Electric arc furnace water-cooled pipe rupture and molten steel explosion

Introduces the case that continues into chunk 2 — modern 150 MW electric arc furnaces (scaled up from 50 MW since the 1970s) require water-cooled walls because radiant heat tripled with the power increase; water leaks into molten steel cause explosions. Tom describes getting consulting calls that begin "we had an explosion in our casting facility."

Most recently — a year or two ago — they had a big electric arc furnace. We talked about the big electric arc furnaces, almost the size of this room, with these big 3-foot to 3-and-a-half-foot diameter carbon electrodes. The walls — they used to make about 40 or 50 tons of steel in one of those vessels, but to increase productivity over the last 25 years they've done all kinds of things. They put in new transformers and got to 150 megawatts of power, up from about 50 megawatts. They go from 40 tons to 120 or 150 tons that they're melting. Those are big arcs — just think of an arc in the middle of this room that's about the size of a small car, melting tons of steel. There's a lot of radiation to the walls, and when you triple the power you triple the radiant energy to the walls. In the old days the small furnaces could have a ceramic wall maybe 2 feet thick, and it would erode away over time, but you could go in and reline it every six months or