Overview of the DOE studies of recovery boiler floor tube cracking
- and others
Cracking of the stainless steel layer of coextruded 304L/SA210 recovery boiler floor tubes has been observed in an increasing number of black liquor recovery boilers. Because failure of such tubes is a serious safety concern as well as an economic issue, this project was initiated with the objective of identifying alternate materials or process changes that would prevent tube cracking. Tensile stresses are essential for the most likely failure mechanisms, i.e., fatigue or stress corrosion cracking, therefore stresses were measured at room temperature and modeling was used to predict stresses under operating conditions. Laboratory studies have identified conditions under which composite tubes crack due to thermal fatigue and stress corrosion. Floor tube temperature measurements have defined the magnitude and frequency of temperature fluctuations experienced by such tubes, and smelt corrosion studies have measured the degradation rate when molten smelt comes in contact with tubes. Based on these observations, certain materials appear more likely to resist cracking and certain process changes should help avoid conditions that cause composite tube cracking.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 672108
- Report Number(s):
- ORNL/CP-97302; CONF-980647-; ON: DE98004897; BR: ED1902000; TRN: AHC2DT07%%268
- Resource Relation:
- Conference: TAPPI - 1998 international chemical recovery conference, Tampa, FL (United States), 1-4 Jun 1998; Other Information: PBD: Mar 1998
- Country of Publication:
- United States
- Language:
- English
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