Summary for dm water cooling tower Discussion
DM water in cooling tower service is discussed as a question of long-term fouling rather than immediate heat-transfer loss. Aditya Nagori asked whether demineralized water would reduce heat transfer compared with other waters. Ted Mooney said he had never heard of including water quality or conductivity in heat-transfer calculations, but noted that DM water should have less tendency to form scale, so it may be better for heat transfer over time. A later question from Ashish Kumar asked about reusing regenerated ion-exchange water as cooling-tower makeup to reduce effluent and save raw water. Ted Mooney said he did not fully follow the process, but cautioned that even with clean makeup water a cooling tower still needs blowdown to prevent contaminants from concentrating, so the reuse idea sounded questionable.
Q. Is DM water a suitable utility for cooling in equipment? Let’s say we have a cooling tower running with DM water, so does DM water have properties which creates less heat transfer as compared to other types of water?
Aditya Nagori
Employee – Himachal Pradesh, India
September 1, 2023
A. Hi Aditya
I have personally never heard of including the quality or conductivity of the water into any heat transfer calculations. However, DM water should have less of a tendency to form scale over time, so in the long term it may be better for heat transfer.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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⇩ Similar, related, Q&As — oldest first ⇩
Q. Hi,
I am arul kumar, working as design engineer in Chennai. I am designing a cooling tower. I have to use the DM water for that as the water is going into precision equipment. I know that DM water in contact with air will generate carbonic acid. I am going to add pH booster. will it enough or any special precautions should I take. Will pH will develop rapidly or gradually in the circuit.
Regards,
Arul Kumar K.
product designer – Chennai, Tamil Nadu, India
May 19, 2008
A. Hi, Arul. pH change and carbonic acid are only the beginning of your problems! Cooling towers are open to the atmosphere and will collect garbage of all sorts unsuited to ‘precision equipment’ from pollen to acorns to bird droppings to acid rain :-(
But there is a special type of cooling tower that may suit your needs, called an “atmospheric cooler” or “evaporative condenser” or such (the name probably varies by geography, but every cooling tower manufacturer will be familiar with it).
In this device, there are two circuits, one exposed to the atmosphere and one not exposed. It functions like a combination cooling tower and heat exchanger but is much cheaper & simpler than two separate units, and costs little more than a standard cooling tower.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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May 19, 2008
Reuse regenerated water in Cooling tower as a makeup
Q. Is there any possibility to reuse to the regenerated water generated and used as a makeup in Cooling tower. this is reduced the effluent generation and save the raw water.
DM water technique: Ion Exchange with (Raw water tank to Pump– Sand Filter–SAC–Degasser–WBA–SBA—MB–DM Water)..
ASHISH kumar
– INDIA
September 4, 2018
A. Apologies Ashish, but I have little idea what you’re talking about :-(
Are you saying you want to collect the backwash water after regeneration of these ion exchange columns and use it in your cooling tower? That sounds like a questionable idea because even when clean water is used you must have a ‘blow-down’ rate to keep the contaminants in the cooling tower water from getting too concentrated.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.