Tag Archives: equipment maintenance

Outotec to provide proactive condition monitoring system for grinding mills

Outotec is looking to maximise grinding mill availability with a new modular system that provides all control functions required for the safe operation of equipment, and its associated lubrication systems, as well as continuous condition monitoring.

The Outotec Mill Control System allows for advanced condition monitoring strategies, including remote expert support, to ensure maximum mill availability, the company says.

It proactively detects anomalies using diagnostic data from IO-Link instruments to determine instrument health and detect installation problems before they cause downtime, according to the company.

Remote connectivity hardware is included as standard, enabling connection to Outotec’s Connected Services for remote diagnostics and support. Plant owners can also take advantage of Outotec’s cloud-based Asset Analytics service to gain valuable insights over the condition and performance of their assets, the company says.

“The system uses standard hardware and software components that are common across Outotec product lines for improved availability of support resources and spare parts and meets all relevant EU safety directives and other key international safety standards,” Outotec said.

IO-Link technology, an international standard according to IEC 61131-9, enables digitalisation and smart instruments by allowing for extended diagnosis of sensors and actuators, and the use of IO-Link instruments contributes to time and cost savings as the single interface means fewer input/output spares are required, according to the company.

In addition to increased mill availability, Outotec says it Mill Control System significantly reduces the commissioning time and cost associated with implementing similar systems, provides a shorter engineering lead time and superior installation quality thanks to “simplified wiring and termination design” as well as standardised software and hardware modules; comes with reduced project risks as the complete solution is delivered under one contract; and ensures compliance and reduced risk with state-of-the-art safety-rated hardware.

Air Springs Supply provides silent solution for vibrating machinery issues

A broken coil spring isolator or actuator in conveyors, vibrating screens, crushers, tanks and bin hoppers can bring processes to a complete halt, sending in maintenance staff to undertake the heavy and hazardous task of disassembling and returning to service vital machinery used in industries such as bulk material handling and mineral processing.

Actuation and isolation specialists, Air Springs Supply Pty Ltd, provides silent rubber solutions to such issues with complementary products engineered by Firestone Industrial to overcome both breakage and noise issues endemic to vibrating machinery, it says.

This includes solid no-maintenance Marsh Mellow™ rubber and fabric-reinforced bias ply isolators, which offer high load capacity with constant vibration isolation through changing loads, according to Air Springs Supply. Marsh Mellows will not bottom out like coil springs and offer low natural frequencies to provide excellent isolation (including forced frequencies in the range of 800-1,200 cycles a minute at 13-20 Hz), the company said.

Ruggedly engineered bellows-type air springs Airstroke® pneumatic actuators, which are friction-free for immediate response, and complementary Airmount® pneumatic actuators, which do not require periodic maintenance or lubrication, provide another solution. They are available in sizes ranging from 58-940 mm in diameter and 445 kN force capacity, meaning they can be used for delicate tasks and conveyors, through to heavy shakers, screens and crushers, the company said.

Air Springs Supply said: “Before Marsh Mellows were developed to solve problems with metal springs – including breakdown, replacement and noise – solid rubber springs were either physically too large or became unstable laterally when they were made long enough to provide good isolation.

“The concept of ‘stacking’ rubber springs answered the latter problem but introduced the need for complicated mechanical guide systems to control the lateral movement.”

The Marsh Mellow fabric-and-rubber spring solved this problem and provided a new way to make use of the many advantages of rubber as an isolator, Air Springs Supply Sales and Marketing Manager, James Maslin, said.

“The basic construction of the Marsh Mellow spring includes a solid rubber core with a hollow centre and fabric-reinforced body,” he said. “The controllable variables of this construction are the keys to the extreme design flexibility that the Marsh Mellow spring offers. And the same springs can eliminate potential problems of broken coil springs causing fragment damage to vibrating, stamping and metal forming equipment.”

Marsh Mellow Die Springs can be compressed by up to 40% of their free height at a cycling rate of 50 cycles/min or less, the company said. Cycling rates of up to 300 cycles/min can also be attained.

“Marsh Mellow Springs’ high load capability means fewer springs may be needed in an application, resulting in less overall cost,” the company said. “A spring with a smaller overall size than an all-rubber spring of identical load capacity can be chosen, which is an important factor where space is restricted.”

Airstroke pneumatic actuators and complementary Airmount Isolators provide a further alternative to metal springs, the company says. In effect, these are heavy-duty balloons that both contain no internal moving parts to break or wear. The resulting lack of internal friction and inherent rapid cycling capability makes them very suitable for actuation tasks such as conveying equipment and vibrating machinery, the company said.

“They are also outstanding isolators, in which role Airmounts reliably achieve isolation efficiencies often well exceeding 99%,” Air Springs Supply said. “Their outstanding performance suits them to applications such as suspending vibrating screens or motors and compressors commonly found throughout industrial plants, where they are generally used where weights exceed 100 kg per mounting point.”

A common materials handling isolation application is isolation of bin vibration. This type of vibration is typically used to maintain a homogeneous mix or flow of material inside a hopper where it must be isolated from bin supports to prevent structural fatigue.

Steel springs can be used, but they must be tuned to one specific load and a single height. Air springs provide a high degree of isolation compared with other methods, where they are used down to disturbing frequencies of 3-4 Hz, according to the company. Isolator inflation can be changed to compensate for different loads or heights without compromising isolation efficiency.

Airstrokes and Airmounts offer 40-40,000 kg of pushing or lifting power and strokes (extensions) of up to 350 mm, powered by simple, basic compressor equipment found in nearly every factory, Air Springs Supply said.

Metso reviewing Vereeniging operations in South Africa

Metso says it is initiating consultations to evaluate the potential closure or other alternatives for its operations in Vereeniging, South Africa.

The Vereeniging unit provides pumps, spare parts, consumables, and repair services for the mining industry and has around 200 employees, the company says.

The move is part of the global supply footprint development strategy in its Minerals operations. Similar reviews across regions in Metso’s Minerals Consumables business area have led to the closure of the rubber and poly-met wear parts manufacturing facility in Ersmark, Sweden, and a discontinuation of the Isithebe foundry in South Africa.

Sami Takaluoma, President, Minerals Consumables business area at Metso, said: “Our strategy is to utilise synergies of the most efficient manufacturing and sourcing opportunities globally. We are continuously developing our supply footprint to deliver the best value, availability and quality for our customers.”

WesTrac gets flexible with used, refurbished and as-new parts division

Caterpillar dealer WesTrac is spinning out its FlexiParts™ & Mining Services business to focus on sourcing and selling cost-effective parts, components and attachment solutions from its global network.

The new division will provide clients with access to a broad range of used, refurbished and as-new parts, it said.

A new website at www.flexiparts.com.au with an extensive online inventory is supporting the business online.

“The newly-branded business has operated as a division within WesTrac for some time and is now being established as a separate entity focused on sourcing and selling cost-effective parts, components and attachment solutions from their global network,” WesTrac said.

FlexiParts & Mining Services also allows customers to sell unwanted machinery and parts and will purchase and dismantle machines to ensure there is a large range and diverse inventory on hand, the company said. As well as Cat parts and equipment, the business sources and sells a broad range from other OEM brands. Exchange and outright purchasing options are also available for non-powertrain products, it added.

Travis Cargill, WesTrac General Manager Mining & FlexiParts, said the service was being ramped up in response to customer demand for more flexible solutions, differentiated price points and faster delivery times, which are not always possible when waiting for new parts and components.

“The major advantage of FlexiParts & Mining Services is that it provides customers with cost-effective options, sourced specifically for their needs, from anywhere in the world,” Cargill said.

“That often reduces wait times that can occur when purchasing new parts and provides customers with significant savings.

“It’s also important to note that while the business is evolving into a standalone entity, it will continue to maintain its close ties with other divisions within WesTrac and retain in-depth familiarity of customer sites and requirements.”

Another major benefit provided to FlexiParts & Mining Services customers is the provision of transport frames, specifically designed to allow safe transportation of a broad range of items, the company said.

Danielle Bull, WesTrac General Manager Product Support, said WesTrac has a duty of care under the Chain of Responsibility legislation to ensure safe transportation of bulky items, which is a key concern for customers.

“We’ve put a lot of emphasis on ensuring we can provide fit-for-purpose transport frames for a large range of parts, so customers know they not only have access to well-priced parts, but delivery to site will be a seamless process.”

Is your oil breathing?

When it comes to heavy mining equipment, effective oil breathers are of paramount concern, according to Harshvardhan Singh*.

Why is oil breathing necessary?

As far as operating environments for vehicles go, mine sites are about as harsh as it gets. Dust, dirt, mud, water, humidity, temperature variations, road conditions, and unpredictable operator driving behaviour are some of the factors that regularly test a vehicle’s efficiency.

For a vehicle to run smoothly, the internal mechanisms should be properly lubricated. Lubricants, as we all know, not just lubricate but also cool, clean, and provide noise dampening and sealing. Mining vehicles typically use four main types of lubricants – engine, transmission, axle and hydraulic. The brands and grades used can vary from one original equipment manufacturer to another based on the type and size of equipment.

Similar to humans bodies, , the blood circulating within the body should be healthy for it to function properly. The same is true with machines, where the health of lubricants should be in good condition to achieve higher machine reliability. Oil breathers play a vital role in ensuring oil is kept in optimal condition, eliminating build up of air pressure within an enclosed system containing oil. If this pressure is allowed to build up and is not vented efficiently, it can result in oil leaks, oil contamination and power losses.

Anatomy of a breather

A breather has a small vent or vents and its body can be made up of either steel or other material. Breathers generally have an inbuilt filter element made of paper, foam or fibre media. A typical desiccant breather (breather with a drying agent) uses silica gel to remove moisture and a filter media to remove particles greater than three microns in size.

Oil breather types and functions

  1. Engine oil breathers, or crankcase breathers: during the process of combustion, some combustion gases escape past the piston rings and enter the crankcase. The breather is a small pipe located inside the engine bending downwards, which helps depressurise the crankcase by releasing these gases to the atmosphere. This helps achieve better engine performance, lower oil consumption and lower oil degradation.
  2. Hydraulic oil breathers: these breathers are mounted on hydraulic tanks to prevent ingress of contaminants and water from the surroundings into the system. They also help remove the occurrence of a buildup of pressure or vacuum due to temperature or volume changes.
  3. Transmission oil breathers (pictured above): these breathers are mounted on transmissions to maintain air pressure equilibrium when the air inside expands and contracts due to heating and cooling of transmission oil during vehicle operation. The inbuilt filtration media blocks entry of contaminants and moisture, which can enter the system with air suction.
  4. Axle oil breather (pictured below): these breathers are mounted on differential housing. While in operation, the air inside the axle assembly heats up and expands, increasing the pressure. This pressure needs to be vented out to the atmosphere. When the axle assembly cools down, the air inside contracts and creates a vacuum. The breather helps in serving this process.

Maintaining oil breathers

The condition of oil breathers needs to be checked at every scheduled maintenance interval. The breathers should be replaced if the condition is found to be critical, in addition to the recommended change period mentioned in a vehicle’s manual. One of the best ways to check if the breather is working is to pass compressed air through the breather or blow air in manually via mouth. If the breather is not choked, air will pass through the breather. This method can only be used for checking axle breathers and transmission breathers. For hydraulic breathers, generally visual inspections are carried out to check condition.

Breathers – especially axle breathers – can be repositioned to a higher position on the machine in order to protect them from mud, which gets splashed on axle assemblies during vehicle operation.

*Harshvardhan Singh works as a Senior Service Engineer with an international mining equipment firm in Ajmer, India

Radicon’s Bloxwich on gearbox maintenance in mines

As IM goes to press on its first monthly issue of 2020, which includes its annual feature on mine maintenance, Giles Bloxwich, Service Manager at Radicon, has warned miners that they need to prepare for gearbox failures with an effective maintenance program.

He issues this warning knowing full well that these components can take anywhere from 3-14 months to build and some operators have lost as much as £1 million/d ($1.32 million/d) as a result of gearbox failure and subsequent downtime.

As with other gearboxes, industrial gearboxes such as those used in mining, see bearings tire, oil seals break down and oil thin as they get older. All of these issues reduce the amount of protection for the gearbox, with wearing and damage accelerating at a startling pace when you get unprotected metal on metal, according to Radicon.

“Mining is one of the harshest of environments and, over time, gearboxes get a hell of a lot of battering,” Bloxwitch (pictured) said. “Underground conveyors, in particular, operate in the most extreme of conditions. An oil change every 12 months or more frequently is definitely needed.”

When Radicon was working with former coal miner, UK Coal, oil samples would be tested every three months, with the company looking at the viscosity of the oil and contamination levels. If the oil was too thin, or contamination was beginning to reach worrying levels, an oil change would be undertaken.

As well as analysing oil regularly, Radicon also recommends undertaking vibration analysis along with scheduled bearing and seal checks. New bearings and seals should, if they are good quality, last for around five years but this can be a lot less in a mine, according to the company.

“Bearing life is the limiting factor of gearbox life,” Bloxwitch said. “If a bearing collapses, gears will drop out of mesh causing shaft breakage and gear tooth damage. This is expensive to rectify and can lead to weeks of downtime.”

Bearings will also be affected by shock loads and jams, according to Bloxwitch, with Radicon recommending replacing bearings before they fail.

“You cannot see inside a bearing, so it’s impossible to know for sure that a bearing is damaged,” Bloxwitch said. “We always tell our customers to be cautious and, if they do have a jam or a shock load, to consider the bearings damaged and to monitor their gearbox closely.”

One method of monitoring is recording and analysing vibration, as this will identify issues with gear mesh or bearing wear. Radicon believes that vibration testing should be carried out every three months, if not more often.

As well as vibrations and the level of metal content in the oil, noise and heat are two other indicators that a service is needed, Radicon said. “If a gearbox becomes louder and hotter during operation, then it could well be time to undertake routine maintenance as the viscosity of the oil could have reduced to such a level that bearing wear is occurring,” the company explained.

Some bearings now feature a temperature probe and an accelerometer, which allows vibration and heat levels to be recorded. “It’s not commonplace but is worthwhile,” Bloxwitch said. “Adding this functionality to the gearbox means operators will be alerted as soon as something changes and that can save them thousands of pounds, if not tens or hundreds of thousands!”

As well as regular oil changes, vibration analysis and following a maintenance program that replaces consumables regularly, including bearings, breathers and seals, keeping the gearbox as clean as possible is another way of prolonging the unit’s life.

MachineMax to help miners cut back on idle time

MachineMax has launched a new online Savings Calculator that, it says, will help mining companies save millions by cutting back on idling costs.

The tool, which takes just two minutes to complete, according to the global provider of software solutions, is based on data that considers the types of machines users are looking to save money on, fleet size and the hourly rate of an operator to calculate the figure.

The cost assumptions are modelled based on data collected from customers or industry standards, it said.

For instance, companies could save up to £1 million/y ($1,282,153) if they have around 27 heavy equipment machines idling for 1,000 hours PA where idling costs are estimated at £38,000 each, the company said.

MachineMax’s savings calculator also has an advanced savings option, giving users more accurate results based on actual site costs including maintenance and fuel.

Jennifer Thomson, Business Strategy Manager at MachineMax, said: “This calculator is an excellent tool to highlight how much a company can save by decreasing equipment idle time. On a mine site, some idle time cannot be completely avoided however it may be an indicator of an underlying bottleneck or process inefficiencies which can be resolved. Either way, equipment tends to be idle more than necessary.”

Idle time results in unnecessary direct operating costs as the machine is still running, consuming fuel, contributing towards emissions all while under the control of the operator, Thomson said. All of this has an associated cost.

She added: “There are also indirect operating costs associated to idling, as the engine is running there is unnecessary wear on components, hourly based maintenance occurs more frequently than necessary including premature filter and fluid changes and warranty hours are used over a shorter period.

“Furthermore, if the machine is idling then by implication it is not being productive so there is an opportunity cost to missing out on revenue from missed production.”

The calculator is looking to highlight the direct and indirect cost savings from cutting down idle time, she concluded.

Cat cuts electric rope shovel downtime

Caterpillar says it has developed a propel drive system upgrade for Cat® 7495 and 7495 HF electric rope shovels that improves maintenance access, decreasing downtime by days.

The upgrade, which has operated successfully for thousands of hours in field validation, reconfigures the crawler undercarriage to allow drive shaft and tumbler replacement from the outboard side, Cat says. Improved component design, meanwhile, extends durability and increases component life to further reduce costs.

“The new design slashes maintenance time and enhances safety by enabling access to drive components without removing the propel transmission,” the mining OEM said. “Additionally, Caterpillar engineered the upgrade to be a direct replacement. No machining of the crawler frame is required for installation.”

The new robust design sees thrust loads evenly distributed on large tapered roller bearings as opposed to bronze thrust plates, while the bearings are sealed and continuously purged with fresh grease to keep them free of contaminants, Cat says. The result is increased durability in harsh environments and alignment with 25,000 h planned rebuilds.