A common saying in the water treatment industry is that cooling tower manufacturers do not know (or care) about water treatment. Likewise, the cooling tower manufacturer says he knows how to cool water and does not address water treatment.
"Should filters be used on cooling water systems?" is a question I am
often asked. So what do I say? Well, it depends on a number of
considerations, but my first response is absolutely an unqualified
"Yes." Filters are a cost-effective investment. Filters remove
suspended solids from the cooling water and thus reduce many problems.
So, what are these considerations?
"Do all closed chilled water systems need water treatment?" is a
question I have been asked numerous times. Why is it asked? Well, I
know of persons who have been in charge of closed chilled water systems
that do not use any water treatment chemicals whatsoever -- and operate
An oxidizing microbiocide is as any chemical that is an oxidizing
agent. They are chemicals that kill and destroy not only the
microorganism but also the nutrients found in cooling water. Their
action is essentially "wet oxidation" or "burning" under water. No
microbiological organism is immune to this action -- provided that the
oxidizing biocide can reach the microorganisms.
Cooling water microbiological control is important all year long -- and
even more important during the warm days of summer. This is not only
due to warmer water temperatures but also due to more nutrients and
microbiological organisms entering the cooling tower system from the
What is MIC? It stands for microbiologically influenced corrosion --
yes, corrosion in water systems due to microbiological organisms. These
microbes do not "eat" metals such as mild steel, stainless steel,
copper alloys or galvanized steels. Rather, they produce byproducts
that are corrosive to these metals.
Cooling tower water systems are composed of three major sections:
cooling tower, chiller or heat exchangers, and piping. Each section
must be considered when designing a cooling tower water system. Often,
initial capital cost of equipment is a strong driving force. Little, if
any, water treatment costs are incorporated in the design and equipment
Part 1 identified the steps in setting up a
corrosion monitoring program, including the use of corrosion coupons. Two additional corrosion-monitoring techniques are available: electric
resistance (ER) and linear polarization resistance (LPR). In Part 2, I'll look at these methods in detail.
These are some of the common questions end users and owners often ask.
However, often they are asked after equipment replacement has occurred
or about to be due to corrosion. Here, I hope to
provide you some guidelines and helpful advice for corrosion testing of
the components in your cooling water system so that they will last
Check out the September 15, 2020 edition of Process Cooling: Improving cooling system reliability with filtration, cooling water corrosion control, choosing a water filtration system, new products and much more!