**Nomenclature**

*<sup>h</sup>*1—size between the parallel planes of two adjacent knives (mm); *<sup>x</sup>*1—grain feed (kg·s<sup>−</sup>1); *<sup>x</sup>*2—rotation frequency of the lower disk (min<sup>−</sup>1); *x*3—separation surface gap (mm); *x*4—number of knives at the first stages (pcs); *x*5—number of knives at the second stages (pcs); *x*6—knives condition ("Old" ones/"New" ones); *x*7—presence of inserts (present/absent); *<sup>y</sup>*1—power consumption (kW); *<sup>y</sup>*2—grinder performance (capacity) (kg·s<sup>−</sup>1); *<sup>y</sup>*3—particles greater than 3 mm (%); *<sup>v</sup>*—linear velocity (m·s<sup>−</sup>1); *<sup>n</sup>*—rotation frequency (s<sup>−</sup>1); *<sup>R</sup>*—disc radius (m); *<sup>F</sup>*—centrifugal inertial force (N); *m*—mass (kg).
