Application of microwave heating to ceramic processing: Design and initial operation of a 2.45-GHz single-mode furnace

1996 ◽  
Vol 24 (3) ◽  
pp. 1041-1049 ◽  
Author(s):  
A.W. Fliflet ◽  
R.W. Bruce ◽  
A.K. Kinkead ◽  
R.P. Fischer ◽  
D. Lewis ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Single Mode ◽  
Ceramic Processing ◽  
Initial Operation

Validation of measured microwave absorption and temperature change for development of a single-mode-type microwave heating thermogravimetry apparatus

2017 ◽  
Vol 88 (2) ◽  
pp. 024101 ◽  
Author(s):  
Achmad Dwitama Karisma ◽  
Taishu Hamaba ◽  
Tomonori Fukasawa ◽  
An-Ni Huang ◽  
Tomoomi Segawa ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Microwave Absorption ◽  
Temperature Change ◽  
Single Mode

scholarly journals Behaviour of Microwave-Heated Al4SiC4 at 2.45 GHz

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4878
Author(s):  
Takashi Fujii ◽  
Akio Oshita ◽  
Keiichiro Kashimura
Keyword(s):  
Microwave Heating ◽  
Physical Property ◽  
Single Mode ◽  
Dielectric Constants ◽  
Energy Concentration ◽  
Microwave Absorbers ◽  
High Temperature Processes ◽  
Powder Samples ◽  
Higher Temperature ◽  
Electrical Permittivity

The ongoing development of high-temperature processes with the use of microwaves requires new microwave absorbers that are useful at these temperatures. In this study, we propose Al4SiC4 powders as important and efficient microwave absorbers. We investigated both the behavioural microwave heating and electrical permittivity characteristics of Al4SiC4 powders with various particle sizes at 2.45 GHz. The TE103 single-mode cavity indicated that Al4SiC4 powder samples yielded different heating behaviours and dielectric constants for each particle size compared with SiC. By microwave heating ∅50 mm × 5 mm disks of Al4SiC4 and SiC, we demonstrate that for specific sizes, Al4SiC4 can be heated at a higher temperature than SiC. Finally, the results of the two-dimensional two-colour thermometer show that an energy concentration appears at the interface of the microwave-heated Al4SiC4. These phenomena, which are inconsistent in individual physical property values, can be explained without contradicting microwave heating physics.

Materials processed by indirect microwave heating in a single-mode cavity

2006 ◽  
Vol 32 (8) ◽  
pp. 911-915 ◽  
Author(s):  
D. Grossin ◽  
S. Marinel ◽  
J.-G. Noudem
Keyword(s):  
Microwave Heating ◽  
Single Mode ◽  
Single Mode Cavity

Phase transformations in Si-based alloy powder mixtures induced by microwave heating in a 2.45 GHz single-mode applicator

2010 ◽  
Vol 18 (11) ◽  
pp. 2030-2033 ◽  
Author(s):  
Song Li ◽  
Guoqiang Xie ◽  
Dmitri V. Louzguine-Luzgin ◽  
Ziping Cao ◽  
Noboru Yoshikawa ◽  
...  
Keyword(s):  
Phase Transformations ◽  
Microwave Heating ◽  
Alloy Powder ◽  
Single Mode ◽  
Powder Mixtures

scholarly journals Experimental Observations of Thermal Spikes in Microwave Processing of Ceramic Oxide Fibers

1994 ◽  
Vol 347 ◽  
Author(s):  
Gerald J. Vogt ◽  
Wesley P. Unruh ◽  
J. R. Thomas
Keyword(s):  
Microwave Heating ◽  
Hot Spots ◽  
Hot Spot ◽  
Single Mode ◽  
Microwave Cavity ◽  
X Ray Diffraction ◽  
Thermal Spike ◽  
X Ray ◽  
Heating Behavior ◽  
Fiber Processing

ABSTRACTMicrowave heating of alumina/silica fiber tows in a single-mode microwave cavity at 2.45 GHz has produced a surprising thermal spike behavior on the fiber bundles. During a thermal spike, a “hot spot” on the tow brightens rapidly, persists for a few seconds, and then rapidly extinguishes. A hot spot can encompass the entire tow in the cavity or just a localized portion of the tow. Some local hot spots propagate along the fiber. Thermal spikes are triggered by relatively small (<15%) increases in power, thus having obvious implications for the development of practical microwave fiber processing systems. A tow can be heated through several successive thermal spikes, after which the tow is left substantially cooler than it was originally, although the applied microwave electric field is much larger. X-ray diffraction studies show that after each temperature spike there is a partial phase transformation of the tow material into mullite. After several excursions the tow has been largely transformed to the new, less lossy phase and is more difficult to heat. Heating experiments with Nextel 550 tows are examined for a plausible explanation of this microwave heating behavior.

scholarly journals Optimization of the Microwave-Assisted Carbothermical Reduction Process for Metals from Electric Arc Furnace Dust with Biochar

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1765
Author(s):  
Anton Anzulevich ◽  
Leonid Butko ◽  
Dmitrii Kalganov ◽  
Dmitrii Pavlov ◽  
Valentin Tolkachev ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Effective Permittivity ◽  
Plane Waves ◽  
Reduction Process ◽  
Single Mode ◽  
Spherical Particles ◽  
Source Distribution ◽  
Eaf Dust ◽  
Valuable Metals ◽  
Heat Source Distribution

The main purpose of this work was to extract valuable metals from EAF dust with the addition of biochar, using microwaves to control and optimize the carbothermical reduction process. To achieve better microwave penetration and the most homogeneous electromagnetic heat source distribution possible in a sample, the content of EAF dust and biochar in centimeter-size spherical particles prepared by the pelletization process was considered to be radially heterogeneous. The content of EAF dust was determined experimentally and the effective permittivity, permeability, and thermal conductivity of the EAF dust as well as biochar–EAF powder mixture were determined using effective medium approximation. The microwave heating of a multilayered pellet of biochar-containing EAF dust was simulated and investigated. The influence of the distribution of the components within the pellet on the effectiveness of the microwave heating was investigated, as was the influence of the biochar conductivity. The interaction of the pellet with both plane waves in free space and with H10 mode waves in a single-mode waveguide was considered. The most optimal distribution of EAF dust and biochar within the pellet for the reduction process was determined.

scholarly journals Effect of Microwave Drying, Calcination and Aging of Pt/Al2O3 on Platinum Dispersion

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 348 ◽  
Author(s):  
Xavier Auvray ◽  
Anthony Thuault
Keyword(s):  
Microwave Heating ◽  
Single Mode ◽  
Microwave Treatment ◽  
Microwave Drying ◽  
Conventional Heating ◽  
Bet Surface Area ◽  
Great Ability ◽  
Subsequent Calcination ◽  
Platinum Dispersion ◽  
Al2o3 Catalyst

The effect of heating method employed for drying and calcination during the synthesis of 1 wt% Pt/Al2O3 catalyst was investigated. Conventional heating (CH) in resistive oven and microwave heating (MW) in single mode were applied, and the Pt dispersion and Brunauer-Emmett-Teller (BET) surface area were measured to characterize the samples. It was evidenced that the fast and homogeneous heating offered by the microwave heating led to higher Pt dispersion. However, this benefit was only achieved when the subsequent calcination was performed in a conventional oven. The aging in microwave oven of conventionally prepared—as well as MW-prepared—catalysts demonstrated the great ability of microwave irradiation to accelerate platinum sintering. After 1 h at 800 °C under microwave, catalysts showed a dispersion of 5%. Therefore, microwave treatment should be considered for accelerated catalyst aging but should be avoided as a calcination technique for the synthesis of highly dispersed Pt/Al2O3.

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