Water & Wastewater Asia Jul/Aug 2018

WATER & WASTEWATER ASIA July / August 2018 48 / INSIGHT BY Tom O’Donnell, Director of Business Development for Neptune™ Chemical Pump Company and PSG ® H ydraulic and solenoid metering pumps, along with filter feeders, can be go-to technologies for injecting and dosing the chemicals that are critical in delivering optimal boiler operation. There is no question that water is the life blood of boiler operation, whether the boiler is used for power generation or as a way to heat commercial buildings, hospitals or schools. With water being so integral to the boiler’s ability to produce the steam that can be converted into heat, it is imperative that the water – which can be rife with impurities that can result in rust, scale, corrosion and, ultimately, boiler failure – be properly treated so that the impurities are removed or neutralized. Boiler-water treatment generally involves the injection of any of a wide array of chemicals into the boiler water. These chemi ca l s mus t be dosed at highly accurate rates and speeds so that they themselves do not interfere with the quality of the water and the operation of the boiler. The operator must therefore identify and employ the right type of chemical-injection technology -- one that will deliver reliable injection and flow rates no matter the amount of chemical required. This white paper will illustrate how hydraulic and solenoid actuated diaphragm metering pumps, along with filter feeders, can be the ultimate solution for the accurate, reliable injection and dosing of chemicals that are critical tomaintaining proper boiler operation. The Challenge It’s a fact of boiler life that impurities in water will leave solid deposits like scale, rust and corrosion as steam evaporates. Over time, the accumulated deposits will thermally insulate the boiler’s heat-exchanger surfaces, which will not only gradually reduce the boiler’s rate of steam generation, but also cause boiler metals to approach failure temperatures. This is where the treatment of boiler water enters the picture. The different types of boiler-water chemicals are designed to perform different functions, depending on the boiler system and water utilised. Some chemicals are added to maintain desired pH levels and minimize the water’s solubility, i.e. the ability to be dissolved. Other chemicals can be added to consume oxygen before it can corrode the boiler, prevent foaming, precipitate dissolved solids before they form scale on steam-generating surfaces, and remove any precipitates from the vicinity of the steam-generating surfaces. Series 500 and Series 600 Hydraulically Actuated DiaphragmMetering Pumps from Neptune™ are ideal for boiler- water treatment applications because they are robustly designed for precise injection of chemicals and longevity