Tag Archives: conveyor belts

Martin Engineering expands conveyor training scope with LMS integration

Martin Engineering has added new online conveyor training content specifically designed to integrate with Learning Management Systems (LMSs) so users can assign, monitor and certify progress of all participants during its courses.

The new offering from Martin Engineering includes eight self-paced modules that address methods to identify, understand and correct common bulk conveying issues to improve safety on powerful and potentially dangerous systems, while complying with regulations, maximising productivity and achieving the lowest operating costs.

“Online conveyor training is delivering critical knowledge to companies around the world, and that’s never been more important than in these pandemic-restricted times,” Training Manager, Jerad Heitzler, said. “But, even as the popularity of these programs continues to rise, larger firms face challenges integrating the content into their LMSs so they can ensure thorough and convenient training for all employees – at all levels – across multiple sites. These modules create a verifiable record of employee training, so customers can track and confirm the participation of individuals company-wide.”

Organised into 90-120 minute segments, the virtual classes cover topics such as best practices for safety, fugitive material control and belt tracking.

With the training modules easily accessible and conveniently located in company-wide LMSs, the new Martin content gives customers complete control over scheduling and tracking, the company says.

“This is the type of training that everyone should have, and companies no longer need to rely on an outside vendor to schedule individual or group sessions,” Heitzler continued. “It delivers an in-depth and consistent understanding of conveyors and their hazards, ensuring that personnel at all levels can work safely and efficiently around these powerful systems.”

Martin Engineering has been providing training for much of its 75-plus year history, helping customers better control bulk material flows while reducing the risks to personnel. Designed to maximise employee engagement, the modules deliver topic-specific, non-commercial content that can be put to immediate use, and the new format allows even the most remote locations to take advantage, the company says.

The eight modules cover essential subjects that include an introduction to the concept of total material control, with content on transfer points, belting and splices, as well as belt cleaning, alignment and dust management.

“This system is created using a SCORM 1.2-compliant format, so it will integrate seamlessly with most existing LMSs,” Heitzler added.

SCORM is a widely used set of technical standards that provides the communication method and data models that allow eLearning content and LMSs to work together. All eight modules are currently available in English, Spanish and Portuguese, and can be provided in a variety of formats to meet the requirements of specific customers and their LMSs.

“Seven of the eight modules have a test at the end, requiring a minimum score of 70% to move on to the next module,” Heitzler said. “SCORM allows the content to interact with the LMS and leverage any features that a customer’s system has, which could include tracking the progress of each learner, providing reports or issuing certificates of completion.”

He concluded: “With this new effort in place, Martin has taken another step forward in global conveyor training. We’ve emerged as an LMS content provider to deliver greater flexibility and control over employee learning, helping customers attain the highest levels of efficiency and safety.”

Fenner Dunlop addresses critical conveyor uptime with iBelt BeltGauge

Fenner Dunlop has introduced mobile capability to its suite of iBelt conveyor technology with the BeltGauge solution offering a new way for customers from all commodities and conveyor industry applications to accurately monitor health of the conveyor, the company says.

The fixed BeltGauge solution has been installed at multiple sites since its launch in September 2020, with the industry appreciating how lightweight the mobile unit is when compared with competitor products, according to Conveyor Technology Manager at Fenner Dunlop, Sam Wiffen.

“We have been experiencing high interest and up-take with the fixed BeltGauge unit, however we recognised that some customers required a more mobile solution,” Wiffen says.

“In order to be functional for the mobile context, we needed the unit to be lightweight, flexible and adjustable – properties which have been incorporated into the design and are a strong point of difference from competitors.”

The mobile BeltGauge unit is made from 3D printing a wide range of engineering composites and plastics-based compounds. This contributes to the safety of conveyor technicians by reducing manual handling risks on site.

“The segmented mobile BeltGauge design allows us to install the scanning units in tighter spaces, without having to overhang the unit above handrails,” Wiffen says.

Both the mobile and fixed BeltGauge have been designed to meet all customer requirements, regardless of geographic or commodity group, and are applicable for surface and underground mining applications, the company says.

“The mobile BeltGauge is designed for customers with critical conveyors, who are comfortable with periodic data and are more focused on the ability to record belt thickness across a range of operational conveyors,” Wiffen explains.

Unlike traditional manual thickness testing, the mobile BeltGauge provides customers with a full-length profile of the belt. Because of the mobile nature of the unit, multiple conveyors can be scanned in a single shift, according to the company.

Reporting directing into iBelt’s DigitalHub portal means customers have access to same-day results, the company says.

The iBelt mobile BeltGauge is currently in operation with Fenner technicians in the Hunter Valley of New South Wales and Mackay in Queensland, with field trials currently underway in Western Australia.

Sales and Engineering Manager, Shailendra Borade, explains that developments to the mobile BeltGauge also include the ability to collect belt thickness readings while the conveyor is running, allowing customers to conduct maintenance inspections without stopping production.

“For our customers in Western Australia and other similar sites, who operate 24/7 and have very few shutdowns in the year, this means they can scan the belt before shutdown, review the data, and plan and forecast belt changeouts with latest information and improve belt life and asset health,” Borade says.

“This is huge asset for our customers, reducing overall downtime and improving production efficiency.

“Operating in a niche industry, it’s crucial that we are able to differentiate our products and services, while providing added-value to the customer.”

As Fenner Dunlop expands the range of iBelt products, both mobile and fixed applications will be considered, it says.

Conveyor Components tackles belt alignment with latest control solution

Conveyor Components Company has added a Tilt Action (TA) belt alignment control solution to its offering for use on most belt conveying systems and wastewater filter presses.

The model TA is available in weatherproof or explosion-proof enclosures, with 120 VAC or 240 VAC input power rated microswitches, the company said.

This belt alignment control has dry, unpowered 20 amp SP/DT microswitches, or 15 amp DP/DT microswitches, to allow control of four separate output functions. The unit is bi-directional, able to operate in either direction and the red-coloured roller is highly visible from a distance.

The trip points are field-settable with a simple set screw adjustment on the cam, while the housing is cast aluminum, with optional epoxy coating available for corrosive environments.

Hawk Measurement Systems releases OptioLaser L100 and L200 level transmitters

Hawk Measurement Systems has released new laser level transmitters that, the company says, are ideal for level, distance and position measurement of solid and liquid surfaces.

The OptioLaser L100 (pictured) and L200 Laser Level Transmitters use a laser that is uniquely different due to the very narrow beam that can measure long and short distances at virtually any angle, Hawk says. On top of this, the OptioLaser L100/L200 is made completely of stainless steel and is extremely rugged, built for the harshest of environments.

Leon Botha, OptioLaser Product Manager, explained that the accurate and durable design of the laser sensors was necessary due to the wide range of applications and industries Hawk caters to.

“The OptioLaser sensors can measure anything from a flat metal plate on the side of any overhead crane, to the top of material stored in a silo,” Botha said. “They are ideal for long- and short-range applications where the unit needs to see through a narrow opening or tube.”

Botha added: “These sensors are being used with great success in many areas such as blocked chute detection, material handling, positioning, plastic pellet silos, conveyor belt edge control, ore pass levels and bin levels, to name a few.”

The OptioLaser L100/L200 Laser Level Transmitters are fully programmable and include simple to use software, Hawk says. The lasers can be configured for either distance or level measurement and will be useful in applications such as mining.

Scrapetec keeps conveyor belts on track with newest component

Scrapetec has added to its range of conveyor components with the new PrimeTracker belt tracker, which, it says, eliminates problems associated with conveyor belt systems, including misalignment, abrasion and belt damage.

Thorsten Koth, Sales and Distribution for Scrapetec, explained: “For optimum performance of a conveyor system, it is critical that the belt always runs straight on the conveyor, without sideways movement. Our new PrimeTracker belt tracker has been designed to automatically guide a conveyor belt back into the correct straight-line position, to prevent costly downtime and component replacement.”

One advantage of the Scrapetec PrimeTracker is that it is always operates in the idling position, unless there is sideways movement of the belt, Koth said. This system corrects misalignment immediately by guiding the belt back into the correct position, with no damage or abrasion to the belt or tracker, he added.

“This is unlike conventional belt trackers that slide over the belt surface causing possible abrasion and belt damage – rather than adopting free rotation,” he said. “Conventional belt trackers, with tapered edges, never idle and are always in a braking mode.

“What’s also notable, is the cylindrical shape and pivot bush that allow this belt tracker to swing and tilt during operation and to always be in full contact with the belt. Added to this, the Scrapetec PrimeTracker has the same peripheral speed over the entire surface of the belt, where traditional crowned rollers have different speeds at the centre and edges of the system.”

Other advantages include easy installation, low maintenance requirements and protection of belt edges and structure of the conveyor belt, according to Scrapetec. A strong corrugated EPDM rubber hose protects this system from dust and sand, while the rubber pivot offers soft suspension of the tracker shaft, ensuring extended service life of the system, the company added. This system can be installed in front of every return pulley, above and below the belt.

Autonomous conveyor belt condition monitoring in times of a crisis

As the digitalisation of processes in mines progresses, machines linked into the Industrial Internet of Things (IIoT) gain in importance, according to Bernd Küsel of CBG Conveyor Belt Gateway.

An important part of predictive maintenance and accident prevention is the continuous examination and diagnosis of steel cord conveyor belts, which are mainly used in the long-distance conveying of ores, coal and other raw materials. These conveyor belts are essential to many mining and loading facilities.

Many operators still rely on inspection personnel from service companies equipped with portable devices to inspect conveyors, but their appointment can be problematic. And, with today’s travel restrictions, this is close to impossible.

The problem comes as such inspections provide an insufficient picture of the condition of a conveyor belt that is reliant on interpretation by trained persons, with portable devices that only cover parts of a conveyor belt, according to Küsel. Moreover, inspections only offer a snapshot in time without the possibility to intervene in the case of threatening belt defects that could lead to a total failure of the conveyor system.

In times of crisis, such as the current COVID-19 pandemic, it is even more important to use a self-sufficient, automatic diagnostic system, according to Küsel.

“The virtually maintenance-free CBGuard scanner provides complete knowledge of the condition of the conveyor belt in real time,” he says. “It is operated from the user’s control centre or via the Internet.”

Damage can be repaired at the best possible time for the customer, reducing unnecessary downtime and the associated costs and loss of production that come with this.

The CBGuard scanner can be an indispensable part of a predictive maintenance program, Küsel says.

“With it, conveyor belts can be integrated into the IIoT, ie into seamless communication with other electronically monitored systems. CBGuard provides a complete, detailed knowledge of the condition of the conveyor belt – non-stop and online,” Küsel said. “Virtually every cubic millimetre of the conveyor belt is checked during operation. The CBGuard scanner compares the detected values with the target values in real time. Every critical change triggers a reaction. The operating personnel are immediately informed of serious errors via SMS. In addition, the exact thickness of the entire conveyor belt can be measured and outputted as a contour map.”

The CBGuard Life Extender, meanwhile, detects internal damage such as steel cord breakage, corrosion, misplacements and other defects of the tension member. The exact condition of each steel cord can be viewed on a monitor in real time. The same applies to certain belt breakers and conductor loops.

Damage such as holes, foreign bodies, protruding ropes, edge breakage, bubbles, rubber cover abrasion and even insufficient belt cleaning are detected. Each defect automatically generates a predetermined, individual reaction. Information about the findings is additionally available at any time as a photo, video or inspection report, which tells personnel exactly what kind of damage it is, how severe it is and the location of said damage.

The CBGuard scanner also prevents fatal consequences caused by splice defects, Küsel said. As the weakest links in a conveyor belt, splices pose a greater risk to the operation – with potentially devastating consequences.

The CBGuard Life Extender scans all splices. Every single splice is individually assigned in the database and compared with its target state. Any critical deviation generates an alarm or a stop of the system in case of threatening defects.

“No other method available on the market can provide such exact and comprehensive results,” Küsel said.

The way CBGuard works is similar to that of X-ray machines in the healthcare sector or in airports.
The device consists of an X-ray generator with a tube, a receiver module and a control unit. The generator produces artificial X-rays from electricity, with the ionising rays penetrating the moving conveyor belt and then hitting the receiver module – an amorphous silicon imaging field.

It is a process like that of photo diodes in a digital camera. Countless, seamless images are continuously generated and defined by CBGuard’s smart software – based on advanced face and palmprint recognition algorithms – checking the condition of the belt, while accounting for the individual structure, size, colour and position of deviations and reporting them as a specific event (eg damage).

“Using a CBGuard is safe,” Küsel said. “The device complies with all international regulations on radiation emission. It does not contain radioactive material!”

The compact design and low weight of the CBGuard makes for a quick and easy installation on almost any belt conveyor. The scanner is also almost wear-free, according to Küsel, as it has no moving parts or contact with the conveyor belt.

All functions of the CBGuard Life Extender can be remotely controlled via TCP/IP, with maintenance or programming work possible from anywhere in the world. The analysis software runs under Windows 7 and 10, and the program is intuitive and easy to use, he said.

CBGuard has proven its performance in over 300 applications, according to Küsel, noting that large copper mines in Peru and Chile rely on CBGuard. There are many other applications in Australia and Asia in the limestone and coal sectors, he added.

The CBGuard scanner ensures fully automatic, complete monitoring of steel cord conveyor belts making inspections by personnel or devices that only cover a part of the conveyor belt spectrum unnecessary, Küsel says.

The gain in safety, the independence from personnel availability and the reduction of capital expenditure and operating expenditure are convincing arguments for the use of a CBGuard, he explained.

On the operation expenditure side, for example, there is no longer a need to employ internal maintenance personnel or outsource external services to inspect the belt. Such inspections, typically carried out weekly, are conducted in belt ‘creep mode’ and involve a full shut down, according to Küsel.

“With the CBGuard, you do not have any production downtime because it is carrying out the inspections all the time at the normally operating conveyor, at its normal speed,” he said.

Belt repairs also only occur when necessary, with details of failures coming from the CBGuard. “You will see serious damage immediately, so you can repair them before they get worse and cost much more money to fix,” he said.

This also provides capital expenditure benefits, with the CBGuard telling operators when and which part of the belt is worn out. In many cases, only part lengths will have to be changed, not the entire belt length.

This comes with inventory benefits too, with companies no longer having to carry extensive stock belting as the CBGuard is able to predict in good time when the belt will need to be replaced.

Martin Engineering delves into the danger zone for conveyor belt best practice

In bulk material handling applications, a conveyor is typically a massive, complex and extremely powerful system. It is usually constructed of rubber belting, set on rolling idlers, wrapped around large steel drums at each end and driven by a high-torque motor. As such, a conveyor presents enough danger zones that the entire system should be considered a hazard, according to Martin Engineering.

In most applications, a conveyor belt moves at a relatively constant speed, commonly running somewhere between 0.5-10 m/s. An Olympic sprinter has a reaction time of about 0.18 seconds when poised at the starting line and totally focused on the race. If this athlete becomes tangled in a conveyor belt traveling 1.5 m/s, the person would be carried 0.27 m before even realising what has happened.

A ‘regular’ worker would likely require a longer time to react, Martin Engineering says. For simplicity’s sake, assume it would be twice the athlete’s reaction time, so the worker would be pulled twice as far, introducing the potential to strike many more components or to be pulled farther and harder into the first one.

In addition, most conveyors are engineered with the ability to start remotely. The system may go from dormant to active at any time at the push of a button, and that ability can suddenly catch a worker unaware, leading to serious injury or death, the company says.

Martin Engineering Process Engineer, Dan Marshall, said: “When a conveyor belt is moving, there will usually be more tension on the carrying side. If the conveyor is merely stopped and de-energised, that tension may remain in the belt in the form of stored energy.”

A system under tension will always try to approach equilibrium, according to Marshall; that is, it will try to release the energy. This release will likely come in the form of a pulley slip, which occurs when the belt slides around the head pulley to equalise the tension. The distance the belt will move is proportional to the amount of tension stored and the belt’s modulus (elasticity), possibly several feet. If a worker is on the belt or close enough to be pulled in during this sudden release of energy, injuries or death can occur.

“There’s a simple rule of thumb regarding conveyors: if it’s moving, don’t touch it,” Marshall continued. “The most common way to prevent inadvertent contact is with suitable guarding that renders the moving components inaccessible.”

For maintenance or repairs, procedures for lockout/tagout/block-out/test-out should always be followed when working on a stationary conveyor, and systems should be equipped with anti-rollback devices (also known as backstops) on the head pulley.

Many of the moving parts on a conveyor belt system are rotating components. These parts include idlers, drive shafts, couplings, pulleys and speed sensors. Items rotating at a high speed pose the risk of entanglement or entrapment.

“All moving machine parts should be guarded with adequately constructed, properly installed, functioning and well-maintained guards,” Marshall said.

There are many pinch points on a conveyor, components that the belt touches or comes near, including the drive pulleys, snub pulleys, idlers, stringer, chute walls and deflectors. If a worker’s limb travels with a conveyor belt, it will meet one of these components. The limb, as well as its attached worker, will become trapped between the belt and the obstruction.

The same thing can happen with a tool, which can pull a worker into the entrapment faster than the person can let go.

“Effective fixed guards should be absolute in their protection; workers should not be able to reach around, under, through or over the barrier separating them from moving components,” Marshall added.

Many of the fatalities around conveyors have happened when a worker was cleaning fugitive material from the structure or components of a conveyor system. The process of cleaning may put a worker in proximity to a very dangerous machine, according to Martin Engineering. The need to shovel, sweep or hose off accumulations puts the worker within arm’s length of the conveyor, and often closer.

Airborne dust can cause numerous health risks, ranging from material build-up in the lungs to explosions. Categorised as either respirable or inhalable according to particle size, dry, solid dust particles generally range from about 1 to 100 microns in diameter.

According to the EPA, inhalable coarse particles are 2.5-10 microns in size. They are typically caught by the human nose, throat or upper respiratory tract. In contrast, fine respirable particles (under 2.5 microns) can penetrate beyond the body’s natural cleaning mechanisms (cilia and mucous membranes), traveling deep into the lungs and causing long-term or chronic breathing issues.

While it is virtually impossible to prevent all fugitive material from escaping a conveyor structure, taking practical steps to minimise it as much as possible helps reduce the dangers it can introduce, the company says. When clean-up is necessary, performing the job while the conveyor is running should not be an option. Operators concerned with the cost of lost production from stopping a conveyor to clean need only consider the consequences of an accident to confirm the wisdom of this rule.

Until recently, the engineering of belt conveyors to carry bulk materials hadn’t changed much in the last half-century, despite the fact that virtually every requirement for safety, regulatory compliance and production performance has been raised during that time. Standards continue to tighten and industry best practices now often exceed government requirements.

“Using these new and emerging technologies, even poorly performing conveyors often don’t need to be replaced or rebuilt, but merely modified and reconfigured by knowledgeable and experienced technicians installing the right modern equipment,” Marshall concluded. “Specialised conveyor training and trusted resources from global suppliers are helping to raise operator awareness to make conveyor systems cleaner, safer and more productive.”

ASGCO, WAGNER-Schwelm and NILOS combine conveyor belt expertise

ASGCO® “Complete Conveyor Solutions” says it has signed a tri-lateral distribution, manufacturing and intellectual partnership agreement with WAGENER-Schwelm® and NILOS® to extend its ability to service and provide ASGCO products to servicing distributors, end-users and original equipment manufacturers around the world.

Aaron Gibbs, President of ASGCO, said the integration of highly precise German engineering from WAGENER and NILOS, combined with the manufacturing, marketing, sales and service strength of ASGCO will bring customers “excellent, highly engineered, ‘best in the world’ conveyor belt vulcanising products” manufactured in the US.

“By providing our ASGCO conveyor products through the NILOS service branches and then also incorporating the WAGENER and NILOS range of products into ASGCO’s product line, this will provide the ‘best in class’ range of conveyor material handling solutions for our customers,” he said.

Thomas J Ziller, Owner of WAGENER-Schwelm and NILOS, said the partnership will provide the “strongest and most innovative range of products in the conveyor belting industry”.

“The knowhow transfer in both directions guarantees sustainable and high-end production as well as increases our after-sales service around the world,” he said.

WAGENER-Schwelm has decades of experience in the development and manufacturing of portable and stationary vulcanising presses, for splicing and repairing conveyor belts, while NILOS is known for the application-oriented development of high-quality and innovative hot and cold vulcanising materials, compounds, cements and other conveyor belt related products.

ASGCO, founded in 1971, is a leading manufacturer, distributor and service provider of proprietary conveyor and screening equipment and accessories to improve the safety and performance of bulk material handling systems.

Mato Products makes its mark on conveyor belt cleaning market

Mato Products, a Multotec company, says it has expanded its bulk handling equipment reach into the design of innovative belt cleaning systems for a number of mineral and metals markets.

The company has long been a household name in clip fasteners for conveyor belts, especially in the underground coal sector. It company operates one of only three high production Mato machines in the world, and significantly the only one outside of Germany.

After over 30 years of operation, this Mato unit was overhauled in 2016 in an intense six-month refurbishment. It was upgraded from 180 t to 360 t capacity, speeding up production and ensuring both ongoing cost-effectiveness and reliability of supply for customers, according to the company.

Mato said: “The company’s exciting line of belt cleaning equipment has for some time now been gathering momentum. Its popularity has extended well beyond the coal sector into other materials handling and mineral processing applications, even in diamond mining.”

According to Benjamin Sibanda, Managing Director of Mato Products, over-feeds at transfer points often lead to material build-up on the inside of a belt.

“As mines and other industrial facilities raise their environmental standards, they want to avoid problems like duff heaps under conveyors, which can cause pollution,” Sibanda said.

The Mato MCP3-S primary cleaner, installed at the head pulley is designed to be an aggressive head pulley cleaner, yet friendly to the conveyor belt surface and suitable for use with mechanical fasteners, the company said.

“It offers a high level of cleaning due to its blade profile, and the spring tensioning system ensures the blade is in constant contact with the belt for the life of the blade while achieving up to a maximum of 75% cleaning.”

Sibanda said: “The secondary Mato MUS2 belt cleaner is one of our latest design belt cleaners and offers an M-TRAK slide on cushion and blade for easy installation and maintenance.”

The M-TRAK is designed to eliminate lengthy maintenance downtime and ensures blade alignment is 100% true across the entire conveyor belt width, according to the company. Blade replacement is simple with the design of the slide-on and slide-off principle, eliminating the need for special tools or training when maintenance is performed, Mato said.

Sibanda continued: “The unique design of our MUS2 cushion is based on the principle of a parallelogram whereby the cushion also stays true to the conveyor belts surface ensuring the angle of attack is maintained. This cleaner’s primary duty is to remove fines and duff, to almost zero carry-back.”

Blades on the cleaners come in a range of materials suited to different applications, including polyurethane and tungsten.

While the application in South Africa was initially mainly underground, equipment variations for surface have now also been developed and introduced to market, Mato said. The plant tail-end cleaner is based on the same concept but is mounted on channels rather than on stringer pipes.

“This product includes innovative blade stoppers,” Sibanda said. “When the blade is worn to a certain level, the mounted flat plate does not touch the belt, for better protection.”

Mato has also engineered closer integration between its fastener clips and the belt cleaners.

“For instance, we have added a profile to the clip which optimises the life of both the clip and the tungsten tip on our secondary belt cleaner,” Sibanda said. “The skiving process embeds the clip slightly into the belt ensuring the mechanical splice is on the same surface as the conveyor belt thereby minimising the impact on the tungsten tip as well as lowering noise levels. Longer life of both means less downtime for the customer and greater reliability.”

Sibanda said all the offerings in Mato’s conveyor belt systems range helps to improve the lifespan of equipment at loading points. The energy of ore transfer is absorbed, and wear resistance is increased by Multolag ceramic products.

Martin Engineering’s tips for cleaner, safer and more production conveying

Martin Engineering, a supplier of bulk material handling solutions, is urging mining companies to take another look at their conveyor belt cleaners and devise a strategy that can reduce operator and operational risk, as well as overall operating costs.

The company says: “Given the number of conveyor-related accidents that occur during routine maintenance and cleanup, every bulk material handler has a vested interest in technologies to help reduce hazards and prevent injuries.

“Seemingly mundane tasks such as adjusting belt cleaners and removing spillage often require employees to work near the moving conveyor, where even incidental contact can result in serious injury in a split second. Further, spillage can contribute to the risk of fire by interfering with pulleys and idlers and by providing potential fuel. Even worse, in confined spaces, airborne particles can create the right ingredients for an explosion.”

The buildup of fugitive material can occur with surprising speed, according to the company.

“As the table below illustrates, spillage in an amount equal to just one sugar packet (about 4 g) per hour will result in an accumulation of about 700 g at the end of a week. If the rate of escape is 4 g/min, the accumulation will be more than 45 kg/week, or more than 2 t/y. If the spillage amounts to just one shovelful per hour (not an uncommon occurrence in some operations), personnel can expect to have to deal with more than 225 kg/d of fugitive material.”

Reducing carryback

Although there are several belt cleaning technologies available to conveyor operators, most designs in use today are blade-type units of some kind, using a urethane or metal-tipped scraper to remove material from the belt’s surface, according to Martin Engineering.

“These devices typically require an energy source – such as a spring, a compressed air reservoir or a twisted elastomeric element – to hold the cleaning edge against the belt. Because the blade directly contacts the belt, it is subject to abrasive wear and must be regularly adjusted and periodically replaced to maintain effective cleaning performance.”

The ability to maintain the proper force required to keep the blade edge against the belt is a key factor in the performance of any cleaning system, the company said. Blade-to-belt pressure must be controlled to achieve optimal cleaning with a minimal rate of blade wear.

The company said: “There is a popular misconception that the harder the cleaner is pressing against the belt, the better it will clean. Yet, research has shown there is an optimum range of blade pressure, which will most effectively remove carryback material. Increasing tension beyond this range raises blade-to-belt friction, thus shortening blade life, increasing belt wear and increasing power consumption – without improving cleaning performance.

“Operating a belt cleaner below the optimum pressure range also delivers less effective cleaning and can accelerate blade wear. A belt cleaner lightly touching the belt may appear to be in working order from a distance whereas excessive amounts of carryback are being forced between the blade and the belt at high velocity.”

This passage of material between the belt and the blade creates channels of uneven wear on the face of the cleaner, according to the company, with these channels increasing in size as material continues to pass between the blade and the belt.

The company continued: “A common source of blade wear that often goes unnoticed – even with a properly installed and adjusted cleaner – is running the belt empty for long periods of time. Small particles embedded in the empty belt’s surface can create an effect like sand paper, increasing the wear rate of both the blade and the belt. Even though the cargo may be abrasive, it often has moisture in it that serves as a lubricant and coolant.

“Another potential source of wear is when the cleaner blade is wider than the material flow, causing the outside portion of the cleaning blade to hold the centre section of the blade away from the belt. As a result, carryback can flow between the belt and the worn area of the blade, accelerating wear on this centre section. Eventually, the process creates a curved wear pattern sometimes referred to as a ‘smiley face’ or ‘mooning’.”

As urethane cleaner blades wear, the surface area of the blade touching the belt increases, according to Martin Engineering. This causes a reduction in blade-to-belt pressure and a corresponding decline in cleaner efficiency. Most mechanically-tensioned systems, as result, require periodic adjustment (re-tensioning) to deliver the consistent pressure needed for effective carryback removal.

“To overcome the problem of the blade angle changing as the blade wears, a radial-adjusted belt cleaner can be designed with a specially-engineered curved blade, known as CARP (Constant Angle Radial Pressure),” Martin Engineering said. “With this innovative design, the changes in contact angle and surface area are minimised as the blade wears, helping to maintain its effectiveness throughout the cleaner’s service life.”

Air tensioning

New air-powered tensioning systems are automated for precise monitoring and tensioning throughout all stages of blade life, reducing the labour typically required to maintain optimum blade pressure and extending the service life of both the belt and the cleaner, Martin Engineering said.

“Equipped with sensors to confirm that the belt is loaded and running, the devices automatically back the blade away during stoppages or when the conveyor is running empty, minimising unnecessary wear to both the belt and cleaner,” it said. “The result is consistently correct blade tension, with reduced power demand on start-up, all managed without operator intervention.”

For locations lacking convenient power access, one self-contained design uses the moving conveyor to generate its own electricity. This powers a small air compressor to maintain optimum blade pressure at all times.

Maintenance

Even the best-designed and most efficient of mechanical belt cleaning systems require periodic maintenance and/or adjustment, or performance will deteriorate over time.

Martin Engineering said: “Proper tensioning of belt-cleaning systems minimises wear on the belt and cleaner blades, helping to prevent damage and ensure efficient cleaning action. Belt cleaners must be engineered for durability and simple maintenance, and conveyors should be designed to enable easy service, including required clearances for access. Service chores that are straightforward and ‘worker friendly’ are more likely to be performed on a consistent basis.

“The use of factory-trained and certified specialty contractors can also help ensure that belt cleaner maintenance is done properly, and on an appropriate schedule. Further, experienced service technicians often notice other developing system or component problems that can be avoided if addressed before a catastrophic failure occurs, helping conveyor operators avoid potential equipment damaging and expensive unplanned downtime.”

The company concluded: “By setting the cleaning goal necessary for each individual operation and purchasing a system adequate for those conditions, as laid out in CEMA standards, it’s possible to achieve carryback control and yet obtain long life from belt cleaners.

“The bottom line is that properly-installed and adjusted belt cleaners help minimise carryback and spillage, reducing risk and overall operating costs.”