What should be the apparent viscosity target of a coal-water slurry fuel for combustion?

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:324768

Pisupati, S V; Morrison, J L; Scaroni, A W ^[1]

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1. Pennsylvania State Univ., University Park, PA (United States)

The rheological properties of a coal water slurry fuel (CWSF) affect its handling, atomization, and combustion behavior. The flow behavior and apparent viscosity are two rheological properties that are often specified by the end user. A pseudoplastic (shear thinning) flow behavior is preferred since there is a decrease in the apparent viscosity as the fuel is pumped to, and then atomized into the boiler. Specifying an apparent viscosity target for the CWSF is more problematic since there are often competing forces to maximize the solids loading of the fuel while minimizing the apparent viscosity. The apparent viscosity is a function of the particle size distribution of the coal, the solids loading of the CWSF, the physical and chemical properties of the coal, and the additive package used to prepare the CWSF. Targeting an apparent viscosity is necessary during the formulation and production of a CWSF. The trade off between maximizing the solids loading in order to increase the BTU content and maintaining an acceptable apparent viscosity to ensure good atomization behavior is not well established. In order to better define this trade-off, an investigation was carried out to examine the interrelationship between solids loading, apparent viscosity, atomization behavior, and the combustion performance of a CWSF. The CWSF was prepared in a continuous ball mill and isolated in a storage tank. Small batches of CWSF were taken from the storage tank and then diluted to determine how the changes in the CWSF`s rheology and solids loading affected it`s atomization and combustion behavior.

• DOE Contract Number: FC22-92PC92162
• OSTI ID: 324768
• Report Number(s): CONF-970931--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ATOMIZATION
COAL
COAL PREPARATION
COMBUSTION PROPERTIES
FUEL SLURRIES
LOADING RATE
RHEOLOGY
VISCOSITY
WATER