In the past 15 to 20 years, mainstream cooling water treatment technology focused on better chemical additives – typically polymers – to grab dissolved and suspended solids floating in the cooling water and either float them or sink them where they can be easily removed to avoid the precipitate problem described yesterday. This is essentially adding plastic to the water, a practice common in municipal water and wastewater treatment. Better polymer chemistry has allowed industrial and institutional utilities to reduce rinse water and even remove hazardous and corrosive acids to maintain a pH that won’t result in scale.
So, how can we further reduce the amount of fresh water used for cooling? And avoid using millions of gallons of chemicals – which result in millions of gallons of chemicals drained into municipal sewage systems?
Two new companies focus on purifying the water without polymers and other such chemicals and potential pollutants.
EnviroTower, based in Toronto, precipitates and filters calcium carbonate hardness using electrostatic charge. This system uses 20% less water and requires less energy by avoiding the need for cooling tower sludge washing.
Water Conservation Technology International, based in Temecula, Calif., goes a step further. Water-CTI removes the water’s hardness in the make-up water through high-efficiency softeners and concentrates the water in the cooling system as much as possible. So no water is purposely discharged from the system. It maintains water chemistry prevents corrosion, scaling, and biological growth. In protecting water quality, this technology dramatically reduces the quantity demand, so that it is not corrosive, not scale forming and not even an active environment for biological growth. A major aerospace company is adopting this technology enterprise-wide for water conservation, and a U.S. automaker headquarters in southern California has used Water-CTI system for 3 years, allowing it to use Title 22 recycled wastewater from the municipality, rather than fresh water! Its overall cooling costs (for water, energy and chemicals) dropped of 75%.
Whether it is industrial water recovered from other processes, municipal wastewater or cooling system blowdown recycle, we need to look at ways to reduce the amount of fresh water used for this massive cooling requirement. Paul Puckorius, a recognized expert in cooling water treatment, agrees that water reuse is the next step.
Water supplies—and the ability of local wastewater infrastructure to treat high-tech cooling tower discharge—can no longer be taken for granted.
The companies that make cooling efficient and adopt recycling mechanisms to make their systems more robust will be at the cutting edge. Especially in the age of computer and Internet information dependence, water is critical to the data that drives our world. This means that whether or not a cooling tower is currently billowing steam in front of your workplace, the rewards and consequences of cooling technology advancements will have serious effects on your business operation.