What causes fluctuations in the pH value at the outlet of the dechlorination tower?
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This post was last edited by sunjl1981 on 2013-1-6 at 20:42. The pH value at the outlet of the dechlorination tower fluctuates greatly, and these fluctuations occur irregularly; it can reach around 11 at its highest and around 2.5 at its lowest. The liquid level in the dechlorination tower is stabilized by adding alkali and sodium sulfite. I hope the seniors can help analyze it. ， ， -
How do you add acid? Is there a problem with the instrument?
Check whether there is a vacuum leak in the dechlorination system, and whether it occurs periodically.
Our factory also encounters this issue frequently, though it isn’t periodic. I believe it is mainly due to an excessive amount of material entering the dechlorination system; the unstable flow rate of this material ultimately leads to excessive levels of pH and ORP, and these issues often occur suddenly.
Is the vacuum level and the addition of acid stable? Also, is the location where the measuring instruments for adding acid and alkali are placed appropriate? In our case, the pipeline used for monitoring the addition of acid is not suitable, resulting in a very slow reaction
The pH of the imported products is very stable, ranging between 1.0 and 1.25. The vacuum is also very stable. I just couldn’t figure out what was going on.
Check whether the liquid level in the tank of the anode system is stable; large fluctuations in this level can cause fluctuations in the free chlorine level in the disinfection system. The solution is to stabilize the liquid level, which will result in smaller fluctuations in the free chlorine level in the disinfection system
Please try adjusting the PID parameters of the control valve for level regulation, so that the OP value changes smoothly
Adding acid makes the system likely to become unstable; the brackish water for which the pH is measured after acid addition before it enters the dechlorination tower is sent to the brackish water discharge tank. The discharge tank operates under negative pressure, and many of the pipes involved in this negative-pressure system are unstable, so it’s possible that these pipes won’t allow fluid to flow through them.
It is possible that the amount of alkali added was insufficient, while too much hydronium was added, resulting in a fluctuation in pH toward acidity. The level control valve for the liquid entering the dechlorination tower needs to be regulated more stably. Additionally, the level of brackish water remains too low, and the level of free chlorine is too high, which has an adverse effect.