Particle circulation and solids transport in large bubbling fluidized beds. Progress report

Technical Report · Thu Apr 01 00:00:00 EST 1982

OSTI ID:6125642

Homsy, G M

We have undertaken a theoretical study of the possibility of the formation of plumes or channeling when coal particles volatilize upon introduction to a fluidized bed, Fitzgerald (1980). We have completed the analysis of the basic state of uniform flow and are currently completing a stability analysis. We have modified the continuum equations of fluidization, Homsy et al. (1980), to include the source of gas due to volatilization, which we assume to be uniformly distributed spatially. Simplifying these equations and solving leads to the prediction of a basic state analogous to the state of uniform fluidization found when no source is present within the medium. We are currently completing a stability analysis of this basic state which will give the critical volatilization rate above which the above simple basic state is unstable. Because of the experimental evidence of Jewett and Lawless (1981), who observed regularly spaced plume-like instabilities upon drying a bed of saturated silica gel, we are considering two-dimensional periodic disturbances. The analysis is similar to that given by Homsy, et al. (1980) and Medlin et al. (1974). We hope to determine the stability limits for this system shortly.

• Research Organization: Stanford Univ., CA (USA). Dept. of Chemical Engineering
• DOE Contract Number: FG22-80PC30244
• OSTI ID: 6125642
• Report Number(s): DOE/PC/30244-T4; ON: DE85008523
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
FLUIDIZED BED
FLUID MECHANICS
BUBBLES
COAL
DEVOLATILIZATION
FLUIDIZATION
FLUIDIZED-BED COMBUSTION
PARTICULATES
PLUMES
PROBES
RESEARCH PROGRAMS
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
COMBUSTION
ENERGY SOURCES
FOSSIL FUELS
FUELS
MATERIALS
MECHANICS
OXIDATION
PARTICLES
THERMOCHEMICAL PROCESSES
014000* - Coal
Lignite
& Peat- Combustion