PROBLEM 1

A dry pharmaceutical evaporator uses a proportional controller to optimize the vacuum in

the evaporator. The coupled vacuum valve-process transfer function is:

0.5/(s + 1)(0.5s + 1)

The transmitter transfer function is: s+3/6

a) Derive the characteristic equation for the closed-loop control system to a change in

the set point = 1.

b) Based on your characteristic equation from a) is the system stable for. (1) Kc = 9, (ii)

Ke=11, () Ke 13?

c) Simulate your answers in b).