Weir Minerals engineers developed the Warman® WRT® impeller and throat sleeve combination using a novel integrated design method-significantly improving the wear life of Warman® AH® pumps. It began with an extensive research and development program by Weir Minerals engineers to better understand the wear characteristics of the inlet and outlet of the centrifugal slurry pump impeller. This is part of Weir Minerals' efforts to reduce the total cost of ownership of its range of products. The climax of the project resulted in a new impeller and matching hose sleeve design, providing significant advantages for users of Warman® AH® pumps.

Using years of wear data from the popular Warman® AH® pump design, design engineers compared this "real world" data with computational fluid dynamics (CFD) simulations. This allowed them to obtain a correlation between the predicted and actual results of the standard five-blade slurry impeller. The final design of the new impeller uses unique blades on the rear shroud to simplify the flow through the impeller outlet. This improvement also provides higher efficiency, which reduces absorbed power and improves net positive suction head (NPSH) performance.

Recently tested in a gold mine with a large amount of clay in the slurry feed, the Warman® WRT® impeller and throat sleeve combination performed well. The mine faces the challenge of increasing mud viscosity due to high clay content. In addition, the clay contains sharp, rough quartz particles, which can cause severe impact and abrasion on the leading edge of the impeller blade of the installed pump. The mine needs to increase its output, but due to the viscosity of the slurry, existing competitors' impellers cannot maintain the required level. The Weir Minerals team recommended the Warman® WRT® impeller and hose sleeve combination, which were retrofitted into the Warman® pump.

"After installation, the Warman® WRT® impeller works well and the variable speed drive (VSD) is reduced while providing the same throughput. These results are due to the lower NPSH characteristics of the new WRT® impeller and pumping of viscous clay mud without producing Cavitation ability. The pump was inspected after 1,200 hours of operation with Warman® WRT® impeller and throat sleeve. The leading edge of the impeller blade of the Warman® impeller has some wear, but the front cover is almost not worn. Warman® with WRT® technology The pump continues to achieve a wear life of 1,500 hours, which is 125% longer than the average wear life of a competitor impeller of 670 hours."

Due to the higher efficiency of the impeller, less solid recirculation, longer wear life of the two components and less rebuild of the pump, this has achieved considerable savings for the mine. This technology also helps save energy costs because the pump consumes less power.

WRT® parts are interchangeable and can be retrofitted to all current Warman® AH® pumps. This can be done during normal maintenance shutdowns, at which point the two standard components can be removed and Warman® WRT® components can be installed. All settings, assembly and general maintenance remain unchanged. There is no need for speed change, nor any special assembly tools.

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