Boiler Troubles: Causes and Consequences
Boiler troubles are a common issue that can arise when a boiler is not properly maintained or operated. One of the primary causes of boiler troubles is caustic alkalinity, which refers to the presence of high levels of dissolved salts in the water used for steam making. If the water does not meet the required standards, it can lead to a range of problems, including corrosion, scaling, and foaming.
Caustic Alkalinity
Caustic alkalinity is defined as a concentration of 0.15 to 0.45 parts per million in the water used for steam making. If this level is exceeded, it can have serious consequences for the boiler and its operation. Hard water, which contains high levels of dissolved salts, is particularly prone to causing caustic alkalinity. When hard water is heated to produce steam, it can lead to the formation of wet steam, also known as priming.
Priming
Priming occurs when water droplets are present in the steam produced by a boiler. This can happen when the boiler is fed with hard water and heat is applied to produce steam. The resulting steam may come out with water droplets, which can lead to a range of problems, including corrosion and scaling. Priming can be avoided by using soft water, which reduces the risk of dissolved salts being present in the water.
Foaming
Foaming occurs when oily impurities are present in the water used for steam making. When heated to produce steam, these impurities can form persistent foam on the surface of the water. This can lead to a range of problems, including reduced efficiency and increased maintenance costs. Foaming can be caused by a variety of factors, including the presence of suspended impurities in the water, high water levels in the boiler, and repeated temperature fluctuations.
Preventing Priming and Foaming
There are several measures that can be taken to prevent priming and foaming in boilers. Using soft water, which is free from dissolved salts and suspended impurities, can help to reduce the risk of these problems. Additionally, using anti-foaming agents, such as castor oil, prior to the entry of water into the boiler can help to prevent foaming.
Scales and Sludges
Scales and sludges are another common problem that can arise in boilers. Scales are hard, thick deposits that form on the inner walls of the boiler when dissolved salts are present in the water. This can lead to a range of problems, including reduced efficiency, increased maintenance costs, and even explosions. Sludges, on the other hand, are loose, slimy deposits that can form in the feedwater of a boiler.
Caustic Embrittlement
Caustic embrittlement is a phenomenon that occurs when sodium hydroxide comes into contact with certain types of materials, such as stainless steel or aluminum. This can lead to the formation of brittle crystals that can crack and shatter, causing damage to the boiler. Caustic embrittlement can be prevented by using soft water and adding compounds, such as sodium phosphate, to the feedwater.
Preventing Scales and Sludges
There are several measures that can be taken to prevent scales and sludges from forming in boilers. Using soft water, which is free from dissolved salts, can help to reduce the risk of these problems. Additionally, adding compounds, such as sodium sulfite, to the feedwater can help to prevent scaling and sludging.
Conclusion
Boiler troubles are a common issue that can arise when a boiler is not properly maintained or operated. Caustic alkalinity, priming, foaming, scales, and sludges are all potential causes of these problems. By using soft water, adding anti-foaming agents, and preventing scaling and sludging, it is possible to minimize the risk of these problems and ensure that a boiler operates efficiently and safely.
"WEBVTTKind: captionsLanguage: enwelcome to vuecam the chemistry animations channel boiler troubles water for steam making water is required for the generation of steam for various industries for different purposes steam is useful for generation of electricity sterilization mechanical efforts energy storage and treatment of concrete the water for steam generation should not have any suspended or oily impurities should not have any dissolved organic or inorganic compounds should not have excess dissolved oxygen and carbon dioxide should not have any color odor and the ph value should be nearer to seven should not have hardness more than 0.2 parts per million should have the caustic alkalinity in a range of 0.15 to 0.45 parts per million if the water used for steam making does not satisfy the requirements just mentioned then there will be possibilities of development of boiler troubles there are many types of boiler troubles these are carryover the process of carrying of water by steam along with the impurities is called carryover this phenomenon may be due to priming and or foaming priming when the boiler is fed with hard water and heat it to boil steam is produced as the hard water is used to produce steam this steam may come out with water droplets the production of wet steam is called priming foaming and the boiler is fed with hard water containing oily impurities and heat it to boil along with steam persistent foam is produced on the surface of the water the production of persistent foam on the surface of the water is called as foaming the reasons for the priming are water containing dissolved salts presence of suspended impurities in water use of hard water higher water levels in the boiler sudden rise in temperature repeated temperature fluctuations improper design of boiler and high steam velocity priming can be avoided by using soft water using the water free from dissolved or suspended impurities using a boiler of proper design avoiding sudden rise in temperature avoiding higher levels of water in the boiler maintaining normal steam velocities avoiding temperature fluctuations and use of mechanical purifiers presence of oily or soapy impurities difference in the concentration of solute or suspended particles between the surface of the water and the water at inner region are the common reasons for foaming the following measure should be taken to avoid foaming use of calculated quantities of anti-foaming agent like castor oil prior to the entry of water into the boiler coagulants like sodium aluminate should be added to sediment the suspended oily impurities replacing the concentrated boil or water by fresh water drawbacks of priming and foaming we cannot judge the level of water in the boiler excessive heating requires consumption of more fuel loss of heat results in the decrease in the steam pressure the overall performance of the boiler also decreases wet steam causes the corrosion of the machinery like the blades of turbine scale and sludge when boiler is fed with hard water and heat it to boil steam is produced as the water evaporates the concentration of the dissolved salts increase beyond the saturation point as a result a hard and thick precipitate is formed on the inner walls of the boiler and is called a scale sometimes in the colder regions of the boiler a loose slimy precipitate may be formed in the boiler feed water this is called sludge disadvantages of sludge as sludges pour conductors of heat more amount fuel is required to boil the water this increases the cost due to the excess fuel electricity personnel and time sludge can decrease the performance of the boilers due to the deposition it curvatures sludges can choke the narrow pipes formation of sludge in the boilers can be prevented by using soft water by down operation frequent removal of the concentrated water and properly designed boiler the following are the disadvantages of the scales like sludge scales are also poor conductors of heat so more amount of fuel is required to boil the water this increases the cost due to the excess fuel electricity personnel and time as the consequence of prolonged heating the efficiency of the boiler decreases and the steam is produced at a slow rate boiler safety is decreased due to the presence of scales in high pressure boilers due to the choking of the narrow areas in the boiler due to the scale formation there is a possibility of explosion of the boiler due to the development of high pressure formation of scales can be avoided by using soft water caustic embrittlement and the boiler is fed with water containing dissolved sodium carbonate and heat it to boil steam is produced after the completion of the work fire is extinguished hot water is drained off but when we observe the boiler wall we can see tiny cavities into these cavities hot water containing sodium carbonate clogs sodium carbonate converts to sodium hydroxide and reacts with boiler material forms fe3o4 sodium carbonate reacts with hot water to form sodium hydroxide so produced sodium hydroxide reacts with boiler material to form sodium ferrite further sodium ferrite reacts with water to form sodium hydroxide and ferrosofaric oxide it can be observed from the above reactions that sodium hydroxide is regenerated and further attacks the boiler material as time proceeds the majority of the boiler material is attacked converts to ferrosofaric oxide and thus becomes brittle this phenomenon is called caustic embrittlement caustic embrittlement can be prevented by use of soft water use of sodium phosphate in the external treatment instead of sodium carbonate addition of compounds like sodium sulfite danone and lignin prevents the caustic embrittlement due to blocking of the cracks thereby preventing the infiltration of alkali thanks for watching please like subscribe and sharewelcome to vuecam the chemistry animations channel boiler troubles water for steam making water is required for the generation of steam for various industries for different purposes steam is useful for generation of electricity sterilization mechanical efforts energy storage and treatment of concrete the water for steam generation should not have any suspended or oily impurities should not have any dissolved organic or inorganic compounds should not have excess dissolved oxygen and carbon dioxide should not have any color odor and the ph value should be nearer to seven should not have hardness more than 0.2 parts per million should have the caustic alkalinity in a range of 0.15 to 0.45 parts per million if the water used for steam making does not satisfy the requirements just mentioned then there will be possibilities of development of boiler troubles there are many types of boiler troubles these are carryover the process of carrying of water by steam along with the impurities is called carryover this phenomenon may be due to priming and or foaming priming when the boiler is fed with hard water and heat it to boil steam is produced as the hard water is used to produce steam this steam may come out with water droplets the production of wet steam is called priming foaming and the boiler is fed with hard water containing oily impurities and heat it to boil along with steam persistent foam is produced on the surface of the water the production of persistent foam on the surface of the water is called as foaming the reasons for the priming are water containing dissolved salts presence of suspended impurities in water use of hard water higher water levels in the boiler sudden rise in temperature repeated temperature fluctuations improper design of boiler and high steam velocity priming can be avoided by using soft water using the water free from dissolved or suspended impurities using a boiler of proper design avoiding sudden rise in temperature avoiding higher levels of water in the boiler maintaining normal steam velocities avoiding temperature fluctuations and use of mechanical purifiers presence of oily or soapy impurities difference in the concentration of solute or suspended particles between the surface of the water and the water at inner region are the common reasons for foaming the following measure should be taken to avoid foaming use of calculated quantities of anti-foaming agent like castor oil prior to the entry of water into the boiler coagulants like sodium aluminate should be added to sediment the suspended oily impurities replacing the concentrated boil or water by fresh water drawbacks of priming and foaming we cannot judge the level of water in the boiler excessive heating requires consumption of more fuel loss of heat results in the decrease in the steam pressure the overall performance of the boiler also decreases wet steam causes the corrosion of the machinery like the blades of turbine scale and sludge when boiler is fed with hard water and heat it to boil steam is produced as the water evaporates the concentration of the dissolved salts increase beyond the saturation point as a result a hard and thick precipitate is formed on the inner walls of the boiler and is called a scale sometimes in the colder regions of the boiler a loose slimy precipitate may be formed in the boiler feed water this is called sludge disadvantages of sludge as sludges pour conductors of heat more amount fuel is required to boil the water this increases the cost due to the excess fuel electricity personnel and time sludge can decrease the performance of the boilers due to the deposition it curvatures sludges can choke the narrow pipes formation of sludge in the boilers can be prevented by using soft water by down operation frequent removal of the concentrated water and properly designed boiler the following are the disadvantages of the scales like sludge scales are also poor conductors of heat so more amount of fuel is required to boil the water this increases the cost due to the excess fuel electricity personnel and time as the consequence of prolonged heating the efficiency of the boiler decreases and the steam is produced at a slow rate boiler safety is decreased due to the presence of scales in high pressure boilers due to the choking of the narrow areas in the boiler due to the scale formation there is a possibility of explosion of the boiler due to the development of high pressure formation of scales can be avoided by using soft water caustic embrittlement and the boiler is fed with water containing dissolved sodium carbonate and heat it to boil steam is produced after the completion of the work fire is extinguished hot water is drained off but when we observe the boiler wall we can see tiny cavities into these cavities hot water containing sodium carbonate clogs sodium carbonate converts to sodium hydroxide and reacts with boiler material forms fe3o4 sodium carbonate reacts with hot water to form sodium hydroxide so produced sodium hydroxide reacts with boiler material to form sodium ferrite further sodium ferrite reacts with water to form sodium hydroxide and ferrosofaric oxide it can be observed from the above reactions that sodium hydroxide is regenerated and further attacks the boiler material as time proceeds the majority of the boiler material is attacked converts to ferrosofaric oxide and thus becomes brittle this phenomenon is called caustic embrittlement caustic embrittlement can be prevented by use of soft water use of sodium phosphate in the external treatment instead of sodium carbonate addition of compounds like sodium sulfite danone and lignin prevents the caustic embrittlement due to blocking of the cracks thereby preventing the infiltration of alkali thanks for watching please like subscribe and share\n"
