Solution:
Thickness of shell required for internal pressure:
(Allowable stress of shell material a design temperature = 98.1 MN/m2 )
The shell thickness observed to be small compared to diameter for rest of calculation following dimension will be used = Do = Di = (Di +t) = 2.5 m
Axial stress due to pressure: 
Axial stress due to dead weights: 
Assume constant thickness of shell,
W insulation = weight of insulation for a length of X meters =
Wliq = wt of liquid supported for a distance X from tap
No. of trays = 
Liquid wt on the trays are calculated on the basis of water and 0.070 m depth.
weight of top head = 7.5 × 10-3 MN
weight of ladder = 3.65 × 10-4 (X) MN
weight of trays = 
Hence, Wa = wt of attachments = 
Stress due to wind load: 