Boiler water treatment, a supercritical industrial process
To be covered by - IP - CHEALET - D 40 from DACAUXI
What are boiler water treatment chemicals?
• The efficiency of the boiler majorly depends on the feedwater used.
Untreated water, such as water from rivers, municipality bores and taps can cause severe damage to the boiler. Hence, it's critical to completely remove, or chemically modify the various substances present in untreated water. This is an important step in all chemical process which will avoid any potential damage to the boiler. The chemicals used in treating the feedwater are called the boiler water treatment chemicals.
• Hazards of using untreated water in boilers
• Boilers are mainly known for their heat transfer abilities. When untreated
water is used, the heat transfer ability is drastically reduced and leads to overheating, pressure drop, tube failure and efficiency loss. This is due to dissolved salts and minerals present in water, which eventually gets deposited over the sides of the boiler. Moreover, the dissolved gases in untreated feedwater will lead to corrosion of the piping system and reduced efficiency of the boiler. Hence, it is mandatory to conduct a water treatment programme before it is being used in the boilers.
• Boiler water treatment methods on IP-CHEALET-D4O• Oxygen Scavengers to Prevent Corrosion: Corrosion of boilers occurs when
untreated feedwater is used. The dissolved oxygen in the feedwater reacts with the metal scales of the boiler to form oxides. This can be prevented by using oxygen scavengers (also known as oxygen absorbers), that'll remove or reduce the level of oxygen in the entire system. The most commonly used oxygen scavengers are activated charcoal and a mixer of iron powder
with sodium chloride.
• Alkalinity builders: All industrial process work at an optimal pH range,
failing which appropriate results cannot be obtained. Most of the high pressure reactions need a high pH level. To increase the pH level, chemically modified substances called alkalinity builders are added to the boiler. Most industrial process use concentrated sodium hydroxide based alkalinity builders, which are balanced with phosphates, chelants, carbonates and certain polymers.
• Scale and corrosion inhibitors: One of the major issues that affect the operations of industrial boilers is accumulation of salt deposits on the internal lining of the system. As a part of the equipment maintenance, scale and corrosion inhibitors are used. The common inhibitors are catalysed sodium bisulphite, carbohydrazide, diethyl hydroxylamine and cyclohexylamine. Oxygen scavengers also work well as scale and
corrosion inhibitors.
• Sludge conditioners: If the boiler is not maintained properly, suspended
particles tend to settle at the lining of the system. If left untreated, it can drastically reduce the boiler efficiency. A sludge conditioner is often used to remove and clean the boilers. At some instances, it is also used to prevent and control scale formation.
• Other chemicals: In addition to the above said methods to treat feedwater. there are numerous other water treatment methods that are process specific. Condensate line protection and multi-functional treatments are some of the important methods used in treating the boiler feedwater.