Shell and tube heat exchanger - tube length

[StructuresDan]

Hi all,

I know it's a bit of a long shot but I thought I would ask.

I am coding up the initial sizing procedure described in section 3.1.4 of Hewitt's Heat Exchanger Design Handbook, "Approximate Sizing of Shell and Tube Heat Exchangers" in an Excel spreadsheet.

I've come to the point where I need to select the range of shell internal diameters and tube lengths for a given outside tube heat transfer area from Figure 2 (also contained in lots of other references I have found).

Rather than let my customer look up these values from the chart themselves I'd like to have my spreadsheet do it automatically hence I would need the data tables that these curves are based on or equations which have been fitted to the data. I'm sure that this has been done many times in the past and wanted to try and find a reference for this information before I went down the route of reading the data points and fitting some curves myself.

Can anyone help me out with this?

Many thanks

Dan

 

[cheute79]

Dan:

This is a bit outside my expertise, but when I have had custom shell and tube exchangers made, I have always found it easier, faster, cheaper (the big 3 drivers) to have the shell of standard pipe sizes, so for any shell of 12 to 36 inches, the "standard" internal diameters would be STD wall thickness (0.375 inch) x 2 (to capture the total metal cross section) less the diameter (which for 14 to 36 inch pipe is just that). For pipes of 12 inch and less, the OD is about 5/8 to 3/4 inch more than the nominal size, and wall thickness decreasing - but the list isn't that long that it couldn't be readily done in a spreadsheet.

As far as tube sheet length, I don't know of any such easy rule or practice. I tend to go with increments of 6 inches (150 mm), and a minimum length of 3X the diameter.

 

[abeltio]

Take a look at the TEMA Stds for std shell and tube lengths

saludos.
a.

 

[StructuresDan]

Hi,

Thanks for your comments. In the end I ended up digitising the figure using the GetData Graph Digitiser which is free from here:

http://www.getdata-graph-digitizer.com/

It's a great application and will be using it again if I need to and recommend it to you if you ever need to digitise data from scanned pictures.

Many thanks

Dan