Method and apparatus of defibrating a fibre-containing material

A method for defibrating fiber-containing material comprising wood chips, grass, or mechanical, semi-chemical or chemical pulp for use in paper manufacturing, comprising

• i) providing a defibrating device having
• a) a rotatably-mounted first rotor equipped with collision surfaces mounted thereon in concentric peripheries;
• b) a rotatably-mounted second rotor equipped with collision surfaces mounted thereon in concentric peripheries and adapted to rotate in a direction opposite to that of said first rotor, said second rotor in cooperating relationship with said first rotor such that the collision surfaces of said first rotor and the collision surfaces of said second rotor project toward each other and are interspersed,
• c) a housing containing said first and second rotors, and having a feed orifice and a discharge orifice, said feed orifice in communication with a center of said first and second rotors and being sufficiently large that fiber-containing material may be fed freely therethrough at ambient pressure;
• said discharge orifice in communication with a periphery of an outermost rotor;
• ii) feeding said fiber-containing material into said feed orifice of said defibrating device, such that said fiber-containing material is made to flow with the aid of air or liquid to said first and second rotors, and then through said collision surfaces to said discharge orifice to produce defibrated material;
• and
• iii) collecting said defibrated material from said discharge orifice.