pH value of synthetic waste boiler water
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The pH value of the synthetic waste boiler water is low – what causes this? The pH value of the make-up water is around 7.6, while that of the boiler water is approximately 6.2–6.7. Some time ago, the pH value of the make-up water was around 7.6–7.9, and the pH value of the boiler water was around 8.2–8.5.
It mainly depends on what chemicals you add to adjust the pH value. . . . . .
Because I use deoxygenated water for synthesis and purification, and I usually use ammonia to adjust the pH
It is fine to use dilute ammonia water to adjust the pH, but it is necessary to take into account the change in pH after passing through the deoxygenation tank, as this tank can flash off some of the ammonia, thereby lowering the pH!
We also use ammonia to make adjustments
It is fine to use dilute ammonia water to adjust the pH, but it is necessary to take into account the change in pH after passing through the deoxygenation tank, as this tank can cause some of the ammonia to vaporize, thereby reducing the pH of the feed water!
The pH value adjusted by the ammonia you use is within the normal range; it should be set in the outlet pipeline of the deaerator, so there’s no possibility of it being evaporated by the deaerator. If this issue has only appeared recently, you might want to check whether the concentration of ammonia you use is appropriate, as well as whether your ammonia metering pump is functioning properly. Of course, it’s important that the pH value of the deionized water remains normal.
The pH value adjusted by the ammonia you use is within the normal range; it should be set in the outlet pipeline of the deaerator, so there’s no possibility of it being evaporated by the deaerator. If this issue has only appeared recently, you might want to check whether the concentration of ammonia you use is appropriate, as well as whether your ammonia metering pump is functioning properly. Of course, it’s important that the pH value of the deionized water remains normal. Thank you! -----------------
If the pH value of the boiler water is adjusted solely using ammonia, it will decrease as the water evaporates. Why didn’t you install a dosing device in the drum? Sodium phosphate can be added to the boiler – this serves both to adjust the pH and to form calcium phosphate, which can then be removed through continuous blowdown.