Sodium hypochlorite is a corrosive chemical that has disinfection and bleaching properties, and is used in the purification of waste water and the disinfection of drinking water. 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 and necessitate regular downtime and maintenance.
When the pumps were replaced with 520U/R peristaltic pumps supplied by Watson-Marlow , this problem was eliminated.
South East Water is also using the pumps for dosing sodium bisulphite, in order to de-chlorinate the water after disinfection to remove the unpleasant taste. The chemical is dosed in very small quantities, requiring a precision pump.
Previously, it had been necessary to dilute the sodium bisulphite in order to control the dosage procedure accurately. This added an extra degree of complexity to the process which Watson-Marlow’s 520U/R pump handled easily.
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