PURPOSE: To improve conventional inefficient control operations and to eliminate dangerous and heavy jobs at high temp. by controlling the opening of tap holes, the administration is delivery of products, quality control, and closing of the tap holes of a blast furnace automatically.

CONSTITUTION: The opening of the tap hole of a blast furnace 1 is accomplished by an automated hole opener 2 to be driven by pneumatic and oil hydraulic devices 2' and the exchanging of drill bars by an automatic changer 2". The molten iron and slag flowed out through the tap hole flow through a spout 3, and both are separated in a skimmer 4 and are distributively charged into a pan by tilting troughs 7 tilted by devices 7'. The respective charging rates are measured with a molten metal level monitoring device 8 and a weighing device 9 and when a constant amt. is filled in the pan, the distribution is changed over by an automatic driving device. The analysis of components and the measurement of temp. are accomplished as quality control for the molten iron by a temp. measuring device 5 which also serves as an automatic sampling device. The tap hole is closed automatically by a mud gun which is packed automatically. All the above-mentioned devices have measuring and operating controllers which are concentrated in a central control room, whereby all the commands in this room are automated.