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Frozen Coal Crackers

Kategori : Crusher

When Pennsylvania introduced the original Frozen Coal Cracker1 in 1941, it was quickly adopted by the power generation industry. Over the following decades, Pennsylvania has made continuous refinements to the design...refinements which today make this unit the most effective machine available for reducing frozen coal. The Pennsylvania Model FCC continues to be recognized as the standard unit for this application.

1The term "Frozen Coal Cracker" was originated by and is a trademark of Pennsylvania Crusher Corporation.

Frozen Coal - Causes and Effects

Studies found that as coal freezes in rail cars the strength of this bond increases as the free moisture increases.

The compressive strength of the frozen coal also increases as temperatures drop. At -20°F, it has about 80% greater strength than it has at +15°F.

Frozen lumps as large as 4 feet thick are not uncommon in rotary dump operations, creating serious jam-ups in hoppers, in conveying systems and transfer points.

In addition to jamming the coal handling system, frozen coal chunks frequently require that conveying systems be pitched at inclines no greater than 15 degrees. This requires longer conveyors and more space for the entire coal handling system.

 

The Pennsylvania Frozen Coal Cracker Concept

In PCC's analyses of this problem it was determined that most of the major problems caused by frozen coal would be eliminated by a system which performed as follows:

  • The coal is unloaded at rotary car dump station from the rail car or storage directly into the "cracker" via open-throated  hoppers, without using grates over the dump hopper
  • The cracker must have a low profile
  • Frozen chunks larger than the feed opening must be exposed to the shearing action of the teeth on the revolving roll
  • The cracker must reduce the large frozen chunks completely and discharge a minus 6 to 8 inch output size to conveyors.
  • The operator must be able to start the cracker up under a head of coal.
  • The entire breaker plate assembly must be externally controlled.