Effective conveyor, material handling maintenance practices

Conveying and material handling equipment manufacturers offer tips to producers to enhance their maintenance procedures.

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Out with the old, in with the new

Consider replacing high-maintenance parts with new technologies, says Van der Graaf’s Matt Lepp

Proper analysis of maintenance-intensive parts and available solutions can go a long way to reduce time and money spent on conveyor system maintenance. With the wealth of new technologies available to the aggregates market today, many solutions are readily available to replace existing high-maintenance parts with low-maintenance or maintenance-free options, thus lowering costs and increasing system uptime.

A major maintenance concern on any aggregate conveyor is proper lubrication. With drives sometimes located in hard-to-access locations, proper lubrication of critical drive components is not always done at proper intervals, or at all, causing a maintenance-related failure.

Replacement of the failed component with a similar part will not fix the root cause of the issue. Proper analysis of the issue would indicate that replacing the failed component with a reduced-maintenance part would increase system uptime.

For example, replacing a conventional conveyor drive requiring weekly and monthly maintenance with a drum motor requiring maintenance only every 50,000 hours of operation would minimize or eliminate lubrication-related issues, saving maintenance time and money.

Matt Lepp is heavy industrial drive specialist at Van der Graaf.

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Proper scrapers lead to success

Using the right scrapers for your application can’t be overlooked, says Superior’s Tom Koehl

Cleanup around conveyor systems is often related to improper use of scrapers or skirting. Make sure you’re using properly designed belt scrapers for your application and check them daily for accurate tension.

Today, there are models that offer automatic tension. So, if you’re unable to dedicate time to tensioning, it’s a technology upgrade your operation should consider.

Secondly, load zone skirting should be intact and performing as designed. When it’s not, there is spillage and that eventually chews up horsepower, causes early and unnecessary wear to idlers and pulleys, and breaks down belting.

Lastly, any conveyor fitted with a discharge hood is always cleaner than one that’s not.

Tom Koehl is conveyor application engineer at Superior Industries.

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The benefits of accurate belt tension

Martin Sprocket’s Steve Cook stresses the importance of belt tensioning

Many issues for belt conveyor maintenance relate to a few factors. Some of the most common issues that are observed include material spillage, belt slippage, belt tracking and accelerated wear – all of which can be traced back to improper belt tension.

If belt tension is too high, premature wear, including material fatigue and yield failures, can happen in a relatively short amount of time. This is due to excessive shaft deflection, caused by exceeding the design parameters of shafting.

If belt tension is too low, it can cause other significant concerns. Without adequate belt tension, the drive pulley may slip, which, in turn, accelerates drive pulley wear and wear on the bottom cover of the belt.

Another common issue caused by inadequate belt tension is belt sag. This can cause material spillage, especially in the load section. Without proper belt tension, the belt can sag excessively and cause material to spill over the side of the belt. In the load zone, this issue is exacerbated. When excessive belt sag occurs, the belt will not seal properly against the skirting, spilling material that often finds its way to the clean side of the belt and being fed into the tail pulley. Without a belt plow, this may lead to accelerated wear and premature failure on the wing pulley.

To aid these maintenance concerns, periodically check the tension adjustment on a manual take-up system and ensure any automatic take-up systems can move freely and have the properly engineered amount of weight.

Steve Cook is general manager of the idler & pulley division at Martin Sprocket & Gear.

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Regular checkups go a long way

PPI’s Jeff Poe offers simple tips to improve your maintenance

Adjusting idlers to train the conveyor belt is fairly easy.

Adjust your skirt board regularly to prevent spillage or blowout of material in the load zone. Contamination and spillage are primary contributors to increasing maintenance on a conveyor. Hence, controlling it will reduce the maintenance burden.

Check for lagging wear on conveyor pulleys to ensure proper tracking of the conveyor belt, especially using crown faced pulleys, but also for flat faced conveyor pulleys. Keeping good lagging reduces downtime.

Check for failed or failing conveyor idlers and change them immediately to greatly improve the performance of the conveyor and increase overall tonnage by reducing unexpected downtime.

Regularly checking and adjusting belt cleaners helps prevent carryback on a conveyor and reduces wear on all conveyor components while also reducing contamination to conveyor pulley and idler bearings.

Check conveyor mechanical splices regularly to control degradation of the splices and prevent unexpected breakage of the conveyor belt.

Jeff Poe is field engineering manager at Precision Pulley & Idler.

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Componentry key to success

Having the proper equipment is essential to easing maintenance, says Masaba’s Kirby Cline

Aside from regularly scheduled preventive maintenance, the most important thing an aggregate producer can do to reduce the burden of maintenance on their operation is to have the proper componentry on their conveying and material handling equipment.

Some of these suggested components may include abrasive-resistant liners in hoppers and chutes; taller supports at the load area to allow for skid-steer blades to get in and remove fallen material; rubber disc returns to prevent fugitive material buildup; and mine-duty pulleys to extend the life of your pulleys.

The second-most-important item to keep the belt tracking properly is to always make sure the conveyor is level and ensure that the take-ups and belt splices are square. Training idlers can also assist in maintaining proper tracking.

Kirby Cline is western territory manager at Masaba.

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Structural factors to consider

Structure design is one important consideration, says Luff Industries’ Perry Fell

One of the most important aspects for aggregate producers to be mindful of to reduce maintenance starts before the equipment is even running.

The design of a conveyor structure must be such that it will support the worst loading condition from a bending point of view. The structure must allow for and remain square whenever out-of-balance forces occur that would otherwise deform the structure.

Under-designed or damaged structures will affect belt tracking as the structure bends and flexes due to the suspended load, causing unnecessary wear on components, including pulleys, gear box shafts and motors.

Perform a visual inspection on the conveyor structure. Damage can occur from machinery driving into the structure, and lifting and moving techniques of the structure can twist and flex the structure.

There are many styles of conveyors on the market today. Many of these are either truss or channel design. A channel conveyor is usually made of 4-in., 6-in. or 8-in. material, depending on its application.

Truss conveyors are generally built stronger due to their box-style construction. Normal construction of these conveyors is usually made of thick angle iron.

The larger the structure, the less likely the structure will bend during normal operating conditions, preventing tracking issues and decreasing overall maintenance of the conveyor system.

Perry Fell is territory manager for the Ontario, Quebec, Atlantic region at Luff Industries.

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Diagnosing critical to downstream success

Belt Tech’s Chris Kimball suggests solving the root issue rather than just treating the symptoms

Getting to the root cause of maintenance issues can ease the burden of constantly treating symptoms.

Controlling fugitive material is a major factor in maintaining the efficiency and profitability of an operation. Unfortunately, it’s also easily overlooked because it’s so common.

The first adjustment may require a shift in thinking about fugitive material as carryback and understanding the real-world cost and effects, including reduced operating efficiency; reduced plant safety; and increased maintenance costs as fugitive material is hard on pulleys, idlers and other components. When these problems are fully understood, practical adjustments can follow.

Transfer points can present numerous problems, but they’re also a great opportunity for improvement. Taking a closer look at how well they function may reveal a flaw that can be corrected. Because one problem is usually related to another, at times a total system may need to be reengineered. On the other hand, some minor adjustments may be all that’s required.

Another less complicated but highly important issue involves belt cleaning. A properly-installed and maintained belt-cleaning system is key to avoiding carryback material that can build up on idlers and cause belt misalignment and spillage.

Of course, the condition of the belt and the quality of splices will directly correlate to how well any cleaning system works because a badly cracked and worn belt will be more difficult to clean.

Chris Kimball is COO at Belt Tech.

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Effective belt cleaning to reduce carryback

A clean belt is essential to maintenance and uptime, says ASGCO’s Aaron Gibbs

With the need to improve efficiency, safety and productivity at today’s aggregate facilities, good housekeeping and dust and carryback reduction are increasingly important. Belt cleaners are an essential and key part to any clean and efficient conveyor system.

According to the Mine Safety & Health Administration, 39 percent of conveyor-related accidents occur while cleaning or shoveling around conveyors.
Conveyor belt cleaners help remove product carryback and prevent it from falling off at various points along the return side of the conveyor belt.
This mitigates housekeeping and maintenance problems such as excessive build-up and wear on conveyor belt idlers and pulleys; conveyor belt misalignment due to the artificial crown created by the carryback; accumulation of material falling off conveyor belt idlers and structure onto the ground, buildings, vehicles or even people; negative and unsafe work environments; and fines and/or penalties.

Cleanliness is essential for proper conveyor belt tracking. The key to controlling carryback is the installation and maintenance of an effective belt cleaning system. It is sound practice to use a multiple cleaner system to provide more than one pass at removing the material. These systems are typically composed of a pre-cleaner on the face of the head pulley to remove the majority of material, and one or more secondary cleaners installed further along the belt return to remove residual fines.

Tertiary, or follow-up cleaners, can be positioned even further back along the conveyor return to remove any last material.

Aaron Gibbs is president of ASGCO.

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Understanding the impact of carryback

Curbing carryback can improve efficiency and maintenance costs, says Applied Industrial Technologies’ Mark Kenyon

An easy adjustment that can be made to reduce conveyor maintenance costs is ensuring that proper tension is sustained on belt cleaners.

A misadjusted belt cleaner can cause carryback, which results in premature failure on pulley lagging, belts, idlers, bearings, and the bottom of the conveyor belt. An under-tensioned belt cleaner can also cause tracking issues and belt slippage, which impacts overall plant efficiency and can impact the structural integrity of the system.

A little bit of carryback is often ignored or goes unnoticed, but it’s important to understand where that material waste ends up and the impact it has on plant reliability, efficiency and maintenance costs.

Some new belt cleaners can now be tensioned with air springs, eliminating the need for re-tensioning. This maintenance-free design prevents material carryback in between adjustments by keeping constant pressure on the belt throughout the life of the cleaner. This constant pressure also increases the life of the blade by 30 percent, further reducing the amount of time needed to maintain the conveyor.

Mark Kenyon is industry manager of aggregate, cement and mining for Applied Industrial Technologies.