Feedforward control of a distillation column
No Thumbnail Available
Authors
Meeting name
Sponsors
Date
Journal Title
Format
Thesis
Subject
Abstract
"The primary objective of any distillation system is to deliver products of consistent quality. Since the recovery time of industrial sized columns is generally very long, distillation columns controlled only by feedback can produce large amount of poor quality material before control action is initiated. Feedforward control helps to overcome this disadvantage. Because corrective action is taken before the error occurs, it is hoped that no error will exist for propagation around the loop. The disadvantages of feedforward control (3) are: (A) The disturbance must be detected. If it can not be measured, feedforward control can not be used. (B) A model of how the disturbance and manipulated variables will affect the process must be known. This study discusses a potentially useful feedforward control scheme. In this case, the reflux flow rate is the manipulated variable and the feed composition is the disturbed variable as illustrated in Figure 1-3. Because the computer is not yet available for experimental use, a mathematical simulation of the distillation column is used. The simulation program developed by Mr. Jerome D. Cole (4) provides a detailed and relatively accurate model of the distillation column. In order to develop feedforward control, a linearly approximated transfer function is found for small deviations from a typical steady-state value. These transfer functions were determined using a program CSTRIP (5). This thesis presents a determination of the transfer functions to be used in the feedforward control system. It compares the results for dynamic and steady-state feedforward control algorithms for both a step disturbance and a sinusoidal disturbance. In addition, the effect of sampling times for a digital system is studied for the sinusoidal case."--Page 2.
Table of Contents
PubMed ID
Degree
M.S.
Thesis Department
Rights
OpenAccess.
License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License.