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 and orifice plates. The housing includes a first end having a feed chute 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. A rotatable shaft extends substantially along a longitudinal central axis of the housing. Rotors each include a hub coupled to the shaft for rotation therewith, a substantially polygonal-shaped rotor plate centrally fixed to the hub and having apices, and a plurality of vanes each vanes extending approximately radially inward on a side of the rotor plate from an apex. Each orifice plate extends inwardly from the internal sides of the housing to a central aperture which provides an orifice around the shaft. Circumferentially spaced members are located proximate the rotors, wherein the members extend inwardly from the corners of the housing toward the rotors.