Process Equipment Update
Sodium hypochlorite is a highly corrosive chemical that has disinfection and bleaching properties. It is used in the purification of wastewater and the disinfection of drinking water.
proved its worth at Coddle Creek water treatment plant, eliminating the mixed results of a few years previously experienced using a submersible pump dosing powder activated carbon (PAC) from a wet well. After more than three submersible pumps failed in just over a year the maintenance and operations management sought an alternative. The problem was the location of the pump: in the
pump room eight metres above the bottom of the well and additionally, the pump must also be able to resist the PAC’s abrasive nature. So the plant called on Verder GPM to help find a solution. Lance LeBrun, Verder GPM’s regional sales manager
for the Carolinas, recognised that the best pump for the job would be a Verderflex peristaltic pump. Using a flow paced controller, the Verderflex hose pump can transfer and dose variable flows in accordance with the plant’s demand and by their very nature these pumps can gently pump abrasive suspensions such as PAC and lime slurries without any check valves.
Suction lift Given the flow rate, suction and discharge pressures needed, Verder GPM chose the Verderflex VF15 hose pump with its 15mm diameter natural rubber hose. The VF15 is capable of short term flow rates up to 600l/h and continuous flows of 375l/h at pressures up to 12Bar. Use of the high pressure rotor and Verderflex’s reinforced hose technology creates excellent suction lift and easily manages the eight metre lift needed by Coddle Creek. Verderflex manufactures a large range of peristaltic pumps
for many process applications, from small custom tube pumps used in OEM equipment through to the VF125, the largest high pressure peristaltic hose pump in the world and Scada- controlled Smart tube pumps that accurately and consistently dosing process chemicals. The company says that during difficult economic times
customers are increasingly looking for reliable, low cost of ownership engineered solutions over cheaper but high maintenance alternatives and recent studies indicate that more and more customers will be using peristaltic technology in the future.
However, dealing with the chemical can be difficult as it is toxic and emits chlorine when in contact with acids. It naturally releases tiny bubbles of gas, which have a tendency to collect on the small ball valves found in conventional diaphragm dosing pumps. This can cause gas locks in the system, which prevent the pumps from functioning. Because peristaltic pumps retain the fluid completely within the tube and have no valves that can leak or corrode, they can be used for the accurate metering of substances as challenging as sodium hypochlorite, without the associated gas locking and maintenance problems. Peristaltic technology therefore helps to keep costly
downtime at the site to a minimum. It’s a similar story with Verder GPM, the US partner of
Verderflex peristaltic pumps, which has used its expertise to overcome persistent problems at a North Carolina water and wastewater treatment plant. Often overlooked, the reliable peristaltic pump has again
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Small and ruggged Meanwhile Eccentric Pumps has launched its new MiniPump small peristaltic pump. The company says that its latest addition delivers the same performance advantages as the rest of the peristaltic pump product line. With a 6mm, 1mm or 13mm ID hose, the MiniPump is a small and efficient peristaltic pump that covers a pumping range from 1-120 gallons/hr. Eccentric says that its customers have used its small,
rugged peristaltic pumps to solve problems such as handling bleach, acids and alkali, abrasive or corrosive slurries, or other difficult-to-pump fluids and materials. “Our customers appreciate our self-priming, positive flow,
high suction lift, dry running, and sealless peristaltic pump design,” it says. The company also offers replacement hoses for
competitors’ pumps, including Watson Marlow, Bredel, Periflo, Verder, Verderflex and Blackmer. ■
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