Features, Repair and maintenance, Safety systems and solutions, Work health and safety

Balancing maintenance costs for conveyor belts

martin engineering, conveyor belt

If a conveyor belt is not sufficiently cleaned, fugitive dust and material get into machinery and rolling components, raising the potential for fires. Luckily, Martin Engineering is here to help.

Clearing carryback from inadequate belt cleaning can increase the chances of workers making incidental contact with a moving belt, and that is one of the main causes of conveyor belt injuries, according to WorkSafe Australia. 

The need for conveyor belt cleaning is well established. Excessive fugitive material can reduce component and belt life by as much as 30 per cent, while a multiple belt cleaner system contributes less than five per cent to overall belt wear, delivering a significant benefit.  

For operators who have “tried them all” and can’t find a cleaner that works, it could be that the problem isn’t the equipment, but the maintenance. 

It may sound elementary, but there is a great deal of knowledge and skill required to tune a belt-cleaning system to work under varying material, environmental and belt cover conditions while still operating safely, effectively and economically. 

Some manufacturers provide factory-trained direct service personnel and replacement parts, delivering expert maintenance for optimum performance and component life. 

Proper equipment
The number and style of belt cleaners depends on balancing many factors, the first of which is the level of cleaning. Applications like coal mining or power generation cannot tolerate much carryback because of the potential for accumulation to be the fuel in a fire. 

Once the level of cleaning is established, the next task is determining the type and number of cleaners required to do the job. The trend in belt cleaning, regardless of application, is to plan for two or more cleaners per discharge (primary, secondary, tertiary). 

In addition to better cleaning from multiple cleaners, there is a redundancy factor that can provide a longer service interval window. Then the tensioner and the best blade for the application are selected.

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Proper matching of the blade formulation to the application is essential for optimal performance and service life. Image: Martin Engineering

A trained service technician is aware of hazards involved with maintaining belt cleaners. 

Having a trained provider who focuses on safety while being more productive than in-house maintenance can be a significant benefit given the importance of keeping shutdown times to a minimum. 

There are specialised systems for servicing belt cleaners where the belt runs 24 hours a day and cannot be shut down, but virtually all other cleaner maintenance must be performed following lockout, tagout, blockout and testout (LO/TO/BO/TO) procedures.

One primary cleaner design requires no tensioning and virtually no maintenance after initial installation. It features a matrix of tungsten carbide scrapers installed diagonally to form a three-dimensional curve around the head pulley and typically delivers up to four times the service life of urethane cleaners. 

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The CleanScrape primary cleaner takes up less room and requires less maintenance than standard cleaners. Image: Martin Engineering

Expert service
Several researchers, including from the US Bureau of Mines, have established there are ‘sweet spots’ for cleaning pressures for different styles of belt cleaners. Outside of these ranges, the cleaning performance is lower, while the blade wear, belt wear and power consumption are higher. 

Reputable manufacturers design their cleaners and tensioners to achieve optimum cleaning performance versus blade wear. It may seem counterintuitive, but if the cleaner isn’t doing a good job more cleaning pressure can actually make the problem worse. Maintenance personnel must understand these phenomena and know how and when to adjust each style of cleaner. 

Some sophisticated users optimise their cleaning performance versus blade replacement costs by testing different blade materials at different cleaning pressures and changing blade materials and cleaning pressures for different seasons or run-of-mine (ROM) conditions. 

Inspection and monitoring
Some manufacturers offer conveyor inspections and cleaner maintenance as part of a managed service relationship. 

Their monitoring systems can track component wear and update the service technician and/or operations personnel via Wi-Fi or a mobile phone on upcoming service needs. 

There are some new systems that can even adjust belt cleaner tension automatically. The technology will also send an alert through a mobile app in the event of upset conditions. 

Factory-trained service technicians provide an added set of eyes on the conveyors, travelling to and from the equipment to be serviced and logging details in their reports. Because they see so many different applications, these technicians can often alert on problems that maintenance personnel don’t see or have become accustomed to ignoring. 

With factory-direct managed service, the responsibility for maintenance falls on the manufacturer, allowing the staff to focus on other priorities.

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The Martin N2 position indicator reduces the need for regular inspection. Image: Martin Engineering

Return on investment
When calculating the return on investment for professionally installing and maintaining belt cleaners, the analysis should be done over the life of the belt cleaner assembly using a net present value calculation. Other benefits that can be factored in include the savings from avoiding injury, increased equipment availability, improved equipment life, and reductions in citations and fines. 

In addition, facility managers often find that the cash flow values are surprisingly large over the life of the equipment and service relationship.

Belt cleaner maintenance can be time-consuming and pull labour from other essential tasks, so it’s especially important to choose a supplier with trained and experienced service technicians who know the equipment and safety procedures and can respond quickly to customer needs. 

Automated monitoring equipment mitigates some of the issues with blade wear and provides data and alerts when blades need servicing. This can help reduce labour costs and improve safety as a result of to fewer inspections and proactive maintenance. 

Considering a managed service program can make safety and productivity sense and improve profitability with additional positive cash flow.  

This feature also appears in the March-April issue of Safe to Work.

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