Stacker and Reclaimer

A stacker is a large machine used for bulk material handling.Its function is to stack bulk materials such as limestone, ore, coal and grain on the stack.A recycling machine can be used to recycle materials.Gold mining dredgers in Alaska have a stacker which is a fixed part of the dredger.It transports oversized material to tailings dumps.The nominal rated capacity of a stacker is measured in tons per hour (tph).They usually run on rails between the stockpiles in the stockyard.A stacker crane can usually move in at least two directions: horizontally along a track and vertically by luffing (raising and lowering) its boom.The luffing of the boom minimizes dust by reducing the distance required for material such as coal to fall to the top of the stockpile.As the height of the pile increases, the boom tilts upward.Some stackers can rotate the boom.This allows a single stacker to form two stockpiles, one on each side of the conveyor belt.

Stackers are used to stack in different ways such as conical stacking and herringbone stacking.Packing in a single cone tends to result in size separation, with the coarser material moving towards the bottom.Adds additional cones next to the first cone in the original cone layer stack. In herringbone stacking, the stacker travels the length of the pile, depositing material layer by layer.The stacker-reclaimer was originally controlled manually, and there was no means of remote control.Modern machines are usually semi-automatic or fully automatic with parameters set remotely.The control system used is generally a programmable logic controller with a man-machine interface for display and connected to the central control system.

In addition to stacking, the stacker has three basic actions:

• Luffing: This is vertical movement. Stackers use either a winch mechanism with wire or hydraulic cylinders, usually two. Compared to hydraulic actuators, winch mechanisms are very reliable and are still widely used,especially in large stacker cranes.

• Travel: The stacker moves on wide- or narrow-gauge tracks, enabling it to move around the yard as required.For this purpose, traction motors powered by direct current (DC) are connected to 12 to 22 wheels via bevel gears.For manual control, all controls are located in the controller cabin above the boom conveyor or boom.Modern stackers can be controlled remotely.

• Swing: This is the rotation of the stacker about its central axis to align or place the stack where it is needed.This is primarily achieved by a rotary pinion that rotates around a rotary base.This type of gear assembly is called a sun and planetary gear. Axles can be multiple, driven by DC-driven axle motors, and torque is transmitted through bevel or helical gears.

Conveyor belts used in stackers may be made of fabric or wire, depending on the material being handled.They are driven by pulleys which in turn are driven by DC motors.The motor and gear are connected through a fluid coupling.Most stackers are powered by trailing cables.There are basically two types of cable hauling:Power Cord Rotating Reels (PCRD) and Control Cable Rotating Reels (CCRD). A pendulum adjustment is made to ensure these cables are properly aligned when the stacker is traveling.

Reclaimer

A reclaimer is a large machine used in bulk material handling applications.The function of the reclaimer is to recover bulk material such as ore and grain from the stockpile. Stackers are used to stack materials.Reclaimers are volumetric machines with rated capacity in m3/h (cubic meters per hour), usually converted to t/h (tons per hour) based on the average bulk density of the recycled material. Reclaimers typically travel on rails between stockyard piles. A bucket wheel reclaimer can typically move in three directions: horizontally along a track; vertically by "luffing" its boom and rotating by turning its boom.The reclaimer is usually powered by a trailing cable.