Modelling of far-infrared irradiation in paddy drying process

Theoretical and experimental drying of a cylindrical sample by applying hot air and infrared radiation in an inert medium fluidized bed

“…The predicted average moisture content showed good agreement with the experimental data. However, at the end stages of drying with combined infrared and hot air heating‚ the proposed model did marginally underestimate the moisture contents of the drying sample (Hatamipour and Mowla, 2003;Meeso, 2006). The surface temperatures measured in the experiment at different instants and calculated by the model are illustrated Figure 7.…”

“…The change in the rotational state of atoms and molecules is related to wavelengths above 100 micrometers in the region of microwaves. Infrared radiation causes the molecules to vibrate and heat is generated due to the friction that results from their vibration (Naret Meeso, 2006;Ginzburg 1969). Ranjan (1995) assumed that agricultural seeds are a blur material in thermal modeling of infrared and radiation energy.…”

Modeling Moisture Movement in Rice

“…Srikiateden & Roberts (2007) reviewed these mechanisms as reported in different solid foods and described the mathematical equations involved in such mechanisms. Despite the uncertainty about the actual mechanism of moisture movement, most researchers (Mannapperuma, 1975;Steffe & Singh, 1980a;Aguerre et al, 1982;Lague, 1990;Sarker et al 1994;Igathinathane & Chattopadhyay, 1999a;Meeso et al, 2007;Prakash & Pan, 2009) have described moisture movement in rice drying by Fick's laws of diffusion. Using such diffusion mechanism, Lu & Siebenmorgen (1992) have modeled moisture movement during adsorption and desorption processes.…”

“…In addition to average kernel moisture, such models also describe moisture distribution within the rice kernels that can be used to estimate moisture gradients and fissuring in rice. Some studies (Lague, 1990;Yang et al, 2002;Meeso et al, 2007;Prakash & Pan, 2009) have also considered heat transport within the kernel in their models. Different rice varieties have their different physical, thermal and hygroscopic properties.…”

“…instant moisture equilibration of kernel surface to the ambient environment) and Newmann boundary condition. Mannappeeruma (1975), Steffe & Singh (1980a), Lu & Siebenmorgen (1992) and Meeso et al (2007) considered Dirichlet boundary condition and assumed kernel surface moisture M s (kg water/kg dry matter) to have the same moisture as the equilibrium moisture content M e (kg water/kg dry matter) of rice in the ambient environmental conditions. This can be written as: Sarker et al (1994) and Yang et al (2002) equated the outward moving moisture flux to moisture taken away by convective air and obtained the following Newmann boundary condition:…”