Kinetics of drying

Fig. 12. Kinetics of drying and heating granulated aminoplasts with different agglomerating additives (samples 1 through 4) and changes in content of methylol groups...

The kinetics of dry-heat treatments is comparable to that of moist heat sterilization. The organisms that are considered to be representatives for dry-heat sterilization processes are spores of Bacillus subtilis var. nigerP ... 

The dry-heat destruction of endotoxins is complex and poorly understood. Most evidence has shown that destruction follows second-order kinetics with an initial high rate of destruction followed by a slower terminal rate. The kinetics of dry-heat destruction for lipopolysaccharide are expressed in terms of and D, for the initial and secondary first-order reaction rates, respectively. Previous research found that there was greater reduction in the dry-heat resistance of lipopolysaccharide in whole cells than that in the semipurified state. The value for the whole cells was found to be 1.6, and the value was 12. In the semipurified state, was 3.7 and was 29.4. Thus the rate of the destruction was two times faster when whole cells were used. ... 

Drying kinetics was represented by a diffusive model. The models were completed with water sorption equilibrium equation, expressions for product and moist air properties, correlations for convective heat and mass transfer coefficients, and the kinetics of drying and of the selected quality changes in the product as functions of water content and temperature (Di Scala and Crapiste, 2005). Experimental data were obtained from Di Scala and Crapiste (2005) and Roura et al. (2001). 

Sabarez, H., Price, W.E., Back, P.J., and Woolf, L.A. Modelling the kinetics of drying of d Agen plums Prunus domestica), Food Chem., 60, 371, 1997. 

Two main parameters are studied (1) the break-up time which is defined as the time which elapses from the moment when the radius of the thin film formed becomes constant (about 100 /cm) and the appearance of the first hole and (2) the kinetics of dry spot... 

The results concerned with the process of drying are usually expressed either in terms of kinetics of drying, i.e., of loss of liquid, or of profiles of concentration developed through the rubber with the subsequent change in dimension. 

The results are given by way of two figures Figure 7.12 for the kinetics of drying, where the ratio of the weight of liquid as a fraction of the weight of the rubber free from liquid is plotted as a function of time and Figure 7.13 where the profiles of... 

Jezowska, A. 1993. Kinetics of drying in a cyclically shifted spouted bed. Theme issue on spouted beds. Drying TechnoL, ll(2) 319-337. 

As seen from Equations 62.11 and 62.12, the strains and thus the stresses are strongly dependent on moisture content and temperature. So, in order to calculate these mechanical quantities, the kinetics of drying needs to be determined. The drying kinetics is described by the conpled system of differential equations developed on the basis of mass and energy balances and the rate equations for the heat and mass transfer. Assuming that the moisture in pore volnme of dried body consists of liquid (Z) and vapor (v), the local forms of mass balance equations for these constitnents read ... 

Recent studies have resulted in significant advances in the understanding of the thermodynamics of drying hygroscopic materials, kinetics of drying, evaporation... 

FIG. 8 Kinetics of drying of an irregular body containing water. Deformation and shrinkage occur due to the formation of voids or pores as water leaves the matrix during drying. 

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