What action required if N2 supply failure in Dry Gas Secondary seal ?
What action required if N2 supply failure in Dry Gas Secondary seal ?
(OP)
We have the Cycle gas compressor in Polymer plant with DGS. Recently face problem of N2 supply failed from source. So in such condition N2 failure at secondary seal also. in such case what should be the our action ? Immediately compressor need to stop or we can run the compressor for 1 to 2 hrs for taking the safe plant shutdown. If compressor stop immediately, which lead to chunk formation in reactor which is also not desirable.





RE: What action required if N2 supply failure in Dry Gas Secondary seal ?
Johnny Pellin
RE: What action required if N2 supply failure in Dry Gas Secondary seal ?
Thanks for the reply. We have the tandem seal arrangement , both seal facing same direction & seal leak diverted to flare line. In our case buffer gas ( using fresh ethylene)in primary seal & N2 in secondary seal as well as in barrier seal also. In the failure of N2 , plant continued the machine & there is no problem in seal after start up.
RE: What action required if N2 supply failure in Dry Gas Secondary seal ?
RE: What action required if N2 supply failure in Dry Gas Secondary seal ?
RE: What action required if N2 supply failure in Dry Gas Secondary seal ?
In secondary Seal vent to directed to atmosphere & there is no check valve in between.
RE: What action required if N2 supply failure in Dry Gas Secondary seal ?
Typically shutdown is recommended. Depressurization is something to evaluate.
If reactor is endangered by a condition such as no feed forward flow or runaway reaction can occur because compressor is stopped, your process guys should know. But any scenario should have been accounted for upfront, I mean in the validation of the dry gas seal system design before construction and based on some sort of HAZOP assessment.
RE: What action required if N2 supply failure in Dry Gas Secondary seal ?
I am totally agree with.