H2S stripper tower

[hal1981]

Hi all,
i worked in Ammonia unit, and we have a small H2S removal section.
H2S stripper tower in this section has a thermosyphon reboiler warm up by steam. A small flash drum installed on top of stripper. When a liquid level of flash drum increased, the top temperature of stripper decreased.
I don’t understand why that happened!
Thanks

 

[ash9144]

You increased your level to the point of blocking the vapor return of your reboiler, which broke your thermosyphon. Without syphon effect you get no flow through the reboiler and so no energy input and lower temps.