Determination of heat conductivity of waste glass feed and its applicability for modeling the batch-to-glass conversion

2017 ◽  
Vol 100 (11) ◽  
pp. 5096-5106 ◽  
Author(s):  
Miroslava Hujova ◽  
Richard Pokorny ◽  
Jaroslav Klouzek ◽  
Derek R. Dixon ◽  
Derek A. Cutforth ◽  
...  
Keyword(s):  
Heat Conductivity ◽  
Waste Glass

Determination of Temperature-Dependent Heat Conductivity and Thermal Diffusivity of Waste Glass Melter Feed

2013 ◽  
Vol 96 (6) ◽  
pp. 1891-1898 ◽  
Author(s):  
Richard Pokorny ◽  
Jarrett A. Rice ◽  
Michael J. Schweiger ◽  
Pavel Hrma
Keyword(s):  
Thermal Diffusivity ◽  
Heat Conductivity ◽  
Waste Glass ◽  
Temperature Dependent ◽  
Glass Melter

Determination of Heat Conductivity and Thermal Diffusivity of Waste Glass Melter Feed: Extension to High Temperatures

2014 ◽  
Vol 97 (6) ◽  
pp. 1952-1958 ◽  
Author(s):  
Jarrett A. Rice ◽  
Richard Pokorny ◽  
Michael J. Schweiger ◽  
Pavel Hrma
Keyword(s):  
Thermal Diffusivity ◽  
High Temperatures ◽  
Heat Conductivity ◽  
Waste Glass ◽  
Glass Melter

The void fraction of melter feed during nuclear waste glass vitrification

2015 ◽  
Vol 1744 ◽  
pp. 107-112
Author(s):  
Zachary J. Hilliard ◽  
Pavel R. Hrma
Keyword(s):  
Void Fraction ◽  
Melting Process ◽  
Waste Glass ◽  
Expansion Test ◽  
Glass Forming ◽  
Glass Melter ◽  
Temperature Heating ◽  
Fraction Porosity ◽  
Profile Area

ABSTRACTTo efficiently vitrify Hanford waste, the melting process (i.e., melter feed turning into waste glass) must be modeled and optimized. The rate of heat transfer to the melter feed in a waste glass melter, and thus the rate of melting, is strongly affected by the melter feed porosity, especially in the final stages where the glass-forming melt produces foam that insulates the feed from the molten glass. The volume expansion test allows the determination of the melter feed porosity as a function of temperature. This test measures the profile area of the feed pellet as it turns into glass. This contribution presents the calculation of the void fraction (porosity) of the melter feed as a function of temperature, heating rate, and material parameters. The process of finding the void fraction is described as well as results from the application of this process.

Crystallization Behavior of a Ferri-Silicate α-Waste Glass

1985 ◽  
Vol 50 ◽  
Author(s):  
A. D. Stalios ◽  
R. De Batist
Keyword(s):  
Crystallization Behavior ◽  
Crystallization Process ◽  
Waste Glass ◽  
Avrami Equation ◽  
Two Dimensional ◽  
Diffusion Controlled ◽  
Instantaneous Nucleation ◽  
Dimensional Growth ◽  
And Diffusion

AbstractThe crystallization behavior of a ferri-silicate α-waste glass was studied by means of several experimental techniques. The main crystal phase showed a plate-like morphology and was identified as a monoclinic pyroxene. The Johnson-Mehl-Avrami equation was used for the determination of the kinetic parameters of the process. Following both isothermal and non-isothermal techniques, the Avrami exponent, n, was found to be nearly one. The activation energy for crystal growth is Eg = 356 kJ mole−1. The crystallization process is governed by instantaneous nucleation and diffusion controlled two dimensional growth.

Numerical Modeling of Heat and Mass Transport with Inner Heat Exchange in Unsaturated Porous Media

2020 ◽  
Vol 27 ◽  
pp. 166-176
Author(s):  
Jozef Kačur ◽  
Patrik Mihala
Keyword(s):  
Mathematical Model ◽  
Porous Media ◽  
Heat Exchange ◽  
Inverse Problems ◽  
Water Transport ◽  
Heat Conductivity ◽  
Unsaturated Porous Media ◽  
Heat Transmission ◽  
Matrix Heat

We are focused to the numerical modelling of heat, contaminant and water transport in unsaturated porous media in 3D. The heat exchange between water and porous media matrix is taken into the account. The determination of heat energy transmission coefficient and matrix heat conductivity is solved by means of inverse problem methods. The mathematical model represents the conservation of heat, contaminant and water mass balance. It is expressed by coupled non-linear system of parabolic-elliptic equations. Mathematical model for water transport in unsaturated porous media is represented by Richard's type equation. Heat transport by water includes water flux, molecular diffusion and dispersion. A successful experiment scenario is suggested to determine the required parameters including heat transmission and matrix heat conductivity coefficients. Additionally we investigate contaminant transport with heat transmission and contaminant adsorption. The obtained experiments support our method suitable for solution of direct and inverse problems. This problem we have discussed previously in 1D model, but preferential streamlines in 1D thin tubes shadow accurate results in determination of required parameters. In our presented setting we consider a cylindrical sample which is suitable in laboratory experiments for inverse problems.

scholarly journals Remote Monitoring of Molten Radioactive Glass

1991 ◽  
Vol 257 ◽  
Author(s):  
Alfred Schneider ◽  
Kang-Wen K. Li ◽  
Ray F. Schumacher
Keyword(s):  
Continuous Monitoring ◽  
Glass Composition ◽  
Ternary Systems ◽  
Waste Glass ◽  
Rise Velocity ◽  
Savannah River ◽  
Monitoring Method ◽  
Target Composition ◽  
On Line

ABSTRACTAn on-line method is described for the near-continuous monitoring of the composition of a molten radioactive waste glass or, alternatively, for signaling a deviation from the target composition of a waste glass. The principle of this method, proposed by A. Schneider in 1986, is founded on the relation between two specific physical properties and composition in a ternary system. Most glasses currently considered as waste forms can be represented as pseudo-ternary systems. The pair of properties especially well suited for this purpose are the viscosity and density of the molten glass. A novel viscometry method was developed which uses the remotely determined rise velocity of carefully metered gas bubbles. The monitoring method was tested successfully with simulated Savannah River waste glasses. An integrated probe was conceived for a Joule-heated melter for the on-line determination of viscosity, temperature, density, and liquid level. A computer program calculates the glass composition from the measured data, using information from a previously developed data base.

Determination of the Forward Rate of Dissolution for SON68 and PAMELA Glasses in Contact With Alkaline Solutions

2008 ◽  
Vol 1107 ◽  
Author(s):  
K. Ferrand ◽  
K. Lemmens
Keyword(s):  
Waste Glass ◽  
Forward Rate ◽  
Alkaline Solutions ◽  
Dynamic Tests ◽  
Forward Rates ◽  
Rate Of Dissolution ◽  
Uv Visible ◽  
Radionuclide Release ◽  
Good Agreement

AbstractIn the new Belgian disposal design, the nuclear waste glass will be surrounded by a 3 cm thick carbon steel overpack and a 70 cm thick concrete buffer. An initially high pH is expected after water intrusion in the concrete buffer and this may have an effect on the radionuclide release from the waste glass. This study was performed in order to determine the forward rate of dissolution for SON68 and PAMELA glasses (SM513 LW11 and SM539 HE 540-12), conducting dynamic tests at 30°C in contact with alkaline solutions. In these experiments, the silicon concentration in solution was determined by UV/Visible spectrophotometry according to the blue â-silicomolybdenum method. The forward rates of dissolution were quite similar for the three glasses except at the highest pH for which a slightly higher value was found for SM539 glass. For SON68 glass, a good agreement with the previously established interpolation law was observed until pH 11.5, but at higher pH, the interpolation law slightly overestimates the dissolution rate [1].

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