Recomended maximum outlet cooling water temperature 1

[washuchem]

Dear colleagues, Does anyone know of a written document / specification /reference for avoiding cooling water outlet from shell and tube exchangers above 120 F? Scale formation at this temperature occurs, but it is not easy to find a reference document / specs supporting this fact. Thanks

 

[Latexman]

My reference is the company design manual, which says 40-48^oC depending on which plant it is around the world.

Good luck,
Latexman

To a ChE, the glass is always full - 1/2 air and 1/2 water.

 

[EdStainless]

You can always check by taking some typical water analysis and checking the scaling limits.
I am familiar with people using upper limits in the range of 45-50C.

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P.E. Metallurgy, Plymouth Tube

 

[davefitz]

If it is discharged to a sewer or if the drain pipe is unprotected then there is also the OSHA limit of 60 C ( 140 F) , to prevent injuring workers.

"Nobody expects the Spanish Inquisition!"

 

[moltenmetal]

What matters more than cooling water outlet temperature is exchanger tube surface temperatures on the cold side, and the composition of the water.

Some minerals start to drop at 60 C. Most minerals that are of concern for fouling are dropping like a rock at 80 C.

Obviously the type of water matters greatly. If it's closed loop cooling water where the water quality is monitored and treatment is maintained properly, you may be able to push the limits. If it's condensate, as long as you can handle the steam being generated you can ignore the limits, more or less. If it's raw water from a river or lake or worse still a well, look out- you could be in trouble with a water exit temperature of 40 C depending on what's in there.

 

[Christine74]

http://www.hydrocarbonprocessing.co...ouling-in-shell-and-tube-heat-exchangers.html

"A tube wall temperature not greater than 140°F (60°C) is a safe upper limit for treated cooling water."

-Christine

 

[crshears]

If it's raw water from a river or lake or worse still a well, look out- you could be in trouble with a water exit temperature of 40 C depending on what's in there.

If zebra musses are a problem, warmer outlet temperatures can greatly discourage their taking up residence.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[moltenmetal]

...but they'll still be happy to live at the inlet...

 

[Panther140]

Perfect. Gather them all in one spot so they are easy to eradicate. Win Win.

"Formal education is a weapon, whose effect depends on who holds it in his hands and at whom it is aimed." ~ Joseph Stalin