DEVELOPMENT OF A VISCOMETER BASED ON ROTATING CYLINDER METHOD
A new viscometer based on the rotating cylinder me-thod for high temperature melts, particularly for high viscous melts such as molten silicate, was developed in this study. The viscosity of SiO2-CaO-CaF2 system was then measured by using the viscometer. The viscometer developed was comprised of an outer cylinder (crucible) and an inner cylinder. The outer cy-linder containing sample melt was rotated, and a torque generated on the inner cylinder due to viscosity of the sample melt was measured by using a torque sensor. The viscometer was hermetically sealed and the inside atmos-phere was strictly controlled, which was necessary for maintaining composition of sample melts during the mea-surement. The silicon carbide furnace available up to 1873 K was used as a heating unit. Sample (SiO2-37mass％CaO-15mass％CaF2 or SiO2-35mass％CaO-20mass％CaF2) was charged in the cruci-ble as the outer cylinder made of graphite. The sample was heated to 1773 K and fused under argon atmosphere. The inner cylinder made of graphite was then immersed in the molten sample, and the outer cylinder was rotated at the rate of 10 to 60 rpm. Torque generated on the inner cylinder was measured, and the viscosity of the sample melt was determined with calibration curves preliminary prepared. Viscosity of sample melt gradually increased with decreasing temperature and drastically increased by crossing liquidus temperature, which indicates that the precipitates increased the apparent viscosity of the melt. Melt with higher concentration of CaF2 showed lower viscosity. The activation energy for viscous flow over the liquidus temperature showed good agreement with litera-ture data. The viscometer developed in this study was found to be applicable for high temperature melts even if the melt is in the solid-liquid co-existent state.
Taku OKAWRA Osamu TAKEDA Yuzuru SATO
Department of Metallurgy, Graduate School of Engineering, Tohoku University 6-6-02 Aramaki Aza Aoba, Aoba-ku, Sendai, 980-8579, Japan
国际会议
The Ninth Asian Thermophysical Properties Conference(第九届亚洲热物理性能会议 ATPC 2010)
北京
英文
1085-1088
2010-10-19（万方平台首次上网日期，不代表论文的发表时间）