Steel Stack Design
Steel Stack Design
(OP)
Hi all,
I am designing a laterally braced, unlined steel stack and need a little help. The stack is to be a constant diameter of 4.37' with a height of 87.67'. It is to be made of 1/4" plate and will not be lined. Please see attached screen shot for layout of bracing. The top two braces are for lateral support only whereas the bottom brace location can be used for both lateral support and vertical support if need be. I only have two pieces of reference material and they are The Structural Engineering Handbook and the ASME STS-1 - 2006. Where I am struggling, is with the multiple brace points and how that effects the design as far as crosswind loads and vortex shedding is concerned. Do I determine an equivalent static force perpendicular to the wind direction accounting for the vortex shedding of each segment or eliminate this all together? Would this be the same for ovaling? Does anybody know of or have any other reference material that may help me? As always, any and all help/guidance is greatly appreciated.
Thanks,
Shaylon
I am designing a laterally braced, unlined steel stack and need a little help. The stack is to be a constant diameter of 4.37' with a height of 87.67'. It is to be made of 1/4" plate and will not be lined. Please see attached screen shot for layout of bracing. The top two braces are for lateral support only whereas the bottom brace location can be used for both lateral support and vertical support if need be. I only have two pieces of reference material and they are The Structural Engineering Handbook and the ASME STS-1 - 2006. Where I am struggling, is with the multiple brace points and how that effects the design as far as crosswind loads and vortex shedding is concerned. Do I determine an equivalent static force perpendicular to the wind direction accounting for the vortex shedding of each segment or eliminate this all together? Would this be the same for ovaling? Does anybody know of or have any other reference material that may help me? As always, any and all help/guidance is greatly appreciated.
Thanks,
Shaylon






RE: Steel Stack Design
RE: Steel Stack Design
With the tube braced like it is, I wouldn’t think there would be an issue…..but with it being such a small diameter, checking it is probably a good idea.
RE: Steel Stack Design
With the tube braced like it is, I wouldn’t think there would be an issue.....but with it being such a small diameter, checking it is probably a good idea.
RE: Steel Stack Design
RE: Steel Stack Design
Quite true. I've seen similar outer skins on [tall, cylindrical] process equipment.
RE: Steel Stack Design
RE: Steel Stack Design
namanges
RE: Steel Stack Design
Thanks,
Shaylon
RE: Steel Stack Design
http://towernx.com/downloads/Technical_Manual_MP_B...
Indian Standard
http://xa.yimg.com/kq/groups/21948400/449224631/na...
CICIND
http://www.cicind.org/EN/member/pdf/MCSteelComA.pd...
RE: Steel Stack Design
BRITISH STANDARD BS EN 1993-1-6:2007
Eurocode 3 — Design of steel structures
Part 1-6: Strength and Stability of Shell Structures
BRITISH STANDARD BS EN 1993-3-2:2006
Eurocode 3 — Design of steel structures
Part 3-2: Towers, masts and chimneys
Chimneys
RE: Steel Stack Design
My previous post stating that I have come up with a solid design has turned out to be false. Some assumptions I was told to make were not correct. Anyhow, I am having trouble interpreting the ASME STS-1-2006 standard as far as VORTEX SHEDDING goes and whether or not helical strakes should be used. If you can remember, I have a stack that is braced at three points. Please see attached screenshot. I have determined that stiffeners are required to combat ovalling at a spacing of 3D which is twice as far as what Gaylord suggests in the Structural Engineering Handbook. Can anybody shed some light on how to proceed with this design?
Thanks,
Shaylon