8HW Computer Aided Design - April 2000
Part A (20 x 2 = 40 Marks)
- Explain briefly the elements of a digital computer
- What are the different operating systems used in computer?
- What does Hierarchy mean in computer operations?
- What are the various input devices?
- Explain the term 'assembly language'
- State the various thermodynamic properties of a binary mixture
- When do you use steam distillation?
- Explain briefly the use of vapor-liquid equilibrium data
- Explain how do you estimate the density of a gas mixture
- Define the term entropy and enthalpy
- Graphically represent how temperature profile varies with distance in a
counter-current heat exchanger
- Define the term 'relative volatility' and indicate its importance in the
design of distillation columns
- Explain the term limiting liquid to gas ratio in a stripper
- Define the term logarithmic mean temperature
- State the advantage of using backward feed multiple effect evaporators
over forward feed units
- Explain briefly how minimum reflux ratio is determined in a distillation
- State the assumptions made in McCabe-Thiele method of estimating the
number of stages in a distillation column
- Define the term 'number of transfer units' and 'height of transfer units'
in a packed column absorber
- Suggest what type of absorber do you use for absorbing hydrochloric acid
- State the factors to be considered in the selection of a solvent for the
given extraction operation
Part B (5 x 12 = 60 Marks)
- (a) Explain in detail the Central Processing Unit. Write in detail how it
(b) Explain in detail the different components of a computer and state the
different chemical engineering software available
- (a) Develop an algorithm for the determination of vapor liquid equilibrium
data for non-ideal mixtures and to check the thermodynamic consistency
(b) Write the program for estimating the molal volume of an alcohol vapor
using Redlich-Kwong equation of state
- (a) A warm stream enters a heat exchanger at 200oC and is
cooled to 100oC. The cooling stream enters at 20oC and
is heated to 95oC. Write a program to calculate the mean
temperature difference for the following cases: (i) Countercurrent flow, (ii)
1-2 multi-pass and 1-2 cross flow
(b) Develop an algorithm for the determination of overall heat transfer
coefficient for a shell and tube heat exchanger.
- (a) Explain briefly the industrial applications of evaporators and write a
program for the design of a multiple effect evaporator. Indicate clearly the
different steps involved in the mass and energy balances
(b) Develop an algorithm for the design of a short tube calendria
- (a) Write a program to estimate the number of stages for absorption of a
dilute gas stream using Kremser-Brown equation.
(b) Develop an algorithm for the determination of height of a packed column
for a distillation column.