Use of Bromine in cooling tower systems. 1

[glennpan]

Hello,

I understand that many plants are switching from Chlorine to Bromine in cooling tower systems, as it not only works as a biocide but also is much better as an anti-scalant.

Is ORP generally used to control the addition of Bromine into these systems? Does ORP do a good enough job for this type of control?

We are looking at designing a Bromine analyzer, and want to see if this is a feasible application for its use.

Thanks,

Glenn

 

[bwi]

Glen,

Bromine is the better oxidizing biocide in cooling tower applications because of more favorable dissociation curve in the pH 8+ range of cooling towers. Typically the products are used together for the best results since the chlorine helps to activate the bromine. We use a tablet form for cooling tower treatment that is 2 parts bromine and 1 part chlorine and dosed using a brominator. I have seen liquid versions too but our experience is the liquid forms off-gas causing metering pumps to loose prime.

Generally ORP measurement is not routinely used for oxidizing biocide dosing in small to medium sized cooling towers (500 tons or less). Dosage rates can be easily determined from the system volume. These can be confirmed with wet chemistry tests (Hach/LaMotte) and results confirmed with bacteria/fungi tests. ORP controllers are currently available from companies such as LMI (DR5000 ORP Controller), Pulsatron and others.

Large towers, such as power plants, may use ORP measurement, but this market is limited.


Dean