Department
Lewis® vertical sulfuric acid pumps save South American smelter $100K & 200 hours By: Martha Villasenor, Senior Sales Engineer, Weir Minerals
Leaks and failures
A smelter in South America was experiencing pump leakage and failure due to the extremely corrosive, high temperature acid in its sulfuric acid plant. The incumbent horizontal pumps leaked at the shaft seal and volute, causing excessive wear in the pumps’ components. This led to constant disruptions in the process, with failures occurring at least once a week. Additionally, the leaks caused damage to the floor and hazardous working conditions for operators. The facility needed a reliable solution to keep their workers and the environment safe, and to increase uptime, since the plant was operating at only 50-70% of capacity due to the pump failures.
New pump design
The Weir Minerals team completed a full analysis of the sulfuric acid process and proposed a new layout incorporating Lewis® vertical externally mounted (form E) sulfuric acid pumps to replace the incumbent horizontal pumps. By selecting a Lewis® externally mounted vertical pump design configuration, the
Lewis® vertical sulfuric acid pump
facility would not need to build a separate pump tank, which would save on cost and space. Compared to a horizontal pump design, harsh acids do not touch the shaft sealing and won’t compromise the sealing elements in the vertical design of a Lewis® pump, eliminating the risk of acid leaks or spills on operators. Additionally, Lewis® pumps are made from robust construction materials to combat the effects of a corrosive acid environment. Lewmet® nickel-chrome alloy is used for critical wearing parts to provide maximum corrosion resistance.
Saving maintenance time and money
Now the pumps at the plant are no longer leaking or restricting plant capacity. Af-
Leaks in the seal of the incumbent pumps.
ter the layout changes were completed and the Lewis® pumps were installed, the pumps operated for more than 12 months without leaking or needing maintenance. Operators were extremely pleased by how long the pumps lasted and stopped for preventative maintenance after 12 months. Once restarting, the Lewis® pumps continued to operate for another 18 months without downtime. Compared to the incumbent horizontal pumps that lasted only one week, the operation saw a decrease in maintenance time by more than 200 hours per annum. In addition to more reliable and safer operations, the plant no longer needed to
Lewis® vertical pump in operation.
make regular short-term replacements of the pumps’ impellers, volute, and seals, which resulted in a significant cost savings of more than $100,000 per annum.
For more information, please visit
www.global.weir. q
ISO-FLOW™ Trough Distributors with SWIFT-LOCK™ Experience: • Next generation Orifice distributor introduced in 2011 • Developed and patented by Chemetics Features and Benefits: • Orifice distribution provides consistent flow to each downcomer • Air gaps provide hydraulic separation and allow for easy troubleshooting • Calming plates promote even distribution - Integral screens catch chips to minimize plugging and allow easy cleaning - Internal channel minimises header pipes • SWIFT-LOCK™ system - Reduces distributor installation time by 50% - Simplifies tube bank installation/removal – time reduced by 90% - Eliminates 90% of nuts/bolts/washers • SARAMET® Construction for excellent acid corrosion resistance The ISO-FLOW™ Trough Distributor is designed to be installed through tower manways and is ideal for retrofits.
Innovative solutions for your Sulfuric Acid Plant needs Chemetics Inc.
Chemetics Inc.
www.worley.com/chemetics
Chemetics Inc., a Worley company
(headquarters) Vancouver, British Columbia, Canada Tel: +1.604.734.1200 Fax: +1.604.734.0340 email: chemetics.info@worley.com
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(fabrication facility) Pickering, Ontario, Canada Tel: +1.905.619.5200 Fax: +1.905.619.5345 email: chemetics.equipment@worley.com
Sulfuric Acid Today • Spring/Summer 2021
