摘要 |
The invention relates to a melting furnace for vitrifying highly radioactive waste, comprising a melting tank of refractory material and a furnace upper section enclosed by insulation and a steel container. The furnace contains electrodes of ceramic block material for direct heating which comprise part of the wall of the melting tank. Electrical conductors project from the electrodes through the top of the furnace. In order to avoid the danger of the melt flowing into the gaps between the electrodes and the surrounding tank wall and shorting the electrodes, the melt level is maintained below the top surface of the electrodes. In one form of the invention, the electrodes are recessed along the upper edge of the front side facing the melting tank, which recess accommodates a refractory block which is highly resistant to the corrosive effect of the waste at the melt level. The electrodes require no cooling, and are insulated on their back sides which avoids temperature differentials within the electrodes.
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