The pH value issue of boiler water
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The target pH value for the water in my drum boiler is 9-11; if it exceeds this range, how should it be adjusted? What factors can affect the level of pH?
What kind of devices are you?
The pH value of the water in our drum boilers is also between 9 and 11; when it exceeded this range, the cause was always found to be the deoxygenated water used as the source.
1. First, figure out what process is used to produce brine. 2. What process is used for deoxygenated water? 3. Only then is it necessary to specifically identify where the problem lies.
1 is that the dosage of chemicals changes; 2 is that the quality of the water source changes
Is there a problem with the ammonia injection system, or are there fluctuations in the water quality used for feeding?
The drum of different steam generation units has varying requirements regarding water quality, so it cannot be generalized. To prevent acidic water from corroding the metal surfaces of the heating elements, it is necessary for the water quality to be alkaline, meaning that the pH value should be above 7. Generally, the pH value of feedwater is kept between 8.5 and 9.5, while the pH value of boiler water is maintained between 9 and 10. The pH requirements vary depending on the type and specifications of the boiler. A too low pH value can easily cause corrosion of steel ； An excessively high pH value can easily dissolve the protective film on the surface of steel, leading to corrosion or caustic embrittlement. Water quality is usually adjusted by adding chemicals, typically trisodium phosphate. After dilution, it is pumped into the water in the drum using a dosing pump. Adding trisodium phosphate not only causes the calcium and magnesium salts in water to form non-adherent, loose sludge, but it also helps to adjust the alkalinity of the water, keeping the pH value of the drum water within the ranges specified by the regulations.