title: An innovative energy-saving in-flight melting technology and its application to glass production.
abstract: The conventional method used for glass melting is air-fuel firing, which is inefficient, energy-intensive and time-consuming. In this study, an innovative in-flight melting technology was developed and applied to glass production for the purposes of energy conservation and environmental protection. Three types of heating sources, radio-frequency (RF) plasma, a 12-phase alternating current (ac) arc and an oxygen burner, were used to investigate the in-flight melting behavior of granulated powders. Results show that the melted particles are spherical with a smooth surface and compact structure. The diameter of the melted particles is about 50% of that of the original powders. The decomposition and vitrification degrees of the prepared powders decrease in the order of powders prepared by RF plasma, the 12-phase ac arc and the oxygen burner. The largest heat transfer is from RF plasma to particles, which results in the highest particle temperature (1810 °C) and the greatest vitrification degree of the raw material. The high decomposition and vitrification degrees, which are achieved in milliseconds, shorten the melting and fining times of the glass considerably. Our results indicate that the proposed in-flight melting technology is a promising method for use in the glass industry.
authors.affiliation: Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, Yokohama 226-8502, Japan.
authors.forename: Yaochun
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, Yokohama 226-8502, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Department of Chemistry and Materials Science, Tokyo Institute of Technology, Tokyo 152-8550, Japan.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Yano
authors.affiliation: New Glass Forum, Tokyo 105-0004, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Iseda
authors.affiliation: Research Center, Asahi Glass Co. Ltd, Tokyo 100-8405, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Sakamoto
authors.affiliation: Technical Department, Toyo Glass Co. Ltd, Tokyo 100-0011, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Iwamoto
authors.affiliation: Nano Ceramics Center, National Institute for Materials Science, Tsukuba 305-0044, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Inoue
keywords: glass production; heat transfer; in-flight melting; powders; thermal plasmas