DOI: 10.1615/ICHMT.1986.AdvCourseHighTempEq
ISBN Print: 978-0-89116-568-2
Ceramics for High Temperature Heat Exchangers
RÉSUMÉ
Use of engineering ceramic materials in heat exchanger construction could, in principle, permit designs capable of operating with temperatures well above the 950°C limit for available alloys and, thus in a gas flow mode, able to remove more of the available heat from the waste gas stream. This is possible because of the lower high temperature creep and better oxidation and corrosion resistance of selected ceramic materials compared with metals. Several types of silicon carbide are very promising ceramics for tubular heat exchanger application; other potential candidate materials are Si3N4, Al2O3, mullite, MAS and LAS. Ceramic structures offer promise for use in constructing high temperature heat exchangers if thermo-mechanical stresses,leakage, fouling, and fabrication costs can be adequately controlled. The working environments encountered by these heat exchanger materials, depending on the application, include:
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- Gaseous corrosion environments : carburizing, sulphidizing, chlorine, etc. either in oxidizing or reducing mode,
- Liquid corrosion environments : coal ash slags, alkali sulphates, alkali vanadates etc.