Ignition and combustion of ~20 µ m diameter aluminum powder was achieved with a helium–steam-based 2.45 GHz microwave plasma torch as a proof of concept due to interest in utilizing aluminum powder as a fuel source for power generation given the material’s high energy density. Optical emission spectroscopy of the plasma in air, with steam-entrainment, and with aluminum particle injection was obtained in order to observe the radical species present. The combustion products were analyzed with x-ray diffraction (XRD) to determine the post-combustion composition and compared with published XRD data involving aluminum-water combustion. The results revealed that a microwave plasma torch in a steam environment is capable of igniting aluminum particles and sustains combustion between aluminum powder and radicals from water molecules. The torch design results in a mixing delay between the aluminum and steam radical reactants prior to sustained combustion. Enhanced mixing will be pu...

中文翻译：

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使用2.45 GHz微波等离子炬将铝粉与夹带在氦气等离子体中的蒸汽燃烧

使用氦蒸汽的2.45 GHz微波等离子炬实现了直径约20 µm的铝粉的点火和燃烧，这是概念的证明，因为鉴于材料的高能量密度，人们有兴趣将铝粉用作发电的燃料源。为了观察存在的自由基种类，获得了空气中等离子体，夹带蒸汽和注入铝颗粒的发射光谱。用X射线衍射（XRD）分析燃烧产物，以确定燃烧后的成分，并与已发表的涉及铝水燃烧的XRD数据进行比较。结果表明，在蒸汽环境中的微波等离子体炬能够点燃铝颗粒，并维持铝粉与水分子自由基之间的燃烧。火炬的设计导致铝和蒸汽自由基反应物在持续燃烧之前的混合延迟。增强混合效果会更好