OCR Text |
Show 2.1.17 or a particle in a packed bed). The proposed calculation method for devolatilization is also applicable for burning particles, when the boundary condition (11) is replaced by a boundary condition that takes into account the heat transfer to the surface from the surrounding flame. The model (and the equilibrium curves) have been programmed for computation. When the state of the (inert) atmosphere (temperature, radiation temperature, gas velocity) changes arbitrarily with time, the following transients can be calculated with computer - the transient temperature distribution inside the particle (plate, cylinder, sphere or a semi-infinite solid) - the transient moisture distribution (dry/wet basis) inside the particle - the transient mass of the particle (and the transient dry mass and water mass of the particle) - the transient mass flow rate of steam and volatiles from the particle) - the transient density distribution inside the particle - the local generation of steam and volatiles inside the particle Later the model will be developed to include the burning of volatiles around the particle and to estimate the transient species distribution in the off-gas (in inert atmosphere). |