11 replies to this topic

[aliebrahem17]

We have a thermosiphon reboiler having a problem with increasing the steam flowrate beyond specific point
The tube bundle was removed and found clean and the shell it self was clean
Any guess where the problem could be found
The reboiler using LP steam and heating sour water

[latexman]

Can you be more descriptive?  "Having a problem" does not tell us much.  Give the inlet and outlet data (T, P, flow rates), the heat exchanger specifications (tube size and length and number, heat exchange area, MAWPs, etc.), the heat duties, and exactly the physical parameter that is limited.  How do you know the HX is not at it's physical limit?

[breizh]

Hi,

a PID is appreciated, on top of Latexman's requests.

Is it a new problem?

Could be accumulation of inert, could be quality of the steam? should be saturated, could be an issue with level ....

Nothing wrong with your process???

Many things, in fact.

Breizh

[aliebrahem17]

Thank you breeizeh and latexman for your reply

Actually I don't know how to add a PID here, for your question is it a new problem, yes it is
We used to feed to the column 39 m3/HR with approx 5000 kg/h steam
Now with control valve opening 100 % the steam flow is approx 4200 kg /HR , the steam is saturated, pressures 3.5 bar, temp 175 degree C

Edited by aliebrahem17, 25 November 2024 - 04:04 PM.

[breizh]

Hi,

Probably good to check your instruments (valve, Flowmeter).

You may not have issue with heat transfer, I did not read carefully your post.

To add document, please click the More Reply options button, choose your file and attached it, simple?

Breizh

[aliebrahem17]

Instruments already checked and nothing wrong, and if you suspect that the CV chocked, bypass opened and no increase in flowrate beyond 4200

I can't find More in Reply button
Is it necessary to open the web from a PC??

[breizh]

Hi,

First click on Edit then Use full  editor button

 

Breizh

[latexman]

Is it necessary to open the web from a PC??

I'm not sure it's required to add attachments, but I find it much easier from a PC than using the "Full Version" on my iPhone.

[latexman]

I can't find More in Reply button

When editing a post, you’ll see “Use Full Editor”. On a new post, you’ll see “More Reply Options”. Both give you the same functionality. The attachment functions are below the text box.

Open your eyes.  Don't give up so easy.

[aliebrahem17]

I tried to do but there is no such buttons
I will try from pc later

[latexman]

On your phone, at the very bottom, under the “Post” under the reply text box, do you see “Full Version”. If you activate that you might be able to do it on your phone. I’d rather get on my laptop than do that. I recall it’s not so easy to get it back into the phone mode. Things get small and you have to enlarge where you have to hit the Phone Mode icon and I’m not very good at it. So, I don’t! I use my laptop.

[EnggExp]

What is the control loop? Auto/ Cascade ?
What is the process outlet temp and steam pressure on the shell?
What is the FT span?
Did you verify field vs DCS position?
Did the process inlet temp change?
Condensate control loop functioning properly? Could you confirm shell isn’t backed up ?
Did the composition of process inlet stream change?
Process inlet stream phase composition change?