Shaft less spiral is specially designed for handling difficult heterogeneous materials like urban solid waste, screenings and floating matter, de-watered, thickened, conditioned sludge, packaged food, creams or pastes, waste from: meat, fish, fruit and vegetable processing. It offers a larger volume capacity and the possibility of handling particularly difficult materials such as those that tend to become tangled up or those that present highly variable particle size. It has completely enclosed trough, which prevents any material leakage. It is an alternative concept to the traditional shafted screw conveyor. The material is conveyed by an extra-heavy-duty shaft less screw that slides on a low-friction, wear-resistant liner inside the conveyor trough housing.