Water disinfection specialists Portacel use Watson-Marlow 504U/RL peristaltic pumps for dosing sodium hypochlorite and sodium bisulphite solutions in primary, secondary and final disinfection stages.
Dosing is closely controlled and monitored, with flow rates varying from 1 to 2 litres/hour. System layouts and concentrations of additive vary.
Watson-Marlow Bredel pumps were selected for their ability to provide a high, repeatable standard of volumetric accuracy - up to ± 0.5% , wide flow rate capability and low maintenance characteristics, combined with Portacel's own long term operational experience of the pump's performance.
Equally important is the pump's performance when handling media containing entrained air or gas. In this application, release of oxygen is liable to occur. When the pump is at rest, the resultant gas build-up creates priming difficulties in reciprocating and other traditional positive displacement pump types.
The design of the Watson-Marlow Bredel pump obviates air locks and associated problems. Normally operating 24 hours a day, the pumped media remains enclosed within the tube throughout the pumping process, with no risk of gland or seal leakage, and unaffected by chemical corrosion or crystallisation. Pumps are fitted with small bore Marprene tubing, selected for optimum service life on chemical handling applications.