Bisan Chemicals And Engineers Private Limited

• Prevention of Scaling and Deposits:

  • Problem: Raw water naturally contains dissolved minerals like calcium, magnesium, silica, iron, and carbonates (collectively known as Total Dissolved Solids or TDS). When this water is heated and converted into steam in a boiler, these impurities do not evaporate with the steam. Instead, they become highly concentrated within the boiler water.

  • Effect of Impurities: As concentration increases and temperatures rise, these minerals exceed their solubility limits and precipitate out, forming hard, insulating layers of "scale" or "deposits" on the internal surfaces of boiler tubes and drums. Silica scale is particularly problematic because it's very hard and difficult to remove.

  • DM Plant Solution: A DM plant removes virtually all these dissolved mineral ions, producing water with extremely low TDS (often  <1 ppm or conductivity <1 µS/cm). This demineralized water prevents scale formation, ensuring that heat transfer surfaces remain clean.

  • Benefits:

    • High Thermal Efficiency: Clean boiler tubes allow for maximum heat transfer from the fuel to the water, directly reducing fuel consumption and operating costs.

    • Prevents Localized Overheating & Tube Failure: Scale acts as an insulator, causing the metal underneath to overheat. This can lead to tube bulging, cracking, and catastrophic failure, resulting in costly repairs and dangerous shutdowns. Demineralized water eliminates this risk.

    • Reduced Maintenance: Less scale means less frequent chemical or mechanical cleaning (descaling) of the boiler, significantly reducing maintenance downtime and costs.

  2. Prevention of Corrosion:

  • Problem: Even small amounts of dissolved gases (primarily oxygen and carbon dioxide) and certain ions (like chlorides and sulfates) in boiler feed water can be highly corrosive to boiler metals, especially at high temperatures and pressures.

    • Oxygen Pitting: Dissolved oxygen can cause localized pitting corrosion, leading to sudden failures.

    • Acidic Corrosion: Carbon dioxide (from bicarbonate/carbonate alkalinity breakdown) forms carbonic acid, which lowers pH and causes general corrosion in condensate return lines and boilers. Chlorides and sulfates can also exacerbate corrosion.

  • DM Plant Solution: DM plants remove these corrosive ions and significantly reduce the overall conductivity of the water. While DM plants don't directly remove dissolved gases, the high purity of DM water makes subsequent deaeration (mechanical and chemical) much more effective. Lower conductivity also means fewer pathways for electrochemical corrosion.

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A DM Plant for Boiler Feed is a specialized water treatment system designed to produce highly purified water for use as feed water in industrial and power plant boilers. "DM" stands for Demineralization (or deionization), which is the process of removing almost all dissolved mineral salts and ions from water.

Why is Demineralized Water Crucial for Boilers?

Boilers operate at high temperatures and pressures. Even trace amounts of impurities in the feed water can cause severe problems:

1. Scaling: Minerals like calcium, magnesium, silica, and iron, if present in the water, will precipitate and form hard deposits (scale) on the boiler's heat exchange surfaces (tubes, drums). This scale acts as an insulator, drastically reducing heat transfer efficiency, increasing fuel consumption, leading to localized overheating, and eventually causing tube failures and boiler shutdowns.

2. Corrosion: Dissolved gases (especially oxygen and carbon dioxide) and ions like chloride or sulfate can make the boiler water corrosive, leading to pitting and general corrosion of boiler metal. This compromises the structural integrity of the boiler, leading to leaks, ruptures, and safety hazards.

3. Carryover & Foaming: High levels of dissolved solids can cause the boiler water to foam, leading to water droplets being carried over with the steam. This reduces steam quality, can damage downstream equipment (e.g., steam turbines),

Prevention of Scaling and Deposits:

• Problem: Raw water naturally contains dissolved minerals like calcium, magnesium, silica, iron, and carbonates (collectively known as Total Dissolved Solids or TDS). When this water is heated and converted into steam in a boiler, these impurities do not evaporate with the steam. Instead, they become highly concentrated within the boiler water.

•  Effect of Impurities: As concentration increases and temperatures rise, these minerals exceed their solubility limits and precipitate out, forming hard, insulating layers of "scale" or "deposits" on the internal surfaces of boiler tubes and drums. Silica scale is particularly problematic because it's very hard and difficult to remove.

   

• DM Plant Solution: A DM plant removes virtually all these dissolved mineral ions, producing water with extremely low TDS (often  <  1 ppm or conductivity  < 1 µS/cm). This demineralized water prevents scale formation, ensuring that heat transfer surfaces remain clean.

   

• Benefits:

  • High Thermal Efficiency: Clean boiler tubes allow for maximum heat transfer from the fuel to the water, directly reducing fuel consumption and operating costs.

     

  • Prevents Localized Overheating & Tube Failure: Scale acts as an insulator, causing the metal underneath to overheat. This can lead to tube bulging, cracking, and catastrophic failure, resulting in costly repairs and dangerous shutdowns. Demineralized water eliminates this risk.

  • Reduced Maintenance: Less scale means less frequent chemical or mechanical cleaning (descaling) of the boiler, significantly reducing maintenance downtime and costs.