Reducing maintenance downtime in mining shovel lift

Routine maintenance is required on a P&H 4100XPC Electric Rope Shovel after every 30,000 hours of operation.

These machines – which are used on coal in Australia – require maintenance in which the upper section is lifted off the car body to machine bearing surfaces and inspect and repair structural components. Weighing approximately 1000 US tons (approx. 907,000kg), lifting the upper car body requires a significant amount of force and control.

The maintenance team at Joy Global (now part of Komatsu) reached out to Enerpac to deliver a shovel lift system to undeck a P&H 4100XPC shovel in approximately one hour and be transported on the highway without oversized load permits.

The EVO synchronous lift technology involved in this US lift – technology which is widely deployed by Enerpac for heavy precision lifts in Australia and New Zealand – provided the speed and safety of the lift that were critical components in reducing labor and equipment.

The solution

The EVO system included four 500 US ton cylinders with 72 inches of stroke (approx. 1829mm), an EVO synchronous control unit and four custom 8000 series hydraulic pumps. Each pump was built to operate in extremely cold or hot environments.

“Enerpac had previously built a similar shovel lift system for Joy Global’s maintenance team in Chile. The second-generation system built for Joy Global’s service team in Gillette, Wyoming, provided significantly more speed,” said Warren Baltineshter, Australasian Mining and Heavy Lift Solutions manager for the global Enerpac organisation, which has operated throughout Australasia for more than 50 years.

The EVO synchronous control unit enabled a single operator to control the entire lift and ensure each lifting point remained within 3/8 of an inch (9.525mm). The shovel was successfully undecked in approximately one hour and the entire system was transported on the highway without oversized load permits.

Products involved were four custom 500-ton cylinders with 72 inches of stroke, four custom 8000 series hydraulic pumps and an EVO synchronous control unit.

EVO lift system

Enerpac’s EVO synchronous lifting systems replace manual control of hydraulic heavy lifting with PLC control of multiple cylinder lifts, offering accuracy, safety and productivity benefits for precision lifting of heavy resources industry machinery.

The EVO system is the evolutionary result of Enerpac’s 25 years of experience in specialised hydraulic engineering and lifting technology, using digitally controlled hydraulics to accurately and safely lift some of the largest and most challenging structures on earth, including mineral and oil and gas processing equipment.

Recent examples range from 1500 ton grinding mills in Western Australia to the superlifting and launch of a 43,000-ton floating oil production system in Malaysia for the Gumusut-Kakap offshore field.

The latest EVO synchronous system offers eight standard hydraulic control modes and can control 4, 8 or 12 points with one hydraulic power unit (HPU). A master control unit is also available that offers daisy chain control of multiple EVO systems, giving a maximum of 192 lifting points.

Instead of whole teams of lifting personnel trying to manually co-ordinate with each other lifts by hydraulic cylinders dispersed around a job, the EVO series synchronous lifting system integrates the high-pressure hydraulic cylinders involved with a PLC system to monitor and control precise movement and positioning of heavy loads.

Through an integrated human machine interface (HMI), all movements are managed from a central control position that displays live operation with real-time status updates for each lifting position.

The multifunctional EVO-Series can be used with multiple standard 700 bar (10,000 psi) single- or double-acting cylinders and is offered with a 5 HP or 10 HP hydraulic power unit with 250 litre reservoir.

Accuracy is one of the main benefits of using the EVO system, which also offers increased productivity, with less staffing required than for manually controlled lifting.

“With synchronous lifting, one operator controls the entire precision lifting process, during which the status of every lifting point is constantly monitored and displayed,” Baltineshter said.

“Time saving is another advantage of synchronous lifting. The process does not have to be stopped after any incremental value, checked, manually re-measured and corrected. The EVO-System carries out these actions during the entire lifting process, even with low lifting or lowering speeds. Depending on the application, time savings up to 60 percent can be achieved.”

Safety benefits of the PLC-controlled system include elimination of the potential for error with the multi-operator manual control approach. The digitally precise EVO-system incorporates warnings and stop functions. It offers full monitoring and control, with programmable failsafe monitoring and safety alarms.

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