The effects of particle size on microwave heating of metal and metal oxide powders
The effects of particle size on microwave heating of metal and metal oxide powders
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DOI：
10.1016/j.powtec.2014.02.008
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发表时间：
2014-04-01
影响因子：
5.2
通讯作者：
Saed, M.
中科院分区：
文献类型：
--
作者：
Crane, C. A.;Pantoya, M. L.;Saed, M.
为了了解颗粒尺寸对微波吸收的影响，重要的是要将良好的块体导体（如铝或铜）的吸收与电介质（如氧化铁 (Fe2O3)）的吸收分开。这项研究通过实验检验了微波与不同材料（例如铝和氧化铁）的粉末压块的耦合随颗粒尺寸的变化。电磁室将每种材料的压实粉末样品暴露在频率为 3.3 GHz 的微波中，并捕获样品表面的原位二维空间温度测量值，以量化微波加热。结果表明，对于非导电氧化剂（Fe2O3），减小粒径会增加微波吸收，因为有效表面积和有效电导率增加。相反，减小导电金属（Al）颗粒尺寸会导致微波吸收降低，因为颗粒尺寸与趋肤深度的比率被证明是控制能量吸收的关键参数。这项研究有助于人们对微波能量如何与金属和金属氧化物压实颗粒相互作用（作为粒径的函数）有新的认识。 (C) 2014 Elsevier B.V. 保留所有权利。
To understand the effect of particle size on microwave absorption, it is important to separate absorption in good bulk conductors (like aluminum or copper) from dielectrics, like iron oxide (Fe2O3). This study experimentally examined coupling microwaves to powder compacts of discretely different materials such as aluminum and iron oxide as a function of particle size. An electromagnetic chamber exposed compacted powder samples of each material to microwaves at a frequency of 3.3 GHz and in-situ 2-D spatial temperature measurements of the sample surface were captured to quantify microwave heating. Results show that for the non-conductive oxidizer (Fe2O3), decreasing the particle size increased the microwave absorption because of the increase in effective surface area and effective conductivity. In contrast, decreasing the conductive metal (Al) particle size resulted in decreased microwave absorption because the ratio of particle size to the skin depth was shown to be a critical parameter controlling energy absorption. This research contributes to new understandings of how microwave energy interacts with metal and metal oxide compacted pellets as a function of particle size. (C) 2014 Elsevier B.V. All rights reserved.