The KÖLLEMANN Self-Cleaning-System is used to convey any material considered as not conveyable with screw-conveyors, it uses the high lateral speeds between the two shafts which are turning in the same direction. In order to increase this effect even further, we have put our excessive know-how into this development in order to achieve that one of the shafts is running with twice the speed as the first one rotates. With this unique system, the KÖLLEMANN Screw-Heat-Exchangers are able to convey sticky and adhesive material in a condition like cold petroleum jelly. Due to the high cleaning efficiency, the whole system operates with lowest residues on the shafts and enables an optimum heat-transport.