which is to give a high radial acceleration to the material to be disintegrated before touching the rotor blades 2 1 the input material crashes first against the distributing cone or disc 2 4 which distributes it equally over the whole circumference wear blades 2 5 are fixed to the ends of the rotor blades 2 1 they act at the same time to prolong the acceleration path in order to avoid that long pieces of input material twist around the tools and build up at least one shear off or cleaning knife 2 6 is fixed to the end of one rotor blade instead of a wear blade in order to avoid that material enters the narrow gap between rear side of the rotor 2 and base disc of the tool ring 3 where it could produce friction and cause fire radially arranged ribs 2 7 produce scavenging air which is centrifugally accelerated this air keeps the gap clean tool ring 3 consists of a base disc 3 1 a hollow wheel for the drive 3 2 a mechanical or hydraulic drive 3 3 and two types of tools the first type is an interchangeable tool 3 4 which can be executed in any suitable geometry and height the second type of tool or large tool carrier is not interchangeable but welded in between base disc 3 1 and counter ring 3 9 in order to give the necessary transversal stabilty to the tool ring 3 the working edges of.