Assuring optimal performance, adaptability and overall coal yard competitiveness means more than just avoiding catastrophe.
By Ron Pircon, Benetech
Identifying fire and catastrophe will always be among the most urgent concerns for coal yard operators. Potential trouble spots that can lead to fire and other damage must be prioritized and managed immediately. Consulting companies can help identify these firetraps and recommend steps to prevent disaster and minimize fire hazard potential.
Unfortunately, many coal yards end the evaluation process there, stopping short of evaluating vulnerabilities that affect operational integrity. As a result, they miss opportunities to improve efficiency.
Since many coal yards are 40 years old or more, most need to refit and update equipment to code, increase throughput and make other modifications due to a fuel switch and/or the inability to accurately blend fuel. As a result of today’s more stringent environmental controls, better understanding of sub-bituminous coal characteristics and coal blending opportunities, coal yard assessments must go beyond traditional disaster protection evaluations and take a wide view of factors that affect operations.
A comprehensive coal yard assessment can save hundreds of thousands of dollars a year and lead to more efficient operation and coal delivery. Issues that must be addressed include pollutants, current and future trends in coal operations (such as fuel flexibility, coal blending, changing market conditions and demand) workforce issues and coal yard efficiencies that minimize total cost of ownership (TCO).
Coal yard evaluations must be updated to address the many changes coal processing is undergoing.
Trend toward Sub-Bituminous Coals – Increasing use of sub-bituminous coal requires better understanding of coal transfers, storage and Powder River Basin/bituminous coal blends. While introducing Powder River Basin (PRB) coal into the mix can lower a plant’s fuel cost and reduce ash production and air emissions, it is more difficult to burn and more susceptible to spontaneous combustion when stored. That means coal spillage and dust become larger issues. Coal blending, storage and capacity plans must be introduced and/or reevaluated to accommodate the new properties and risk index of the plant’s coal operation.
Workforce Reductions -Workforce reduction, coupled with the recent upsurge in coal yard activity, has required plants to run harder with fewer people. Plants must set up more efficient operations that require less manpower for cleaning and dust maintenance. New equipment is available that streamlines coal yard operation, with a specific focus on PRB compatibility. Coal transfer solutions that eliminate loading idlers, skirt boards and the hooded area on the bottom of the exit side of the transfer chute eliminate much of the maintenance that was required before these options were available. Such systems not only address the diminishing workforce problem, but also can have a significant positive effect on the company’s bottom line.
Coal Yard Risk Index
Coal yard risk overviews are emerging (such as Benetech’s Risk Index) to address the trends currently affecting operation and innovative methods are being developed to secure safe and efficient coal yards.
Benetech’s steps for evaluating the plant for fire and efficiency requires
- Identifying vulnerabilities
- Establishing “Best-in-Class” remedies
- Implementing performance standards, and
- Monitoring progress with re-evaluation techniques built into the ongoing process.
Identifying Vulnerabilities – The coal yard must be evaluated for its coal-handling operation and equipment. The condition assessment of coal crushers, conveyors, hoppers, transfer points, storage silos and bunkers all play a part in a safe and efficient operation. Outdated or faulty equipment can result in coal spilling on equipment or on the plant floor, presenting combustibility risks. Once all equipment is evaluated, each step in the coal transfer process is rated in quantitative measures, such as probability and expected value. Immediate hazards, such as potential hot spots that can lead to fire and other damage, are prioritized.
Coal transfer systems can reduce cost of operation by eliminating skirt boards, seals and associated maintenance. Photo courtesy of Benetech
Once all equipment is evaluated, each step in the coal process is rated in quantitative measures, such as probability, replacement value and the cost of business interruption. Immediate hazards, such as potential “hot spots” that can lead to fire and other damage, are prioritized.
“Best-in-Class” Remedies – Under a Risk Index program three different dust handling technologies can be implemented to minimize dust, which is the major cause of coal yard catastrophe and inefficiency. These methods are dust containment, dust collection and dust suppression. One or more – or even all of these dust management technologies – can be incorporated at each plant.
These techniques are performed from the rail/barge unloading facility to the stockpile, from the stockpile to the crusher station, from the crusher station to the tripper room and to the coal storage bunker. Each area is assigned a numerical grade with color-coding for “hot spot” identification. The Risk Index report contains a management summary and includes support documentation to determine where and why areas are at an elevated risk.
Implementing Performance Standards – Once the equipment condition is assessed and the dust handling methods are implemented, performance standards must be devised to eliminate, contain and monitor identified risks. Benchmark reports must be developed for continued vigilance of risk factors. Action plans need to be established, which may include suggestions relating to cleaning and operating procedures, training programs, equipment adjustment or possibly plant reconfiguration.
Questions to be addressed when setting up performance standards take into account continuing trends in coal blending, pollutant emissions and reduced workforce. They include:
- How does the plant maintain its newly attained low-risk operation?
- How does the plant maintain its best-cost-of-ownership ratio?
- Who is responsible for cleaning/operating procedures?
- Have training programs been upgraded?
Monioring Progress with Reevaluation Techniques – Adhering to accepted performance standards is key to the coal yard’s continued success, both in terms of safety and reduced operating expenses. Once performance standards are established, regular monitoring intervals must be implemented. The risk index program incorporates monthly sampling to ensure continued compliance with set standards, along with a scheduled monthly meeting to review findings and address any deviations that arise.
This is often the easiest step to ignore and the hardest to maintain. Once dust containment and suppression equipment are installed, many coal yards will consider the system fixed and assume it will take care of itself in the future. Although innovative technologies will address new trends by setting up the coal yard infrastructure to store, transfer and burn blended fuels and control spillage and dust, plant managers must ensure that workers are adjusting to updated operating methods and that the elevated requirements of plant safety are understood. Monitoring progress and re-evaluating procedures will ensure that the updated coal yard is continuing to operate safely and efficiently.
Ron Pircon is president and CEO of Benetech and has more than 22 years of dust management experience involving system design, fabrication, installation, testing and service. The company currently provides dust management programs to utilities that burn over 60 million tons of PRB annually. He has co-authored several papers in dust suppression designs and product selections.