Location
Belgium
Industry
Chemical
Six Schegler Vigor pumps and four Verido sump pumps
Each configured for its specific duty in a continuous leaching process.
Ultra-high chromium 424 wet-end parts
For consistent wear behaviour and resistance to an acidic, abrasive slurry.
Brayston double mechanical seals
Fed from one redundant thermosyphon unit, for leak-free running and predictable maintenance.
Challenge
At a chemical processing plant in Belgium, a continuous leaching installation handles two distinct slurry circuits.
In the first, a solid process residue is brought into contact with a liquid, causing certain components to dissolve. The result is a slurry of liquid, dissolved substances, and undissolved solids that are pumped to filter presses for separation. This process runs in cycles across multiple vessels in series.
In the second circuit, the neutralized water from the first process is either returned to the process or sent to water treatment.
The slurry in the first circuit is acidic to mildly acidic throughout the process, with a pH ranging from 1 to 7, a density between 1.3 and 1.5 kg/dm³, and an abrasive solid fraction. The second circuit operates at around pH 9, with a limited solid content and dissolved salts.
Both circuits needed pump configurations that could handle these conditions reliably, avoiding leakage and without requiring constant maintenance attention.
Solution
Vaikon delivered a complete pump package for both circuits, with every pump configured for the duty it has.
The slurry side runs on Schegler Vigor Vi3x2 horizontal pumps. Four of them move slurry from the storage vessels toward the filter presses and a buffer tank. Three pumps run in cycles of roughly 25 minutes every two hours, while the fourth draws from the buffer tank and runs more often in shorter bursts. On the water side, two more Vi3x2 pumps take over after neutralization: one returns water to the process for reuse, the other sends water from a filtration unit on to treatment.
The Vigor is a dimensionally interchangeable alternative to the Warman AH pumps the plant already ran, so the new units fit straight into the existing layout, with custom adapter pieces wherever the pipework did not line up. Vaikon also refurbished two of those existing Warman AH pumps and converted them to the same double mechanical seal setup rather than replacing them, since Vaikon services and refurbishes these models as well.
All wet-end parts are cast in ultra-high chromium white cast iron, known as Schegler material 424. With around 30 percent chromium, it holds up well against acidic, chloride-bearing slurries, which is exactly what this process requires. Using the same alloy across every pump keeps wear behavior and spare parts consistent throughout the installation.
Each Vigor is fitted with a Brayston double mechanical seal. The double seal holds a pressurized barrier fluid between two sealing faces, so the slurry stays where it belongs and there is no leak path to manage. To supply all of those seals from one point, a standalone thermosyphon feeding system keeps the barrier fluid at pressure automatically. It works on two pumps, so the supply to the seals does not depend on a single one.
Four Schegler Verido VE40 vertical pumps complete the scope, built in the same 424 alloy for the sump duties on site. With everything in place, Vaikon commissioned the full installation and trained the operators on it.
Result
The new configuration put an end to the failure pattern that had plagued the original pump. Duplex wet-end materials resist the combined attack of acid, chlorides and heat. The double mechanical seal removed the leakage path that had caused acid attack on the back plate and created a safety risk.
Keeping the existing base and piping in place reduced the scope and cost of the transition. The plant retained its installation footprint while gaining a pump configuration that can handle what runs through it.
The thermosyphon feeding system keeps the seal protected continuously, without anyone needing to intervene.
