Cold top (all electric) melters

Question 1

What are the characteristics of cold top melters?

Answer 1

~ deep tanks

~ the melt is covered by a floating blanket of batch that condenses volatiles

~ rotating chutes distribute the batch over entire surface

~ electrodes enter through refractory walls or batch layer

Question 2

What are the materials used to make cold top/all electric melters?

Answer 2

~ made of refractory metals, graphite, or semiconducting SnO2 (Mn most widely used)

~ graphite is used when constant release of cobubbles is acceptable

~ Pt and SnO2 are used when their chemical inertness justifies their high cost

Question 3

What’s the thermal efficiency of all electric melters?

Answer 3

~ 2-3x higher than that of fuel-fired melters with regenerators (but they are much more expensive)