Cooling blast furnace hearth with inbuilt plates - each having coolant pipes alternatively connectable to emergency high pressure coolant supply

The lower region of a blast furnace is cooled by plates interposed between the lining and the shell. The plate are in horizontal and vertical rows and each plate includes coil pipes arranged in two planes parallel to the shell. The coil pipes are connected in vertical rows. In one of the planes in each plate there are >=2 coil pipes, those pipes in the uppermost row of plates being connected to corresp. pipes in plates cooling the upper region of the furnace while those in the lower row are connected to normal pressure coolant supply lines. In the other vertical plane there is one pipe per plate which can be connected either to the normal collant supply or to an emergency high pressure supply, both coolants being collected from the uppermost row of the lower region. If molten metal penetrates the lining the high pressure coolant supply is brought into use to increase heat extn. and prevent breakout of molten metal.