Process-optimized hammer mill

A hammer mill for batchwise operation in which milling material introduced into a milling chamber is held for a specific treatment time, the hammer mill comprising:

• a rotor rotatably arranged in the milling chamber and having pendulum-mounted hammers fitted thereon;
• a stationary mill housing surrounding the rotor, said stationary mill housing enclosing a cylindrical milling chamber in a rotor region;
• a supply shaft aligned so as to open tangentially into the milling chamber approximately in a gravitational force direction, said supply shaft being closable by a movable closure wall in a transition region between the milling chamber and the supply shaft;
• an emptying device fitted on a bottom of the milling chamber in the gravitational force direction for discharging a coarse fraction of the milling material from the milling chamber in a batchwise manner;
• wherein the supply shaft has one of a rectilinear and prismatic design with a cross-section and a length dimensioned so as to have a capacity such that, when compared with the milling chamber being filled to a full extent with a loose fill of milling material, the supply shaft receives at least 1.1 times said full extent of the loose fill;
• a longitudinal guide arranged in the supply shaft for displacing the movable closure wall back and forth along the length of the supply shaft between a raised standby position and an operating position lowered onto a circumference of the milling chamber such that the milling material introduced into the supply shaft when the closure wall is in the raised standby position is forcible into the milling chamber and held therein by the movable closure wall being displaced in the direction of the milling chamber, wherein the specific treatment time is approximately accurately maintained for all loose fill in each batch;
• an introduction opening arranged in the supply shaft beneath the movable closure wall when in the raised standby position, wherein a receiving volume of the supply shaft located beneath the introduction opening is large enough for a complete milling-chamber fill to be received therein;
• an introduction hopper fitted on the outside of the supply shaft in front of the introduction opening, said introduction hopper being closed at a bottom and receiving a milling-chamber fill, wherein the introduction hopper includes a discharge opening which opens into the introduction opening of the supply shaft;
• wherein a pivot path of the pendulum-mounted hammers is limited to a rear, at least in the rotation direction, via stops arranged such that a forced-back striking position of at least one of the pendulum-mounted hammers corresponds approximately to a tangential position directed rearwards in the rotation direction or to a position pivoted by not more than approximately 10.degree. beyond the tangential position, such that the hammers in the forced-back striking position project with their leading longitudinal side beyond discs of the rotor which bear the hammers .