Mick De Maeyer

Scoping, project lead (A-Z), Follow up (results, adjustments).

A customer had a persistent Legionella problem on a cooling system, fed with canal water. The canal water itself also tested positive for Legionella. Over a long period of time, continuous infections of more than 1.000.000 cfu/l were registered. A conventional treatment with bleach and non oxidizing organic biocides were ineffective, due to: high pH, short holding time, high temperatures and other mechanical difficulties. To prevent a potential shutdown of the cooling tower, Kurita was contacted. We implemented our state of the art Dilurit BC S technology. In a short period of time we were able to reach a level of "No Legionella species detected".

Scoping, project lead (A-Z), Follow up (results, adjustments).

A customer was using a conventional bleach treatment for their cooling systems. The system metallurgy was based on stainless steel which could tolerate a max chloride concentration of 100 ppm. Although the system was fed with RO water (which contains almost no chlorides) the maximum cycles where 12.5 due to the chloride input of bleach. After switching to our Dilurit BC S technology we managed to increase the cycles to 25 without increasing the corrosion pressure. This resulted in a blow down decrease of 30% which resulted in a lower chemical consumption of corrosion inhibitors. Besides the high increase of cycles, all biofilm was removed. No Legionella contaminations where detected during this trial and all biofilm was removed, which increased the heat transfer in the heat exchanger resulting a lower production cost.