Cooling Towers
• The Problem
• Water Quality
• Chemical Dependence
• Water Waste
• Advantages Of Using Ozone
• The Ozone Treatment System Is Simple
• Ozone Cooling Tower FAQ
The Objective:
Maintain the highest purity of water with the least amount of water
waste and chemical use. Chemical use in cooling towers leads to an
ever-increasing TDS, which must be reduced by eliminating water (blow
down/bleed off), then refilling with raw/lower TDS water. This is a “vicious
cycle” that will never end unless one of the TDS increasing culprits is
eliminated or reduced: That being “chemicals”.
The Problem:
Cooling Tower water quality tends to be extremely poor. Cooling Tower
traditional treatment is based upon extreme chemical use only. This
means that you, the “water treatment professional” has a chance
to create an entirely new income base, and aid in environmental
integrity & responsibility.
I. Water Quality control is difficult due to:
Evaporation rate
Environmental contaminates
Extreme chemical use
II. Chemical Dependence is promoted by an industry that serves
and maintains cooling towers. Most cooling tower manufacturers do
nothing about recommending or selling treatment equipment along with
the towers. In most cases it’s left up to the end users to set up the
treatment method. The cost of chemicals is lower on the front end than
water treatment equipment, but far higher based upon the on going
nature of the use.
III. Water Waste:
It’s not uncommon to see a (IE) 3,000-gallon cooling tower continuously
draining and replenishing raw water just to lower TDS. This
ever-increasing TDS is contributed to a great degree by the
chemicals that are used for treatment.
Not only is there an extreme amount of water being wasted on a daily bases, but the environmental impact from the chemical laden wastewater is deplorable. This chemically laden wastewater will eventually make into our lakes, streams, river, and ground water, and is becoming the subject of more stringent EPA regulations.
Advantages Of Using Ozone
• Bacteria/virus elimination/prevention
• Organic Build-up elimination/prevention
• Blow-down reduction/elimination
• Bleed-off reduction/elimination
• Improved clarity.
• Scale reduction.
• Cooler running temperatures where scale is inhibited or reduced.
• Reduction or elimination chemicals needed for algae control.
All this with no regularly scheduled maintenance on the ozone unit!
The Ozone Treatment System Is Simple
Just 3 Easy Steps...
Principle of Operation:
Ozone is injected into the water flow created by a separate circulation
pump. This pump pulls the water from the towers sump or basin and
sends it to the ozone injection, contact tank, and scale/filtration. Lastly,
the treated water returns back to the sump or basin.
The principle is to treat the water and eliminate/reduce the:
• Scale forming minerals
• Organics
• Harmful microbes.
The clean water is then used to clean the entire sump, basin,
pipes, and peripheral equipment.
I. Ozone Injection:
Ozone is injected it into the side stream flow. Oxidation starts to take
place immediately on microbes, organics, bacteria, and virus.
II. Contact/Mixing Chamber:
A contact tank helps to further the ozone’s ability to oxidize particles
allowing them time to react prior to returning to the system. As water
flows down the Off Gas Tank, ozonated water rises and mixes any gas
in the incoming water.
III. Filtration, Scale Control, Particle Removal:
Possibly the most important aspect of any water treatment is the removal
of the particles that have been oxidized. Without this step, all you have
done with the ozone is change the structure of the particles by making
them larger, insoluble, &/or heavier. This step is necessary for systems
that require scale control, and particulate removal.
We are very careful not to construct too large of an ozone unit to handle the bacteria, scale, and algae.
The problem encountered at this point is corrosion. If you carry too high of an ozone residual to de-scale down line you stand a chance of creating a corrosive situation in the sump and its adjacent equipment.
For this reason we have utilized existing water treatment technology and equipment in conjunction with ozonation. The result is a system that works without high maintenance, dangerous chemicals, or costly corrosion.
Ozone Cooling Tower FAQ
How does the maximum service flow rate relate to the total system
flow rate?
It doesn't. It relates to the total system gallonage. Our formula is: total
gallons / 4-5 (turnovers per day) / 60 = gpm of the side stream system.
This equals approx. 0.004 gpm/gal (treatment gpm / system capacity).
Therefore, it’s crucial that we know the total water volume rather than the
tonnage. Tonnage to gallon capacity varies greatly per tower
manufacturer.
What is the ozone dosage in grams/hr or lbs/day?
Each ozonator produces a set ozone production in gr/hr.
The Si = 1.2 gr/hr; 22HD = 2 gr/hr; 32HD = 3 gr/hr; 42HD = 4 gr/hr; etc.
We convert the measurement to lbs/day when over 24 gr/hr.
The typical dosage is: 1 gr/hr to every 5 gpm of treated water.
IE: 10 gpm side-stream ozone treatment system would include a
2 gr/hr ozonator (22HD).
Is the ozone flow controlled by the amount of residual in the
system or is it wired to the tower pump or system pump control box?
We supply a timer/control box assembly that controls the ozone unit
and circulation pump. Operational time will depend upon water and
tower conditions. As the conditions improve the operational time
can be reduced.
Does the ozone system eliminate the scaling?
Yes, we can design the ozone system to eliminate hardness/scale
that can build-up on the tower, piping, pumps, and peripheral equipment.
We us a combination of ozone + water softening to eliminate the scaling.
This affords a lower cost system by using a smaller ozone unit. Our
system is set so the water is not completely soft and will not be corrosive.
Does the ozone system control algae?
Yes, we can design the ozone system to eliminate algae but this
denotes a larger ozonator. Algae are plants with roots and are quite
resistant to ozone. We can use ozone only, or ozone + a slight
chlorine or bromine residual to eliminate algae. The ozone + chlorine
or bromine option affords a much lower priced system since
the ozone unit used will be much smaller.
Is it true that ozone systems create a corrosive condition?
In the “old days” when ozone was first used on towers corrosion
became an issue. This was due to the over use of ozone, or the
excessive dosage injected. There are some companies that are
still convinced that more is better and ozone can do “everything”.
This can lead to costly corrosion problems.
Our philosophy is to use the ozone where it is best suited:
• Organic inactivation
• Bacteria, virus, microbe elimination/reduction
• Clarifying
• Odor control
For scale and algae control we utilize tried-n-true water treatment
equipment that has been successful in all phases of the water treatment
industry for over 50 yrs. This affords the use of smaller and less
expensive ozone equipment and avoids corrosive conditions.
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