Process Dynamics and Control 4th. Edition by Dale E. Seborg, Thomas F. Edgar, Duncan A. Mellichamp, Francis J. Doyle | 9781119285915 | 1119285917 | Holooly

Process Dynamics and Control

138 SOLVED PROBLEMS

Question: 18.6

A 2 × 2 process has the following steady-state gain matrix: k = [ 1 K12 10 1 ] (18-62) Calculate the determinant, RGA, eigenvalues, and singular values of K. Use K12 = 0 as the base case; then recalculate the matrix properties for a small change, K12 = 0.1.

Verified Answer:

By inspection, the determinant for the base case i...

Question: 12.5

A blending system with a measurement time delay can be modeled as G(s) = 1.54e^−1.07s / 5.93s + 1 Calculate PI controller settings using the following tuning relations: (a) IMC (τc = τ/3) (b) IMC (τc = θ) (c) ITAE (disturbance) (d) AMIGO

Verified Answer:

The calculated PI controller settings are Kc ...

Question: 12.10

A control loop exhibits excessively oscillatory behavior even though there have been no recent equipment, instrument, or personnel changes. Suggest a general troubleshooting strategy to diagnose the problem.

Verified Answer:

Oscillatory control loops are often the result of ...

Question: 13.2

A conventional distillation column with a single feed stream and two product streams is shown in Fig. 13.2. The feed conditions are disturbance variables. Determine the control degrees of freedom NFC and identify potential MVs and CVs.

Verified Answer:

For a typical distillation column, five input vari...

Question: 17.5

A digital controller is used to control the pressure in a tank by adjusting a purge stream. The control valve is air-to-open, and the process model has been identified as G= GvGpGm= (-20e^-s)/(5s+1) The gain is dimensionless, and the time constant and time delay are in minutes. The sampling period

Verified Answer:

First adjust the process time delay for each contr...

Question: 10.3

A feed mixture of two components is separated in a distillation column, as shown in Fig. 10.8 where F, D, and B are molar flow rates and z, y, and x are mole fractions of the more volatile component. Assume that the three flow rates are constant: F=4 mol/min, D=B=2 mol/min. During normal operation

Verified Answer:

The error of closure for the steady-state componen...

Question: 10.4

A flow control loop consists of a differential pressure flow sensor/transmitter, a digital PI controller, an I/P transducer,a control valve, and a valve positioner. Determine the reliability, failure rate, and MTBF for this control loop.

Verified Answer:

Using the failure rate data in Table 10.1, the cal...

Question: 19.2

A free radical reaction involving nitration of decane is carried out in two sequential reactor stages, each of which operates like a continuous stirred-tank reactor (CSTR). Decane and nitrate (as nitric acid) in varying amounts (Di and Ni, respectively) are added to each reactor stage,as shown in

Verified Answer:

The six steps described earlier are used to formul...

Question: 21.1

A manufacturing plant produces 10,000 plastic bottles per day. Because the product is inexpensive and the plant operation is normally satisfactory, it is not economically feasible to inspect every bottle. Instead, a sample of n bottles is randomly selected and inspected each day. These n items are

Verified Answer:

The

\bar{x}

control chart in Fig. 2...

Question: F.3

A mass fraction of an impurity X varies randomly between 0.3 and 0.5 with a uniform probability distribution: f(x) = 1/0.2 Determine its population mean and population standard deviation.

Verified Answer:

Substituting f(x) into Eq. F-7 gives

\mu _{...

Loading...