Conveyor chutes are used in bulk handling to perform a variety of operations. In particular, the loading of a belt conveyor, and the transfer of material from one moving belt conveyor to another, are important tasks. Such operations are widely used for the transport of both coarse grain material (such as cereals, mineral ore and coal) and fine powders (as used in the chemical and pharmaceutical industries).
Optimal chute design ensures efficient transport without spillage and blockages, and with minimum chute and belt wear. The importance of optimal design is accentuated with the trend towards higher conveying speeds.
To demonstrate the different aspects of the operation of high-speed conveying, the two-belt system shown has been considered.
The granular material is initially stored in a rectangular hopper, and is loaded onto the upper belt using a feed chute with lateral skirts. The material is transferred to the lower belt at 90o via a transfer chute, comprised of a box containing two curved impact plates.
Numerical simulations using DEM were performed for belts (both upper and lower) having a width of 450 mm and speed of 2.5 m/s. The granular material consisted of spherical particles with diameters distributed between 15 and 30 mm, a density of 2500 kg/m3 and a flow rate corresponding to 47 t/hr.
The animations presented below show the operation of the feed and transfer chutes. The angle of the feed chute produces a constant loading of the belt, while the skirts guide the material onto the central region. The impact plates of the transfer chute produce a smooth change of the material flow direction.