Articles & Case Studies
Verderflex mixes Lime for Chemical Dosing applications
Posted: Thursday 5th July 2012
The scenario
Verder have provided hundreds of pumps all over the UK for water authorities that needed a reliable solution for dosing in sewage and waste water treatment sites. Verderflex Dura peristaltic pumps play an integral part in a site’s lime dosing system for sewage and waste water treatment. Lime is mixed
by a tank and mixer then dosed into the effluent by Verderflex Dura pumps to balance the pH prior to nitrification. The automatic dosing system monitors the pH level and adjusts the speed of the pumps to meet the exact dosing requirement.
The problem
At the Severn Trent Barston STW, despite having an excellent Verder dosing system, legacy mixing equipment to mix the lime chemical was not effective with lime chemical settling in ‘dead spots’ in the tank – causing incorrect concentration of chemical and waste.
The solution
The Verderflex dosing system proved a great success and solved the maintenance and reliability issue Severn Trent had with the old metering pump system. Due to this success Verder were asked to look at the mixing of the lime in the storage tank. The solution was to install a VF40 pump unit to act as a mixing / recirculation pump. The pump turns over the volume of the tank every 12 hours and ensure the lime does not settle. As a result of this, the lime dosing process at Severn Trent at Barston is now trouble free.
