I would like to ask everyone: why can trisodium phosphate only be added to the boiler water (water treatment inside the boiler)? If it is added to the boiler feed water...
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As the title suggests, I would like to ask everyone: why can trisodium phosphate only be added to the boiler water (water treatment inside the boiler)? What would happen if it were added to the boiler feed water?
The formation of calcium and magnesium scale occurs when the concentration of calcium and magnesium salts in water exceeds their solubility; these salts precipitate out of the water and adhere to the rough metal surfaces exposed to heat, thus forming scale. The reasons why its concentration exceeds the solubility are as follows: First, as water is heated and evaporates continuously, the salts in the water become increasingly concentrated ； Secondly, the solubility of some calcium and magnesium compounds decreases as temperature rises ； There are also some water-soluble calcium and magnesium compounds that, during heating, undergo chemical reactions to form substances that are insoluble in water. To prevent this type of scale, it is necessary to minimize the hardness of the make-up water, prevent leaks in the condenser, and carry out chemical treatment inside the boiler. Our plant uses phosphate treatment; this method involves adding a phosphate solution when the boiler water is alkaline, thereby maintaining the concentration of phosphates at a certain level. The calcium ions in the water then react with these phosphates to form basic calcium phosphate, while a small amount of magnesium ions reacts with silicate ions to form serpentine. Both of these reaction products are insoluble compounds that remain as dispersed, soft sludge in the boiler water, allowing them to be easily removed through the boiler’s blowdown system without sticking to the heating surfaces and forming secondary scale.
No problem, I’ll just add it to the water supply
What size is the boiler in your home? Is the steam desuperheating water made from feedwater? If so, how do you control the sodium ions in the superheated steam?
If added to the feed water, as the desalted water enters the steam, salt deposition will occur, which is not good for the turbine and heat exchangers, right?
The desuperheating water is taken from the water supply pipeline; there’s definitely no chemical added to the steam, as it’s added inside the steam drum