Equipment Design and Optimization - Plant Design and Economics - Chemical Engineering Previous Year Questions

Minimum input required to calculate the ‘blank diameter’ for a torispherical head is

A vertical cylindrical tank with a flat roof and bottom is to be constructed for storing 150 m³ of ethylene glycol. The cost of material and fabrication for the tank wall is Rs 6000 per m² and the same for the roof and the tank bottom are Rs 2000 and Rs 4000 per m², respectively. The cost of accessories, piping and instruments can be taken as 10% of the cost of the wall. 10% of the volume of the tank needs to be kept free as vapour space above the liquid storage. What is the optimum diameter (in m) for the tank?

The total cost (C_T) of an equipment in terms of the operating variables x and y is
\[ C_T = 2x + \frac{12000}{xy} + y + 5 \]
The optimal value of C_T, rounded to 1 decimal place, is ______.

A viscous liquid is pumped through a pipe network in a chemical plant.
The annual pumping cost per unit length of pipe is given by
C_pump = 48.13 q² μ / D⁴
The annual cost of the installed piping system per unit length of pipe is given by
C_piping = 45.92D
Here, D is the inner diameter of the pipe in meter, q is the volumetric flowrate of the liquid in m³ s⁻¹ and μ is the viscosity of the liquid in Pa.s.
If the viscosity of the liquid is 20 × 10⁻³ Pa.s and the volumetric flow rate of the liquid is 10⁻³ m³ s⁻¹, the economic inner diameter of the pipe is _______ meter (round off to 3 decimal places).