Stacker

Krupp coal stacker featuring tripper conveyor and non-slewing, luffing boom at RTCA Kestrel Mine

A stacker is a large machine used in bulk material handling applications. A stacker's function is to stack bulk material such as ores and cereals onto a stockpile. A reclaimer can be used to recover the material.

Stackers are nominally rated in tph (tonnes per hour) for capacity and normally travel on a rail between stockpiles in the stockyard. A stacker can usually move in at least two directions typically: horizontally along the rail and vertically by luffing its boom. Luffing of the boom minimises dust by reducing the height that the coal needs to fall to the top of the stockpile. The boom is luffed upwards as the stockpile height grows.

Some stackers are able to rotate by slewing the boom. This allows a single stacker to form two stockpiles, one on either side of the conveyor.

Stackers are used to stack into different patterns, such as cone stacking and chevron stacking. Stacking in a single cone tends to cause size segregation, with coarser material moving out towards the base. Raw cone ply stacking is when additional cones are added next to the first cone. Chevron stacking is when the stacker travels along the length of the stockpile adding layer upon layer of material.

Stackers and Reclaimers were originally manually controlled manned machines with no remote control. Modern machines are typically semi-automatic or fully automated, with parameters remotely set.

The controlling system used is typically a PLC (programmable logic controller) with an HMI (human-machine interface) for display connected to a central control system.

Most stackers are electrically powered by way of a trailing cable.

See also

• Reclaimer

This article about a mechanical engineering topic is a stub. You can help Wikipedia by expanding it. v • d • e