# Pune University Previous Year Question Paper

## B.E. (Chemical) PROCESS DYNAMICS AND CONTROL

## (2008 Pattern) (Sem. – I)

Time :3 Hours] [Max. Marks :100

Instructions to the candidates:

** 1) **Answers to the two sections should be written in separate books.

** 2) **Neat diagrams must be drawn wherever necessary.

** 3) **Pigures to the right indicate full marks.

** 4) **Assume suitable data, if necessary.

SECTION – I

QI) a) Discuss the incentives for Chemical process control. [8]

b) Derive the Input-output model for CSTR. [8]

OR

Q2) a) Derive the transfer function of single tank liquid level system. Draw a suitable sketch. [8]

b) A thermometer showing steady state temperature of 30°C is suddenly immersed into a hot bath at 150°C. If the time constant of thermometer is 7 sec, determine the following : [8]

i) Thermometer reading after 7 sec.

ii) Time required to read 90°C on Thermometer.

iii) Time required for 90% response.

Q3) a) Derive the transfer function for damped vibrator. Comment on type of dynamic response of the system. [8]

b) Discuss the characteristics of underdamped response and plot the graph of overshoot and decay ratio versus damping factor t. [8]

OR

Q4) a) Define P, I 8 D controller and derive their transfer functions. Discuss their open loop and closed response with neat diagrams. [8]

b) A second order process with following transfer function is controlled by P controller. Assuming servo problem and neglecting the dynamics of final control element and measuring instrument i.e Gf(5) = Gm(s) = I; The open loop process is Gp(s)^{–} _{2} ^ [8]

Determine the following :

i) Closed loop transfer function.

ii) Order of response.

iii) Closed loop gain, time constant.

iv) Offset.

Q5) a) Define stability of the process and discuss the Routh-Hurwitz criteria. [6]

b) Draw the root locus diagram for the system with following transfer function: [IP]

Gp( s) – ——– ^{1}——–s( s +1)( s + 2)

OR

Q6) Define controller tuning and discuss the following tuning methods; [18]

a) Time integral performance criteria.

b) Reaction curve method.

c) Ziegler Nichols method.

SECTION – II

Q7) a) Sketch the Bode diagram for PD controller. [9]

b) Sketch the Nyquist diagram for PI controller. [9]

OR

Q8) a) Derive the response of general first order system to sinusoidal input.

Define amplitude and phage lag. [9]

b) Discuss the following : [9]

i) Dead Time system.

ii) Nyquist stability criteria.

iii) Gain margin 8 phase margin.

Q9) Draw a neat sketch and write short notes on : [16]

a) Inverse Response system.

b) Feed forward control 8 feedback control.

OR

QI 0) Draw a neat sketch and discuss in detail about : [IT]

a) Adaptive control.

b) Inferential control.

QII) Draw the instrumentation diagram for Adiabatic plug flow reactor control and discuss in detail about its functioning. [16]

OR

Q12) Write short notes on : [16]

a) PLC 8 SCADA systems.

b) Digital approximation of classical controllers.

c) Data Bus concept.

d) Role of digital computers in control.

Awesome totally free of charge{ hosting up until 3GB NAME