Introduction to belt conveyor technology
02nd March 2023In this context, non-conventional means non-troughed. An emerging technology in belt conveyor is the Doppelmayr Ropecon system. This system has applications in rough terrain regions and environmentally sensitive zones. The conveyor can pass over these regions at a high level, as the conveyor is supported by cables between pylons like a suspended cable bridge. The span between the pylons can be up to 1500 m. The conveyor is a box-type flat belt with flexible vertical concertina side walls. The belt is supported by axles and wheels that travel on the suspended cables. That means the items that require maintenance, i.e. the wheels and bearings, travel around the system and back to a convenient point where the work can be safely done. The longest length to date is approx. 3500 m, and highest capacity approx. 3500 tph.
Other non-conventional conveyors include High Angle Conveyor (HAC), Cable Belt, Pipe-types, Rail conveyor, Aerial ropeways, Sicon and Aerobelt.
The HAC system uses an additional belt conveyor to create a sandwich. The upper belt applies pressure to hold the material in place as it moves up the steep incline.
Cable Belt conveyors use a cross-reinforced belt supported by cables on each side. The belt is almost flat, with a slight curve, so the supporting belt is separated from the tension member. (A conventional trough belt conveyor has the tension member within the belt.) The cables are supported by wheels spaced out several metres apart. The longest length is 31 kM + 20 kM and capacities around 4000 tph are located at a bauxite mine, Worsley Alumina Pty Ltd Western Australia.
Pipe conveyors are similar to a conventional trough conveyor, except the belt is wider so that it can wrap up into a circular or pipe shape. The idler rollers, say six in a hexagonal pattern, hold the belt in the pipe shape. Pipe conveyors can bend around smaller vertical and horizontal curves than conventional troughed belt conveyors. Pipe conveyors are good for dusty materials and conveying in and around process plants. The longest lengths are > 8 kM with capacities near 4000 tph.
Aerial ropeways come in a couple of forms. There is the classic bucket hanging from a rope (like the chairs on a ski lift). The bucket would hold several cubic metres of material. Doppelmayr and others supply this type of machine for low volumes over difficult or complex routes. Aerobelt conveyors are like conventional troughed belt conveyors, except the belt is supported by a cushion of air instead of idlers. There is an air plenum in the shape of a trough with many holes to allow the air to leak out and form the cushion. The longest length is near 800 m, and the speeds range up to 7 m/s. The maximum capacity is near 400 tph.
The Sicon conveyor has the belt hanging like a teardrop-shaped pouch, with the tension cables on the edge. These belt conveyors are good for dusty materials and conveying in and around process plants. The highest capacity is around 1000 tph and longest length 2.5 km.