By Ed Orvidas
Businesses across all industries are establishing sustainability programs, which have resulted in the development of plant metrics on water and energy use. Because these metrics - and their associated costs - are often part of corporate sustainability goals, the demand is growing for industrial water treatment solutions that can reduce overall water consumption in various plant operations.
Culligan recently unveiled a line of reverse osmosis (RO) products as part of its Matrix Solutions™ water treatment systems. The RO line offers customers a range of options based on their unique water quantity and quality requirements, from 0.2 gallons per minute to over 300 gpm. When more modifications or customizations are required, Culligan can specifically engineer a solution to meet the customer's application requirements.
For many manufacturers, the addition of an RO unit to an existing boiler treatment system can deliver a significant ROI based on the energy and chemical savings. Ideally, the decision to add an RO unit should be based on two factors: the amount of condensate a plant is returning and the required boiler operating parameters.
In certain manufacturing applications, a plant is unable to return large amounts of condensate (distilled, highly purified water) to a boiler system because the steam becomes a part of the product manufacturing process. For example, steam can be used to make flavors or it can be consumed as part of the product itself, such as in the case of puffed rice cereal. For plants with low condensate return levels, higher blowdown rates are required, lowering boiler feedwater cycles.
In these situations, the addition of an RO unit can ensure the water going to the boiler is highly purified, allowing the system to operate at high cycles of concentration and resulting in a lower blowdown rate; equaling less water, less chemicals and energy (heat) lost throughout the process. In fact, under the right operating conditions, RO can be justified simply by the energy savings resulting from reduced blowdown frequency. For example, by reducing boiler blowdowns from 15 percent to two percent with the addition of an RO unit, a global beverage manufacturer was able to average $61,000 per year in energy savings.
Likewise, using highly purified RO water can improve a manufacturer's ability to meet boiler operating parameters set by the American Boiler Manufacturers' Association, including limits on silica, conductivity and alkalinity. Exceeding these limits can negatively impact end products and a plant's boiler treatment system. For example, high levels of alkalinity can lead to foamy boiler water and carry over, which can ultimately contaminate steam that is released. Dissolved solids within this steam can create scale within steam pipes and contamination can affect a product's taste.
High alkalinity can also lead to the creation of carbonic acid, which can lower the pH level of a boiler's condensate, causing iron to dissolve and travel back to the boiler; ultimately resulting in a ruined condensate system. Oftentimes, neutralizing amines are added to neutralize the pH effect of the carbonic acid. However, usage limits on these products have been set by the FDA due to carcinogenic risks and they can lead to harmful defects should they make contact with the product.
Using RO ensures impurities are removed before the water even reaches the boiler treatment system (e.g. 98% of all dissolved impurities including alkalinity is already removed). Increasing make up water quality makes it much easier to maintain operating parameters and decrease reliance on neutralizing amines.
Conclusion
The impact of increasing boiler make up water quality on overall sustainability metrics cannot be overlooked. The addition of an RO system permits a significant reduction in water consumption, decreases the cost of blowdown water treatment, reduces reliance on chemicals and lowers energy (heat) usage levels, which can lead to lower overall fuel consumption. Additionally, using highly purified RO water can ensure that manufacturers are continuously in compliance with operating parameters set by the American Boiler Manufacturers' Association; ensuring efficient equipment and plant operation.
About the Author: Edward Orvidas is a Strategic Account Manager at Culligan International. Previously, he spent seven years in field sales with Betz in the industrial water treatment chemical market. Has also has 18 years of water equipment purification experience in a variety of roles with Arrowhead Industrial Water, U.S. Filter and Siemens. Orvidas can be reached at [email protected]. IWW
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