An Analysis of Temperature Distributions in Microwave Heating of Foods with Non-Uniform Dielectric Properties

2004 ◽  
Vol 37 (7) ◽  
pp. 858-862 ◽  
Author(s):  
Noboru Sakai ◽  
Cong Wang ◽  
Shigeru Toba ◽  
Manabu Watanabe
Keyword(s):  
Dielectric Properties ◽  
Microwave Heating ◽  
Temperature Distributions

Technique for Measuring the Dielectric Properties of Minerals as a Function of Temperature and Density at Microwave Heating Frequencies

1990 ◽  
Vol 189 ◽  
Author(s):  
Johanna B. Salsman
Keyword(s):  
Dielectric Properties ◽  
Microwave Heating ◽  
Research Effort ◽  
Coaxial Line ◽  
Dielectric Constants ◽  
Dielectric Constant And Loss ◽  
Electrical Conductivities ◽  
Natural Density ◽  
The Common ◽  
Method Of Measurement

ABSTRACTAs part of the research effort on investigating the effects of microwave energy absorption on the chemical and physical properties of minerals and ores, the Bureau of Mines, Tuscaloosa Research Center has developed a technique of measuring the dielectric constant and loss tangent of minerals at the common microwave heating frequencies. The objective was to establish a reliable data base to aid in predicting the effects of microwave heating on minerals.In this phase of microwave research, the Bureau measured the dielectric properties of powdered minerals with medium to high electrical conductivities (a ≥ 0.02 Mho/m) in the frequency range of 300 MHz to 3 GHz using an open-ended coaxial line probe connected to an HP 8753A network analyzer. Since the minerals were prepared as powders, techniques were used to relate the measured dielectric properties of the powdered minerals to the dielectric properties of the mineral at Its theoretical or natural density. Also, these measurements were performed as a function of temperature, from 25° to 325° C.The measured values of the dielectric constants and loss tangents using this method were accurate within ±5 percent. This report describes the method of measurement and discusses the results of the Bureau's investigations into dielectric properties of minerals.

Dielectric Relaxation Process and Microwave Heating Mechanism in ε-Caprolactone as a Function of Frequency and Temperature

2014 ◽  
Vol 931-932 ◽  
pp. 205-209 ◽  
Author(s):  
Mohd Johari Kamaruddin ◽  
Anwar Johari ◽  
Ramli Mat ◽  
Tuan Amran Tuan Abdullah ◽  
Siti Hamidah Mohd Setapar ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Microwave Heating ◽  
Processing System ◽  
Debye Model ◽  
Microwave Energy ◽  
Dielectric Relaxation Process ◽  
Microwave Assisted ◽  
Heating Mechanism ◽  
Wide Range ◽  
Properties Of Materials

Dielectric properties of materials play a significant role in design of microwave assisted processing system. This paper is focused on the dielectric properties of ε-caprolactone (ε-cap) which is the monomer for the biodegradable polymer, Poly (ε-caprolactone) (PCL). The dielectric properties of ε-cap were measured across a wide range of frequencies (0.1 GHz5.0 GHz) and temperatures (20-150oC). Then the measured dielectric properties data was modelled using Debye model in order to relate quantitatively the dielectric properties to microwave heating mechanisms. The analysis carried out gives a clear picture of interaction of ε-cap with microwave energy and its heating mechanism in microwave assisted polymerisation process. This study concluded that microwave heating mechanism of the ε-cap in the measured range may be dominated by the dipole reorientation.

Analysis of temperature distributions in Kamaboko during microwave heating

2005 ◽  
Vol 71 (2) ◽  
pp. 187-192 ◽  
Author(s):  
Weijie Mao ◽  
Manabu Watanabe ◽  
Noboru Sakai
Keyword(s):  
Microwave Heating ◽  
Temperature Distributions

Simulation of Hybrid Heating

1994 ◽  
Vol 347 ◽  
Author(s):  
Daniel J. Skamser ◽  
D. Lynn Johnson
Keyword(s):  
Dielectric Properties ◽  
Microwave Heating ◽  
Microwave Field ◽  
Alumina Fiber ◽  
Hybrid Heating ◽  
Fiber Preforms

ABSTRACTA hybrid microwave heating arrangement used to heat alumina fiber preforms has been modeled to determine what conditions are needed to create significant differences in temperature across the specimen while still maintaining control of the temperature. The model assumes a uniform external microwave field and dielectric properties for the specimen as a function of temperature. The results of the model show that significant differences in temperature can be attained while still having control of the temperature at the center. Experiments show that the temperature at the center can be held at 1000°C and still allow a difference in temperature of 50°C between the center and the surface of the specimen to be present.

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