Discussion on adding acid to the anode tank
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This post was last edited by sunjl1981 on 2013-1-7 00:27. In chlorine production plants, acid is added at the inlet of the anode cell; then large amounts of brackish water are returned to the electrolyzer. There are also acid addition pipelines at the inlet of each individual cell, as well as before the dechlorination tower. Questions: 1. The relationship between the brine returning to the tank and the flow rate entering the tank. 2. The amount of acid added to the anode tank (approximately) and how pH is controlled. 3. The amount of acid added at the inlet of the dechlorination tower and how pH is controlled. Last edited by yzhms on 2009-4-16 17:47. # hcbbs
1. The flow rate into the tank is determined based on a proportional relationship between the current in a single tank and a coefficient related to the saltwater, thereby establishing the saltwater flow rate. The amount of acid to be added to the 2 anode solution is determined based on the acidity level at the outlet of each cell. The control range is generally around 2 to 4. 3 Generally, the control range for the amount of acid added at the inlet of our dechlorination tower is around 1 to 2.
The ratio of fresh brine to secondary brine returning to the chlorine engineering electrolyzer is 1:1, and the pH value of the anode solution tank is maintained between 2.0 and 2.5; no additional acid is added before the brine enters the dechlorination tower here.
1. The relationship between the brine returning to the tank and the flow rate entering the tank is as follows: for Asahi Kasei and similar electrolyzers, it is 1:7 (total amount of saltwater entering the tank)； Chlorine engineering: 1:1 (amount of refined salt water fed into the tank), but there are also ratios of 1:1.1 (amount of fresh salt water fed into the tank) and 1:0.7 (amount of fresh salt water fed into the tank). I don’t know much about other electrolyzers; I hope experts who are familiar with them can offer some guidance ； Thank you! 2. pH value controlled by the amount of acid added to the anode tank: 2–4 when acid is added; 2–5 when no acid is added. 3. pH value controlled by the amount of acid added at the inlet of the dechlorination tower: around 1.3, with some values ranging between 1–2. Last edited by 181128425 on 2009-4-17 21:58
Asahi Kasei electrolyzer: The inlet brine flow rate is 1/7 of the inlet salt water flow rate, and the acidity at the electrolyzer inlet is less than 0.15N. Output: 0.001---0.005N. PH264 is at 2---2.5PH; the acid addition in the dechlorination tower is controlled at 1.0---1.5PH
1. The relationship between the flow rate of the brine returning to the tank and the flow rate of water entering the tank is inverse; the higher the flow rate of brine, the lower the concentration in the tank and the higher the pH value. 2. The amount of acid added to the anode tank (approximately) and the control of pH value: This is determined based on the pH value of the liquid exiting the tank, with a value of 3 being ideal. 3. The amount of acid added at the inlet of the dechlorination tower and the control of pH value: Our target pH value is 1.5–2
Brine is added to the electrochemical cell in Beihua Machinery & Electronics in order to protect the titanium tubes from corrosion when acid is added to the cell; therefore, a certain amount of brine containing free chlorine is introduced to maintain its strong oxidizing properties, thereby preventing the titanium tubes from being corroded by the acid. The principle for adding acid to the electrolytic cell is based on the properties of the membrane. The pH of the sulfonic acid membrane is 1, while that of the carboxylic acid membrane is 3. The pH at the outlet of the anode solution in the Beihua Electromechanical cell ranges from 0.001 to 0.005, meaning that the pH of the anode solution is above 3. As for the dechlorination tower, depending on the actual conditions, the anode solution here contains high levels of free chlorine; therefore, the pH is kept around 1.