are the benefits of filtration?
solids are the most common and one of the more troublesome
contaminants in cooling water. The cooling tower acts as an
air-scrubber and constantly adds solids to the cooling water. This
increases the cost of chemical water treatment because increased
suspended solids requires additional chemicals for treatment. Like
any treatment program, if not properly controlled this will also
result in increased energy costs. Increased chemical treatment
costs, increased chiller head pressure, and a greater need to the
clean tower basin all result from poor control of suspended solids.
to cooling water filtration are:
energy Consumption, quantified by measuring changes in
condenser approach temperatures.
chemicals are required when suspended solids are removed from
the cooling system.
downtime by reducing the time needed to clean the tower basin,
tower fill and condenser tubes.
downtime can be the greatest savings of all if plant
production is impacted.
filtration increase my water costs?
Electric H20 filters can use city water or system water in
backwashing mode. If system water is used (recommended) the amount
of backwash only reduces the amount of bleed in the cooling
system. Backwash can be adjusted to optimize the bleed/backwash
relationship to avoid additional water consumption.
can I quantify the savings?
analysis of the suspended solids in the cooling water can be
performed using a particle count of a cooling water sample. Then a
second sample can be taken after the filtration system has been
installed to provide a reasonable comparison. Electric H20 can
select the filtration media based on the kind of contaminant in
your water and the results of the water analysis or particle
can be quantified by establishing a baseline. Determine the
condenser approach temperature and running hours for the prior
cooling season and track the increase in the condenser approach
temperature over the course of the cooling season. Your chiller
manufacturer or Electric H2O can assist with this calculation
through a comprehensive software modeling program. Savings
introduced by the filter can then be quantified by measuring the
condenser approach temperature for the cooling season after the
improvements have been made.
chemicals in the water treatment program are also a benefit.
You may be able to reduce chemical treatment expenses by as much
as 20%. This is dependent upon your contract and the level of
suspended solids in the cooling water.
staff is experienced in water treatment and can recommend
improvements that may include other aspects of cooling water
treatment besides filtration. A third eye or opinion is always
How do I determine which filter to use?
can be accomplished using several different methods. Often the
application will dictate how much filtration is required. Media
filtration, where 97% of the solids are removed down to a 0.5
micron level, can be achieved through side-stream filtration. This
level of filtration will remove most of the contaminants in the
cooling water and will provide the greatest benefit. We recommend
selecting a filtration system that is designed for a flow rate 5-10%
of the cooling water recirculating rate or by calculating total
cooling water system volume and dividing by either 60 or 48. This
will determine the appropriate system turnover.
are also useful filtration technologies in cooling water treatment.
They are physically smaller than media filters and can be installed
on a side-stream loop or full-stream loop. Separators remove
particulate based on specific gravity and particle size. Efficiency
is less than that of a media filter, but separators are effective in
removing the visible particulate found in the tower. Consult your
Electric H20 representative for a comprehensive comparison of the