Question
Instrumentation and Process Control Question on P&ID equipment symbols
Consider the control structure for the overhead section of a distillation column shown in the figure. The composition controller (CC) controls the heavy key impurity in the distillate by adjusting the setpoint of the reflux flow controller in a cascade arrangement. The sign of the controller gain for the pressure controller (PC) and that for the composition controller (CC) are, respectively,
A
negative, negative
B
negative, positive
C
positive, positive
D
positive, negative
Answer
positive, negative
Explanation
Solution
The correct option is (D) :positive, negative