Study on stability of electric field in multimode microwave heating cavity

2016 ◽  
Vol 50 (2) ◽  
pp. 321-330 ◽  
Author(s):  
Z.-M. Tang ◽  
K.-M. Huang ◽  
Y.-H. Liao ◽  
T. Hong ◽  
H.-C. Zhu
Keyword(s):  
Electric Field ◽  
Microwave Heating

scholarly journals Research on Electromagnetic Sensitivity Properties of Sodium Chloride during Microwave Heating

2020 ◽  
Vol 39 (1) ◽  
pp. 54-62
Author(s):  
Hua Chen ◽  
Junjiang Chen ◽  
Weijun Wang ◽  
Huan Lin
Keyword(s):  
Sodium Chloride ◽  
Electric Field ◽  
Water Content ◽  
Heating Rate ◽  
Microwave Heating ◽  
Resonant Cavity ◽  
Relative Dielectric Constant ◽  
Heating System ◽  
Heating Process ◽  
Heating Efficiency

AbstractThe multimode resonant cavity is the most common cavity. The material often shows on selective heating performance during the heating process due to the effect of microwave heating having a closely relationship with the electromagnetism parameters. This paper is based on finite difference time domain method (FDTD) to establish the electromagnetic-thermal model. The electromagnetic sensitivity property parameters of sodium chloride including relative dielectric constant, loss angle tangent and water content of sodium chloride is studied during the heating and drying process. The heating rate and the electric field distribution of sodium chloride, at the different water content, were simulated with the electromagnetic characteristic parameters changing. The results show that with the electromagnetic sensitivity property parameters varying, the electric field strength, heating rate and steady-state temperature of the heating material will all have a variety in the cavity. Some measures are proposed to improve the heating efficiency and ensure the stability of the microwave heating system in the industrial application.

Numerical Simulation of Microwave Heating for Soot Oxidation

2014 ◽  
Vol 564 ◽  
pp. 256-262 ◽  
Author(s):  
Haitham B. Al-Wakeel ◽  
Z.A. Abdul Karim ◽  
Hussain Hamoud Al-Kayiem
Keyword(s):  
Electric Field ◽  
Microwave Heating ◽  
Penetration Depth ◽  
Soot Oxidation ◽  
Small Samples ◽  
Front Face ◽  
Maximum Temperature ◽  
Ignition Point ◽  
Transient Thermal ◽  
The Mathematical Model

This paper presents the simulation of microwave heating by coupling high frequency electromagnetic with transient heat transfer using finite element method edge base of ANSYS software. Helmholtz equation of electric field has been formulated from Maxwell equations to predict electric field and the mathematical model of transient thermal analysis was included. Three cases have been examined numerically to investigate electric field, dissipated heat, temperature distribution and weight loss of soot at operation frequency 2.45 GHz. The simulation results showed that heat is generated from inside to outside of soot. The temperature at penetration depth increased till ignition point and after further heating, maximum temperature was attained, followed by temperature decreases due to mass transport. Maximum electric field was found to be located on the front face for the small samples with dimensions less than penetration depth. The predicted results have been compared with experimental results which show the validity of the simulation.

Studies of Nonthermal Effects During Intense Microwave Heating of Crystalline Solids

1992 ◽  
Vol 269 ◽  
Author(s):  
John H. Booske ◽  
Reid F. Cooper ◽  
Leon McCaughan ◽  
Sam Freeman ◽  
Binshen Meng
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Microwave Heating ◽  
Microwave Absorption ◽  
Relative Magnitude ◽  
Material Surface ◽  
Absorption Coefficients ◽  
Ion Energy ◽  
Absorbing Materials ◽  
Theoretical Analyses

ABSTRACTReports of enhanced sintering rates associated with microwave heating may be due to nonthermal lattice fluctuation statistics. Recent theoretical analyses reviewed in this paper confirm the feasibility of this phenomenon for a wide variety of situations involving very different microwave absorption mechanisms. For materials with weak microwave absorption coefficients, the effect is expected to be uniformly distributed throughout the volume. For strongly absorbing materials, however, the effect is expected to be concentrated near the material surface, with a characteristic exponential penetration depth of Lnt ∼ 10 - 100 μm. An “observable” nonthermal effect depends on the relative magnitude of the microwave electric field strength |E| and the lattice ion energy relaxation rate γ with the most pronounced effects occurring for larger values of |E| and smaller values of γ.

Analytical Investigation of Microwave Heating

2010 ◽  
Author(s):  
Mohammad Robiul Hossan ◽  
Prashanta Dutta
Keyword(s):  
Temperature Distribution ◽  
Analytical Solution ◽  
Electric Field ◽  
Microwave Heating ◽  
Analytical Investigation ◽  
The Body ◽  
Limiting Factor ◽  
Cylindrical Shape ◽  
Closed Form Analytical Solution ◽  
Poynting Theorem

Microwave heating is very popular and widely used for warming up foodstuffs quickly. However, non-uniform temperature distribution obtained from microwave heating is a major limiting factor for its application outside the food industry. The rapid decay of incident microwave and the potential existence of standing wave are responsible for non-uniform heating. Therefore, it is important to study the coupling between microwave propagation and energy transfer in the system to predict temperature distribution. In this paper, a closed-form analytical solution is presented to predict the temperature distribution within a cylindrical shape foodstuff under microwave heating by solving an unsteady energy equation. The simplified Maxwell’s equation is solved for electric field distribution; Poynting theorem is employed to calculate microwave power from electric field. The results show that the temperature in the body is very sensitive to size and time. This analytical solution can be used to investigate the influence of various parameters on microwave heating.

scholarly journals New Approach for the Prediction of the Electric Field Distribution in Multimode Microwave-Heating Applicators With Mode Stirrers

2004 ◽  
Vol 40 (3) ◽  
pp. 1672-1678 ◽  
Author(s):  
P. Plaza-Gonzalez ◽  
J. Monzo-Cabrera ◽  
J.M. Catala-Civera ◽  
D. Sanchez-Hernandez
Keyword(s):  
Electric Field ◽  
Microwave Heating ◽  
Field Distribution ◽  
Electric Field Distribution ◽  
New Approach
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