8. Research and development
Larger diameter units
An important step is to establish the limits of height and diameter of this new technology. There seems virtually no limit to the height of the machine, although a practical limit of 10 metres is currently recommended. The cost per unit volume of material handled reduces with increasing elevator diameter. To date 63, 76, 101 and 152 mm (2 ½", 3", 4" and 6") diameter elevators are in use. A 203mm (8") diameter elevator is under construction in the U.S to elevate ceramic beads to a height of 6m (20 feet) at a rate of
25 tonnes per hour. A 254mm (10") diameter elevator section was recently tested in Australia for R & D.