Boilers are of vital importance in the running of any process industry. Boiler manufacturers take utmost care while manufacturing them to ensure that they are highly efficient and durable for their respective clients. However, boiler manufacturers advise keeping a check on some commonly found problems in boilers that may prove threatening towards the efficiency of boilers.
Rakhoh Boilers design, manufacture, and install highly efficient and sturdy boilers in various processing plants and industries for over 30 years. As a leading boiler manufacturer in India, Rakhoh provides top-notch quality boilers and boiler-related services to their clients. Despite that, there are problems that industrial boilers face if the boilers are not checked or maintained regularly.
Here are 5 majorly found problems in Industrial Boiler:
Carry-Over:
When the water is not separated from the mixture of steam and water, the contaminant of the solid, liquid or gaseous fuels leaves the boiler drum along with the steam that results in carry-over. It may not seem to pose a serious threat, but it affects the steam performance of the boiler, especially in steam traps, turbine blades, and valve bodies.
Some of the reasons that cause Carry-Over are:
Drum size:
The three-element drum control level has introduced the design of smaller diameter drums. The diameter of the drum should be such that the distance between the water-steam interface and driers is appropriate to avoid carry-over.
Feedwater:
A high amount of a contaminant in feed water leads to a high level of carry-over in the boiler. Feedwater containing dissolved oxygen results in generating iron oxide, consequently releasing increased iron in boiler water and high carry-over.
Fluctuating Load:
An increase in steam demand leads to lower drum pressure that results in a phenomenon called priming. Due to priming, slugs of water are carried along with steam resulting in high carry-over.
Steam Pressure:
Low steam pressure increases the steam volume inside the boiler. It results in the steam velocity in the internals being at a lower pressure which causes hindrance in the separation of water droplets from steam, resulting in carry-over.
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Solutions to Avoid Carry-over:
- Proper Feed Water Treatment
- Ensure Water Levels are Low
- Avoid any external material leakage in the feed water of the boiler
- Seek the guidance of boiler manufacturer on boiler and feed water treatment
Corrosion:
Corrosion in boilers destroys the boiler metal due to the pitting of dissolved oxygen in the boiler water. It results in deep holes or penetrations through the metal of the boilers that may affect the overall performance of the boiler and reduces the boiler life.
Some of the main reasons for corrosion are:
Presence of Oxygen in Boiler Water:
When the water is heated, the dissolved oxygen starts to release and reacts with the iron metal of the boiler. It forms ferric oxide or Rust that leads to corrosion.
Presence of Carbon Dioxide in Water:
Similar to the presence of oxygen, corrosion results due to the carbon dioxide in the boiler water.
Negligence towards Maintenance:
One of the reasons for corrosion is neglecting regular maintenance and servicing of boilers. Corrosion, if overlooked, may cause consequences like boiler explosion.
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Solutions to Avoid Corrosion:
- Ensuring ventilation under high temperature and vacuum conditions
- Adding Sodium Sulphite or Sodium Sulphide
- Regular Checking and Maintenance by Boiler Manufacturer
Foaming:
Foaming in a boiler occurs when the steam bubbles are gathered from the generated steam rising through the water in the boiler. When left unchecked, it forms deposits in the tubes in the boiler leading to their failure. Foaming decreases the efficiency of boilers and causes fluctuations, contaminations, and scaling in the boiler.
Some of the main reasons for Foaming are:
Bubble Formation:
The formations of small bubbles on the water surface are difficult to get rid of. It leads to foaming in the boiler.
Presence of Alkalis and Oils:
The presence of chemicals such as alkalis and oils with the solid elements in the boiler water react and produce foam. It reduces the surface tension of water and increases foaming.
Lubricating Boilers:
The oiling or lubrication in boilers serves as one of the primary reasons for foaming in boilers.
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Solutions to Avoid Foaming:
- Proper treatment of water and removal of oil or alkalis from it before feeding it in the boiler
- Neutralizing the surface tension by using anti-foaming means such as castor oil
- Removal of oil traces by introducing sodium aluminates
Priming:
When the droplets of water are carried away along with steam during the steam production in the boiler, it results in the formation of ‘wet steam’. It is known as ‘Priming’ that reduces the energy efficiency and leads to deposits of salt crystals in turbines and superheaters. It reduces the lifespan of the boilers and the boiler components.
Some of the main reasons for Priming are:
Higher Water Level:
Excessive water level leads to its releasing along with steam which in turn results in high carry-over.
Steam Pressure below Boiler design:
It is essential to adjust the boiler steam pressure as per the design made by the boiler manufacturer. Lower steam pressure results in a higher level of priming.
Oily components in the boiler water:
The presence of oil in the boiler water results in foaming and the water gets released through steam.
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Solutions to Avoid Priming:
- Filtering of water before feeding it to the boiler
- Blow-down of the sediments from the boiler
- Ensuring a low level of salts in the boiler water
Scaling:
Scaling is caused by the formation of contaminated water on heat transferring surfaces of the boiler. It hampers the heat transfer. Scaling results in the higher use of fuel than is usually required to produce steam. Scaling may lead to up to a 20% decrease in the efficiency of the boiler.
The most primary reason for Scaling is:
Hard Water in Boiler:
The presence of calcium and magnesium salts (carbonates or sulfates) or higher concentration of silica as to the alkalinity of the boiler water causes scaling in the boiler.
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Solutions to Avoid Scaling:
- Blow-down operations can assist in the removal of scales that are found on the surface of the boiler.
- Chemical treatment such as Calcium Sulphate along with Ethylenediaminetetraacetic Acid aids in removing hard scales
- Brittle scales can be removed through thermal operations.
Conclusion:
It is important to maintain and upgrade your industrial boiler to ensure its proper functioning. Seek the expert advice of your boiler manufacturer to know the best methods to prevent any service disruption of the boilers. Boiler manufacturers in India as well as throughout the world suggest regular servicing and upgrading of boilers. Boiler manufacturers believe that the proper maintenance of the boilers leads to an up to 90% increase in boiler efficiency.
Rakhoh Boilers with their expertise of more than 38 years are a leading boiler manufacturer in India for industrial steam boiler and provide excellent and timely boiler services like boiler retrofit and upgrades, energy audit, steam trap assessment, plant maintenance, customer training program and much more