As the amount of acid added increases, the pH value does not change much.
Thread Content
This post was last posted by sunjl1981 on 2013-1-6 23:29 Editor: In the electrolytic cell of the chlorine engineering used by our company, we found in the last week that the amount of hydrochloric acid added to the light brine of the anode outlet has continued to increase (an increase of 10% in one week), but the pH has not changed significantly. Analyze the pH of the light brine of the anode outlet. Normal, the quality of the brine is normal, the meter display has been calibrated and is normal (consistent with the analyzed data), the tank voltage is normal, the purity of chlorine is normal, the hydrogen and oxygen content are normal, so what is the reason for the increase in the amount of acid added? I would like to ask my friends for your advice. Thank you in advance!!! #hcbbs
“The cell voltage is normal, the purity of chlorine is normal, and the hydrogen and oxygen content are normal. "Normal does not necessarily mean that the membrane will not leak. Especially if the original membrane leaks, the leakage will gradually increase.
You have increased the amount of acid added to the light brine out of the tank, which means that your chlorate content has increased, and the amount of hydroxide moved from the cathode chamber into the anode chamber has increased. The added hydrochloric acid has reacted with the chlorate in the light brine, so although you have added more hydrochloric acid, the pH value has not changed. In serious cases, the pH value of the light salt water you leave the tank will also increase, and the oxygen content in the chlorine will also increase. Be observant.
However, is this increase so obvious in less than a week? If it is like what you said, how should it be handled? Continue running and keep increasing the amount of acid according to changes in pH. What measures should be taken? Please advise, thank you!
pH is a logarithmic relationship, and only changes in order of magnitude will be reflected. In addition, it is necessary to calculate the amount of increase and then evaluate the condition of the membrane.
The amount of acid added to the light brine added to the tank has increased, which means that your chlorate content has increased. The amount of hydroxide moved from the cathode chamber into the anode chamber has increased. The added hydrochloric acid has reacted with the chlorate in the light brine.
Keep the amount of acid added unchanged, and check whether there are any changes in the purity and oxygen content of chlorine, and the pH value of the fresh brine coming out of the tank. If it develops in a bad direction, it means there is a problem with the membrane, or increase the amount of acid added or replace the membrane.
As chlorate increases, the pH value of the outlet brine should also increase. The author said that the analysis data is normal and the instrument data is also normal. Is the concentration of hydrochloric acid stable? Is acid added to the battery?
The above situation is happening in our company now. Now we can't keep up with the addition of acid, so we are running with reduced current. Please give me some suggestions.
In a word, the current efficiency has dropped. This phenomenon often occurs in the later stages of the operation of the ion membrane. Suddenly one day the acid cannot be added in place, which attracts everyone's attention! !
Pay attention to the temperature changes. Is flocculant added?