Peristaltic pumps from Watson-Marlow Bredel neutralise pH problem at WTW
Viscous lime slurry was used to maintain a neutral pH during the water treatment process, but caused frequent blockages in diaphragm pumps previously used for the purpose.
Watson-Marlow Bredel supplied two peristaltic hose pumps to overcome this problem successfully while substantially reducing the time and cost of maintenance required.
Based in Mossley near Manchester, Buckton Castle Water Treatment Works (WTW) supplies up to 50 megalitres of water a day to over 120,000 people in the Tame Valley.
The water is supplied to the site from reservoirs in the Greenfield and Swineshaw valleys. The water treatment process involves the addition of lime slurry to the water supply at several points to maintain the required pH level.
The alkaline solution is added first during the coagulation process, which causes unwanted particles in the water to stick together so that they can be extracted from the solution. Lime slurry is dosed again into the water to correct the pH during two stages of filtration before it enters the supply pipelines.
The diaphragm pumps used earlier by the WTW for the purpose were frequently blocked by the viscous slurry at low flow rates, causing maintenance problems and increased downtime.
The peristaltic pumps supplied by Watson-Marlow Bredel however, eliminated the blockage problem.
Peristaltic pumps are designed to allow only the tube to be in contact with the fluid, eliminating any risk of the fluid and the pump contaminating each other.
If the fluid should ever enter the pump casing, it will not cause a problem as the chamber level switch will stop the pump. The hose is the only wearing part in the pump and can be replaced without dismantling the pump, keeping maintenance simple and economical.
Buckton Castle WTW is currently using ten Watson-Marlow Bredel peristaltic pumps including SPX15 units (maximum flow 2.3gpm, discharge pressure 110 psi) and SPX25 units (maximum flow 11gpm, discharge pressure 232 psi).
Process Technician at Buckton Castle, Mike Whittam says that the Watson-Marlow pumps are a great improvement for the treatment works. Having worked with Bredel pumps before, he is aware of their ease of use and low maintenance requirements
Key benefits of Watson-Marlow Bredel peristaltic pumps:
- Capable of pumping viscous and high density fluids
- Accuracy (±1%) of the flow rate increases suitability for dosing applications
- Fitted with camlock connectors to fix any problem quickly and efficiently
- Enhanced hose clamping and flange design in SPX25 enables quick hose change and increased effectiveness of the sealing system
- Designed to prevent backflow, eliminating need for valves and significantly reducing blockages
- Accuracy of the delivered volume and flow rate can be fully tailored through the size of the pump, the rotor speed and the tube diameter
- Safety features include pressure relief switches and pressure sensors