Cement plant overcomes remote conveyor issues with power generation technology
An innovative cement manufacturer in the Midwestern U.S. has implemented a unique power solution at a remote conveyor location that lacked convenient electrical access. The patent-pending design uses the kinetic energy of the moving belt to generate enough electricity to drive an automated dust suppression system, a pneumatic belt cleaner tensioner and a series of air cannons, helping operators at the Illinois Cement Plant reduce fugitive dust and spillage, increase cargo flow efficiency and minimize labor costs for cleaning and maintenance.
The Martin Roll Gen System is designed to create a self-contained mini power station that allows operators to run electrical monitoring systems, safety devices and a variety of other components. With the ability to be retrofitted on existing idler support structures, the generator can be employed on virtually any steel roller. The device is considered a significant step toward eliminating power production obstacles, as conveyors move into the next generation of “smart systems” that are predicted to be more sustainable and autonomous.
“Running auxiliary power can be both complicated and costly, requiring expensive labor and oversized cables to accommodate the inevitable voltage drop over long runs, as well as transformers, conduit, junction boxes and other components,” commented Andrew Timmerman, Product Development Engineer at Martin Engineering. “And using even a small conventional generator to provide power introduces a different set of issues, including flammable fuels.”
The long ride
Conveyor #107-1 is the longest outdoor conveyor system on the Illinois Cement site, running 182 m and discharging either onto the #107-2 stack-out conveyor or the 75 m belt leading directly into the plant, based upon immediate production needs. It is a 762 mm mechanically-spliced belt with a 35º trough that travels at 2 m/s, conveying nearly 272 t/h of limestone.
Material arriving from the quarry can be either wet, dry and dusty or anything in between, depending on the season and weather. The changing work environment presented challenges throughout the entire conveying system, with different weather conditions triggering various types of carryback. Cleanup was labor-intensive.
“The primary cleaner blades we had in place wore quickly, causing spillage that required us to take personnel from other areas to clean the buildup,” explained Illinois Cement Maintenance Planner Brian Brandner. “We were out there cleaning or adjusting the tension to minimize spillage a few times a week. When it got really cold, we wouldn’t have as many issues with dust or carryback, but the frost accumulation required us to keep the belt running at all times, which lowered the blade life and caused undue wear on the belt.”
Phase one of the Martin Engineering solution involved placing a “smart” dust suppression system at the transfer point between the 153 and 107-1 conveyors.
Phase two included an automated, pneumatically-tensioned belt cleaner and air cannon system at 107-1’s discharge zone. Both components are powered by the Roll Gen System.
To manage the dust, technicians installed a Martin Surfactant Dust System at the transfer point between 153 and 170-1 to deliver a chemically-enhanced water spray as a topical treatment for material at the point of emission. Triggered by a sensor as soon as the load enters the transfer point, the system supports dust mitigation measures already in place to minimize the labor needed for maintenance and replacement of the dust collector cartridges.
Cleaning the belt
Close to the mid-point of the system, conveyor 107-1 begins a gradual 6 m rise and discharges into the transfer chute leading either to the stack-out conveyor feeding the storage area or the main conveyor entering the plant. At that transfer point, technicians installed a Martin QC1 Primary Cleaner XHD (extra heavy duty) tensioned with an Automated Blade System (ABS).
Connected to a small 24V DC air compressor and a control panel powered by the Roll Gen, the ABS pneumatic tensioner delivers precise monitoring and tensioning to reduce the labor typically required to maintain optimum blade pressure through manual adjustment. Equipped with sensors to confirm when the belt is running empty, the system automatically backs the blade away, minimizing unnecessary wear to both the belt and cleaner. Upon detection of an empty belt, the system is set to run for one full belt rotation to clean the surface thoroughly before pulling away. The result is consistently correct blade tension with reduced power demand on start-up, all managed without operator intervention.
Transfer chute flow
While monitoring the results of the installation, Martin Engineering technicians observed that the decreased spillage resulted in a proportional increase in fines discharged down the transfer chute. Exposed to the outside environment, the chute began to form significant buildup along the sides, at the diverter gate and on the internal shelf meant to slow the flow of material. The technicians had a solution to this unexpected result, and to mitigate the buildup, they installed a Martin Hurricane Air Cannon.
Results
The use of multiple technologies working in tandem to control material flow and prevent fugitive particles has dramatically improved the material handling system’s efficiency. The modifications have helped Illinois Cement reduce labor and equipment expenses, considerably cutting the manpower needed to clean spillage along the conveyor path. The result is a cleaner, safer and more productive operation.
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