An apparatus pulverizes material composed of wet or dry discrete objects into relatively smaller particles with shock waves created by flowing the material through a housing having alternating rotors (92, 94, 96, 98) and orifice plates (128, 130, 134, 136). The housing includes a feed chute (78) for introducing the material into the housing, a second end having an opening for removing the smaller particles, and internal sides meeting in corners, which extend longitudinally between the first and second ends. Rotors extend along a rotatable shaft in the housing, each rotor including a polygonal shaped plate and radially extending vanes.