An advanced heat exchanger has been designed for high temperature, highly corrosive applications. The design is based on the use of ceramic composite components to assure long life and reliability. A prototype unit has been built and will be field tested in a waste incinerator facility.

Candidate ceramic composite materials were exposed to the incinerator flue gases in order to predict their performance. Test samples consisted of continuous fiber reinforced ceramic composites (CFCCs), and a particulate silicon carbide (SiCp) reinforced alumina composite.

Alumina matrix CFCCs in some cases exhibited much better strength retention than in earlier tests. Zirconia matrix CFCCs, on the other hand, showed lower strength retention; fiber damage due to corrosion was observed only in the zirconia matrix materials. Fiber damage was observed in both types of fibers investigated: high purity alumina and alumina-20% zirconia.

The SiCp reinforced alumina composite showed excellent strength retention following the test. This was due to the suppression of the formation of aluminum oxide nodules on the surface. In earlier tests oxide nodules had acted as stress concentrators, causing substantial strength loss.

Subject
Coatings, Materials, Metal surfaces, Tubes, Zirconium, Corrosion testing, Silicon carbide, Flue gas, Incinerators, Composites, Fibers, Ceramics, Corrosion probes
Keywords:
Ceramic composite, heat exchanger, corrosion, ceramic fiber, incinerator
© 1994 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).
1994
Association for Materials Protection and Performance (AMPP)
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