Exam Question
(a) State the purpose of boiler water treatment; (4)
(b) Chemicals added for maintaining desired quality and (6)
(c) Tests that are carried out to ensure the desired quality. (6)
Class 4 (4th Engineer)
MEP
📅 Jul 2022
Reference Answer
### (a) Purpose of Boiler Water Treatment (4 Marks)
The primary purpose of boiler water treatment is to ensure the safe, efficient, and reliable operation of the boiler by preventing internal damage and maintaining steam purity. This is achieved through a multi-faceted approach targeting specific water-related problems:
1. **Prevention of Scale Formation**: Untreated feed water contains dissolved mineral salts, primarily Calcium (Ca) and Magnesium (Mg) compounds, which constitute 'hardness'. Upon heating, these salts precipitate out of solution and form hard, insulating scale on heat transfer surfaces (tubes, furnace walls). Scale significantly reduces heat transfer efficiency, leading to increased fuel consumption. More critically, it can cause localized overheating of tube metal, leading to plastic deformation ('bulging') and eventual catastrophic failure.
2. **Control of Corrosion**: Corrosion is the electrochemical degradation of boiler metal. Treatment aims to prevent it in several forms:
The primary purpose of boiler water treatment is to ensure the safe, efficient, and reliable operation of the boiler by preventing internal damage and maintaining steam purity. This is achieved through a multi-faceted approach targeting specific water-related problems:
1. **Prevention of Scale Formation**: Untreated feed water contains dissolved mineral salts, primarily Calcium (Ca) and Magnesium (Mg) compounds, which constitute 'hardness'. Upon heating, these salts precipitate out of solution and form hard, insulating scale on heat transfer surfaces (tubes, furnace walls). Scale significantly reduces heat transfer efficiency, leading to increased fuel consumption. More critically, it can cause localized overheating of tube metal, leading to plastic deformation ('bulging') and eventual catastrophic failure.
2. **Control of Corrosion**: Corrosion is the electrochemical degradation of boiler metal. Treatment aims to prevent it in several forms:
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