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

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.

2013 ◽  
Vol 58 (3) ◽  
pp. 919-922 ◽  
Author(s):  
K. Granat ◽  
B. Opyd ◽  
D. Nowak ◽  
M. Stachowicz ◽  
G. Jaworski

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.


2020 ◽  
Vol 9 (1) ◽  
pp. 119-130
Author(s):  
Kaihui Cui ◽  
Tianqi Liao ◽  
Chen Qiu ◽  
Hua Chen ◽  
Junwen Zhou

AbstractThis paper aims to investigate the heating behaviors of Y-TZP arrays under microwave irradiation. In this study, a three-dimensional numerical model of the microwave heating system was developed by COMSOL Multiphysics software. The numerical model was verified by microwave heating experiment, and the average root means square errors (RMSE) between the simulation and experimental data also confirmed the reliability of the model. The varying position and arrays of materials were applied to predict and visualize the three-dimensional distribution of the electromagnetic field and temperature during the microwave heating process. The results show that the temperature field distribution in microwave cavity was highly sensitive to the dielectric materials, the arrangement of the Y-TZP array interfered with the distribution of standing waves. The results can serve as references for the study to design and optimize the ceramic’s application in terms of microwave heating.


2020 ◽  
Vol 863 ◽  
pp. 97-102
Author(s):  
Huynh Duc Thuan ◽  
Tran Anh Son ◽  
Pham Son Minh

In this paper, an induction heating system was applied to the heating stage in the injection molding process. Through simulation and experiment, the heating process was estimated by the temperature distribution and the heating rate. In the simulation, the mold temperature was increased from 30°C to 180°C in 9 s. Therefore, the heating rate was higher than 16°C/s, which represents a positive result in the field of mold heating. Additionally, the temperature distribution revealed that the higher temperature is concentrated on the gate area, while the outside of the mold cavity is at a lower temperature. The same parameters were applied to both the experiment and the simulation, and the results were in good agreement.


Processes ◽  
2018 ◽  
Vol 6 (9) ◽  
pp. 142 ◽  
Author(s):  
Weiquan Ma ◽  
Tao Hong ◽  
Tian Xie ◽  
Fengxia Wang ◽  
Bin Luo ◽  
...  

Oleic acid needs to be heated when it is utilized for biodiesel production, but, as a low-loss solution, oleic acid is difficult to heat by microwave. An efficient heating method for oleic acid is designed. A high loss material porous media is placed in a quartz tube, and a microwave directly heats the porous medium of the high loss material. The oleic acid flows through the pores of porous media so that the oleic acid exchanges heat during this process and rapid heating of oleic acid is achieved. A coupling model, based on the finite element method, is used to analyze the microwave heating process. The multiphysics model is based on a single mode cavity operating at 2450 MHz. An elaborate experimental system is developed to validate the multiphysics model through temperature measurements carried out for different flow velocities of oleic acid and different microwave power levels. The computational results are in good agreement with the experimental data. Based on the validated model, the effects of different sizes, porosities, and materials on microwave heating efficiency are analyzed.


Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 146 ◽  
Author(s):  
Haopeng Wang ◽  
Yue Zhang ◽  
Yi Zhang ◽  
Shuyin Feng ◽  
Guoyang Lu ◽  
...  

Microwave heating is an encouraging heating technology for the maintenance, recycling, and deicing of asphalt pavement. To investigate the microwave heating properties of asphalt mixture, laboratory tests and numerical simulations were done and compared. Two types of Stone Mastic Asphalt (SMA) mixture samples (with basalt aggregates and steel slag aggregates) were heated using a microwave oven for different times. Numerical simulation models of microwave heating of asphalt mixture were developed with finite element software COMSOL Multiphysics. The main thermal and electromagnetic properties of asphalt mixture, served as the model input parameters, were measured through a series of laboratory tests. Both laboratory-measured and numerical simulated surface temperatures were recorded and analyzed. Results show that the replacement of basalt aggregates with steel slag aggregates can significantly increase the microwave heating efficiency of asphalt mixture. Numerical simulation results have a good correlation with laboratory test results. It is feasible to use the developed model coupling electromagnetic waves with heat transfer to simulate the microwave heating process of asphalt mixture.


2018 ◽  
Vol 15 (1) ◽  
pp. 47-55
Author(s):  
Xuebing Li ◽  
Haifen Yang ◽  
Ning Wang ◽  
Tijian Sun ◽  
Wei Bian ◽  
...  

Background: Morin has many pharmacological functions including antioxidant, anticancer, anti-inflammatory, and antibacterial effects. It is commonly used in the treatment of antiviral infection, gastropathy, coronary heart disease and hepatitis B in clinic. However, researches have shown that morin is likely to show prooxidative effects on the cells when the amount of treatment is at high dose, leading to the decrease of intracellular ATP levels and the increase of necrosis process. Therefore, it is necessary to determine the concentration of morin in biologic samples. Method: Novel water-soluble and green nitrogen and sulfur co-doped carbon dots (NSCDs) were prepared by a microwave heating process with citric acid and L-cysteine. The fluorescence spectra were collected at an excitation wavelength of 350 nm when solutions of NSCDs were mixed with various concentrations of morin. Results: The as-prepared NSCDs were characterized by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The fluorescence intensity of NSCDs decreased significantly with the increase of morin concentration. The fluorescence intensity of NSCDs displayed a linear response to morin in the concentration 0.10-30 μM with a low detection limit of 56 nM. The proposed fluorescent probe was applied to analysis of morin in human body fluids with recoveries of 98.0-102%. Conclusion: NSCDs were prepared by a microwave heating process. The present analytical method is sensitive to morin. The quenching process between NSCDs and morin is attributed to the static quenching. In addition, the cellular toxicity on HeLa cells indicated that the as-prepared NSCDs fluorescent probe does not show obvious cytotoxicity in cell imaging. Our proposed method possibly opens up a rapid and nontoxic way for preparing heteroatom doped carbon dots with a broad application prospect.


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

Author(s):  
Hong-Seok Park ◽  
Xuan-Phuong Dang

This paper presents potential approaches that increase the energy efficiency of an in-line induction heating system for forging of an automotive crankshaft. Both heat loss reduction and optimization of process parameters are proposed scientifically in order to minimize the energy consumption and the temperature deviation in the workpiece. We applied the numerical multiobjective optimization method in conjunction with the design of experiment (DOE), mathematical approximation with metamodel, nondominated sorting genetic algorithm (GA), and engineering data mining. The results show that using the insulating covers reduces heat by an amount equivalent to 9% of the energy stored in the heated workpiece, and approximately 5.8% of the energy can be saved by process parameter optimization.


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