Modeling convective drying

To model convection drying both the heat transfer to the coated web and the mass transfer (qv) from the coatiag must be considered. The heat-transfer coefficient can be taken as proportional to the 0.78 power of the air velocity or to the 0.39 power of the pressure difference between the air in the plenum and the ambient pressure at the coatiag. The improvement in heat-transfer coefficients in dryers since the 1900s is shown in Figure 20. The mass-transfer coefficient for solvent to the air stream is proportional to the heat-transfer coefficient and is related to it by the Clulton-Colbum analogy... 

Convection Drying Modeling. Models of the drying process have been developed to estimate whether a particular coating can dry under the conditions of an available dryer. These models can be mn on desktop personal computers (see Computer technology). 

Ramaswamy, H.S. and van Nieuwenhuijzen, N.H. 2002. Evaluation and modelling of two-stage osmo-convective drying of apple slices. Dry. Technol 20, 651-667. 

Zhang GJ, McFarlane NA (1995) Sensitivity of climate simulations to the parametrization of cumulus convection in the CCC-GCM. Atmos Ocean 3 407 146 Zhang L, Moran MD, Makar PA, Brook JR, Gong S (2002) Modelling gaseous dry deposition in AURAMS a unified regional air-quality modelling system. Atmos Environ 36 537-560... 

ABSTRACT Internal temperature distribution and mass were measured during drying and pyrolysis of cylindrical samples of wood of 0, 14 and 44% moisture. A onedimensional model of drying and pyrolysis is modified to reflect the anisotropy of the wood. Inclusion of an instant axial convective mass flow is shown to reduce the time of conversion compared to simulations with no axial flow. This mass flow, contrary to a convective mass flow through a porous structure, is not in thermal equilibrium with the solid phase. The gas leaves at a lower temperature compared to the temperature of the solid phase and is thus neglected in the energy equation. 

Cay, A., Tarakcioglu, I., Hepbasli, A., 2010. Exergetic analysis of textile convective drying with stenters by subsystem models Part 2—parametric study on exergy analysis. Drying Technology An International Journal 28 (12), 1368—1376. 

K. Molnir, Investigation of batch convective drying of capillary pored materials bared on double-layer model, Thesis of Cand. Sc., Budapest, Hungary, 1978, pp. 113-130. 

In the following sections we show how to construct a suitable model of the process and how to solve it for a given case. We win show only deterministic models of convective drying. Models beyond this range are important but relatively less frequent in practice. 

Kechaou N., Roques M., 1990, A model for convective drying of nonporous shrinking spheres, IDS90, 1, 369-373. 

V. Strongin, I. Borde, A mathematical model of convective drying incorporating sorption isotherms, in A.S. Mnjnmdar (Ed.) Advances in Drying 1987, Hemisphere, New York, 1987, pp. 249-278. 

The use of such a detailed mechanistic picture of the pore structure in modeling the convective drying of paper is described by Harrman and Schultz [70]. The alternative approach is to consider the capillary-porous web as a continuum having equivalent thermodynamic properties to the pore system [71]. This approach has recently been described in detail by Lampinen and Ojala [72]. 

Harrman, M. and Schultz, S. 1990. Convective drying of paper calculated with a new model of the paper structure. Drying TechnoL, 8(4) 667-703. 

The denaturation kinetics of proteins during convective drying can generally be expressed by the first-order reaction kinetics model (Equation 49.5) (Skelte and Anthony, 1996 Oldfield et al., 1998 Haque et al., 2013b) ... 

The rate of convective drying depends on the temperature of the drying medium, its humidity, and fiow rate. In computer-simulated drying processes based on mathematical models, the temperature and humidity of the drying medium can be controlled directly, but the gas velocity is adjusted indirectly... 

Perre P. and Turner I.W., A complete coupled model of the combined microwave and convective drying of softwood in an oversized wavegnide. Proceedings of IDS 1996, Vol. A, 1996, pp. 183-194. 

Advanced Modeling of Convective Drying - Understanding Quality 211... 

Leonard, A., Crine, M., Jomaa, W., 2006. Modelling of the convective drying of resordnol-fonnaldehyde resins influence of the drying conditions on the induced stress tensor. Proceeding of 15 International Drying Symposium (IDS2006), Budapest, Vol. A, 273-278. 

Mayor, L., Sereno, A. M., 2004. Modelling shrinkage during convective drying of food materials a review. J. Food Eng. 61 373-386. 

Adhikari, B., Howes, T., Bhandari. B. R., Troung, V., 2003. Surface stickiness of drops of carbohydrate and organic acid solutions during convective drying Experiments and modeling. Drying Technol. 

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