The issue of electrolyzer switching
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This post was last edited by sunjl1981 on 2013-1-6 at 20:47. At today’s test drive plan meeting, the managers asked some questions that I wasn’t familiar with; as a person from the process engineering field, it was really embarrassing for me. I’m here specifically to discuss this with all of you in the industry: 1. Our company uses 6 Asahi Natural Cycle electrolyzers (with an annual production capacity of 100,000 tons). Assuming that 2 of these electrolyzers are currently in operation while the others are shut down, how can we switch from using these two electrolyzers to the other two, while keeping the production volume unchanged? During this transition, there should be almost no changes in the levels of chlorine, hydrogen, and caustic soda. 2. The sequence in which the various processes related to caustic soda are initiated – namely, primary brine, secondary brine, electrolysis, dechlorination, and chlorohydrin treatment – what is the most reasonable and economical order for these processes? # hcbbs
For the first question, there is definitely some change; it’s impossible for no change to occur. To minimize this change, it’s necessary to reduce the current in one cell while increasing the current in another. As for the second question, the sequence is as follows: preparation work, 1) primary brine, 2) dechlorination of secondary brine, 3) chlorohydrogen treatment, 4) electrolysis – with the increase in current starting at steps 1, 2, 4, then 3
There is no fixed order for starting the engines; the main thing is to meet all the necessary conditions for powering them up.
Surely, the two backup units should be turned on first. Once the voltage at EDIZA stabilizes after a while, and measurements on site show no issues, then everything is fine. At that point, the two units that were prepared for use can be shut down. It’s important to remember to use the DCS to maintain stable gas pressure – simply unlocking it will do. The parallel pressure is very crucial; the chlorine pressure can fluctuate quite a bit
There are changes; the other two electrolyzers can be put into liquid circulation first. When operating, stop one unit while keeping the other running; pay attention to changes in chlorine and hydrogen levels, and be sure to adjust the current slowly