An automated controller1 has been developed that maintains sodium-to-phosphate congruency in industrial boilers. Possible control schemes were selected from common control algorithms with additional modifications added to optimize control potential. The two most promising controllers were tested on a 165 psig (1.14 MPa) package boiler, with the final control package field tested in a 900 psig (6.21 MPa) black liquor recovery boiler. This optimized control package uses a self-correcting computerized chemical feed system to produce accurate boiler chemical concentrations. Results show excellent phosphate control, with pH (which reflects congruency) maintained within ± 0.04 pH over 24 hr.

Subject
Acids, Recovery boilers, Pipeline integrity management, Acidity, Constants, Feedwater, Phosphates, Pumping, Solutions, Rectifiers, Sodium, Boilers, Steam
Keywords:
Control, Congruent, Coordinated, pH, Boiler, Phosphate, Sodium
© 1995 Association for Materials Protection and Performance (AMPP). All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of AMPP. Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
1995
Association for Materials Protection and Performance (AMPP)
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