May 23, 2016 at 4:48 pm #21616
Paul R OrlowskiKeymaster
I would like to discuss what are the possible reasons for the rise in steam chest pressure in sour water stripper reboiler.
Steam used is MP steam and chest pressure rises so high that it equilises with steam pressure and steam flow hence gets reduced.
The reboiler is a kettle type reboiler and sour water feed is from cracker units namly DCU/FCCU/CDU/VDU.
The sour water is suspected to have some hydrocarbon content which is not completely seperated.
Also there is no physical damage on tube side, this has been verified.
Moreover the condensate pot level is not mainted normally and equilisation line has to be kept throttled hence.
Any insights would be helpful.
Engineer, Operations at HPCL-Mittal Energy Ltd
Senior Process/Production Engineer at Indian Oil Corporation Ltd. Panipat Refinery, Haryana
1. There is a great possibility that fouling occurred in reboiler due to carry over of hydrocarbon, which lead to low heat transfer in reboiler resulting in less steam flow and high chest pressure.
2. Check condensate pot level and codensate header back pressure which might restrict condensate flow
3. Check column level, in case of high level reboiler vapor space will be low resulting in low heat transfer.
ENGINEER at Saudi Aramco Total Refining and Petrochemicals
Fouling of reboilers tubes in SWS are having more chances
Handling phenolic stream of sour water have chances of hydrocarbon ingress in stream which lead to form carbon residue in tube side during contact with high temperature of steam in shell side
Engineering Consultant, Imerge Solutions Limited
We have experienced these problems with a client in the UK, but couldn’t trust the instruments, fouling up of the tapping points, once we installed an automated rodding device on the impulse lines, the problem disappeared.
Thanks everyone for your inputs.
Dear Mr LAKHVINDER SINGH
It is becoming very difficult to maintain condensate pot level as if equalization valve kept open beyond 2 threads leaves empties and goes high beyond LT range if kept closed.
For checking the column level the overflow from reboiled goes to column bottom so that won’t be controlling th reboiler vapour space. Level inside reboiler is always as high as overflow baffle in shell side of reboiler.
Dear Mr. Ian Beattie
Instruments have been checked and found working fine, so that is not the problem in our case. The most probable cause seams to be HC fouling.
Are there any mitigation measures?
And what could be done to clean the tubes. Hydrojetting didn’t do much good. Chemical cleaning has been proposed, are there any other measures?
Dear Mr. MOHAN PADMANABAN what solutions do you suggest? Any help is appreciated.
nabil el amoury
Oil and Gas Production and Utilities at SAMIR, Morocco
If all instrumentations is good you must :
-use the skim oil to evacuate any HC
-Check the operation of steam trap
-recirculate stripped wated to clean the exchangers and improve heat transfer
SECTION HEAD (OPERATION UNIT HEAD) – Refinery Operations: SULPHUR BLOCKS (ATU/ARU, SRU, TGT, SWT) at KNPC- MAA REFINERY
There is good discussion over here, but the main reason for fouling of tubes are Presence of Hydrocarbon, Ammonical salts and some time phenolic salts resulted into low heat transfer and chest pressure high, or course we need to check …Show more
Bineet Ghosh Thanks a lot. Nice discussion.
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