Premixed filtration combustion of micron and sub-micron particles in inert porous media: A theoretical analysis

Abstract

An analytical model for one-dimensional premixed filtration combustion of volatile fuel particles-air mixture is presented. It is presumed that fuel particles first vaporize and a gaseous fuel with definite chemical structure is formed, which is subsequently oxidized in the gas phase. Flame structure is considered in the three zones. In the preheating vaporization zone, the mixture is heated until it reaches ignition temperature. In the reaction zone, the combustible mixture burns and the post flame zone is occupied by the combustion products. The temperature and mass fraction profiles are obtained of gaseous fuel in these three zones at a semi-infinite inert porous media. Thereafter, the effects of various parameters such as gas velocity, porosity, fuel particles diameter, number density of fuel particles, and heat of chemical reaction on the temperature and mass fraction profiles are investigated.

Influence of Electrospinning Parameters on the Morphology of Electrospun Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Fibrous Membranes and Their Application as Potential Air Filtration Materials

“…A steady flow state in the membrane medium with a bead-on-string morphology is quite difficult to create, which also affects the diffusion kinetics of the aerosol particles [60,61]. According to the sieve effect, the filtration performance for three aerosol particle sizes through a membrane structure with bead-onstring fibers is suitable for trapping particles larger particles and unsuitable for filtering particles smaller than 2.5 µm [62,64]. The pore size and packing density of a fibrous structure are somewhat influenced by the bead-on-string morphology of the fiber.…”

Effects of surface morphology of electrospun polystyrene fiber on its air filtration performance

“…The presence of beads in a fibrous structure affects the pore size and packing density of the membrane to a large extent, and besides, it influences the filtration performance during particle removal from a gas stream as well. This is of utmost difficulty to achieve a stable slippage flow condition in the membrane made from beaded fibers, which also influence the diffusion of the aerosol particles [32]. Primarily depending on direct collection (sieve effect), the filtration performance for three sizes of aerosol particle of membrane made from beaded fibers is qualified for handling particles with larger size, however, incompetent in removing particles with size smaller than 2.5 mm.…”

Self-ignition of dust cloud in a hot gas

“…Several theoretical and experimental results of thermal convection and radiation heat transfer to and from dust clouds of organic and non-organic particles display that the particle size plays an important role in determining the temperature-time history of a particle and its ignition temperature. Smaller particle sizes enhance fast heating by conduction and convection from the hot gas as well as the effect of the external radiation, which might be emitted from the combustion zone [15][16][17][18][19][20][21][22][23][24][25]. The explosion characteristic parameters in all of these studies depend upon the type of dust material, the dust cloud state, the environmental conditions, explosion device type, and so on.…”