The device has a cylindrical chamber (3) integrated with a crushing unit i.e. cylindrical crushing rotor (15), and defined by two parallel plane sides. Two lateral clearances (16) are integrated to a central shaft (17) carried by the parallel plane sides of the chamber. The crushing unit comprises multiple calibration rings (19), and is arranged parallel to the lateral clearances. External edges (19') of the calibration rings define a virtual cylindrical envelope beyond which active parts of cutting or crushing tools are projected. The active parts are composed of crushing hooks.