Comminution of waste and other materials

Comminution apparatus comprising:

• an outer comminution drum;
• and
• an inner comminution drum,
• said outer comminution drum having a hollow portion and having a longitudinal axis,
• said inner comminution drum having a longitudinal axis and positioned within said hollow portion outer comminution drum,
• said longitudinal axes being substantially parallel to each other, but not coaxial,
• said outer and inner comminution drums, being rotatable about their respective longitudinal axes;
• said inner comminution drum having outwardly directed inner drum projecting macerating features on its outer surface,
• said outer comminution drum having inwardly directed outer drum projecting macerating features on its inner surface,
• wherein during rotation of said inner and outer comminution drums, said outwardly directed inner drum projecting macerating features, and said inwardly directed outer drum projecting macerating features, periodically pass side by side adjacently at a closest approach of the outer surface of said inner comminution drum to the inner surface of said outer comminution drum, in a side by side intermeshing of their paths relationship;
• side by side being with reference to circular paths said projecting macerating features follow;
• and
• wherein during rotation of said outer comminution drum, and said inner comminution drum, about their longitudinal axes said projecting macerating features come into close proximity, but do not make contact, with each other nor with the surface of the other comminution drum.