5 replies to this topic

[umarkhankk]

Hi gentlemen,
I am using a air cooled heat exchanger for cooling down the bottom product of Debutanizer tower that is stabilized condensate, for about 03 months it has been getting leakage from tubes side like unfortunately one tube a month, so we plug them, Could any expert help me out finding the possible causes because we already have plugged 04 tubes.
The operating conditions are,
operating pressure 215 psig,
inlet temperature 390 F,
outlet temperature 125 F,
flow rate 300 bbls.
the copper strip test of condensate is 1.

Regards
Umar Khan
umarkhankk@hotmail.com

[Technical Bard]

With such a high differential temperature on the process side, thermal stresses to the tube/tubesheet connections could be your problem - particularly if you see significant changes in process temperature or day/night ambient temperature changes. What material of construction are the tubes?

[fallah]

Umar Khan,

It may occured due to high vibration. Is it equipped with vibration sensor to inform the operator by alarm on High/High High vibration level?

Fallah

[Zubair Exclaim]

Check following :

1- check the design pressure and temperature of air cooler provided by your vendor against the highest pressure and temperature you experience. Dont use general set points you mentioned. take out the graphical trends from dcs or what ever system you have and match peaks.

2-what fallah just said applies


3-level or flow control valve of bottom : what kind of sensitivity does it have. check the PID values of it specially i would recommed some one to look at the "I" value. in simple words If your valve is opening/ closing too fast or its action is very quick, it may cause pressure shocks

4-or it simply could be a manufacturing fault, have a welding expert look into it

[S.AHMAD]

1. In absence of any details, we can only guess.
2. Please tell us more about the characteristic of leakage, the location (inlet/outlet, middle, joints etc), the material of construction, the mercury content of condensate etc.
3. Any pictures?

Edited by S.AHMAD, 12 April 2012 - 04:16 AM.

[Fire on dire]

Dear Umer beta ,
kesa hai larkay. abbas here

Some thing is causing (or had caused) the pressure to increase inside the tubes, check following:

• d/s FT turbine (possibility of clogging)
• d/s LV chocking (may caused pressure inside air cooler to exceed dp of tubes 300 psig)
• possiblity of tubes fouling
• measure vibrations and welding joints during SD.