4 replies to this topic

[deltaChe]

Dear Sir/Madam

Sorry to bother you this trivial. The condensate form in these three horizontal condensers and drained directly to the storage tank.
The seal leg has to be set up to prevent the siphoning of liquid from the seal loop.
How can I determine the minimum height of the seal leg for these three condensers.
I used the following formula, the pressure difference between the tank and condenser
and neglect the pipe head loss.
The minimun height I got seems not meet with the height marked in the P&ID.
Please kindly informed me any paper or book on this issue or point me any thing wrong in this issue.
Hmin=P1-P2*10.2/sg - h(pipe loss)
Hmin= the minimum seal leg height
P1,P2 = 10^5 pa
sg = process fluid specific gravity = 1.3

Really appreciate your help, and thank you very much.

Attached Files

•  condenser hydraulic.pdf   19.18KB   825 downloads

[katmar]

I agree with your formula (except for the missing brackets). It should be
H_min = (P1-P2) * 10.2 / sg - h(pipe loss)
This shows that the heights on the diagram are too small if the SG is 1.3

An important note is that to avoid siphoning the seals dry when flow is established the piping must be made self venting, or else there must be siphon breaks connecting the top of each seal leg to the outlet of condenser C.

[breizh]

Hi ,
To support your query .


http://www.graham-mf...eID=48&catID=17

Breizh

[deltaChe]

Dear Mr. Breizh

Thank you very much for your information. The attached you post is for vaccum condensation, but
in my case is not.
And, I doubt the formual I wrote H_min = (P1-P2) * 10.2 / sg - h(pipe loss)
is not rignt and it seems to me that P1 + H*g/10.2 - h(pipe loss) = P2. Please share any comment if you have.

Thank you very much.

[breizh]

(P1-P2 ) / (Ro*g) = H min

H should be Hmin + head loss in the line

Ro= 1300 kg/m3; g =9.81 SI ;H m ; P1-P2 = pascal

Similar to what Harvey wrote .

Breizh

Edited by breizh, 10 October 2011 - 06:29 PM.