Throat structure for large blast furnaces - includes track for overhead crane and platforms for maintenance workers

The structure has girders between the gas outlet ducts to carry equipment for the assembly, maintenance and repair of the devices used for charging the blast furnace etc.; and platforms are provided for workers. The novelty is that the gas ducts are connected by a hollow frame just above the top of the furnace; the girders are located above the frame and are also connected to the gas ducts. One of the girders is pref. used to join the top of two gas ducts to form a rigid structure, and cross-braces are used to provide rigidity for the platforms. Suitable for use on very large blast furnace, permitting easy assembly and repairs.