Linde cryogenic hydrogen recovery unit maintenance
Linde cryogenic hydrogen recovery unit maintenance
(OP)
Hey all,
We have a hydrogen recovery unit working on the basis of cryogenic separation. It has a pressure regulating valve at hydrogen product line. That valve is installed with in the cold box and it's actuator assembly is outside for easy maintenance.
We have to remove that actuator along with valve plug for maintenance. This means that cold box internals will be exposed to outside atmosphere.
Do we need to derime the cold box for this activity or simply remove tha actuator plug assembly with positive nitrogen flow through the cold box.
Is it also necessary that we have to derime the cold box for even minor maintenance or not?
Thanks
We have a hydrogen recovery unit working on the basis of cryogenic separation. It has a pressure regulating valve at hydrogen product line. That valve is installed with in the cold box and it's actuator assembly is outside for easy maintenance.
We have to remove that actuator along with valve plug for maintenance. This means that cold box internals will be exposed to outside atmosphere.
Do we need to derime the cold box for this activity or simply remove tha actuator plug assembly with positive nitrogen flow through the cold box.
Is it also necessary that we have to derime the cold box for even minor maintenance or not?
Thanks





RE: Linde cryogenic hydrogen recovery unit maintenance
You are not getting any answers to this question I assume is because the translator program you used mis translated the word "derime" We don't know what that word means. Can you try again?
Regards
StoneCold
RE: Linde cryogenic hydrogen recovery unit maintenance
http://www.eng-tips.com/viewthread.cfm?qid=115300
I don't see why the plant would need to be derimed if you can ensure there's little or no influx of air when the valve's top works have been removed. Keeping a purge on it should work. Not sure nitrogen is the best solution since it will liquify or solidify at LH2 temperature, but it isn't clear from the OP if that's an issue or not. Is the nitrogen going to get into any area of the plant where it would need to be removed? For liquid hydrogen systems, we've always used helium as a purge gas.
RE: Linde cryogenic hydrogen recovery unit maintenance
My question is that we have to remove the pressure control valve plug for maintenance. We have 02 options
1) Derime the plant which means we have to heat up the temperature from -185 to 25 oC for hand over which is a time consuming activity.
2) We can hand over the valve just after depressurizing the cold box with out heating it to positive temperature.
My question is related to 2nd option, is it possible to remove the plug from the system having that low temperature or we have to take any precautions for that.
Hope you can understand what i need to know.
Thanks
RE: Linde cryogenic hydrogen recovery unit maintenance
My apologies. I guess it was just my ignorance.
Best of luck on your repair.
StoneCold
RE: Linde cryogenic hydrogen recovery unit maintenance
RE: Linde cryogenic hydrogen recovery unit maintenance
RE: Linde cryogenic hydrogen recovery unit maintenance
RE: Linde cryogenic hydrogen recovery unit maintenance
What is your opinion
RE: Linde cryogenic hydrogen recovery unit maintenance
RE: Linde cryogenic hydrogen recovery unit maintenance
RE: Linde cryogenic hydrogen recovery unit maintenance
RE: Linde cryogenic hydrogen recovery unit maintenance