HTRI/TEMA requirement for shell & tube design with tube inlet axial nozzles

[LNGprocesseng]

Dear all,

I am designing a shell and tube heat exchanger with the following process characteristics:

-Tube Side: Gas Refrigerant
-Shell Side: Fresh Water

I get a constraint from general installation of my project to put "axial inlet nozzle" on tube side and I have a warning on HTRI software which is a copy/paste from TEMA:

"Consideration shall be give to the need for special devices to prevent erosion of the tube ends under the Following conditions:
- Use of axial inlet nozzle
- Liquid pv2 in excess of 6000 (8928)…."

Regarding the pv2 criteria, I am very far from this limit however I do get an axial inlet nozzle.

My question is quite simple, I don't get the requirement, which special device am I supposed to provide due to the fact I use axial inlet nozzle, if any ? Or is it just generic warning message?

Thanks in advance, I did not find any similar topic on internet.

 

[EdStainless]

What is the material of construction? What is the flow velocity in the tubes?
With an axial inlet it is likely that you will have very poor flow distribution unless you take some measures to 'spread it out'.
I have seen small HX like this where we plugged the outer two rows of tubes (25%) and the performance didn't change at all.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[Christine74]

Looks like a generic warning message to me. "Special devices to prevent erosion of the tube ends" probably refers to tube ferrules which protect the tube IDs from impingement and erosion for the first few diameters.


-Christine

 

[Compositepro]

I believe this is mainly referring to the use of a baffle plate so the inlet flow does not impinge directly onto the tube sheet.

 

[saplanti]

Could pv2 be a noise criteria that may indicate critical vibration on the tubes?

 

[saplanti]

The following std clause 5.5.1 has the criteria;

https://www.standard.no/pagefiles/1130/p-001r3.pdf

 

[saplanti]

I apologise, the std in the shorcut is for the process piping only, not for the heat exchangers.