Shell and tube HX - recommended tube/shell velocity

[espnloser]

I am using HTRI and would like some recommendations for good tube and shell velocities for liquids and gases.

Right now i am using 0.75 inches for the tubes with liquid in both the shell and tube. However, my tube velocity is 0.02 m/s. I read that 1-3 m/s (3-10ft/s) are good velocity numbers in reference to fouling.

Any advice would be appreciated

peace

 

[StoneCold]

As a general note I would suggest that keeping your renolds numbers in the turbulent regieme is the first step and then look at the velocity to see that it is high enough to keep fouling down.

regards
stonecold

 

[vpl]

espnloser

I believe the 1-3 m/sec numbers are reasonable. I've found that with flow rates below 1m/sec (or 3 ft/sec in USA units) that you will get considerable fouling unless you have an exceptionally clean water source. You also create ideal conditions for MIC (microbiologically induced corrosion). On the upper end, the trouble with going above 3 m/sec (10 ft/sec) is that you can get significant erosion of the tubes unless they're made from very erosion-resistant material.

In regard to StoneCold's comment: I agree that you need to keep your flow in the turbulent region. However, since velocity is one of the components of the Renolds number, there should not be any conflict.

Patricia Lougheed

Please see FAQ731-376 for tips on how to make the best use of the Eng-Tips Forums.