Side wall of the ultra high power electric arc furnaces for steelmaking

A water cooled panel for use as a part of an inside wall within an outer shell in an ultra-high power electric arc furnace, comprising walls forming a panel having a plurality of hollow water channels extending therethrough, said panel having a first side facing toward the outer shell and an oppositely directed second side facing inwardly into the furnace, a water inlet and a water outlet connected to the first side of said panel for flowing water through said water channels, a plurality of fins formed on said second side and extending therefrom inwardly into the furnace, said fins being spaced apart forming multi-sided chambers closed by said second side and said fins and open to the inside of the furnace, a castable refractory deposited into and filling the space within said multi-sided chambers, said fins comprising a plurality of first fins and second fins extending transversely of said first fins, said first fins being at least 10 mm in thickness, said first fins extending horizontally and projecting into the furnace from said second wall for a dimension of at least 70 mm and said first fins being spaced apart in the vertical direction in the range of 30 to 80 mm, and said walls and said fins being formed of one of copper and a copper alloy.