Bulk material flow through hoppers, stockpiles, silos or chutes can become compacted, and in some cases blocked. Blockage types include rat holes, arches, bridges and clinging material.
Material bulid-up in silos, hoppers, and bunkers causes live capacity issues and the reduced amount of material flow from the silo, hopper, bunker and chute, this creates a number of knock-on issues. Material build up reduces plant efficiency as the live capacity is reduced and less material actively flows through the silo, hopper, bunker and chute, and into the plant. This means material is more likely to run out and reduces efficiency.
Live capacity also affects product flow in areas like the chute, and it will also change the impact zone. This then leads to increased wear in areas not designed to wear and increases the chance of misalignment. Misalignment leads to spillage, belt wear, structural damage and reduced belt life.
In order remove material build-up, flow aid devices are used to promote the movement of bulk materials through hoppers, stockpiles, silos and chutes.
Air cannons or air blasters use compressed air to create an explosive force that is used to dislodge and prevent build-up, blockages and clinging material from the walls of hoppers, stockpiles, silos or chutes. Vibrators utilise vibrations to shift clinging materials.
In some areas, it is appropriate to remove material build-up in a silo or hopper with a silo cleaning device. Silo cleaning tools like the bin whip regain live storage capacity and recover lost material. The bin whip machine is an air powered, manually controlled device for the cleaning of silos/bins internal surfaces.