FLUE GASES DUCTS: ROUND vs RECTANGULAR

[roker]

Hello,

Where can I find guidelines or can someone advise on the issue of the duct shape, in our case the cross section of the required duct is 3.25 sq.meter.

regards,
roker

 

[MikeHalloran]

Square or rectangular duct uses more material per unit length. By the time you're finished reinforcing it, a _lot_ more material.

In a rectangular duct, it's slightly easier to fabricate a short radius bend ... not that a short radius is a good idea.

I wonder if anyone made flues rectangular before the appearance of baghouses, which tend to be rectangular for more defensible reasons.

Transitions, e.g. from rectangular baghouse apertures to round ducts, are a little harder to manufacture than simple joints. They're harder to draw, too, which may be the real reason rectangular flue ducts first appeared.



Mike Halloran
Pembroke Pines, FL, USA

 

[metengr]

http://www.cuservices.net/duct_design.html

https://www.asce.org/bookstore/book...tations-Industrial-Applications/dp/0784401128

As you can see from the above, I would suggest some research on the subject. There is much more information.

 

[doct9960]

roker,

Also check for guidelines from the environmental agency in your jurisdiction, like EPA (

http://www.epa.gov)

in the US.

Here's an interesting read...

http://rmb-consulting.com/san/rectduct.htm

 

[cycguy]

For design of a rectangular duct use ASME, Section 8,Div.1, Appendix 13. The rectangular duct will need reinforcing depending on the pressure.