Astragalus slice is one species of stem and root medicinal herb with the widely curative effects, also a special and typical plant porous material, and the drying operation is one of important processing technologies in its storage and further practical application. This paper characterizes the microstructure of Astragalus slices dried by microwave technique at 200 W by using scanning electronic microscope (SEM). The study also compares Astragalus slices dried by microwave with those untreated and discusses the drying mechanism. Result shows that as compared to the untreated sample, the microwave dried sample behaves much shorter drying time with more and larger pore and open structure on the surface layer of matrix, but without significant change about the distribution status of cytoplasm inside parenchyma cells. Further analysis suggests that the vapor diffusion is the dominant mode of moisture transfer inside matrix during the microwave drying process of sample, resulting in the well-preserved structures of sample, including parenchyma cell and trachea. This is also helpful for maintaining the distribution status of cytoplasm, particularly avoiding the agglomeration of biological macro-molecular, which is benefit to improving the permeability of moisture transfer path, leading to the rapidly dehydration of moisture. This work seems to be helpful for developing the optimized drying technology of plant porous material focused on micro-mechanism and the quality of dried products.
Skip Nav Destination
ASME 2009 Heat Transfer Summer Conference collocated with the InterPACK09 and 3rd Energy Sustainability Conferences
July 19–23, 2009
San Francisco, California, USA
Conference Sponsors:
- Heat Transfer Division
ISBN:
978-0-7918-4358-1
PROCEEDINGS PAPER
Mechanism on Mass Transfer in Micro-Scale During the Microwave Drying of Plant Porous Materials Available to Purchase
Junhong Yang,
Junhong Yang
Tianjin University, Tianjin, China
Search for other works by this author on:
Qianqian Di,
Qianqian Di
Tianjin University, Tianjin, China
Search for other works by this author on:
Liqiu Wang
Liqiu Wang
The University of Hong Kong, Hong Kong, China
Search for other works by this author on:
Junhong Yang
Tianjin University, Tianjin, China
Qianqian Di
Tianjin University, Tianjin, China
Jun Zhao
Tianjin University, Tianjin, China
Liqiu Wang
The University of Hong Kong, Hong Kong, China
Paper No:
HT2009-88389, pp. 667-674; 8 pages
Published Online:
March 12, 2010
Citation
Yang, J, Di, Q, Zhao, J, & Wang, L. "Mechanism on Mass Transfer in Micro-Scale During the Microwave Drying of Plant Porous Materials." Proceedings of the ASME 2009 Heat Transfer Summer Conference collocated with the InterPACK09 and 3rd Energy Sustainability Conferences. Volume 3: Combustion, Fire and Reacting Flow; Heat Transfer in Multiphase Systems; Heat Transfer in Transport Phenomena in Manufacturing and Materials Processing; Heat and Mass Transfer in Biotechnology; Low Temperature Heat Transfer; Environmental Heat Transfer; Heat Transfer Education; Visualization of Heat Transfer. San Francisco, California, USA. July 19–23, 2009. pp. 667-674. ASME. https://doi.org/10.1115/HT2009-88389
Download citation file:
13
Views
Related Proceedings Papers
Related Articles
The Effects of Sublimation-Condensation Region on Heat and Mass Transfer During Microwave Freeze Drying
J. Heat Transfer (August,1998)
Influence of Irradiation Time, Particle Sizes, and Initial Moisture Content During Microwave Drying of Multi-Layered Capillary Porous Materials
J. Heat Transfer (February,2002)
An Analytical Solution and Sensitivity Study of Sublimation-Dehydration Within a Porous Medium With Volumetric Heating
J. Heat Transfer (August,1994)
Related Chapters
Numerical Study on Coupled Heat and Mass Transfer in Potato during Hot-Air Drying
Inaugural US-EU-China Thermophysics Conference-Renewable Energy 2009 (UECTC 2009 Proceedings)
Numerical Simulation of the Heating Behavior of Zirconium Oxide in Microwave High-Temperature Reactor
Inaugural US-EU-China Thermophysics Conference-Renewable Energy 2009 (UECTC 2009 Proceedings)
Introduction
Thermal Management of Telecommunications Equipment