Are there any electrolyzers with zero pole distance? Please share your experiences regarding the use of polarization rectifiers
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This post was last edited by sunjl1981 on 2013-1-6 at 23:55. As far as I know, a polarization rectifier is a device that, when stopped, uses a weak current to carry out electrolysis while also protecting the cathode. Its purpose is to prevent the dissolution of the cathode coating caused by the reverse current that occurs when the electrolyzer stops. During use, because Asahi Kasei failed to provide clear instructions, a mixture of hydrogen chloride was formed while the vehicle was parked, resulting in an explosion. I wonder what experience everyone has # , , &
I’m not exactly sure about the specific details either. Last year, severe power outages occurred due to weather conditions; after the polarizing rectifier was connected, there was no circulation of current, which led to a mixture of hydrogen and chlorine exploding and causing heavy losses
1. When the electrolytic cell is being heated, a forward current is applied using a polarizing rectifier to prevent galvanic reactions from occurring in the cell, which could affect the peeling of the coating； 2. During the heating process, a different polarization current is applied depending on the temperature at the exit of the tank: the higher the temperature, the higher the polarization current ； 3. Polarization is also an electrolytic process that produces chlorine and hydrogen. In the absence of circulation, the membrane in the gas phase area inside the cell dries out, allowing hydrogen to mix with chlorine; a high hydrogen content in chlorine poses a danger ； 4. After parking, polarization is activated automatically; during this process, circulation must be ensured, and nitrogen should be introduced to protect the electrolyzer ； 5. Owner’s situation: no circulation, dry film, mixture of chlorine and hydrogen, explosion ； 6. If nitrogen is present, the amount filled is insufficient. :handshake
I have experienced this twice: power loss occurred, and when the power was restored, polarization was activated automatically, but the cycle had not yet been established. I immediately instructed the operator to deactivate it, and no abnormalities occurred.
We use tanks from chlorine production facilities. Everyone understands the role of polarization current, but there is controversy regarding when it should be activated. If it is turned on too early when the electrolyzer suddenly loses power, there is a risk of explosion. In the past, the polarization current in chlorine production systems was linked to the moment the electrolyzer lost power – it would be activated as soon as the electrolyzer lost power – and as a result, in some cases severe leakage of the ion membrane led to explosions in the electrolyzers. After learning from this painful experience, the Japanese changed their approach: when the electrolyzer suddenly loses power, it is no longer possible to apply polarization voltage. In such cases, more water should be added to the electrolyzer to fill the gaseous space; the anode of the electrolyzer should be kept under slight negative pressure. The sampling valves at the top of each individual anode should be opened quickly to ensure that each anode remains under negative pressure relative to the outside atmosphere, while nitrogen should be quickly introduced to the cathode to maintain pressure. Only when the workers on site see overflow at both the anode and cathode do they notify the team to apply polarization voltage. During normal start-up and shutdown processes, polarization is applied only after overflow occurs; in short, it is necessary to ensure that both the anode and cathode of the electrolyzer are at a state of overflow before applying polarization, and polarization must be stopped before the liquid filling cycle in the electrolyzer is halted. This is my personal opinion; I’d appreciate some guidance!