During the winter months, coal being transported by rail from the mine to Public Service of Indiana Power's (PSI) 1000 MW Cayuga plant often freezes. Traditionally, plant personnel used poles and long shovels to break up the five to six feet clumps of frozen coal as they traveled from the rail cars into hoppers and through mechanical feeders to the conveyors below. However, this process was slow, laborious and labor intensive. Breaking the frozen coal and cleaning up the spilled coal by hand also slowed the coal unloading process.
Although the mine applied anti-freeze in the rail cars and on the coal, this was not always adequate to compensate for snow and ice that accumulated before loading and during the 50 mile transit to the plant. At one time the plant's management had considered installing a mechanical "coal cracker." However, the cracker's cost and extra maintenance made the economics unacceptable. As a result, the plant continued to break up the frozen coal manually and accept the reduction in productivity for the few winter months of the year when freezing was a problem.
Nonetheless, Public Service of Indiana (PSI) was still interested in coming up with a long-term solution to the frozen coal. In 2000, PSI contacted Arizona-based XMS Equipment (formerly a subsidiary of Xtek, Inc., of Ohio) about designing a pair of modularized and portable crushers.
Unlike the coal cracker initially considered, where the rolls would be in contact with the coal throughout the year, the rollers of the portable crushers could be removed during the non-winter months. Removing the rollers when not required reduces wear. After putting the project out for bid, PSI awarded the contract to XMS Equipment for a cost of approximately $300,000. This did not include the cost of any electrical work.
The coal-fired Cayuga plant has two 500 MW vintage 1970 Combustion Engineering boilers. Coal, 10,000 tons/load, is delivered to the plant by train. After arriving at the plant the coal is transferred to a 300 ton capacity hopper. From the hopper it is then transported to an in-plant bunker while the coal not required for immediate...