Three generic-type non-chromate chemical treatments based upon zinc and/or polyphosphate together with organic scale control agents are currently employed in open recirculating, fresh water cooling systems at ten Esso refineries in Europe. These treatments control the fouling tendency of the cooling water and also protect carbon steel components from corrosion. In addition, specific copper corrosion inhibitors are used where copper-alloys are present while chlorination forms the basis for microbiological control with all treatments. In a well-designed and well-operated system with close control of cooling water chemistry and chemical inhibitor injection, all treatments effectively control corrosion, scaling and fouling to maintain process throughput and system operating reliability. In particular, pH/alkalinity control is critical with all treatments to avoid exceeding the treatments' scale control capability at high pH, and its corrosion inhibition capability at low pH. Oil ingress is the most common operating upset which can not only foul the system but can also interfere with corrosion inhibition and microbiological control.

Subject
Phosphonates, Chlorination, Acidity, Corrosion scales, Phosphates, Heat exchangers, Corrosion inhibitors, Cooling water, Zinc, Fouling, Scaling, Chemical treatment, Oil
© 1984 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).
1984
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.