A holistic approach to conveyor belt monitoring

Conveyor systems play a major role in in the mining, minerals and metals industry, and unexpected downtime can be costly - but now there is technology that enables continuous monitoring of conveyor assets that can reduce maintenance costs and improve uptime.

In the mining, minerals and metals industry, it is often thought that materials handling begins where processing ends and therefore does not have a significant impact on overall quality and value. However, the transportation of materials is a critical piece of the production process and can significantly impact the overall cost-effectiveness of an operation, especially if a system should fail. Central to the transportation systems of many mining and plant facilities is the conveyor belt, a seemingly low-cost and low-priority piece of equipment in the supply chain. Yet from a maintenance perspective, conveyors can cause substantial setbacks to operations if left unchecked and can be costly to maintain.

Traditionally, routine maintenance and monitoring of conveyor systems has been a low priority for operations. This is because usually, what are considered more urgent matters take precedence, such as pumps and mills. But it is also partly because conveyors often stretch for many kilometres, in remote locations that aren’t easily accessible by foot or vehicle. Typically, operators tend to wait until there is a fault with a conveyor and then conduct maintenance or replace on a timed basis (such as in the case of idlers) in the hope of avoiding failures. But the challenge with this approach is that unplanned downtime can result in catastrophic production and financial losses.

The cost of unplanned maintenance

In today’s increasingly cost-conscious manufacturing environment, companies are under greater pressure to improve equipment reliability to achieve operational objectives and reduce maintenance costs. Central to an efficient operation, however, is achieving a high level of capacity utilisation, with plants needing to make the best use of their existing capacity. By measuring overall equipment effectiveness (OEE), plant managers can identify gaps between ideal and actual operational performance. These issues, comprising quantifiable OEE gaps, can be converted into the tactical and strategic steps that influence productivity, which can significantly impact overall business results. And at sites like mines, ports, cement plants and iron and steel mills, materials handling can constitute a major contributor to the overall business results.

Transporting products like iron and coal using conveyors is tough on these systems, resulting in the need for continuous maintenance and parts replacement. But scheduled maintenance on conveyors can easily fall to the last priority, as it is often labour intensive and difficult to monitor all areas, regardless of good intentions.

The process of belt inspections typically involves a maintenance staff member, who walks the length of a belt to visually inspect for faults, or in some cases, drives alongside it. But when conveyor belts can be up to 50 kilometres long and in hard-to-reach locations, such as at high altitude in tunnels through mountains, this monitoring can be difficult to deploy. Such an environment makes it near impossible or expensive to adopt traditional conveyor monitoring techniques.

But correlating with the drop in preventative maintenance can be a rise in shutdowns and unplanned downtime. Some operations have reported that conveyor outages account for up to 50% of their unscheduled disruptions. So when a shutdown could easily result in hundreds of thousands of dollars in lost production per hour, it is essential that conveyors operate as efficiently as possible, with maximum availability to an operator.

Past approaches

There are a number of existing monitoring solutions that address specific aspects of a conveyor system, but none of these offer operators a complete picture of the health of their conveyor belt. Typical ‘point’ solutions can provide details about specific areas of the conveyor belt but may not assist in prioritisation or integration with other point solutions. In an increasingly resource-constrained environment, operations should consider the benefits of an integrated solution, combining measurement technologies with decision support capabilities, for optimal conveyor health.

Managing the health of conveyor belts is complex, with numerous measurement requirements for complete monitoring of the system. This includes the detection of cover defects, edge damage, belt rips, pulley health, belt wear, internal defects, wander and steel cord damage. It also involves monitoring for drive health and idler health, as well as material off-loading and chute blocking. Moving from an ad hoc approach to conveyor monitoring to an online and integrated conveyor belt management system requires careful planning and a methodical approach.

Figure 1: Managing the health of conveyor belts is complex, with numerous measurement requirements for complete monitoring of the system.

A holistic approach

While point solutions may have been a reasonable approach to monitoring systems in the past, increasing cost pressures and shortages of skilled resources necessitate a more streamlined and efficient approach. An effective and holistic conveyor health monitoring solution extends the service life of a conveyor system and proactively identifies areas in need of attention before operations are impacted. This ultimately contributes to saving a company time and money by better managing resources and avoiding a costly shutdown affecting production.

New industrial technologies, like Honeywell Process Solutions’ recently introduced BeltAIS (Belt Asset Inspection System) suite, allow operators of mining, minerals and metals facilities to minimise the impact of conveyors on their overall equipment effectiveness. They are designed to detect, monitor and report on the health of the conveyor belt and associated components. With visibility into the actual health status of conveyor equipment, users from operations, maintenance, reliability and other departments can gain a consistent understanding, enabling effective planning and execution of maintenance.

Figure 2: The camera used by the Honeywell BeltAIS.

Holistic solutions minimise the total cost of ownership of conveyors by improving maintenance predictability and reducing operational downtime due to faults. They also reduce labour costs and allow staff to address more critical maintenance issues. For example, rather than rely on multiple standalone monitoring solutions, users can employ such a solution to maintain a continuous, online view of all conveyor maintenance requirements and perform a wide range of monitoring and analysis functions. Such systems not only integrate numerous systems, but provide an intuitive, user-friendly interface to the conveyor that improves the effectiveness of plant maintenance and operations personnel.

Better-timed maintenance

With pressures to cut maintenance costs to improve profitability, a different approach to maintenance can also result in significant savings for operations. Traditionally, all maintenance and monitoring has been conducted in-house, placing considerable strain on resources. This can result in less critical maintenance activities being deferred or not done, increasing operational risk. Thus, rather than deploying a continuous conveyor defect monitoring solution, users have the option of rotating the monitoring solution across a number of belts in operation. For example, deploying the technology monthly across each belt can give operators a clear picture of the rate of degradation and the frequency required for belt replacements or maintenance activities. Operators can also elect to operate such a solution as an outsourced service.

Learnings across industries

The first solution in Honeywell’s BeltAIS suite is the BeltAIS Cover Defect Monitoring System. It is a video-based decision support tool designed to perform repeated defect analysis of a conveyor belt’s surface. This helps to identify potential risk zones and assist in degradation analysis, upon which further action can be initiated.

While continuous monitoring of belt defects is a new concept to the mining, minerals and metal industry, it’s a technique that has been tried and tested in pulp and paper manufacturing. The same camera-based solution is used in the pulp and paper industry to monitor for defects in the papermaking process. In that environment, small defects (less than a few millimetres) introduced during manufacture can result in a catastrophic loss of product. The location of tears and other defects can be narrowed down to within centimetres and tracked through the paper machine. This technology has been adapted and updated with tailored algorithms to make it as effective in the harsh environment of resource extraction. The system provides a metre-by-metre analysis with video images for later retrieval and review.

Materials handling may begin where the traditional processing operation ends; however, this is a part of the supply chain that can have significant impact on the overall cost-effectiveness of an operation. And in the mining, minerals and metals industries, conveyor belt systems can contribute a significant part of unforeseen maintenance costs, which can usually be avoided through a comprehensive predictive maintenance strategy.

By deploying a holistic solution to conveyor maintenance, users can expect to achieve noteworthy cost savings through better planning and a reduction of downtime. Operators can also reduce replacement costs through more timely and strategic maintenance, and minimise an unnecessary amount of maintenance through more insight into the rate of degradation unique to each operating belt. Automated and online monitoring also reduces the need for manual inspection, reducing labour costs and allowing staff to address more critical issues. Finally, a reduction of catastrophic belt failures will significantly impact a company’s bottom line.