What chemicals are used in boiler water treatment?
The softening chemicals used include soda ash, caustic and various types of sodium phosphates. These chemicals react with calcium and magnesium compounds in the feed water. Sodium silicate is used to react selectively with magnesium hardness.
What is the purpose of boiler water treatment?
Boiler water treatment is used to control alkalinity, prevent scaling, correct pH, and to control conductivity. The boiler water needs to be alkaline and not acidic, so that it does not ruin the tubes. There can be too much conductivity in the feed water when there are too many dissolved solids.
What chemical is added to control hardness in a boiler?
Phosphates. Phosphates are used to react with calcium hardness in the boiler water.
Why trisodium phosphate is used in boiler?
Trisodium phosphate (Na3PO4), also known as TSP, is a common boiler water conditioning chemical that establishes moderately alkaline conditions in the boiler to minimize corrosion and reduce scaling where hardness ingress occurs.1 Feb 2021
What is pH of boiler feed water?
Boiler water should be maintained at pH 11. Generally, the higher the pH (basic), the less soluble some solids are in the water. The lower the pH (acidic), the more soluble these solids are.
What is Calgon treatment of boiler feed water?
Calgon = sodium hexa meta phosphate The process involves the addition of calgon to boiler water. It prevents scale and sludge formation by forming highly soluble calcium hexa meta phosphate complex compound with CaSO4. 4) Describe the demineralization process of softening of hard water.
What is boiler water treatment?
Boiler water treatment, a supercritical industrial process. “The industrial revolution was another of those extraordinary jumps forward in the story of civilization,” the quote by Stephen Gardiner clearly explains how industrialization has changed all aspects of our life today.
What are the inhibitors of a boiler?
The common inhibitors are catalyzed 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.
How to prevent corrosion in boiler?
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.
What is the effect of untreated water on a boiler?
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 chemical ly modify the various substances present in untreated water.
Why is untreated water used in boilers?
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.
What are the major issues that affect the operations of industrial boilers?
Scale and corrosion inhibitors: One of the major issues that affect the operations of industrial boilers is an accumulation of salt deposits on the internal lining of the system. As a part of the equipment maintenance, scale and corrosion inhibitors are used.
What is an alkalinity builder?
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.
What is boiler water treatment?
Boiler water treatment; Industrial boilers and steam raising plant are used extensively in many commercial, manufacturing and industrial processes. To ensure that such boiler systems are correctly maintained and operate at optimum efficiency it is essential that the correct boiler water conditions are maintained at all times.
What is the treatment for a steam boiler?
Treatment is typically using a steam volatile Amine which either neutralises the steam pH or uses a filming amine to coat the surface of the tube with a corrosion resistant film. If you require any advice on treatment and recommended programs for your industrial steam boiler please contact us today.
What happens if you leave a boiler untreated?
If left untreated, boiler water derived oxygen will corrode metallic boiler components leading to increased maintenance costs and reduced boiler efficiency. To ensure that such boiler systems are well maintained and operate at optimum efficiency it is essential that the correct water conditions are maintained at all times ...
What causes scale in boiler water?
Scale is caused by the accumulation of hardness salts in the boiler water which, if not removed can cause localised overheating, reduced heat transfer efficiency, and in severe situations tube failure.
Is it important to use the right chemicals for a steam boiler?
Ensuring you are using the best boiler water chemicals for your application is very important as using the wrong chemicals can be much more costly in the long run and may not provide adequate treatment for your steam boiler.
Do you need a duplex softener for a steam boiler?
In many cases for an industrial steam boiler, a duplex softener is required as there is a need for no interruption to soft water supply to the hotwell, if you are unsure about what system is best for your application then contact Accepta today. Contact us for expert advice. Category: Chemical Treatment Products.
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What chemicals are used to prevent scale and corrosion in the feed-water system?
Chemicals added to react with dissolved oxygen (sulphate, hydrazine, etc.) and chemicals used to prevent scale and corrosion in the feed-water system (polyphosphates, organics, etc.) should be fed in the feed-water system as continuously as possible.
How to condition sludge in boiler?
There are two general approaches to conditioning sludge inside a boiler: by coagulationor dispersion. When the total amount of sludge is high (as the result of high feed-water hardness) it is better to coagulate the sludge to form large flocculent particles. This can be removed by blow-down.
How is calcium sulphate reacted to water?
Consequently calcium sulphate must be reacted upon chemically to cause a precipitate to form in the water where it can be conditioned and removed by blow-down. Calcium sulphate is reacted on either by sodium carbonate, sodium phosphate or sodium silicate to form insoluble calcium carbonate, phosphate or silicate.
What chemical reacts with calcium and magnesium compounds in the feed water?
These chemicals react with calcium and magnesium compounds in the feed water. Sodium silicate is used to react selectively with magnesium hardness. Calcium bicarbonate entering with the feed water is broken down at boiler temperatures or reacts with caustic soda to form calcium carbonate.
What is external treatment?
External treatmentis the reduction or removal of impurities from water outside the boiler. In general, external treatment is used when the amount of one or more of the feed water impurities is too high to be tolerated by the boiler system in question.
What are some chemicals that are used to scavenge oxygen?
Certain synthetic organic materials are used as anti-foam agents. The chemicals used to scavenge oxygen include sodium sulphite and hydrazine. Various combinations of polyphosphates and organics are used for preventing scale and corrosion in feed-water systems.
What is anti-foaming agent?
Anti-foaming or anti-priming agents: mixture of surface-active agents that modify the surface tension of a liquid, remove foam and prevent the carry over of fine water particles in the steam. The softeningchemicals used include soda ash, caustic and various types of sodium phosphates.
Boiler Water Treatment
It is because Scale formation and corrosion are the main two factors that determine the efficiency of the internal parts and as well as lifetime of the boiler. Badly corroded and scaled boiler can fail within very short time.
SCALE FORMATION IN BOILER
Depending upon the sources boiler water contains various types of salts and impurities. Under operating conditions all the salts comes out of the water. These salts cause formation of scale inside the boiler. The more the water contains solids and salts the more the boiler is prone to scale formation.
Boiler Water Treatment for Scale Formation
Boiler Water treatment for scale formation or Scale formation can be prevented in two ways.
What is coagulant ?
BOILER COAGULANT is a liquid sludge conditioner designed to prevent the formation of solid and sticky deposits in boilers.
Dosing instructions for boiler water treatment
Normal dosage is 20ml daily/tone of boiler water capacity. Typically this equates to 0.1-0.3 liters/day. This is the recommended initial dose.
2.What is corrosion?
Before starting corrosion we should first know basic terms related corrosion.
Corrosion of boiler metal
It is an electrochemical reaction of iron where corrosion occurs at cathode as the boiler metal oxidizes and dissolves.
What causes corrosion in boilers?
Corrosion in lower-pressure boilers is frequently the result of air ingress and dissolved oxygen concentration during unit downtimes.
What are the factors that affect steam and boiler water?
Even with proper chemistry control, a variety of mechanical factors may influence boiler and steam system conditions, including: Fluctuations in the boiler water level, which can either expose tubes to overheating or overwhelm steam separators and introduce contaminants.
Why do boilers need to be taken out of service?
Boilers often need to be taken out of service for a variety of reasons, including seasonal shutdowns, temporary lapses in production, maintenance, or annual inspections by the insurance provider. Plant personnel often forget major corrosion will occur in steam generators without proper layup procedures.
What happens if you carry over impurities from a boiler?
Carryover of excess impurities from the boiler can cause significant downstream problems. In units equipped with steam turbines, contaminant ingress may potentially lead to catastrophic conditions such as turbine blade cracking and subsequent failure.
What causes mechanical carryover in a boiler?
In low-pressure boilers, mechanical carryover (the entrainment of water in the steam) can be caused by a high concentration of dissolved solids in the boiler water, result ing in surface tension reduction and boiler water destabilization, and potential foaming in the steam drum.