2 replies to this topic

[ngneer]

I calculated for heat balance of direct contact steam condensation batch system. 3500 kg of sat steam at 100 degree C was entered to the system and condensed by 0.43 m3/min of ambient water. Then both water and condensate fall to the tank. Tank contain about 16 m3 of water and temperature is 85 degree C after finishing.

The latent heat of sat 3500 kg steam for phase changing at 100 degree is about 8000000 kJ but I doubt that water can obtain that heat only 4000000 kJ for increase temperature from 31 up to 85 degree C. If we need to recover the whole 8000000 kJ back, I thing that ambient water should be entered more than 0.43 m3/min.

Did I wrong for calculation?
OR
Is there any heat loss or factor I forgot to consider?

FYI: Amount of water and steam just be approximated, It's no actual value

Thank you so much.

[Art Montemayor]

ngneer:

If you seek comments or advice on your calculations, you should submit them for the Forum to have full access to all your basic data and algorithm.

Be sure to supply ALL your basis, references, and step-wise algorithm to allow the Forum to fully analyze your logic and math. This is not to insinuate that you have math errors, but in a serious and normal engineering project within an engineering company, ALL calculations are submitted for detailed peer review. No calculations should go to a client or outside the company without being reviewed - and approved. This is normal, industrial practice so your submittal for review should follow that practice.

Await your reply and submittal (in an orderly, detailed spreadsheet format please).

[Zauberberg]

Heat balance figures for both streams appears to be in the same ball park/order of magnitude (approx. 2,200 kJ vs. 1,620 kJ) so better revise your calculation procedure. I have used ASME steam tables.

Some heat may be lost to the ambient air as well. But, as Art has said, upload your calculations so that we can give further comments.