The Study on the Uniform Drying of Microwave Heating System with Multiple Waveguides

2013 ◽  
Vol 329 ◽  
pp. 219-223 ◽  
Author(s):  
Woo Seong Che ◽  
Jun Ma
Keyword(s):  
Electromagnetic Field ◽  
Objective Function ◽  
Microwave Heating ◽  
Heating System ◽  
Temperature Uniformity ◽  
Uniform Temperature ◽  
Heating Method ◽  
Uniform Electromagnetic Field ◽  
Parallel Type

Microwave heating is an important heating method that is widely used in industries. Developing a uniform electromagnetic field inside the cavities might be a crucial challenge to avoid localized overheating. The uniformity of the electromagnetic field is governed by the configurations of the waveguides. To better understand the design of cavities, the simulations are carried out. This paper discussed the comparison in result between two configurations of waveguides and introduced the use of uniformity objective function in order to evaluate the temperature uniformity. As conclusion, it was found out that using the perpendicular type of waveguides had better uniform temperature than using the parallel type.

Research on Electromagnetic Field Optimization for Microwave Hot Recycling of Asphalt Mixtures

2012 ◽  
Vol 462 ◽  
pp. 575-579 ◽  
Author(s):  
Tong Sheng Sun ◽  
Zhi Sheng Zhang ◽  
Ling Feng Tang
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Energy Distribution ◽  
Microwave Heating ◽  
Field Experiments ◽  
Heating System ◽  
Asphalt Mixtures ◽  
Electromagnetic Propagation ◽  
Recycled Asphalt ◽  
Electromagnetic Model

In order to investigate the law of electromagnetic propagation within microwave heating system, Maxwell's equations are applied to build electromagnetic model of recycled asphalt mixtures. Energy distribution of electromagnetic field in asphalt mixtures is researched based on the Poynting theory. The optimization model of electromagnetic field and structure are established by building relationship between electric field and magnetic field. Experiments of microwave heating allochroic silicagel are performed, which demonstrates the accuracy of electromagnetic field optimization.

scholarly journals The Effects of Absorbing Materials on the Homogeneity of Composite Heating by Microwave Radiation

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7362
Author(s):  
Betime Nuhiji ◽  
Matthew P. Bower ◽  
William A. E. Proud ◽  
Steven J. Burpo ◽  
Richard J. Day ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Temperature Distribution ◽  
Electromagnetic Radiation ◽  
Heat Distribution ◽  
Temperature Uniformity ◽  
Geometric Complexity ◽  
Uniform Temperature ◽  
Better Regulation ◽  
Absorbing Materials ◽  
Complexity Increase

When cured in a microwave, flat thin composite panels can experience even heat distribution throughout the laminate. However, as load and geometric complexity increase, the electromagnetic field and resulting heat distribution is altered, making it difficult to cure the composite homogeneously. Materials that absorb and/or reflect incident electromagnetic radiation have the potential to influence how the field behaves, and therefore to tailor and improve the uniformity of heat distribution. In this study, an absorber was applied to a composite with non-uniform geometry to increase heating in the location which had previously been the coldest position, transforming it into the hottest. Although this result overshot the desired outcome of temperature uniformity, it shows the potential of absorbing materials to radically change the temperature distribution, demonstrating that with better regulation of the absorbing effect, a uniform temperature distribution is possible even in non-uniform composite geometries.

A Microwave Heating System for Improving Temperature Uniformity in Heated Tissue*

1979 ◽  
Vol 14 (2) ◽  
pp. 145-149 ◽  
Author(s):  
J.W. Hand ◽  
Susan P. Hume ◽  
J.E. Robinson ◽  
Julia C.L. Marigold ◽  
S.B. Field
Keyword(s):  
Microwave Heating ◽  
Heating System ◽  
Temperature Uniformity

Usefulness of Foundry Tooling Materials in Microwave Heating Process

2013 ◽  
Vol 58 (3) ◽  
pp. 919-922 ◽  
Author(s):  
K. Granat ◽  
B. Opyd ◽  
D. Nowak ◽  
M. Stachowicz ◽  
G. Jaworski
Keyword(s):  
Electromagnetic Field ◽  
Microwave Heating ◽  
Loss Factor ◽  
Perturbation Technique ◽  
Resonant Cavity ◽  
Precise Determination ◽  
Heating Process ◽  
Basic Criterion ◽  
Measurement Results ◽  
Heating Technology

Abstract The paper describes preliminary examinations on establishing usefulness criteria of foundry tooling materials in the microwave heating technology. Presented are measurement results of permittivity and loss tangent that determine behaviour of the materials in electromagnetic field. The measurements were carried-out in a waveguide resonant cavity that permits precise determination the above-mentioned parameters by perturbation technique. Examined were five different materials designed for use in foundry tooling. Determined was the loss factor that permits evaluating usefulness of materials in microwave heating technology. It was demonstrated that the selected plastics meet the basic criterion that is transparency for electromagnetic radiation.

Comparative study of conventional and microwave heating of polyacrylonitrile-based fibres

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Guozhen Zhao ◽  
Jianhua Liu ◽  
Lei Xu ◽  
Shenghui Guo
Keyword(s):  
Microwave Heating ◽  
Surface Defects ◽  
Energy Dispersive Spectrometer ◽  
Xrd Analysis ◽  
Economic Benefits ◽  
Heating Time ◽  
Oxidation Temperature ◽  
Conventional Heating ◽  
Heating Method ◽  
Molecular Arrangement

Abstract The effects of the conventional heating method and the microwave heating method on polyacrylonitrile-based fibres in the temperature range of 180–280 °C were investigated. Fourier transform infrared spectroscopy, X-ray wide-angle scattering, Raman spectroscopy, energy-dispersive spectrometer, scanning electron microscopy and bulk density were used to characterise the properties of the samples. Results show that the microwave heating method can shorten the pre-oxidation time, reduce pre-oxidation temperature and reduce the number of surface defects. The pre-oxidised fibres obtained by the microwave heating method exhibit not only good crystallite size but also a smooth surface. Atomic morphology and molecular arrangement are orderly inside the fibre. The FT-IR spectrum shows that the oxidation reaction occurs at 220 °C, and the CI value of PAN fibers stabilised by microwave heating is the larger than the fibers stabilised by conventional heating. XRD analysis shows that fibers stabilised by microwave heating have low stack domains. The SEM and Raman spectra indicate that hydrogen peroxide can improve the surface finish of the fibers and reduce defects. Microwave heating can reduce the pre-oxidation temperature by about 20 °C and shorten the heating time. The economic benefits of using this method are significantly improved.

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.

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