Weir’s WARMAN ® DWU: the dirty water workhorse The WARMAN ® DWU (dirty water unit) is a high-head hybrid pump for mine dewatering applications that combines the efficiency of a clear-water pump with the robustness of a WARMAN ® slurry pump. Marnus Koorts, General Manager for OEM Products at Weir in Africa, highlights the features and niche uses of this locally manufactured workhorse.
M anufactured in South Africa for global mine dewatering applications, the WARMAN ® DWU pump is noted for its high efficiency, with high-chrome components that provide excellent wear characteristics and solids handling of dirty water with specific
gravities (SGs) up to 1.05. “The WARMAN DWU pump serves a market that is under-serviced, in my view,” says Marnus Koorts, General Manager for OEM Products at Weir in Africa. “It fits into a niche between high-efficiency clear-water pumps and wear-resistant mill circuit slurry
pumps, and I don't believe there is another product that fits this niche quite as well,” he says, adding that it is particularly well-suited to the harsh mining environment. In general, he says there is a significant divide between slurry-pump and clear-water pump providers. Slurry pumps generally focus on wear life and maximising solids-handling capacity, while clear-water pump providers concentrate on energy efficiency and dis- charge head. “Our DWU sits between this divide, designed for mining environments where the water is not clean, but neither is it slurry. Clear-water pumps have tighter tolerances and a wider range of materials of construction because they don’t have to resist abrasive wear. On the other end of the spectrum, slurry pumps are generally less efficient, primarily because wider tolerances are needed to reduce wear rates. “Clear-water pumps are machined to achieve the tolerances necessary for efficien - cy, while slurry pumps are cast and skimmed to get the material composition needed for abrasive resistance,” he explains, adding that this leads to an inherently rougher finish, which leads to lower comparative efficiencies. Additionally, while slurry pumps are more robust, they are not generally required to pump high heads: a cyclone feed pump typically operates with a pressure head of 30 m or less. “But for dewatering from a deep mineshaft or pit, water may have to be lifted hundreds of metres in a single stage to transfer it away from where it has settled. Minimising the number of pumps installed to achieve the high discharge heads required is where the WARMAN DWU unit shines,” Koorts points out. Underground water is generally quite clean at the source, but as it flows into a mine or pit workings, fine dust particles or solid residue from mining activities can con- taminate the fluid. The water used to cool the drill bits, for example, is often sourced from open underground dams, so it is not clean; it contains small but significant levels of suspended solids. Mineshafts also experience ongoing water seepage, so there is a need to
The WARMAN DWU pump’s high-chrome components provide excellent wear characteristics and performance in dirty water.
The WARMAN DWU pumps can be interfaced with diesel engines on trailer or skid-mounted pontoon barges.
16 ¦ MechChem Africa • January-February 2025
Made with FlippingBook flipbook maker