Boiler Pressure and Boiler Feed Treatment

How to Choose the Appropriate Industrial Water Treatment Based on the Type of Boiler

Industrial boilers are used to generate steam for various applications, including power generation, heating, and process steam. The quality of the boiler feed water used in these boilers is crucial to their performance and longevity, so the water must be treated to remove impurities that can cause scaling, corrosion, and fouling.

There are various water treatment options available for industrial boilers, including water softeners, reverse osmosis (RO) systems, and deionizers (DI), but the appropriate water treatment for industrial boilers method varies by the boiler pressure. Consider the following when selecting industrial water treatment for boilers.

Low-Pressure Boilers

Low-pressure boilers operate at a pressure of up to 15 psi (pounds per square inch). In these boilers, water treatment is usually achieved through the use of an industrial water softener specifically designed for critical water requirements such as the Zero Hardness™ water softener. This high efficiency, low hardness leakage softener system is ideal for water tube boilers, which have very high standards for water quality. The water softener removes minerals such as calcium and magnesium from the water that can cause scaling in the boiler. This is done through ion exchange in which the calcium, magnesium and other positively charged ions are exchanged for sodium ions. The softened water is then used in the boiler, which prevents scaling and improves the efficiency of the boiler.

High-Pressure Boilers

High-pressure boilers operate at a pressure of between 15 and 800 psi. In these boilers, the water treatment must meet more rigorous requirements than low-pressure boilers, so industrial reverse osmosis (RO) is a water treatment method that is often chosen for high-pressure boiler water treatment. Industrial reverse osmosis involves the use of a semi-permeable membrane to remove dissolved solids and impurities from the water. The water is forced through the membrane under pressure, and the purified water is collected on the other side of the membrane. Reverse osmosis can remove up to 99% of the dissolved solids in the water, including alkalinity and negatively charged ions, which can prevent scaling, corrosion, and fouling in high-pressure boilers.  Reverse osmosis systems are often paired with water softeners in series to ensure that no hardness leaks into the boilers. Depending on size and water parameters, the softener can be place in front of the reverse osmosis system or behind it as a polisher to polish the last little bits of hardness prior to the boiler.

Superheat Boilers

Superheat boilers operate at a pressure of over 800 psi and a temperature of over 700°F. In these boilers, the water treatment must be even more rigorous than in high-pressure boilers. Industrial deionization (DI) is a water treatment method that is most appropriate for superheat boilers. Deionization involves the use of ion exchange resins to remove all ions from the water. This results in boiler feed water that is completely free of dissolved solids, which can prevent scaling and corrosion in superheat boilers.  To make the ion exchange process more efficient, the water is often purified by a reverse osmosis system prior to the deionization system.

Given that the appropriate water treatment method for industrial boilers will vary based on the pressure in the boiler, it is important to consult with an experienced engineering team to choose the appropriate water treatment method for your boiler to prevent scaling, corrosion, and fouling, which can reduce the efficiency of the boiler and lead to costly repairs. Contact Industrial Water Solutions today for expert advice and the design of a boiler feed water treatment that will be appropriate for your boiler environment.