Damn this is genius. Instead of working on a vacuum like a traditional screw lift, this works on pressure increasing its efficiency.,(reply>), TeslaKaniv I’d disagree they said this is used in sand and sand is an abrasive so overtime it would erode it smooth reducing the friction.,(reply>), Hmm. I'd say it relies on a friction of cylinder walls instead of a friction of the screw to move grain. There is move surface contact area and therefore less slippage.