Bessemer Converter

This 10-ton Bessemer Converter was originally installed at the A. M. Byers Company in Ambridge, Pennsylvania. Built by the Pennsylvania Engineering Corporation at its New Castle, Pennsylvania, plant in 1930, it was one of the last commercially operated bessemers in the United States. In the Bessemer process, molten blast furnace iron is converted to steel by burning out carbon and other impurities with a blast of air forced through the molten bath by tuyeres. Developed during the 1840 - 1860 period but not commercially utilized until 1864 with the first successful plant at Wyandotte, Michigan, the process ushered in the Age of Steel, and vessels of this type became a workhorse of the American steelmaking industry and of steelmaking abroad. By 1883, close to 1.5 million tons of steel were processed in bessemers, accounting for more than 88 percent of total United States production. Bessemer steel production peaked in 1906 at more than 12 million tons, accounting for 52 percent of total United States production, with about 5 million tons produced in Pennsylvania, mostly in the Pittsburgh area. With the advent of other steelmaking processes, Bessemer steel production in the United States became negligible by the late 1960s. In operation, air at 20 to 35 pounds per square inch enters at the blast pipe, passes through the hollow trunnion and down to the wind box, which distributes it to the tuyere; it then passes through the molten iron charge and, after combining with carbon, silicon, and manganese, is discharged from the nose of the vessel. A complete blow could be accomplished in 8 to 12 minutes, after which the vessel was tilted by the turning gear and the steel was poured into a ladle for teeming into ingots.

Pittsburgh, Pennsylvania · United States