Boiler Feed Water Treatment for Industrial Boilers
Updated: Feb 13, 2019
A boiler is a closed device used largely in various industries, business, and modern procedures to generate steam by applying heat energy to water at a particular pressure. The principle function of boiler is efficient heat transfer to the feed water. The boiler feed water should be treated legitimately to avoid scale, corrosion of the boiler system. Boiler water treatment is an industrially practiced process which involves chemical modification of substances which causes potential damage to boilers. The main function of boiler water treatment chemicals is to ensure that the boiler water is maintained at appropriate conditions so that the boiler system operates efficiently. Boiler water chemicals mainly include corrosion inhibitors, oxygen scavengers, pH booster chemical, and boiler antiscalant chemicals.
Boiler Corrosion and Scale Inhibitors
Undesirable metal oxides deposits, mineral scales, sludge are typical issues encountered in boiler treatment plants. Boiler corrosion inhibitor makes a holistic approach to minimize corrosion of the boiler system. It passivates the metal surface by forming a protective layer which restrains access of corrosive substance to metals.
The boiler corrosion control chemicals are mainly the following-
DEHA - Diethyl Hydroxyl Amine reacts with the dissolved oxygen of feed water forming acetates, nitrogen and water which are harmless byproducts for the boiler system. It goes out of the boiler with the steam, and functions as a metal passivating agent in the return line system.
Morpholine - Morpholine acts as a corrosion inhibitor by increasing the pH of the boiler water .It finds application in both low and high pressure boilers.
Cyclohexylamine - Cyclohexylamine inhibits corrosion by preventing carbonic acid formation in the boiler system. Its principle application is in low pressure boiler system because it can remain with condensate steam for longer runs and at various steam pressures.
Polyamine -It is a blend of neutralizing amines intended for inhibiting amine carbonate deposition in the boiler system. It is suitable for low and medium pressure boiler systems.
Boiler Corrosion Inhibitor
The products which CHEMTEX caters under boiler corrosion inhibitor are condensate line corrosion inhibitor, DEHA, Morpholine, carbon dioxide corrosion inhibitor etc. These products have been successful to combat the unfavorable impact of scale build up and corrosion in boiler units in various industries.
Dissolved oxygen of feed water is one of the potential elements causing corrosion of boiler system. If not properly treated this oxygen can cause pitting and scale formation, destroying piping and boiler tubes as well as interfere with heat transfer and the operation mechanism.
There are many types of oxygen scavengers, but the ones most commonly used in boilers are:
Sulphites – It aids in the instant removal of oxygen from boiler water and also has a pH buffering action which helps to avoid scale formation.
Hydrazine hydrate,DEHA - These compounds react with the dissolved oxygen and convert it into byproducts which are harmless for the boiler system.
Proper pH maintenance of feed water is an integral part of boiler water treatment process to reduce corrosion. Having precise pH value can give adequate hydroxide to the reaction between calcium and phosphate and magnesium with silica. Failure in this results in sticky, scale formation in the boiler water circuit which is extremely difficult to remove and must be avoided. Appropriate boiler water alkalinity is usually secured from the natural alkalinity present in the makeup water. But often natural alkalinities are insufficient to create the desirable free caustic range in the boiler water and thus pH adjuster chemicals find their application. Potassium Hydroxide or Sodium Hydroxide are the most common boiler alkaline products.
Boiler Antiscalant Chemicals
Hardness of feed water causes scale formation in the boiler system which has detrimental effect on boiler operations. These depositions result in reduced heat transfer efficiency, localized overheating. Antiscalant chemicals help in combating these factors and ensure desired boiler operation.
CHEMTEX'S Boiler Antiscalant includes Powder Antiscalant, Boiler Sludge Conditioner, Sludge Remover, Boiler Water Phosphate Treatment, Phosphate Polymer Treatment, Sodium Tri poly Phosphate etc. These compounds are based on polymeric dispersant for sludge conditioning, poly-phosphates and polymers for scale and corrosion inhibition. It imparts excellent online cleanliness of boiler internals by preventing scale, metal ions and metal oxide deposits formation.
This Boiler Antiscalant helps to prevent deposition of calcium, iron and iron-oxide. It also aids in removal of existing scale from the water boiler. The optimum balances of products enable complete boiler online cleaning.