UNIT 4 STACKER/RECLAIMER

COLLISION PREVENTION

Collision Potential

There are two potential collision points:

One is between the Stacker boom and the top of the Reclaimer mast.

The other is between the Stacker counterweight and the Reclaimer mast.

Stacker Max. HeightIf the Stacker height is at it’s maximum of 25 degrees, there is no possibility of collision between the Stacker boom and the Reclaimer mast.

Stacker Counterweight to Reclaimer mast collision is still a possibility.

The Stacker must be in Max. Height position (+25 degrees) anytime the Stacker is to “cross over” the ReclaimerIt should also be at Max. height whenever the Stacker is out of service and in “Neutral” position. (To be explained later)

Outgoing Coal ConveyorReclaim

er

Stacker

30 degree Collision Alarm &

Shut Down

(At Max. Height 25 deg.)

Stacker Max. Height – Counterweight Collision Potential

Stacker in Stackout RangeWhen in “Stackout” range, -15 to -1 degrees, ( -1 is full pile height) there is no possibility of the Stacker counterweight colliding with the Reclaimer mast.

In this position however, the Stacker Boom must not be allowed to collide with the Reclaimer mast. A 45 degree separation between the Stacker and the Reclaimer is recommended at all times. At 30 degrees separation an alarm will sound warning of a potential collision. At this point controls for moving either the Stacker or the Reclaimer will be disabled. E & I then has to disable the interlocks and move out of collision range prior to reset.

Outgoing Coal Conveyor

Reclaimer

Stacker30 degree Collision Alarm &

Shut Down (In Stack-out range -1 to -15)

Stacker In Stack-out Range – Stacker Boom to Reclaimer Mast Collision Potential

Stacker Between Stack-out Position and Max. Height

In this position both collision potentials are present. The Stacker should not be left in this position at any time. The only time you should have the Stacker between -1 and 25 degrees is when you are manually moving it to either “Cross-over” or Stack-out position. During moving operation insure separation between both Stacker boom and Reclaimer mast and Stacker counterweight and Reclaimer mast does not enter the 30 degree angle resulting in collision alarm and shut down.

Outgoing Coal ConveyorReclaim

erPosition 1

Stacker(Between -1 and 25

degrees)

30 degree Counter weight

Collision Alarm & Shut

Down

ReclaimerPosition 2

30 degree Mast to Boom

Collision Alarm & Shut

Down

Stacker Between Stack-out and Max. Height – Counterweight & Boom Collision Potential

Stacker Neutral PositionThe Stacker “Neutral”

position refers to the desired

position for the Stacker when it is out of service. It should be lined up with the Rain Bird pole (which

usually is at approximately 180 degrees

radial position) and set at Max.

height of 25 degrees.

Rain Bird Pole

Outgoing Coal Conveyor

Reclaimer

Stacker

180 degree angle

between Stacker and

outgoing coal

conveyor as displayed on

Control screen

Rain Bird

Set at 25 degrees or

Max. Height

Stacker Neutral Position

Varying Neutral Position While Reclaiming

While Reclaiming coal adjust the Stacker Neutral position 10

degrees towards the side from which you are reclaiming. This

prevents the Counterweight Collision

alarm and shutdown from occurring as the

Reclaimer approaches the 30 degree

counterweight limit on the far end of its travel.

10 degree

s

Outgoing Coal Conveyor

Reclaimer

Stacker10 degrees in direction

of Reclaimer

Rain Bird

Maintains greater than 30 degrees between Stacker

counterweight and Reclaimer

mast

Stacker Neutral Position + 10 Degrees in Direction of Active Reclaimer