The overflow line maintains a constant liquid volume in the tank.
Instrumentation: The range for all of the electronic signals is 4 to 20mA.
Current-to-pressure transducer: The 1/P transducer acts as a linear device with negligible dynamics. The output signal changes from 3 to 15 psi when the input signal changes full-scale from 4 to 20mA.
Control valve: The behavior of the control valve can be approximated by a first-order transfer function with a time constant of 5 a (i.e. 0.0833 min). A 1.2-psi change in the signal to the control valve produces a 300 kg/min change in w2.
Composition measurement: The zero and span of the coin- position transmitter for the exit composition are 0 and 0.50 (mass fraction) respectively. A one-minute time delay is associated with the measurement.
Feedback controller: Initially consider a standard PT controller tuned using the IMC relations in Table 12.1. Justify your choice of tc.