Roles of additives and surface control in slurry atomization

Technical Report · Mon Jan 01 04:00:00 EST 1990

DOI:https://doi.org/10.2172/6306931· OSTI ID:6306931

Tsai, S C

This report focuses on the effects of interparticle forces on the rheology and airblast atomization of micronized coal water slurry (CWS). We found that the CWS flow behavior index is determined by the relative importance of the interparticle van der Waals attraction and the interparticle electrostatic repulsion. The former intensifies as the Hamaker constant increases and the interparticle distance reduces while the latter increases as the particle surface charge density increases. The interparticle attraction causes particle aggregation, which breaks down at high shear rates, and thus leads to slurry pseudoplastic behavior. In contrast, the interparticle repulsion prevents particle aggregation and thus leads to Newtonian behavior. Both atomized at low atomizing air pressures (less than 270 kPa) using twin-fluid jet atomizers of various distributor designs. We found that the atomized drop sizes of micronized coal water slurries substantially decrease as the atomizing air pressure exceeds a threshold value. The effects of coal volume fraction, coal particle surface charge, liquid composition and liquid viscosity on slurry atomization can be accounted for by their effects on slurry rheology. 26 refs.

• Research Organization: California State Univ., Long Beach, CA (USA). Dept. of Chemical Engineering
• Sponsoring Organization: DOE/FE
• DOE Contract Number: FG22-88PC88912
• OSTI ID: 6306931
• Report Number(s): DOE/PC/88912-T7; ON: DE91005461
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600* -- Coal
Lignite
& Peat-- Properties & Composition
ADDITIVES
ATOMIZATION
CARBONACEOUS MATERIALS
COAL
CORRELATIONS
DISPERSIONS
DOCUMENT TYPES
DROPLETS
ENERGY SOURCES
FOSSIL FUELS
FUEL SLURRIES
FUELS
HYDROGEN COMPOUNDS
MATERIALS
MATHEMATICAL MODELS
MIXTURES
OXYGEN COMPOUNDS
PARTICLES
PROGRESS REPORT
RHEOLOGY
SLURRIES
SUSPENSIONS
VAN DER WAALS FORCES
VISCOSITY
WATER