Reeling in the years of operation

Demand for new bulk handling systems may be slow, given the state of global commodities markets, but suppliers of components can still find business in upgrade projects on existing machines.

Sweating existing assets harder is, if anything, even more critical at a time of low commodity prices, when doing whatever it takes to raise productivity can help cut overall supply chain costs for dry bulk shippers. 

Working on the principle that ‘time is money’, bulk materials handling operators are dedicating more resources towards extending the life of their capital equipment, in an effort to reduce disruptions from unscheduled downtime.

Engineering firm Heyl & Patterson (H&P) explains that it is a painful truth that handling equipment breaks down over time, and, whenever it occurs, it is almost always costly. 

The most common problems that lead to breakdowns are actually quite preventable. They include improper maintenance, overrunning a machine’s capability, not replacing worn parts, poor electrical connections, and even operation
by untrained personnel or failures to consult the operator manual. Almost all of these mean that someone has ignored the warning signs of an impending stoppage.

The way forward

But there are several reasons why upgrading existing machinery is the way forward. Machinery is often made easier to use by implementing newer technology and components. These reduce the potential for downtime, from
hardware to software, and often offer quicker channels to help with remote support. Replacement parts also play an important role in an operation’s efficiency, while up-todate technology can enhance this through remote support
and remote file transfer. 

The benefits of upgrading a machine a company already owns may equal the gains of purchasing new, but at a far lower cost and with faster implementation. 

Upgrades to mechanical and electrical systems raise performance and efficiency levels in a few key areas, H&P adds. First, they extend component life and greater overall system longevity through better design and operating  features. Second, upgrades reduce maintenance and downtime through more durable and readily available parts. Finally, they allow cost effective delivery while increasing equipment lifetime. 

Mechanical upgrades, in particular, help equipment withstand the rigours of processing loads faster, while electrical upgrades provide improved components for greater throughput, more precision and better diagnostic evaluation,
all with added safety. 

A good example from the past couple of years is the Duluth Ore Dock, where electrical power transfer specialist Conductix-Wampfler undertook a major upgrade to a 51-year-old cable reel system. 

The facility, in Duluth, Minnesota, USA, tranships iron ore and limestone to steel mills throughout the Great Lakes region. The dock is owned by rail operator Canadian National (CN), which also operates the nearby Two Harbors facility. 

At both sites, CN runs large-scale conveying systems, moving iron ore pellets at a rate of 3,000-6,000 tph. A combination of stackers, trippers, and iron ore bridges are on site, all of which are electrically powered. As they work
to move the ore before the cold weather hits, equipment downtime and maintenance can have a severe impact on the success of the season. 

In 2014, CN Duluth was experiencing issues with the old cable reel that supplied power to a tripper. The cable reel was unreliable and required supervision during each move to keep it functioning properly. Failures in its operation were known to result in downtimes of up to five hours while the cable was manually readjusted. Not only was this inefficient, but it represented a potential safety hazard as well. 

To upgrade the equipment, CN contracted  ConductixWampfler, as the company had previously worked on other CN Duluth projects, such as a monospiral cable reel that operated successfully for 20 years. 

According to Mark Zuroske, Conductix-Wampfler’s market development manager for mining and bulk materials handling in the Americas, the electrical supply company is cognisant of the need to work closely with its customers to  help them extend the life of their existing equipment during difficult economic times and limited capex budgets. 

Complex project

Two factors made the project more complex. The size and length of the cable had to be increased, and, on top of that, a tight timeline had to be met for installation, given the need to have the new cable reel operational prior to the onset of winter.

Conductix-Wampfler and CN’s engineering teams worked together on the technical specifications of the project. The new cable reel would have to accommodate an active travel distance of 490m and manage a 4/0 AWG 3 Conductor SHD-GC 5 kV All-Temp Industrite cable, manufactured by Draka, now part of Prysmian Group. The team settled on ConductixWampfler’s new Level Wind Reel (LWR). The LWR design, originally developed by the group’s operation in
France, incorporates a skeleton spool with an internal support design that strengthens the spool, while maintaining maximum rigidity and an overall lighter reel-weight package.

Total weight is around 5t, making the LWR easier for technicians to access the inside of the unit. The reel design also helps with the ventilation of the cable, thus lowering the operating temperature, the de-rating factor, and, ultimately, the size of the cable. The LWR is powered by Conductix-Wampfler’s Permanent Magnetic Coupler drive (MAG Drive) which the equipment supplier says has a number of advantages, such as smooth constant torque, no friction, no loss of cable tension, and low inertia, even when cable tension is high. 

Conductix-Wampfler maintains that flexibility in this type of heavy-duty application is key to minimising downtime and achieving long equipment life. 

The new LWR cable reel, adapted from the French design, was manufactured by Conductix-Wampfler USA in Omaha, Nebraska. It was ordered in July 2014, and delivered to the Duluth facility in mid-September. This enabled CN to have the new reel installed and operational before the 2014-2015 winter season.

“This application is a testament to Conductix-Wampfler’s ability to respond quickly to the need for a customised, highly engineered solution, to meet our customer’s requirements,” says Mark Schechinger, engineered product specialist at Conductix-Wampfler USA. 

Since installation, CN has reported it is already achieving higher degrees of operational safety, increased productivity and cost savings.