Ceramic coating used on MWC furnace walls
- Southeastern Public Service Authority, Portsmouth, VA (United States)
- CETEK, Transfer, PA (United States)
Fire-side corrosion of Municipal Waste Combustor (MWC) furnace walls has been a significant problem for these units. This corrosion can take place quite rapidly. Within less than a year major tube failures have occurred. The corrosion mechanisms and history of various units have been well documented previously. The commonly used answer to this corrosion is use of Inconel 625 weld overlay. It is often applied after erection of units, because the corrosion or its location is unforeseen. Two major problems with the Inconel 625 weld overlay is its high initial cost and the subsequent maintenance due to imperfections in the overlay during its application. Now, a thin, ceramic coating has proven its ability to protect the carbon steel tubes and survive the furnace environment. As of April, 1995, it will have about 10 months of service at the SPSA operated MWC plant. Its cost is a fraction of Inconel 625 weld overlay. Since it forms a continuous coating there are very few imperfections in the coating. One key feature of the ceramic coating is its thermal expansion rate is similar to carbon steel. This eliminates flaking of the ceramic coating. A brief review of the SPSA/NNSY Steam/Power Plant operating characteristics is presented. Maps showing loss of metal (based on ultrasonic testing) in a number of units are presented. Then physical and chemical properties of the ceramic coating are discussed. The costs of various alternatives are compared. This ceramic coating will prove to save MWCs millions of dollars. It can be used to go over poor Inconel overlay work.
- OSTI ID:
- 500956
- Report Number(s):
- CONF-9504119--
- Country of Publication:
- United States
- Language:
- English
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