https://orthmanconveying.com/conveying/shaftless-screw-conveyors/
Orthman’s shaftless screw conveyor uses one continuous helix that rides on a replaceable trough liner. This removes the center pipe and hanger bearings where wet or stringy material tends to build up. It suits sludge, bio-solids, pulp, recycling and wastewater applications, and a perforated liner option can drain liquids as material moves. Orthman is based in Cleburne, Texas.