InfraStructures - August 2015 - DYNAVIS® Technology in Mining: A Golden Opportunity to Save Fuel?

DYNAVIS^® Technology in Mining: A Golden Opportunity to Save Fuel?

Richard Williams, Global Communications Manager ,
Business Line Oil Additives, Evonik Industries
Special Collaboration

In a gravel and sand quarry near the Lithuanian port of Klaipeda a fleet of construction equipment mines sand for road construction. And, at the same time, unseen and unnoticed, an important fuel efficiency field test is underway. The hydraulic fluid in the screening unit has been replaced with a fluid formulated to DYNAVIS^® technology standards, and the experienced DYNAVIS^® Efficiency Team is consulting with the quarry operator.

The DYNAVIS^® technology promise, “More Power – Less Fuel,” is facing one of its most challenging tests, since few field tests are more demanding in terms of heat and cold, weight of material transported, and non-stop production than the operation of a quarry screening unit.

The mining company has heard the claims. If you use a hydraulic oil formulated with DYNAVIS^® technology, you can expect higher efficiency and less fuel consumption, compared to what you will get from a conventional fluid. In fact, to back up the claims, the DYNAVIS^® Efficiency Team has repeatedly put its technology on trial in a series of tests conducted over the past three years. Looking at all the tests, the average minimum fuel savings over a conventional ISO 46 monograde fluid were 5-10%, with a savings of approximately 30% achieved in one test. Most of the tests to date have been conducted in Europe – in Italy, Belgium, Germany, and elsewhere. But the DYNAVIS^® Efficiency Team continues to extend the range. Another test in China has just been finalized, and the team is well aware that the trend toward greater efficiency knows no cultural or geographical boundaries.

The DYNAVIS^® technology brand name is owned by Evonik Industries, a global leader in specialty chemicals driven by an endless pursuit of greater energy efficiency, which it views as a global megatrend. The DYNAVIS® field tests reflect the systematic implementation of its corporate parent’s global strategy.

In each test, the procedure is standardized and straightforward. The oil in the hydraulic system of a piece of construction equipment is drained and replaced with fluid formulated with DYNAVIS^® technology. The average fuel consumption values before and after the change are compared. In the final report, statistical data is complemented with anecdotal observations from the equipment operators, who typically have a keen sense of how well the equipment is performing in terms of responsiveness.

A call from Lithuania
Arunas Aliulis, sales manager of UAB INTRAC Lietuva, the largest CASE construction equipment dealer in the Baltic, established initial contact with the DYNAVIS^® Efficiency Team and invited them to the sand and gravel quarry. The mining company, Vakaru Verslo Projektai, operates a number of wheel loaders and crawler excavators, which feed a screening unit and remove the output. The unit itself is a track-mounted, 36 t Kleemann MS 19 Z. Once the screening unit is in operation, its screen must not be allowed to run empty. Operating with an empty screen can easily damage the unit. As always in professional mining, material flow rates are precisely calculated and all loader and excavator movements are coordinated. If the screening unit stops, the rest of the fleet follows suit, and vice versa.

20 l/h of diesel
Once started, a screening unit remains in continuous operation, which is ideal for the fuel consumption comparison between a typical hydraulic fluid and a fluid formulated with DYNAVIS^® technology. The DYNAVIS^® Efficiency Team was, therefore, pleased with the choice of the screening unit as its test candidate. For this particular unit, Vakaru Verslo Projektai has calculated an average diesel consumption of 20 l/h, based on the unit’s past performance.

Another factor favoring the choice of the screening unit as test subject is a general problem, observed in numerous conveyor belts. The hydraulics supporting and moving belts exhibit a tendency to overheat, particularly at high ambient temperatures and with heavy loads. Conventional hydraulic fluids react to high temperatures by becoming progressively less viscous and “thinner.” An oil that is too thin leads inevitably to a loss of efficiency and an increase in fuel consumption. In extreme cases, this can even lead to a forced shutdown of the machine to allow for cooling. DYNAVIS® technology prevents this loss of both productivity and fuel economy by sustaining a sufficient level of viscosity, even at high temperatures.

Hydraulic through and through
A screening unit like the Kleemann MS 19 Z consists of a double-deck screen and a number of conveyor belts, all of which are hydraulically-powered. Up to 500 t/h of stones or sand are transported from the feed hopper by conveyor belt to the screen. Here the material is graded by grain size through 2 different meshes, and is removed and dumped by 3 discharging conveyors. The source of power for the conveyors, as well as for the track assembly and the hydraulics of the folding device of the belts, is a hydraulic pump powered by a 127 hp diesel engine.

On December 18, 2013, the screening unit’s hydraulic fluid was changed. This was the hour of reckoning for the DYNAVIS^® technology test. The comparison to be conducted with the Kleemann screening unit pitted the DYNAVIS^®formulated fluid against a conventional, but high-quality, hydraulic fluid, which could be expected to offer stiff competition.

The 660 l of conventional fluid were drained, and the entire hydraulic system was flushed, and then freshly filled, with the fluid formulated with DYNAVIS® technology. With the recording of the operating-hour counter at 1,968, it was time for the test to begin.

At the beginning of the test, Vakaru Verslo employees reported that outside temperatures had already reached and remained in the minus 2-digit range weeks before. Start-ups in these freezing temperatures required lengthy warm-ups. Eighty (80) hours into the test, the first observations were reported. Not only had the time required for the daily warm-up phase dropped for a third of its previous duration, but the entire hydraulic system was running significantly more smoothly.

The improved cold-start behavior came as no surprise to the DYNAVIS^® test team. The high viscosity index of the fluid ensured that the DYNAVIS^® formulation would maintain viscosity to perform better at high temperatures as well as provide improved pumpability at low temperatures. And by imparting both better flow and better lubrication, the DYNAVIS®-formulated fluid was also responsible for the smoother running of the screening unit.

Vakaru Verslo operators report fuel savings of 3 l/h
At the end of the test, when the DYNAVIS^® fluid had been in use for a full 6 months, the operators reported that the average fuel consumption for the screening unit had dropped from 20 to 17 l/h. And the relatively long test phase of 6 months meant that the fluid was exposed to the entire range of ambient temperatures – from a frigid -20°C to scorching summer temperatures exceeding 30°C.

Re-engineering or refilling, the choice is an easy one
Mining equipment manufacturers are exploring all options for investigation and reduction of operating costs. In a demonstration at Steinexpo in Nieder-Ofleiden, Germany in 2014, a leading producer of construction machinery related fuel consumption data, obtained by a fleet management system, and transmitted by GPS, to the weight (in metric tons) of material moved per hour. Another focus was on improvements in fuel efficiency achieved by elaborate modification of the motors and gears.

Easier by far is the switch from a conventional hydraulic fluid to one formulated with DYNAVIS^® technology. And in the case of the Kleemann screening unit, the change of oil did not require even one full working day!

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