Liquid oxygen pump surges and shuts down
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Lately, we’ve been experiencing strange phenomena in our air separation unit, and the cause cannot be determined; aside from the issue of the anti-surge valves opening and closing automatically, as mentioned earlier. Now, whether it’s the main pump or the backup pump, the liquid oxygen pump shuts down without any apparent reason; sometimes it shuts down several times a day. After it shuts down, it can start up quickly and then operate normally. The technicians checked everything but were unable to find the cause. Eventually, they claimed that one of the components in the frequency converter wasn’t cooling properly; a fan was added, but the problem persisted. They then said there was too much dust inside the frequency converter, and they even created a special enclosure for it. It’s really unbelievable. . . . . . Hehe, that’s fine. You think there are many tasks related to air separation in our factory; I post some posts about equipment malfunctions every day. I hope to share these with everyone so that we can all improve together.
1. Check the inlet filter of the liquid oxygen pump; a clogged filter can cause air locking in the pump, leading to a sudden drop in pressure, but normal operation can be restored once it is restarted. 2. Check whether there are any current fluctuations when the liquid oxygen pump shuts down; such fluctuations can cause the inverter controlling the liquid oxygen pump to engage in protective action, leading to the shutdown of the pump. This post was last edited by Longsky Eagle on 2009-3-25 17:09.]
Lately, something seems to be wrong with our air separation unit; strange phenomena keep occurring, and it’s impossible to determine the cause. In addition to the automatic full opening or closing of the anti-surge valves mentioned earlier, recently the liquid oxygen pumps – both the main ones and the backup ones – have stopped working for no apparent reason. However, they can be started again right after stopping; sometimes this happens several times a day. The technicians who checked them couldn’t find any cause for the problem. They claimed that it was due to poor cooling of a certain component in the frequency converter, so they added a fan. After using it for half a month, there was no significant improvement. They then speculated that there might be too much dust inside the frequency converter, so they created a special enclosure for it. I’m really amazed – we face many problems with our air separation units. I’m sharing this experience here, hoping that everyone will offer their opinions and apply them in their own workplaces to prevent such incidents.
I’m sorry; I posted the same thread twice, thinking that thread hadn’t been sent yet.
Hehe, thank you so much for sharing! Every outcome has its causes; we are still in the exploratory stage at present and are not yet able to fully explain the existing problems. I believe that such issues will eventually be resolved satisfactorily! ! !
Check for electromagnetic interference； Check the power supply quality
There’s a problem with the inverter! Avoid electromagnetic interference! Otherwise, replace it!
Carefully inspect the processes and equipment instruments
Conduct a thorough inspection, discuss the issues related to the instrumentation, electrical systems, and process parameters to figure out where the problem lies; there must be a reason for it! I hope you find a solution to the problem soon. Stable operation
Check the cause of the shutdown. The power components in the inverter, such as IGBTs, do indeed require cooling. However, it’s winter now and the temperatures are low; if we’re already in summer, then it’s probably not an issue related to ambient temperature. Consider the inlet valve, the filter, the return air valve, as well as voltage fluctuations. Check also the load connected to the same 380V transformer – was there any other large electrical appliance starting or stopping at the time of the shutdown?