Unit 4 Stacker/ Reclaimer Collision Prevention

1. Unit 4 Stacker/ReclaimerCollision Prevention

2. 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.

3. Stacker Max. Height If 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. StackerCounterweight 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 Reclaimer It should also be at Max. height whenever the Stacker is out of service and in “Neutral” position. (To be explained later)

4. Stacker Max. Height – Counterweight Collision Potential 30 degree Collision Alarm & Shut Down Outgoing Coal Conveyor Reclaimer Stacker (At Max. Height 25 deg.)

5. Stacker in Stackout Range When 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.

6. Stacker In Stack-out Range – Stacker Boom to Reclaimer Mast Collision Potential Outgoing Coal Conveyor Reclaimer 30 degree Collision Alarm & Shut Down Stacker (In Stack-out range -1 to -15)

7. 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.

8. Stacker Between Stack-out and Max. Height – Counterweight & Boom Collision Potential 30 degree Counter weight Collision Alarm & Shut Down Outgoing Coal Conveyor Reclaimer Position 1 Reclaimer Position 2 Stacker (Between -1 and 25 degrees) 30 degree Mast to Boom Collision Alarm & Shut Down

9. Stacker Neutral Position The 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

10. Stacker Neutral Position Reclaimer Outgoing Coal Conveyor 180 degree angle between Stacker and outgoing coal conveyor as displayed on Control screen Set at 25 degrees or Max. Height Stacker Rain Bird

11. 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 degrees

12. Stacker Neutral Position + 10 Degrees in Direction of Active Reclaimer Maintains greater than 30 degrees between Stacker counterweight and Reclaimer mast Reclaimer Outgoing Coal Conveyor Stacker 10 degrees in direction of Reclaimer Rain Bird