Estimating static pressure loss for air-cooled heat excahnger 2

[starrproe]

Hi All,

I am working on rerating some existing air-coolers for higher duty.Initial calculations suggest that by increasing the air-flow(using new fans), while retaining existing bundle, the required process parametres can be acheived.

However, since I also need to check suitability of existing fan motors, I need some means of estimating static pressure drop across the bundle for increased air-flow.

Can somebody suggest empirical correlations or reference text where I can get some clue for estimation of new presure drop?

Thanks,
Starrproe

 

[ione]

Take a look at the Robinson Brigss correlation in the attached paper (page 223). Hope it could help

 

[speco]

starrproe,

I suggest you try the Escoa Engineering Manual, which is available online at

http://www.fintubetech.com

I have used their correlations for a long time, and believe they are pretty good. I have check rated a number of exchangers, and find that the static pressure is the most diffucult number to calculate. For the same conditions, different manufacturers will come up with widely varying results. Escoa's results tend to be on the conservative side of the middle.

They are all in Imperial units, by the way.

Regards,

Speco (

http://www.stoneprocess.com)

 

[srfish]

starrproe,

Another correlation is Briggs and Young. You can find a writeup in the Wolverine Heat Transfer Data Book.

We have used this correlation for many years and never had a problem.

One word of caution is to take into account other items in the air flow stream such as hail screens, bug screens and louvers.

http://www.gulleyassociates.com

 

[starrproe]

jone,
Thanks for the text..
speco / srfish,,
Thanks for your valuable suggestions.

Starrproe