| abstract |
A method and apparatus for biological and/or chemical decomposition of waste containing organic matter. The method includes waste pretreatment in which waste is fragmented and homogenised in a pretreatment apparatus ( 10 a , 10 b ) operating on the principle of a multi-ring double action impact mill. The apparatus has either two rotors ( 62, 64 ) or a rotor and stator disposed inside a housing ( 26 ), which rotors and/or stator are equipped with blades having impact surfaces, and which form one or more rings ( 1,2,3 , . . . ) coaxial with the rotor. The waste is fed into the housing through the hub of rings formed by the blades, and travels by the effect of a rotor or rotors, to the outer ring of the ring ( 7 ) formed by the outermost blades, and further to the discharge opening ( 25, 27 ′) at the outer ring. |