Theoretical and experimental studies on flame propagation and quenching of powdered fuels

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:6202043

Kim, Se-Won

A unique combustion test facility was designed and built for the purpose of measuring quenching distance, flammability limit and burning velocity of powdered fuels. A uniform density particulate cloud of aluminum or coal particles was generated at atmospheric pressure between two parallel plate electrodes utilizing the concept of an electrostatic driven suspension. A spark discharge was used to ignite the particle/air mixture, and the burning velocity was measured using high speed movies. The results show that generally the quenching distance, lean flammability limit, and minimum quenching distance increase as the particle size increases while quenching distance of coal decreases as the volatile content is increased. The burning velocity of both aluminum and coal was found to increase as the particle size was decreased. Batch aluminum particles from the can were tested to have a higher quenching distance compared to mono-sized particles of same mean diameter. The quenching distance of irregular aluminum was found to be lower than that of spherical aluminum particles smaller than 25 {mu}m in mean diameter, but the reverse was true for particles larger than 27 {mu}m. A one dimensional time-dependent homogeneous model of flame propagation of aluminum powder was developed using a Lagrangian transformation and finite difference method. The effects of particle size and particle concentration on burning velocity of aluminum powder was investigated with this model. Also a one dimensional model of flame propagation of coal powder (BYU, FLAME code) was tested based on a heterogeneous model of time-dependent non-linear partial differential equations.

• Research Organization: Iowa State Univ. of Science and Technology, Ames, IA (USA)
• OSTI ID: 6202043
• Resource Relation: Other Information: Thesis (Ph.D)
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALUMINIUM
FLAME PROPAGATION
COAL
AEROSOLS
ATMOSPHERIC PRESSURE
DESIGN
ELECTRODES
EQUATIONS
FINITE DIFFERENCE METHOD
FLAMMABILITY
IGNITION
ONE-DIMENSIONAL CALCULATIONS
PARTICLE SIZE
POWDERS
QUANTITY RATIO
QUENCHING
SHAPE
TEST FACILITIES
TIME DEPENDENCE
ULTRAHIGH-SPEED PHOTOGRAPHY
VOLATILE MATTER
CARBONACEOUS MATERIALS
COLLOIDS
COMBUSTION PROPERTIES
DISPERSIONS
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
ITERATIVE METHODS
MATERIALS
MATTER
METALS
NUMERICAL SOLUTION
PHOTOGRAPHY
SIZE
SOLS
014000* - Coal
Lignite
& Peat- Combustion
400800 - Combustion
Pyrolysis
& High-Temperature Chemistry