Achieving benefits using traditional control technologies

Abstract

The basic techniques of cascade and feedforward control are described together with the types of process problem to which they are suited. Their use is illustrated with simple examples. Among these are three-element level control, heat exchanger control and distillation control. The latter example quotes the magnitude of the benefits which can be achieved in practice. Other areas where traditional techniques can be used are given. Amongst these are override controls with an illustration from distillation control, 'valve position control' with an example from a fired heater system and the use of calculated variables demonstrated by heat input control.