The pH value of trisodium phosphate fluctuates! ! What is the reason? ?
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In our factory’s air tank, Na3PO4 is added; the pH level is generally kept between 9 and 11. However, over a long period of time, the pH level can suddenly rise or drop sharply! On-site adjustment doesn’t help much! ! I’d like to ask everyone for their opinions!
Bro, did you add the solid directly? If so, that’s normal – since it didn’t dissolve, the level will naturally fluctuate
Bro, what’s your inspection cycle?
It is added in the form of an alkaline solution! ! It is added after stirring in the alkali tank every time! ! ! And it analyzes each class twice! ! The timing is not correct. After analyzing it repeatedly, I initially thought that the water sampling point in the furnace hadn’t been emptied properly; I even tried to empty it several times, but it still didn’t work! !
We encounter this situation often too! The reasons are mainly as follows: 1. The concentration of the solution varies during preparation, and uneven mixing can also contribute to this issue. 2. Generally, steam drums have continuous blowdown, and changes in the amount of blowdown have a significant impact on the pH value. When the dosage of chemicals remains constant, if less blowdown occurs, the pH value rises over time due to the accumulation of alkaline residues. Similarly, when the amount of waste discharged is high, the pH level drops due to rapid water replacement; therefore, it is important to find an appropriate opening degree for the continuous waste discharge valve. 3. When the steam generation volume changes significantly and the dosage adjustment is not timely, it also affects the pH value
Thank you all for your answers! ! I agree with luckfox’s answer!
Is yours triple-sodium pure? :lol :lol :lol
The problem cannot be solved if the uniformity of chemical addition is not addressed!
Actually, this problem is easy to solve; we have encountered it before as well. 1. Use hot water for dissolution ； 2. Add chemicals at a fixed time and in a fixed amount. For us, the water replenishment rate is around 45 tons per hour, which is an increase of five jin per day ； 3. Inform the operator to make adjustments based on the previous test results, starting from 5 jin ；
The analysis on the 5th floor is quite good, but based on the phenomenon described by the poster, it shouldn’t be a problem related to continuous discharge; since the pH value was within the normal range earlier, this indicates that the opening degree of the continuous discharge valve was also within the normal range. Under normal operating conditions, the continuous discharge valve certainly wouldn’t be adjusted. Well, regarding the issue of gas production volume, the original poster didn’t provide any details, so it’s difficult to determine. The mixing should be electric; then there shouldn’t be any problems, but it might have issues if it’s manual. I think the most likely explanation is that the concentration levels differ in the first option. It’s quite possible that when preparing the solution, the weight ratios were not strictly followed; usually, experience is relied on, and since different people use different methods for preparation, this leads to variations in concentration. I wonder if the original poster agrees?
First, confirm whether the instrument is measuring properly (including whether it is functioning correctly and in proper contact with the medium), before considering the opinions from the 5th, 9th, and 10th floors.