MechChem Africa January-February 2022

⎪ Water, wastewater and pumping solutions ⎪

the pump could do, says Stehle. The perfor- mance of the first unit indeed lived up to its promise, and the customer was quick to order further units. Within a few years, the sales numbers rose steadily as the reputation of the Warman ® DWUpump spreadwidely. “This was quite a new experience for us in the mining sector, where purchasing decisions are usually quite conservative and must be basedlargelyonpastperformance,” he notes. Awareness of the pump was also disseminated through the WeirMinerals global network, and the Warman ® DWU pump found its place in the global product line-up. Today, there are loyal customers inregionsas far apart as Australia andCanada. More choice With time, customers came to Weir Minerals Africa with particular require- ments that could suit the demands of their applications. This led to a wider range of construction materials being introduced in themanufacture of theWarman ® DWUpump. For instance, stainless steel was offered as an option, and a whole range is now available in stainless steel and hard-wearing materials for

acidic applications. Whileitwasdevelopedinitiallywiththecon- ventional gland seal arrangement, there were soon requests for mechanical seals, which are nowastandardoptiononallpumps intherange. “Thenwecame toconsider centrifugal seals or expellers, which required us to implement some design modifications,” Stehle says. “So additional components were added to assist with shaft sealing and we have recently made the whole range available with this centrifu- gal seal option. This allows our customers to eliminatetheuseofcleanwaterwhenoperating the pumps, contributing to our sustainability strategy.” Stehle pays tribute to the expertise of his design team and the power of modern soft- ware design tools, allowing the application of Computational Fluid Dynamics (CFD) to improve performance and increase energy ef- ficiency. The 3D modelling of complex shapes, inconjunctionwith3Dprintingtechnology,now alsoopensopportunities for intricatemanufac- turing results. Combined with the company’s advanced material technology, the wear life of theWarman ® DWUpump canbe continuously improved, and its reliability and sustainability enhanced. www.minerals.weir

The locally designed Warman DWU is also fully manufactured and assembled at the Weir Minerals facility in South Africa.

that deal with either slurry or clear water, but few that address those ‘in-between’ applications,” he

says. “Our design therefore sets out to combinethewear resistance, robustnessand longevityof theslurrypumpwiththeefficiency features of clear water pumps.” The Weir Minerals Africa design team targeted applications such as emptying min- ing ponds and dewatering from underground, where the specific gravity (SG) was up to 1.05. At the same time, the units have to achieve relatively high heads, while running reliably over long periods. “We wanted a high-pressure rating, with the ability to run the pumps in series,” he says. “Pump operators can usually achieve a high head while pumping over long distances and most multi-stage pumps on offer can meet distance and height requirements, but not whenpumpingdirty liquids. Sothisbecameour differentiating factor.” A satisfied first customer Such was the need in the market that our first customer needed little convincing about what

Weir Minerals’ Warman DWU pump was designed specifically for dirty water requirements.

January-February 2022 • MechChem Africa ¦ 11