Great results from retrofitting pumps

Online Editor

Stephen Marshall explains how to improve efficiency and reduce carbon emissions

Over the next decade, innovative new products must address energy efficiency and sustainability challenges. For some OEMs, this may require a strategic re-evaluation. However, for Weir Minerals, it will simply mean continuing to uphold the legacy that has made it one of the leading pump manufacturers.

The popular Warman AH pump is continually evolving and Weir Minerals’ engineers constantly analyse almost 40 years of data from its installations all over the world, examining wear life, component arrangement, material composition and slurry abrasiveness. The firm also explores the hydraulic design and fluid mechanics to improve the pump’s efficiency as part of this process. The Warman WRT (Wear Reduction Technology) pump is the result of this hard work. The WRT is a new impeller and matching throatbush design that provides operators with a superior upgrade for their existing AH pumps.

The new impeller design incorporates a vanelet on the back shroud, streamlining the flow through the impeller outlet. The WRT impeller and throatbush combination delivers improved hydraulic profiles, reduced turbulence, extended-wear performance and lower power consumption.

The WRT parts are retrofittable in the Warman AH range of pumps – provided, of course, that the matching parts are genuine Warman original equipment as manufactured and supplied from one of Weir Minerals’ manufacturing centres. It is straightforward to remove two standard parts and replace them with the Warman WRT parts during a routine maintenance shutdown. All setups, fitment and general maintenance remain the same; moreover, the replacement doesn’t require any speed change or specialised tools.

A recent independent study from a mine in South Africa found that the Warman WRT showed lower deterioration rates and enhanced impeller wear resistance based on pump speed, power, efficiency and changes in critical pump measurements. Over the course of the trial, the Warman WRT impeller lasted twice as long as a polyurethane impeller and four times as long as a steel impeller, reducing the consumption of wear parts.

The study also examined power consumption: improvements in energy efficiency were quantified accurately by adopting a 24-hour baseline methodology. A multi-variable and single variable baseline represented the power usage before WRT impeller installation. The findings proved that the pump with WRT impeller consumed 3.85% less power relative to the baseline. While this might not sound like a lot, on a large pump that operates 24 hours a day, seven days a week, it adds up to a lot of kilowatt-hours (kWh) and, therefore, a significant reduction in carbon emissions.

The results have been even more impressive in other operations. A diamond mine in North America that had installed non-genuine Warman parts in its AH pumps in an attempt to reduce costs was experiencing ongoing reliability issues. Weir Minerals proposed that it evaluate the Warman WRT throatbush and impeller combination in the AH pumps. Based on the trial results, wear life improved by 50%, while efficiency increased by 21%.

As sustainability becomes increasingly essential to miners, OEMs must continue to harness technological innovations to find efficiencies that reduce energy and water consumption wherever they can. It’s not enough for sustainability to be an afterthought or a supplemental benefit; instead, it has to be at the forefront of how OEMs think about and approach engineering and design challenges. Sustainability needs to be embedded throughout organisations as a means of fostering long-term value.

This philosophy, coupled with its technical know-how, has seen Weir Minerals build on the concepts that underpinned the evolution of the impeller and throatbush design that led to the development of the WRT impeller. Research into the hydraulic design features of the AH pump continues to inform the design of other Warman pumps, including the Mill Circuit (MC) duty slurry pump.

Stephen Marshall is Head of Engineering Operations at Weir Minerals

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