Physical and mathematical models of heat and moisture transport in a tunnel dryer

Abstract

The optimization of a drying process within the brick production procedure is of a great importance as it represents another developmental step towards highly efficient bricks with minimized impact on the environment. Therefore, this paper aims at an analysis of heat and moisture transport processes in a tunnel dryer and propose methods and models for computational modelling of processes in brick blocks during drying. The procedure involves modelling of transport processes in the bricks as well as modelling of fluid dynamics in the dryer. In order to make the two-phase modelling approach functional, coupling of all parts is essential within each time step of computations. In case of CFO modelling, it is necessary to define boundary conditions which are defined besides dryer dimensions, drying scheme, air inlets/outlets or brick pallets dimensions also by conservative interface fluxes on the bricks in order to accommodate release or consumption of heat as well as moisture evaporation due to drying. Analogously, the boundary conditions within this modelling are determined based on results of CFO modelling. The temperature and moisture distribution is used to set the surface boundary conditions, the heat and moisture transfer coefficients are set based on flow velocities. This paper represents a starting point for the future works on optimization the brick production process.