A supplier of high quality limestone to US markets is reducing costs and improving safety with a series of innovative conveyor belt cleaners to help eliminate carryback and the problems it causes.
North American Limestone Corporation (NALC) reported that the cleaners from Martin Engineering ? engineered specifically for rock/aggregate applications ? have been so effective the facility no longer has service crews spend up to two hours per day shovelling and washing down accumulation from beneath the conveyors.
By minimising the need for staff to work in close proximity to fast-moving belts, the cleaners help diminish any chance of accidents or injury. Instead, by returning fines to the material flow, the company is able to reduce risk and improve overall process efficiency, saving the complex thousands of dollars in lost material and unproductive maintenance time.
NALC supplies a range of limestone products from its 243 Complex in Cloverdale, Indiana, to a number of industries in the American Midwest, including fine grind materials and high calcium crushed limestone.
The company serves customers in such diverse applications as animal feed production, electric power generation, coal mining, industrial manufacturing and various construction segments. To efficiently produce a consistent volume and quality level, the facility employs an expansive series of crushers, mills, screens and other equipment, with material transported primarily by conveyor.
Over time, material handling system operators began noticing that a growing amount of material was being carried back from the unloading points, which would accumulate and eventually create mounds of spillage that piled up beneath the structure. In keeping with its long term plans to employ industry best practices for bulk handling and fugitive material control in its operations, the company conducted an assessment and contacted Martin Engineering for advice.
According to NALC?s vice president of operations Dana Boyd, carryback ?is a common problem within our industry. If not addressed, not only does spillage create safety hazards but it also adds unnecessary work for the maintenance team when they could be focusing on other priorities?.
To rectify the issue, Martin Engineering recommended the PV primary cleaner with twist tensioner for key locations along the conveyor network. The Martin PV cleaner is a durable, one-piece blade that contains about 20 per cent more urethane than comparable primary cleaners, yielding a longer life in challenging service conditions. The aggressive blade angle can remove even wet, sticky sand from belts 450mm to 1800mm (or 18? to 72?) wide.
The PV cleaner blades feature Martin Engineering?s patented constant angle radial pressure (CARP) design for consistent cleaning throughout all stages of blade life.
The specially engineered curved blade maintains the same contact angle, even as the belt wears, helping to retain cleaning efficiency and allow for residual material fines on the belt to be deposited back into the material flow and not beneath the conveyor.
The belt cleaner and tensioner combination also helped eliminate material build-up on the return side of the belt, which could cause additional problems with the belt or return rollers. When foreign material is trapped between the belt and the pulley, it can allow the belt to slip, causing the non-carrying underside of the belt to wear prematurely.
Even small particles and fines can grind away on the less durable, more easily damaged inside surface of the belt. Further, material that builds up on tail pulleys often causes the belt to wander, which in turn can damage the belt edge and/or the conveyor structure.
Belts at NALC include two-, three- and four-ply construction, according to the load each one is designed to carry, and they run at 31m to 122m (or 100? to 400?) per minute. Mechanical splices are used on all of them, which can be a concern with some belt cleaner designs.
But the unique twist tensioner on the Martin design allows the spliced sections to pass smoothly, without damage to the belt or blade.
Initially installed in March 2012, NALC has found the PV cleaner has all but eliminated carryback and spillage. The tensioner supplies consistent pressure to keep the blade against the belt for effective cleaning, regardless of the state of blade wear, with minimal re-tensioning required.
Engineered to simplify maintenance and reduce costs, the mounting system delivers ?no-tool? replacement, as it?s simply dropped into place and secured with a wire lock pin.
?This cleaner uses an aggressive angle of attack to the belt for improved cleaning efficiency,? Martin Engineering?s senior product specialist Dave Mueller said. ?And the quick replacement feature means never having to deal with corroded bolts or other fasteners during blade changes.?
According to belt maintenance crews, the time and cost savings generated have led to an immediate return on investment. Now the maintenance crew spends less time cleaning up and more time focusing on core business tasks.
?Our maintenance crews have crucial functions they need to address to keep the plant running,? Boyd said. ?Not having to worry about carryback and spillage during these times is important.?
ESS Australia has an exclusive licence with Martin Engineering to distribute its products.
Source: Martin Engineering