Heat and mass transfer during drying of granular products – simulation with convective and conductive boundary conditions. (English) Zbl 0968.76085
Summary: Numerical simulation of grain drying in a vertical cylindrical bed has been carried out under specific boundary conditions: evaporation, which occurs with forced air flowing through the bed, is intensified with a conductive heat flux from the wall. We consider two mathematical models of heat and mass transfer through granular medium: two-temperature model (non-local temperature equilibrium model: NLTEModel), and one-temperature model (local temperature equilibrium model: LTEModel). The air-grain mass transfer is expressed with a drying rate equation outcome from experiments. The solution of the equations set is done by using a finite volume method. Different effects, such as the effect of porosity variation on energy and mass transport, are discussed, and sensitivity to external conditions is determined. Finally, we examine the validity of local thermal assumption.
MSC:
76S05 | Flows in porous media; filtration; seepage |
76R05 | Forced convection |
76T30 | Three or more component flows |
80A20 | Heat and mass transfer, heat flow (MSC2010) |
76T25 | Granular flows |