Firmation of condensed combustion products in dust flames of metals: Coagulation stage

Abstract

The coagulation dynamics of condensed products of vapor-phase or gas-phase combustion of gas mixtures of microdispersed metal particles in dust laminar flame considered taking into account the ionization of the combustion zone due to additives of electronegative and electropositive atoms and due to thermionic emission. The influence of the degree of ionization of a monodisperse coagulating aerosol and the charge of the particles on the coagulation rate constant is studied. It is shown that the rate of coagulation of the aerosol is most significantly affected by the Coulomb interaction of like-charged condensed-phase particles, which, under certain conditions, leads to an early stop of this stage in the condensation of combustion products. Ionization of the coagulating particles gives rise to a dependence of the size of primary particles of combustion products on the environmental parameters affecting their electric charge, and can be used for targeted control of the degree of dispersion of the combustion products.