In our TGTU section of SRU, We have Stripper column which strips out H2S from the amine. The H2S will routed to SRU as feed from the Reflux drum O/H of Stripper Column. In recent days, it has been found that, all of Sudden Stripper Column level is decreasing and the same time The reflux drum get full and get overflow in the Overhead line(O/H). During this time there is a sharp increase in column PDI.
After a while, everything gets Normal after taking some actions (Reboiling steam cutting, reducing amine circulation rate,increasing reflux flow etc..,). This case happens rarely but we couldn't stop it.
What could be the reason for the above case. How to avoid it?