The principle of the method is illustrated in Figure 1. The gas whose diffusion coefficient is measured is inserted through a platinum tube into a cylindrical quartz glass container just above the surface of the molten glass inside the optical cuvette located in the laboratory furnace. After filling with the gas, the container is pushed below the melt level. Gas absorption is measured by the rise of the melt inside the container, which is captured by the video camera through a special hole in the side of the laboratory furnace, see Figure 2. An image analyzer, measuring the distance between the gas-melt interface and the upper end of the container, is used to evaluate the measurement. |
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Figure: Schematics of the experimental setup: 1 - glass melt cuvette 2 - cylindrical quartz measuring vessel 3 - measuring cup holder 4 - moving gas-melt interface 5 - melt level inside the cuvette | Figure: The movement of the gas-melt interface when measuring the water vapor diffusion coefficient of sodium-calcium-silicate glass, temperature 1200 ° C. a) 15000 s, b) 20000 s, c) 40000 s, d) 60000 s |
Diffusion coefficients of gases in melts
Updated: 27.4.2021 11:21, Author: Jan Kříž