Mechanisms of fouling, slagging, and corrosion by pulverized-coal combustion. Quarterly technical progress report No. 6, 1 January-1 April 1983

Technical Report · Sun May 01 04:00:00 EDT 1983

OSTI ID:6259167

Hsu, L L; Stetson, A R; Metcalfe, A G

A number of interesting phenomena have been identified that are believed to be significant to the understanding of fouling/slagging mechanisms. Fouling of boiler and high-temperature heat exchanger tubes by magnetite (Fe/sub 3/O/sub 4/) was found to be due to oxidation of this compound to Fe/sub 2/O/sub 3/ (hematite) as well as interparticle sintering of Fe/sub 2/O/sub 3/ particles. As deposition of Fe/sub 2/O/sub 3/ proceeds, the underlying oxides are converted to grey-colored defect Fe/sub 2/O/sub 3/ as a result of the lowered oxygen potential in the subscale region. Spheroidization of Fe/sub 2/O/sub 3/ was also observed in the deposit from the 1600/sup 0/F tube and it is believed that sphere formation could have occurred in the hot gas stream via liquid melt or on the tube surface via solid-state diffusion under the action of surface tension. In a series of experiments using ground glass powder (simulating coal ash), it was found that fouled glass deposits on the 2000/sup 0/F SiC tube were completely slagged, forming a surface layer of fused glass. At 1600/sup 0/F tube temperature (and lower) no slagging was observed. Instead, the glass particles had spheroidized (and possibly agglomerated) and these glass spheres were partially fused with adjacent spheres. The fused contact regions between glass spheres were rich in sulfur, sodium and silicon. 36 figures, 12 tables.

• Research Organization: Solar Turbines, Inc., San Diego, CA (USA)
• DOE Contract Number: AC22-81PC40272
• OSTI ID: 6259167
• Report Number(s): DOE/PC/40272-T3; ON: DE83013132
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
014000 -- Coal
Lignite
& Peat-- Combustion
42 ENGINEERING
421000* -- Engineering-- Combustion Systems
BOILERS
CHALCOGENIDES
CHEMICAL REACTIONS
COAL FINES
COMBUSTION
DATA
DEPOSITION
ELECTRON MICROSCOPY
EXPERIMENTAL DATA
FOULING
GLASS
HEAT EXCHANGERS
INFORMATION
IRON COMPOUNDS
IRON OXIDES
MICROSCOPY
NUMERICAL DATA
OXIDATION
OXIDES
OXYGEN COMPOUNDS
RESEARCH PROGRAMS
SCANNING ELECTRON MICROSCOPY
SIMULATION
SLAGS
SPECTRA
TEST FACILITIES
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
VERY HIGH TEMPERATURE
X-RAY SPECTRA