• Title/Summary/Keyword: cold crucible melter

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The Study on the Power Consumption for Glass Melting by Cold Crucible Melter (CCM용융에 대한 유리용융 조건 연구)

  • Jin, Hyun-Joo;Lee, Kyu-Ho;Jung, Young-Jae;Bae, So-Young;Kim, Tae-Ho;Jung, Young-Joon;Kim, Young-Seok;Lee, Kang-Taek;Ryu, Bong-Ki
    • Korean Journal of Metals and Materials
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    • v.46 no.2
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    • pp.65-68
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    • 2008
  • Generally CCM (cold crucible melting) is not suitable for melting glass. However, in this study we described the quantitative relationship between the basic property of glass and power balance, the power absorption in the melt, the losses in the coil and the cold crucible, for melting glass in CCM. The dependence of power balance on the applied frequency and the electric conductivity has been found. Above 300 kHz, the glass (B) contained alkali ion which has the low resistance $3.0{\Omega}{\cdot}cm$ at $900^{\circ}C$ and $1.36{\Omega}{\cdot}cm$ at $1,100^{\circ}C$ was melted easily and 60% of the overall power was absorbed in the melt and 30% and 10% of the overall power was lost in the cold crucible and coil respectively. Under the same condition, the glass (A) contained non-alkali ion was not melted easily and 50% of the overall power was absorbed in the melt and 40% and 10% of the overall power was lost in the cold crucible and coil respectively. In conclusion, the small absorbed power of the overall power in melt prevented a successful melting as for glass A, and the successful melting depends on the relative size of the absorbed power in melt irrespective of the melting volume. Hence, as typical for direct induction heating method(CCM), the successful melting strongly depended on the chosen working frequency based on electric conductivity of glass, power balance and the control of the critical power which was absorbed in melt.

Characterization of Glass Melts Containing Simulated Low and Intermediate Level Radioactive Waste

  • Jung, Hyun-Su;Kim, Ki-Dong;Lee, Seung-Heon;Kwon, Sung-Ku;Kim, Cheon-Woo;Park, Jong-Kil;Hwang, Tae-Won;Ahn, Zou-Sam
    • Journal of the Korean Ceramic Society
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    • v.43 no.3 s.286
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    • pp.148-151
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    • 2006
  • In order to examine the process parameters for the vitrification of Low and Intermediate Level radioactive Waste (LILW) generated from nuclear power plants, measurements of several melt properties was performed for four selected glasses containing simulated waste. Electrical conductivity and viscosity were determined at temperatures ranging from 1123 to $1673^{\circ}C$. The temperature dependences of both properties in the molten state showed a similar behavior in which their values decrease as the temperature increases. The values of the electrical conductivity and viscosity at a temperature of 1423K adopted in an induction cold crucible melter process were $0.27{\sim}0.42$ S/cm and $9.8{\sim}42$ dPas, respectively.

Vitrification of Simulated Combustible Dry Active Wastes in a Pilot Facility

  • Yang, Kyung-Hwa;Park, Seung-Chul;Lee, Kyung-Ho;Hwang, Tae-Won;Maeng, Sung-Jun;Shin, Sang-Woon
    • Nuclear Engineering and Technology
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    • v.33 no.4
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    • pp.355-364
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    • 2001
  • In order to evaluate and finally optimize the vitrification condition for combustible dry active waste (DAW), dust and gas generation characteristics were investigated for PE, cellulose, and mixed waste Tests were conducted by varying the operation variables such as melter configuration, excess oxygen amount, and waste feeding rate. Results showed that dust generation characteristics were affected by the operation parameters and the melter's configuration is the dominant one. For all tested DAWs, dust generation was reduced by increasing the waste feeding rate and the excessive oxygen amount in the melter. Among waste types, dust amount was decreased by the order of mixed wastes, PE, and cellulose. Other parameters such as temperature variation and operation time have also affected the dust generation. The optimum condition for the DAW vitrification was determined as the melter's configuration equipped for minimizing the waste dispersion with 20 kg/h of waste feeding rate and 100% of excessive oxygen supply. CO gas concentration in the off-gas was immediately influenced by the combustion state in the melter, but showed similar trend as the dust generation. For the NOx production during the vitrification process, thermal NOx, which is generated from the Post Combustion Chamber (PCC), rather than fuel NOx was assumed to be dominant. The gas cleaning of efficiencies of the PCC, wet scrubber, and Selective Catalytic Reduction system (SCR) were found to be high enough to keep the concentration of pollutants (CO, NOx, SOx, HCI) in the stack below their relevant emission limits.

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Radioactive Wastes Vitrification Using Induction Cold Crucible Melter: Characteristics of Vitrified Form (유도 가열식 저온용융로를 이용한 방사성페기물 유리화: 유리 고화체 특성)

  • 김천우;박은정;최종락;지평국;최관식;맹성준;박종길;신상운;송명재
    • Journal of the Korean Ceramic Society
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    • v.39 no.6
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    • pp.576-581
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    • 2002
  • In order to simultaneously vitrify the ton Exchange Resin(IER) and Dry Active Waste(DAW) generated from the Nuclear Power Plants, a vitrification pilot test was conducted using an induction cold crucible melter. The PCT result evaluating the chemical durability of the vitrified from showed that the final glass was more durable than the benchmark glass. Liquidus temperature for the final vitrified form was 1048 K(775$\^{C}$) fur heat treatment experiments. The value of the compressive strength for the vitrified form was ninety times higher than the regulation limit, 34 kg/㎠. The glasses on bottom, middle and top of the CCM were homogeneous with no secondary phase. The precipitation of the magnetic metal phase was able to be avoided by simultaneously fEeding of DAW with IER containing strongly reducing organics. Volume reduction factor of 74 was achieved through the vitrification Pilot test for mixed waste.