Mass and heat transfer mechanism in wood during radio frequency/vacuum drying and numerical analysis

Jia, Xiaoran; Zhao, Jun; Cai, Yingchun

doi:10.1007/s11676-016-0269-3

Cited by 4 publications

(2 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This indicates the temperature and water vapor concentration in the center of the sample increase as the electromagnetic energy continually converts to heat energy. This is due to the selective heating mechanism of RF heating: the larger moisture content results in a higher energy localization, which facilitates the drying process [ 14 ]. Moreover, since the speed of water migration from the inside to the surface of the sample was relatively stable, the variation of the evaporation speed was reflected on the concentration of water vapor.…”

Section: Resultsmentioning

confidence: 99%

“…Analyzing the combined effects would assist in fully understanding the RF drying mechanism and facilitating the drying process design. Jia et al [ 14 ] developed a one-dimensional mathematical model to describe the transport phenomena of wood during continuous RF combined with vacuum drying. Their study suggested that the dry zone traveled from the end to the center of the wood and the temperature within the wood decreased with water loss.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Radio Frequency Drying Behavior in Porous Media: A Case Study of Potato Cube with Computer Modeling

Xiang-qing

Liu

Zhang

et al. 2022

Foods

View full text Add to dashboard Cite

To study the mechanism of heat and mass transfer in porous food material and explore its coupling effect in radio frequency (RF) drying processes, experiments were conducted with potato cubes subjected to RF drying. COMSOL Multiphysics® package was used to establish a numerical model to simulate the heat and mass transfer process in the potato cube and solved with finite element method. Temperature history at the sample center and the heating pattern after drying was validated with experiment in a 27.12 MHz RF heating system. Results showed the simulation results were in agreement with experiments. Furthermore, the temperature distribution and water vapor concentration distribution were correspondent with water distribution in the sample after RF drying. The water concentration within the food volume was non-uniform with a higher water concentration than the corner, the maximum difference of which was 0.03 g·cm−3. The distribution of water vapor concentration in the sample was similar to that of water content distribution since a pressure gradient from center to corner allowed the mass transfer from the sample to the surrounding in the drying process. In general, the moisture distribution in the sample affected the temperature and water vapor concentration distribution since the dielectric properties of the sample were mainly dependent on its moisture content during a drying process. This study reveals the mechanism of RF drying of porous media and provides an effective approach for analyzing and optimizing the RF drying process.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%