comprises a hopper 120 a case 112 and a control means comprising a first surface 132 inclined in the direction of rotation 126 and a third surface 134 located at its lowest point tangenial to the inner surface of the bore of the case 112 and extending upward therefrom a second surface 136 is located between the first surface 132 and the third surface 134 said second surface may be inclined in the direction of rotation 126 of the rotor 110 the second surface 136 may be supported on a pivot axis 138 so that it may swing or pivot back and forth in the directions indicated by arrows 140 and 142 said second surface 136 may be controlled in its rotation around pivot 138 by a lever arm 144 and a weight 146 which combination tends to push the tip 148 of the second surface 136 toward the surface of the rotor 110 the various surfaces of the processing equipment and hopper may be heated or cooled as may be desirable for efficient operation by channels 150 filled with heat transfer liquids or other conventional means in the operation of the apparatus as shown in fig2 the feed material 122 falls onto the surface of the rotor 110.