你真“懂”工程阿，就是无法解释：”优点多多“的平炉为何被淘汰？

 

The basic oxygen steelmaking eventually replaced the open hearth furnace. It rapidly superseded both the Bessemer process and Siemens-Martin process in the Western Europe by the 1950s and in the Eastern Europe by the 1980s, the last European open hearth furnace being stopped in 1993. In the US, steel production using the energy inefficient open hearth furnaces had stopped by 1992. The last open hearth shop in China was shut down in 2001.

http://en.wikipedia.org/wiki/Open_hearth_furnace