Recently, the dechlorination effect has been poor
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This post was last edited by sunjl1981 on 2013-1-6 at 20:09. The dechlorination effect has not been good for several days now; the parameters remain the same as before, yet the amount of Na2SO3 used is nearly ten times higher than usual. I would appreciate any advice on what might be the problem. Thank you. This post was last edited by yzhms on 2009-3-1 at 00:17. ] # ， ， &
Is it that exaggerated? ? 10 times more! Excuse me, what kind of electrolysis device do you have there?
Check the acid addition situation as well as the condition of the vacuum system. Physical dechlorination and chemical dechlorination are indeed not on the same order of magnitude, so it’s reasonable to use more of the former. Hehe. Also, check the condition before chemical dechlorination. Chemical dechlorination does not work well in acidic conditions.
Analyze the free chlorine level before chemical dechlorination and compare it with previous values; then analyze the free chlorine level before vacuum dechlorination to determine whether there are issues with the vacuum level or problems with the pressure gauge. Is the distributor in the dechlorination tower not performing well in terms of distribution?
1. The instruments are inaccurate, and it is difficult to control the pH value after adding acid or alkali. 2. The vacuum level decreases, resulting in poor physical dechlorination effects. 3. Operation at low load results in a low temperature of the dechlorinated brine.
Reasons for poor dechlorination effect: 1. Low temperature of the brine. 2. Incorrect pH of the brine. 3. Excessively high flow rate of the brine. 4. Insufficient vacuum level in the dechlorination tower. 5. The vacuum pump or jet pump does not meet the requirements. 6. Incorrect pH of the dechlorinated brine. 7. Incorrect concentration of sodium sulfite. 8. Insufficient flow rate of sodium sulfite. 9. Incorrect ORP reading. 10. Analytical errors
I’m not sure whether the original poster is saying that the situation has been poor all the time or that it’s good for a while and then bad again. First, check to see if there is a problem with any part of the vacuum dechlorination process, such as the vacuum pump or the pressure transmitter in the dechlorination tower. In our facility, we encountered a situation where the data on the DCS was normal, but the level of free chlorine was still too high. After investigating various possibilities, we found that the pressure transmitter in the dechlorination tower was showing incorrect data; after the instrumentation technicians fixed it, the dechlorination system worked properly. Next, check whether there are any changes in the amounts of acid and alkali added for dechlorination; it’s best to analyze samples taken at the sampling points and compare them with the readings from the instruments. Finally, take samples from the return water at various monitoring points of D-280 to check for excessive levels of free chlorine. If such levels are present, it means the dechlorination process isn’t working properly, and the issue lies somewhere in the equipment or pipelines. Also, consider whether the concentration of sodium sulfite used is too low. When such problems occur, it’s important to carry out thorough analyses; don’t be afraid of the hassle. If the problems aren’t identified and resolved, the brine processing unit will face difficulties, with a series of other issues arising as well. This post was last edited by limingshuguang on 2009-3-2 at 10:06
As a supplementary note: Could there be a problem with the process pipelines, or is there a leak in the dechlorination system? If the chlorine outlet temperature in the dechlorination tower is below the set temperature, it can lead to chlorine crystallization, which may cause blockages in the pipelines. These also contribute to poor dechlorination efficiency.
First, check three items: 1. The pH value before dechlorination; 2. The vacuum level in the dechlorination tower; 3. The pH value before adding sodium sulfite. Seek help from instrument technicians and analysts to adjust these values. If any of these three aspects is abnormal, simply address the related part.
I believe the poor dechlorination effect is due to the following reasons: 1. Low temperature of the brackish water, 2. Low vacuum level in the dechlorination tower, 3. Improper pH adjustment of the brackish water.
Last night, there was free chlorine in the dechlorination process here; we tried to adjust it all night long but couldn’t get it right. We don’t dare to add sodium sulfite either, because our denitration membranes can’t handle it