Peristaltic benefits
April 1st 2007 Process Engineers at a Severn water treatment works (WTW) are benefiting from accurate chemical dosing, reduced maintenance and reliable operation thanks to the replacement of rotor and stator pumps with peristaltic technology. The peristaltic pumps, supplied by Watson-Marlow Bredel were installed at Bamford Water Treatment Works as part of a project to optimise performance at the site. An integral part of the water treatment process at Bamford is the addition of lime slurry, to control the pH of the water. Water entering the works is dosed with ferric sulphate and a polyelectrolyte and brought to a pH of between 4.7 and 5.1. If the water is lower than this pH, it is dosed with lime in order to bring it up to the required level. The water is then fed from the clarifiers onto a bank of RG filters.At this stage Sodium Hypochlorite is added as a disinfectant. Just before the water leaves the site, further alkaline lime slurry is metered to the supply in order to maintain the required pH level.The lime raises the pH to around 8/9, which assists in the removal of naturally occurring manganese. Bamford WTW had previously been using rotor and stator pumps for this purpose – although two Watson-Marlow Bredel pumps had been used on the site for kalic dosing for several years. The rotor and stator pumps were removed as part of the AMP3 capital programme to upgrade the site. According to the works manager at Bamford Works, the peristaltic pumps supplied by Watson-Marlow offer significant advantages over the previous pump types. "Because there are no glands - there are no leaks, which was always an issue with the rotor and stators.The other important thing for us is that when the tube needs replacing, it's simply a case of a single step operation to complete the task." The works manager is convinced of the benefits of peristaltic technology over alternative pumps types for demanding chemical dosing applications. "The Watson- Marlow Bredel pumps are capable of pumping viscous and high density fluids - which is not necessarily true of other pump types. It's also vital for us that the unit doesn't require high levels of maintenance.As the hose or tubing is the only wearing part it can be quickly replaced without dismantling the pump - and maintenance is therefore simple and cost-effective." More articles from Watson-Marlow Bredel Pumps: | 
