heat exchanger size and flow

[bragamor]

We want to change our actual heat exchanger that has the following specs:

SQ.FT: 250
Tube diameter: 3/4"
# tubes: 250 tubes
Length of tubes: 5 feet

For a bigger exchanger, with the following specs

SQ.FT: 338
Tube diameter: 1"
# tubes: 261 tubes
Length of tubes: 5 feet

How is our flow going to be affected?

thanks for your help on this one

 

[vpl]

Q=[ṁ][Δ]T

Patricia Lougheed

******

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[Chance17]

See attached.
Note that G=mass/(time * area)
Your pressure drop will change by 0.8 power

 

[Chance17]

Trying again to upload my attachment

 

[Chance17]

I apologize.
Through no fault of mine, the link did not upload.
I also misread my chart.
The heat transfer coefficient is proportional to G2/G1 to the 0.8 power.
Pressure drop is proprotional to G2/G1 to the 1.8 power.
G is mass flux i.e lb/hr-ft2

 

[bragamor]

Thank you both for your replies:

Chance17: I still cannot open your file...

vpl: how can i apply the q=mxcxAT formula, are the q are AT equal for both exchangers?

 

[MortenA]

bragamor i think you should hire a professional consultant. This is not a "free consultancy service". What will you do if it does not work as you expect? Tell your boss that "those amateurs (no offence guys) didnt know what they were talking about"?

Or - talk to the vendor...

Best regards

Morten

 

[pmover]

bragamor . . . insufficient information is given to answer your question (spedifically, process flow conditions for both streams). MortenA recommendation is good! changing the physical characteristics of a heat exchanger without obtaining sound technical (heat transfer specialist) information is risky and bound for operational problems.

good luck!
-pmover

 

[bragamor]

Yes probably I am missing lots of information. I found this software that clarify all my doubts in case you want to use it.

http://www.kamlex.com/index.php?option=com_content&view=article&id=52&Itemid=65

Best regards