2/15/2010 New Coal Handling Transfer Chute Technologies Significantly Improve the Operation by Increasing Efficiencies, Reducing Maintenance, and Increasing Operating Margins INTRODUCTION The success of any bulk materials conveyor system is highly dependent upon the proper transfer of the conveyed material from conveyor-to-conveyor and into storage bins and stockpiles. Historically, conveyor systems design has focused on the structural integrity of the system and the selection of the mechanical components. The design of the transfer points has been left to the draftsperson and constrained by predetermined conveyor locations without any design analysis of the material flow characteristics and needs. This approach has resulted in innumerable transfers that are inefficient and expensive. The expense starts with the initial capital investment and continues as a maintenance cost and headache throughout the life of the system. Figure 1. What can happen when transfers are not planned for. There are numerous problems that are encountered due to the poor transfer design that include: • Oversized systems components required to handle poor material transfer. • Additional system components needed to counteract the effects of poor material flow. • Maintenance costs and man-hours due to component wear and failure. • Costs and man-hours for clean up of material clogging in transfer chutes, spilling around the transfer area, and dust buildup on equipment and working areas. • Excessive power consumption. • Maintenance and repair costs to capture and process the visible and respirable dust generated. • Belt damage and wear costs. Figure 2. Spillage due to improper transfer design. • Health risks associated with the higher noise level, spillage, and visible/respirable dust. • Risk of governmental and conservationist actions caused by detrimental environmental effects due to visible/respirable dust and other contaminants. There are a number of suppliers of transfer systems, which are Engineered to handle the material in a manner that reduces or eliminates the problems listed. While each of these systems can positively affect the material transfer in many ways, this paper will deal with the mitigation of the visible and respirable dust with reduced dependence on dust collection systems. Page 1

2/15/2010 ENGINEERED TRANSFERS-REDUCED DUST APPROACH TO COAL HANDLING There are a number of reasons why mitigation of the dust is important to any coal operation; • The dust can build up on and in conveyor mechanical components requiring maintenance to and failure of components. • The dust is in the air and can cause a haze that reduces visibility. This can result in accidents as well as create lower morale. • The dust can settle in the working areas and create a personnel hazard unless regularly cleaned up. • The dust needs to be removed from the environment. This can require expensive capital...

2/15/2010 Flexco Engineered Systems Group, a subsidiary of Flexible Steel Lacing Company introduced the CFMTS, an Engineered control flow material transfer system, in North America in 2003. This particular system was originally developed in Australia where approximately two hundred transfers have been installed over the last ten years. In all cases the visible and respirable dust was reduced significantly. Unless customer requested, none of the Australian installations incorporated dust collection systems, skirt board, or baffle systems, and many did not incorporate sealing between components...

2/15/2010 Due to the engineered transfer design, the coal is being handled smoothly without the material turbulence and impact in the transfer chute or on the receiving belt. This has eliminated the effects caused by the degradation of the material in the old transfer. Specific results include: • The transfer was commissioned from day one with the skirt board mounted at the transfer/receiving belt juncture, but without any sealing rubber installed. It was not needed because there was no spillage of material or visible or respirable dust generated at the transfer. • At this transfer location,...

2/15/2010 o 1.8 mg per cubic meter at the spoon (discharge to the receiving belt o .8 mg per cubic meter approximately 15-20 feet downstream of the spoon at the end of the skirting section. .. Maintenance has dropped dramatically. Instead of trucks required to haul away the spillage, maintenance personnel periodically sweep dust build up into the bunkers. • Midwest Power Generating Station .. Replaced a traditional chute system that was constantly plugging due to high moisture coal. This was constantly stopping production with significant maintenance costs incurred. .. While buildup can still...

2/15/2010 Figure 9 Figure 10 HISTORICAL DATA-BENEFITS OF ENGINEERED TRANSFERS Unfortunately, there is little hard data to substantiate all of these described benefits to the Engineered transfer. Both the suppliers of these transfers and users of them need to collect the hard data that will validate their use and benefits. Following are benefits recognized in the Australian applications over the last ten (10) years. While some are qualitative, others have had hard numbers collected that support the use of these transfers. They are: • Skirt Savings On average 12 man-hours would be spent adjusting...

2/15/2010 (20 X (hourly labor cost) plus the cost of a complete set of liners)/10 (years) X Number of transfer chutes on site = Direct cost savings to the site. • Clean-up Savings Conventional transfer systems are prone to material hang-up, bridging, and blockages. Cleaning out blocked chutes after an emergency stop is a frequent event, and general clean-up costs are ongoing. Assume an ongoing average cleaning requirement of one man-hour per week, per transfer system on site. (1 X 52 X (hourly labor cost) plus the cost of a complete set of liners) X Number of transfer chutes on site = Direct...