein a classifying zone is formed between the rotary cage and the air-guiding system. In the classifying zone one or more baffles are arranged such that the torque acting on the rotary cage is increased—for the same rotational speed—by at least 20% with respect to an embodiment without baffles and/or the separation between the air-guiding system and the rotary cage is chosen such that the torque acting on the rotary cage is increased—for the same rotational speed—by at least 20% with respect to an embodiment wherein the separation of the air-guiding system is without influence on the torque of the rotary cage.

Abstract: The invention relates to a method for monitoring the load state of a grinding system having rotating grinding elements, the dynamic forces exerted by the grinding stock on the grinding elements being detected in a first frequency range which contains the fundamental oscillation of the grinding elements, and in a second frequency range in which the first harmonic of the fundamental oscillation occurs, and measures for reducing the load state being introduced when the first harmonic exceeds a predetermined threshold value in relation to the magnitude of the fundamental oscillation. Such a method permits very reliable and accurate monitoring of the load state of the grinding system.

Abstract: The invention relates to a method for monitoring the load state of a grinding system having rotating grinding elements, the dynamic forces exerted by the grinding stock on the grinding elements being detected in a first frequency range which contains the fundamental oscillation of the grinding elements, and in a second frequency range in which the first harmonic of the fundamental oscillation occurs, and measures for reducing the load state being introduced when the first harmonic exceeds a predetermined threshold value in relation to the magnitude of the fundamental oscillation. Such a method permits very reliable and accurate monitoring of the load state of the grinding system.