I'm afraid I don't quite understand what makes it superior to a normal Archimedes screw pump,(reply>), The original Archimedes screw carries a number of 'pockets' of water up an inclined slope (see Wikipedia for illustrations).   It relies on gravity to keep the water in the pockets; there's lots of airspace above the water; and it could not work vertically.    This machine relies on relative motion between the screw and housing and on friction between the grains of the material; it needs no airspace; and it wouldn't work on a liquid.    Very similar geometry but quite different operating principle.,(reply>), A normal Archimedes screw pump is good at lifting air. This device is horrible at it. Therefore you don't get air mixed in with your particulate, which had all kinds of advantages.<br><br>Also the fact that it works with a huge gap makes it incredibly forgiving.,(reply>), It is not well explained but Archimedes will not work well vertically whereas the Olds works best vertically.  No product damage. Output precisely proportional to speed. In theory you can lift granular product vertically forever. It is really taking off now.  NO.. and I mean no maintenance system.   etc,(reply>), @Яасир Шахид it's one of those things that sounds wrong but is right.  Like the potato paradox.,(reply>), The other advantage is that the bearings can be outside of the tube and completely separated from the bulk material, so you don't have to worry about sealing them again dust and particles, and you don't have to worry about getting grease or oil in the bulk material.