You forgot to mention WHY it's an improvement over conventional screw elevators through. The main advantage is that, since the screw itself is fixed, it moves material much more efficiently upwards because it doesn't have to turn the screw against the resistance of all the grain being pulled down by gravity. It also allows for a large clearance between the screw and the casing cylinder, reducing friction and damage to the grain or equipment.,(reply>), Tbf the inventor did mention that when he was describing it regarding the part about explosive dust,(reply>), Also the screw doesn't have to go all the way to the top