To ensure that steam boiler systems are correctly maintained and operate at optimum efficiency, it is essential that the correct boiler water conditions are maintained at all times. This can be achieved using carefully selected boiler water treatment program.
Steam boilers require water treatment services to;
Prevent oxygen pitting corrosion of boiler internals, deaerator, feed water tank as well as steam condensing piping.
Prevent mineral scale deposition which can greatly affect the heat transfer efficiency. Refer to our “Scale Deposits vs. Energy Costs Graph” technical bulletin below.
Descale existing mineral deposits.
Dispersion of suspended solids and sludge for improved removal via blowdown schedule.
Maximize heat efficiency of steam by monitoring and improving steam purity
Implement most innovative automation controls and feed equipment
PACE Chemicals Oxygen Scavenging Treatment Programs
To prevent pitting corrosion in the steam boiler, the oxygen must be removed from the feedwater by mechanical and chemical deaeration. Mechanical deaeration reduces oxygen content to a fraction of a ppm but the operation of a deaerator or heated feed water tank. Then complete removal requires oxygen scavenging chemical treatment.
PACE Chemicals has several proprietary catalyzed oxygen scavenger treatments to remove this remaining O2 from the boiler feed water. These treatments include catalyzed sodium sulfite and sodium metabisulfite. Sulfite is non-volatile and reacts to form sodium sulfate;
Na2SO3 + ½ O2 = Na2SO4
These reactions could take up to 30 minutes to completely remove the oxygen, therefore a catalyst is recommended to speed up the reaction by 200 times faster. We recommend dosing the oxygen scavenger treatment at the earliest point of feed water system to remove all oxygen before it enters the boiler, such as the storage section of deaerator or the feed water tank (or condensate return tank).
PACE Chemicals Scale Inhibitors
Mineral scale deposits can form in the steam boiler due to the increasing concentration of impurities, steam production and increased temperature. As the impurities become less soluble in water, they precipitate out of solution and form a scale within the steam boiler. Scale deposits act as an insulating material between the water and the boiler metal surface, greatly reducing the heat transfer efficiency and increasing the energy costs. Boiler tubes operate at higher temperatures at the metal surface, and when this temperature is significantly higher due to the scale deposits, the boiler tubes can lose tensile strength and rupture. Some common types of boiler scale consists of calcium, magnesium, iron and silicates.
PACE Chemicals has several proprietary scale inhibitor and dispersant treatment products to prevent these various types of scale from forming in your steam boiler system. We also provide on-line cleaning programs to help dissolved existing mineral scale deposition. Our treatment programs for scale inhibition can include phosphates, phosphonates, polymers and chelants.
PACE Chemicals Condensate Return Treatment
Carbon dioxide is formed by the breakdown of carbonate alkalinity in the boiler. CO2 is not aggressive in dry steam, but will dissolve in condensate water to form carbonic acid. The pH level of condensate becomes acidic and corrosive, sometimes reaching as low as pH 3. Carbonic acid corrosion can be identified by a groove like gouging on the bottom of the return like piping. PACE Chemicals has several proprietary neutralizing amine blends to prevent carbonic acid corrosion in condensate return lines. These amines are dosed into the boiler feed water or into the steam line to neutralize the condensate pH to 8.0-8.5. Our amine blends have different vapour-liquid distribution ratios (DR), which is the tendency to condense with the steam condensate. The higher the DR value, the longer the amine will stay in the vapour phase before it drops out of the steam. Therefore, our amine blends are carefully selected based upon the length of the condensate return line system.
Consult with your PACE representative for more information or email us at firstname.lastname@example.org if you would like a survey of your steam boiler system.