Biofilm in cooling water

[barsballe]

We have an issue with biofilm at a factory producing plastic materials. The plastic materials must be cooled at once after beeing extruded. This is done with both water spray and water bassins.
The water used for cooling is subsoil water. Only treatment before entering the process system is a sand filter. The water is cooled in a plate heat-exchanger. The water cooling systems are not closed systems and are exposed from the surroundings.
The problem is the biofilm produced in the cooling process. The biofilm blocks up nozzles and the plate heat-exchanger.

Do any of you have experience with similar problems and maybe some solutions?

thanks in advance
barsballe

 

[ash9144]

bleach. Cooling systems require chlorine to stop bio activity

 

[Sandy55]

I think you need to consider getting an external contractor in who specialises in Legionella control ASAP. If you have biofilm developing and also have water spray then you are at serious risk of causing deaths among your workforce or the public due to Legionnaires disease. This happened in Edinburgh earlier this year and three people died of the disease with many others hospitalised. If you are found responsible then you are looking at jail time or in the case of an architect in Barrow-in-Furness in the late 1990s, a huge personal fine (£15000 in her case) if you are responsible for the process design.

I think my point is that you need to stop looking at the problems that the biofilm is causing your process and look at the much more serious issue of legionella infection. Removing the risk of legionella development should help remove the biofilm at the same time and also prevent you killing anyone.

Read these:

http://www.hse.gov.uk/pubns/books/l8.htm

http://www.hse.gov.uk/legionnaires/

http://www.nhslothian.scot.nhs.uk/M.../2012/Pages/LegionellaSouthWestEdinburgh.aspx

 

[Sandy55]

Correction - The Barrow-in-Furness outbreak was 2002 and not the late 1990s.

http://en.wikipedia.org/wiki/2002_Barrow-in-Furness_legionellosis_outbreak

 

[bimr]

In addition to the above comments, check with the equipment manufacturer's operating instructions.