Experimental and numerical thermal analysis for direct microwave heating of silicon carbide

Abstract

A comparison between experiment and numerical simulation of microwave heating of a parallelepipedic silicon carbide (SiC) sample is presented. Using a-2.45 GHz single-mode cavity, the evolution of the surface temperature is first experimentally studied for different orientations of the sample. A finite element analysis of this electromagnetic-thermal coupled problem is then conducted with the COMSOL Multiphysics ® software. Despite the different approximations of our model, a good agreement between experimental and numerical results is found, confirming that the heating of SiC depends only on the electric field. The effect of sample orientations and the cavity length on heating is also highlighted and analyzed.

Rapid microwave sintering of centimetric zirconia: Scalability and electromagnetic‐thermal‐fluid‐dynamic simulation

“…In order to optimize the heating, these susceptors are placed in the electrical field/wave vector plane. In this way, the microwave dissipation is optimal and this configuration is less sensitive to the offsets of the maximum electric field location 48–50 . The pyrometer was placed under the heated sample to provide a measure minimizing the influence of the radiation coming from the susceptor.…”

“…In this way, the microwave dissipation is optimal and this configuration is less sensitive to the offsets of the maximum electric field location. [48][49][50] The pyrometer was placed under the heated sample to provide a measure minimizing the influence of the radiation coming from the susceptor. In addition, this configuration allows measuring the displacement of the specimen during the sintering by a displacement sensor placed on the top (magnescale DS812SLR purchased from sensel measurements, with measure length 12 mm, resolution 1 μm).…”

Critical assessment of methods for measurement of temperature profiles and heat load history in microwave heating processes—A review

“…Pyrometers do not require complex optical and scanning equipment, which reduces investment costs. In research and industrial applications, pyrometers are widely established in microwave applications, especially in fields that go beyond food use and that, therefore, provide additional information on calibration (Croquesel et al., 2021; Ghorbel et al., 2021; Lapshinov, 2021) and plant setup, such as realization of microwave‐safe optical windows for pyrometers (Catala‐Civera et al., 2015; García‐Baños et al., 2019).…”

Probing multimode applicator of microwave heating system for E‐field distribution using a silicon carbide sensor and a shielded thermocouple

“…It is suggested here that monitoring of the local average field distributions E 0 (x, y, z) │ P or position-wise distribution of the absorbed microwave power Q MW (x, y, z) │ P such as presented in Figures 4C,D and 5A,B could be useful in the area of microwave applicator design. The current general framework for understanding the working of the applicator part of a microwave heating system (whether of the single-mode-type or the multimode-type) and its design optimization is based on modeling with analytical or numerical calculations [43][44][45][46][47][48][49][50] or multi-physicsbased simulations 25,[51][52][53] or using certain experimental techniques. [54][55][56][57][58] The applicator optimization is in terms of the best coupling of the magnetron output power to the applicator cavity via a short waveguide (and an isolator coupler) or for a given dielectric 'load', or the applicator dimensions being such that the reflection coefficient of the applicator is minimum at the input frequency 56,60 , or in terms of development of strategies for uniform heating of the 'load'.…”

“…[22][23][24] In spite of its size limitation, currently there is increasing use of a single mode applicator in developing different types of microwave heating systems. The recently reported work on experimental and numerical thermal analysis of heating of SiC 25 in a single mode microwave applicator system is a good step ahead in carrying out field monitoring in conjunction with validating numerical modeling results. On this background, we report here the results of our experimentation towards the assessment of electric field distribution in the multimode applicator part of a microwave oven.…”