Stackers – fast, effective and reliable handling of bulk materials in a stockyard operation
In any large-scale stockyard operation stackers play a key role as they deposit the bulk materials in pre-set patterns and systems. Stackers are available in a wide variety of configurations depending upon the required throughput and degree of mobility. They may feature a stacking belt that can be raised or lowered, single or twin booms, a semi or fully automatic control system, and other application-specific features. Fully automatic rail-mounted stackers, for example, are ideal for building up stockpiles for storage or blending beds.
thyssenkrupp stackers combine robustness, fast operation, and high throughputs. They are designed so the user enjoys the benefits of cost effectiveness, reliability, and eco-friendliness. To meet today’s increasingly strict environmental and safety requirements, thyssenkrupp stackers are generally equipped with all the necessary precautionary equipment and systems to minimize the impact of noise, dust emissions, etc. on operators and the surroundings.
Luffing and slewing stacker
This is the most versatile type of stacker since it can slew from one stockpile to another on the other side of the yard, building uniform stockpiles on both sides of the yard feed conveyor. This stacker can build a stockpile in chevron, cone-shell, windrow or strata stockpiling modes. The machine can easily work in combination with each and every type of reclaimer on adjacent rail tracks, as the boom can slew to a position parallel to the rail track, thus allowing other machines to bypass it.
A luffing stacker travels along the entire length of the longitudinal stockpile conveyor to build a stockpile on just one side of the conveyor. A luffing stacker is easy to operate and the most cost-effective solution for a stockpile on one side of the conveyor. Thanks to its simple structure it has fewer mechanical components than luffing and slewing stackers. However, only chevron and cone-shell stacking are possible with this type of stacker. Moreover, bypassing machines on adjacent rail tracks is more difficult as the boom cannot be slewed out of the way.
Combined circular stacker-reclaimer
A circular stacker-reclaimer, which is designed for 360° rotation, consists of a slewing and luffing stacker to stack the material, a reclaimer (portal, side or bridge type), and a central column, which includes a feed and discharge hopper. The stacking and reclaiming systems operate independently. Material is fed to the boom conveyor via an overhead feed conveyor.
The substructure or undercarriage is the structural steelwork from above the equalizers up to the slew bearing. It comes in a plate box girder design, with welded constructions on all the major members. The stacker is designed to transfer loads from the stacker superstructure via the portal into the long travel system as efficiently as practicable.
How a stacker operates
Stackers are high-capacity machines used for stacking and blending material. Working in two directions, a stacker can pile material onto two parallel stockpiles using a slewing and luffing boom. A rail-mounted stacker travels on two rails between the stockpiles. The stopping and starting sequence for the stacking operation is controlled either from the operator's cabin control panel or from a central control room.
Technical facts and figures
|Installations||Over 1,300 installations worldwide|
|Product characteristics||Free-flowing or sticky; lump size up to 250 mm|
|Throughput||Up to 16,000 tons per hour|
|Boom length||Up to 67 m|
|Pile widths||Up to 82 m|
|Pile heights||Up to 31 m|