Process Dynamics And Mathematical Models

General References Seborg, Edgar, and Mellichamp, Process Dynamics and Control, Wiley, New York, 1989 Marlin, Process Control, McGraw-Hill, New York, 1995 Ogunnaike and Ray, Process Dynamics Modeling and Control, Oxford University Press, New York, 1994 Smith and Corripio, Principles and Practices of Automatic Process Control, Wiley, New York, 1985 Open-Loop versus Closed-Loop Dynamics It is common in industry to manipulate coolant in a jacketed reactor in order to control conditions in the...

Flow Measurements

Flow, defined as volume per unit of time at specified temperature and pressure conditions, is generally measured by positive-displacement or rate meters. The term positive-displacement meter applies to a device in which the flow is divided into isolated measured volumes when the number of fillings of these volumes is counted in some man ner. The term rate meter applies to all types of flowmeters through which the material passes without being divided into isolated quantities. Movement of the...

Batch Versus Continuous Processes

General References Fisher, Batch Control Systems Design, Application, and Implementation, ISA, Research Triangle Park, North Carolina, 1990 Rosenof and Ghosh, Batch Process Automation, Van Nostrand Reinhold, New York, 1987. When categorizing process plants, the following two extremes can be identified 1. Commodity plants. These plants are custom-designed to produce large amounts of a single product (or a primary product plus one or more secondary products). An example is a chlorine plant, where...

Chemical Composition Analyzers

A number of composition analyzers used for process monitoring and control require chemical conversion of one or more sample components preceding quantitative measurement. These reactions include formation of suspended solids for turbidimetric measurement, formation of colored materials for colorimetric detection, selective oxidation or reduction for electrochemical measurement, and formation of electrolytes for measurement by electrical conductance. Some nonvolatile materials may be separated...

Electronic And Pneumatic Controllers

Electronic Controllers Almost all of the electronic process controllers used today are microprocessor-based devices. These processor-based controllers contain, or have access to, input output (I O) interface electronics that allow various types of signals to enter and leave the controller's processor. The controller, depending on its type, uses sufficient read-only-memory (ROM) and read write-accessible-memory (RAM) to perform the controller function. The resolution of the analog I O channels...

Feedback Control System Characteristics

General References Shinskey, Feedback Controllers for the Process Industries, McGraw-Hill, New York, 1994 Seborg, Edgar, and Mellichamp, Process Dynamics and Control, Wiley, New York, 1989. FIG. 8-23 Both load regulation and setpoint response require high gains for the feedback controller. FIG. 8-23 Both load regulation and setpoint response require high gains for the feedback controller. There are two objectives in applying feedback control regulating the controlled variable at set point...