

The growth of
microbiological organisms is greatly encouraged by the warm,
incubator- like environment of modern
water based cooling systems
and to a lesser extent heating systems.
These
organisms can form a gummy slime mass which attracts silt, dirt,
and other suspended solids flowing through the system.
Microbiological growth, and the solid particles can
severely restrict heat exchanger tubes, and thus reduce
heat transfer efficiency. Also, these deposits can cause localized
corrosion.
Chlorine is
often used to help eliminate the growth of micro- organisms.
However, chlorine kills only on contact with the micro-organisms.
It simply oxidizes the surface organisms, but not the deposit.
The disadvantage
of chlorine is that it can be corrosive. Proper biological
control maintains a balance between micro-biological growth and
corrosion. Other non-oxidizing biocides are used to help
against acclimation to chlorine.
The best results
can come from a biocide study which evaluates biocide
effectiveness for a specific system.