Boiler Water Treatment Chemicals

This technique of boiler water treatment is adopted to meet following basic objectives

• To prevent the scale formation due to traces of residual hardness from boiler feed water
• To overcome the pitting corrosion due to residual dissolved oxygen
• To prevent caustic embrittlement
• To prevent priming & foaming
• To clarify the boiler water for effective blow down
• To protect the pre boiler equipment and steam condensate from corrosion
• To maintain the steam purity with dry in condition & low in solids

Most recent boilers require cleaner heat – transfer surfaces and to achieve this objective to reduce the fuel costs and expensive downtime, employing appropriate water treatment is the only solution.

Effective water treatment plays vital role in helping to maintain operating efficiency and steam quality and minimize costs. On the other hand, if the feed water is improperly treated where the impurities are allowed to reach excessive concentrations, steam quality would be poor, leading to serious consequences of tube failure.

Important of Boiler water treatment :

Boiler feed water contains dissolved solids, which will get deposited as scales on the heat transfer surfaces during evaporation. As scales have much lower heat transfer capacity than steel, this leads to overheating and failure of the boiler tubes.

Dissolved oxygen/CO2/low pH in the boiler water causes pitting corrosion or lowering the thickness of the steel tubes, leading to failure of the boiler tubes.

Silica volatilizes at higher operating pressures and carries over to the turbine blades.

The Impurities carried over in the steam, causing deposits on turbine blades leading to reduced turbine efficiency, high vibrations, and blade failure. These contaminants can also cause erosion of turbine blades.

Boiler Water Treatment Programme

• Chemical additives and boiler blowdown are used to control the boiler water chemistry. A trained water treatment expert should select proper chemical additives based on steam system design, concentration, and type of impurities present in the water and the end use of the steam.
• Chemical additives report a variety of issues including residual impurities, residual oxygen levels, and the pH level in the water. Phosphate compounds are common additives for boiler water treatment and react with any remaining hard water impurities to create a soft sludge that is eliminated by blowdown.
• Mechanical deaerator should always be kept in operation for effective removal of dissolved oxygen from feed water.
• Even the most efficient deaerator cannot remove the last traces of dissolved oxygen. Though the amount of residual oxygen is minimal, it can still cause severe corrosion. The final traces are removed by the addition of proper oxygen scavengers.
• The required pH in the feed water, boiler water, steam, and condensate water must be maintained since pH is a critical factor in controlling scale buildup and avoiding corrosion.
• Required alkalinity must be maintained in the boiler water to convert magnesium into magnesium hydroxide sludge, which is removed via blowdown. Maintaining the right alkalinity also helps to form a protective iron oxide layer over boiler metal and keeps silica dissolved.
• Filming amines and volatile oxygen scavengers are used to form a protective film and for metal passivation.
• Carryover can be controlled by proper boiler operation, maintaining the correct steam drum water level, and using appropriate sludge conditioners and antifoamers to reduce carryover.
• Continuous blowdown from the steam drum is preferred to control TDS in boiler water, while intermittent blowdown from the mud drum helps remove accumulated sludge.

Boiler water treatment is important to both efficiency and the durability of your boiler. Kimberlite water plus provide boiler water treatment programme to prevent scaling, corrosion, deposition and carry over in the boiler system.

Tacelene Chem® range of boiler water treatment chemicals are formulation of polymers and organo-inorganic chemical treatment programmes.