Column / Tower Design – Wind, Seismic, Skirt

Column

Job ref Pressure unit Internal design pressure Design temperature °C Inside diameter mm Shell height mm, tangent to tangent Course height mm, plate width Skirt height mm Corrosion allowance mm Minimum shell plate mm, for handling and erection Heads

Material

Plate material Rm / Rp0.2 MPa, spec minimum

Allowable stress S at design temp MPa; blank = room value Elastic modulus MPa Joint efficiency E Steel density kg/m³

Internals and attachments

Number of trays Tray weight kg/m² of column area Liquid on each tray mm Bottom liquid level mm above bottom tangent Liquid specific gravity Insulation thickness / density mm, kg/m³

Platforms number, kg each

Ladder and cage kg per m Nozzles, piping, other % of shell weight

Wind IS 875-3 form; set for your code

Basic wind speed Vb m/s k1 (risk) × k3 (topography) Terrain k2 at 10 m / power law α k2 = c·(z/10)^α

Kd·Ka·Kc wind pressure factors Force coefficient Cf 0.7 smooth cylinder Gust factor G Extra width for ladder, pipes mm

Seismic

Horizontal coefficient Ah e.g. IS 1893: (Z/2)(I/R)(Sa/g)

Skirt and foundation

Skirt thickness mm, 0 = choose Bolt circle diameter mm Base ring outside / inside Ø mm

Number of anchor bolts multiple of 4 Bolt allowable tension MPa on stress area Concrete bearing allowable MPa