Process Control

Why to control? History of the control. The role of a chemical and/or biochemical engineers in a team that designs control for a plant or unit operation

 Feed back and feed forward control. Their comparison

 The „languages” of the control science, theory, differential equation – time domain; trandfer function, Laplace transformation, Laplace domain; frequency function, frequency domain, Nyquist diagram, Bode diagram.

 Single input single output (SISO) systems

 Typical mathematical models in the process control study.

Typical test signals. Their correlation, Transfer function, frequency function

Proportional unit, dead time element, first order unit. Their differential equation, transfer functions, responses to typical test signals. Frequency functions.

Examples for first order elements. Thermometer, heat exchanger, buffer vessel, chemical reactor (CSTR)

Determination of the parameters of a first order unit, time constant and process gain. Methods for the determination of the time constant.

Second order elements. Examples, differential equation, transfer function, responses to typical test signals. Demonstration of the effect of elements in series. Damping coefficient, classification of second order units.

Higher order elements, their representation.

Integral unit, derivative unit.

Controllers, Switch on-off controller, P,I, D controllers. Characterization f the P, I and D controllers, their models, features,  functions, area of application.

Controller tuning methods.

Basic controls, flow control, level control, transmitters, case studies,

Actuators, control valves, characteristics.

Control of unit operations.

Control of evaporators, pairing of manipulated and controlled variables.

Control of rectification columns. Control structure, pairing at different kinds of rectification, sensor location, manipulated variables