Chemical Engineering Answers

The transfer function for a P-D controller is

A. Kc(1+τD s)

B. Kc(1 +1/τD s)

C. Kc τD s

D. Kc/τD s

Answer: Option A

Time constant is the measure of

a. Response of the system

b. Dislocation of the system from the desired value. c. Adjustment of the system for a given disturbance in the output d. Describes the resistance of the system

Time constant is the measure of

a. Response of the system

b. Dislocation of the system from the desired value. c. Adjustment of the system for a given disturbance in the output d. Describes the resistance of the system

Which of the following control systems can be adopted for the pure capacitive process

a. Adaptive control system

b. Feed forward control systems c. Feed backward control systems

d. None of these

Draw the Bode plots for Proportional Integral Derivative controller, transportation lag and first order system.

The transfer function of the process, a measuring element and a control valve is given respectively byGp =4/4S+1,Gm=2/2S+1 and Gv=1.5/4S+1. A proportional controller with gain one is used. Find the steady state error for step change of magnitude 3 in the set point. Determine the stability of the process using Routh- Huwritz criteria. If unstable, find two roots that lie on the right hand side of imaginary axis.

Explain about Inverse response with an example,

A step change of magnitude 10 is introduced into the transfer function

Y(S)/X(S)= 4/(2S²+0.3S+0.5),

find the following

a. Percent overshoot.

b. Rise time

c.Maximum value of y(t)

d. Ultimate value of Y(t)

e. Period of oscillations.

Explain different time integral performance criteria and their applications.

Consider a control system with the open loop transfer function is Gol =Kc e^{-0.36S}/12S+1 the pre factor S in minutes and Kc, is the gain of the controller. The frequency for phase. margin of 30° is 4.04 rad/min; find the value of the gain of the controller for a gain margin of 2. °