(Question 13) (a) Make a preliminary mechanical design for the column. The following should be included in your design: (1) Column wall thickness (1) Selection and sizing of vessel heads (ii) Column supporting skirt The following should be included in your design analysis: (i) Internal pressure (ii) Wind loading (i) Dead weight of vessel and content (iv) Elastic stability A distillation column has the following specifications: Length of cylindrical section = 37m Internal diameter = 1.5 m Heads, standard ellipsoidal 50 sieve plates Nozzles: feed, at midpoint, 50 mm inside diameter vapor out, 0.7 m below top of cylindrical section, 250 mm inside diameter bottom product, center of vessel head, 50 mm inside diameter reflux return, 1.0 m below top of cylindrical section, 50 mm inside diameter Two 0.6 m diameter access ports (manholes) situated 1.0 m above the bottom and 1.5 m below the top of the column Support skirt height 2.5 m Access ladder with platforms Insulation, mineral wool, 50 mm thick Materials of construction: vessel stainless steel, unstabilized (304) nozzles as vessel skirt carbon steel, silicon killed Design pressure = 1250 kN/m2 Design temperature = 160 C Corrosion allowance 2 mm Note: 1. There is no significant loading from piping and external equipment 2. Earthquake loading can be ignored