Potassium fluoride improving the ignition and combustion performance of micron-sized aluminum particles in high temperature water vapor

ABSTRACT

To improve the ignition and combustion characteristics and combustion efficiency of micron-sized aluminum particle in high temperature water vapor atmosphere, a self-designed tube furnace setup was used to study the effects of potassium fluoride (KF) on the ignition and combustion characteristics of micron-sized aluminum particle in high temperature water vapor. The ignition and combustion processes, components and morphologies of combustion products, and combustion efficiency were recorded and analyzed by a high-speed photographic system, X-ray diffraction, scanning electron microscopy with energy-dispersive spectrometer, and chemical analysis method, respectively. Results show that the addition of KF to 5 μm aluminum powder significantly decreases its ignition delay time because the hydrolysis of KF generates KOH in water vapor, and KOH corrodes the oxide shell on the aluminum surface to promote the reaction of aluminum with water, which can be proved by the morphologies of the products. The hydrolysis product of KF can destroy the oxidation shell on the aluminum powder surface, but it does not cause the aluminum particles to undergo shell-breaking combustion. As the KF content increases, the oxide shell is dramatically destroyed, so the ignition delay time of aluminum powder in high temperature water vapor decreases. Moreover, the combustion efficiency of aluminum powder with addition of KF increases considerably with increasing of the KF content.

KEYWORDS:

• Potassium fluoride
• micron-sized aluminum
• water vapor
• ignition and combustion

Additional information

Funding

We greatly appreciate the financial support provided by the National Natural Science Foundation of China (Nos. 51676001 and 51376007) and the Project of Jiangsu Provincial Six Talent Peak (No. JNHB-097).

Notes on contributors

Wei Shi

Wei Shi  is  graduate student and working at Anhui University of Technology. His research field is the combusion of high-energy fuels.

Baoxin Dai

Baoxin Dai is  graduate student and working at Changzhou University. His research field is the combusion of high-energy fuels.

Baozhong Zhu

Baozhong Zhu received his master degree in  chemistry from the Guizhou University, Chinese Academy of Sciences, in 2008. His research field is the catalyst combustion.

Yunlan Sun

Yunlan Sun received her Ph.D.degree from the University of Science and Technology of China (USTC) in 2007, Chinese Academy of Sciences. Her research interests are mainly focused on the combusion of high-energy fuels.

Ying Chen

Ying Chen is graduate student and working at Anhui University of Technology. Her research field is the combusion of high-energy fuels.