Blast furnace having a cooling device

In a blast furnace having a hearth bottom and a foundation, the improvement comprising:

• a course of hearth bottom bricks;
• a first group of cooling fluid passages horizontally disposed between said course of hearth bottom bricks and said foundation for controlling the temperature of the hearth bottom;
• a second group of cooling fluid passages horizontally disposed adjacent to or in said foundation for directly controlling the temperature of the foundation;
• a heat insulating layer interposed between said first group and said second group of cooling fluid passages permitting said first and second groups of cooling passages to respectively control the temperatures of the hearth bottom and foundation independently;
• and
• a cooling fluid supply device connected to the first and second cooling fluid passage groups, said supply device supplying a cooling fluid to each of said groups of cooling fluid passages so that the cooling capacity of each group can be adjusted independently of the other.

A blast furnace, comprising:

• a foundation;
• a hearth bottom having hearth bottom bricks;
• a first group of cooling fluid passages horizontally disposed between said hearth bottom bricks and said blast furnace foundation for controlling the temperature of the hearth bottom;
• a second group of cooling fluid passages horizontally disposed adjacent to or in the blast furnace foundation for directly controlling the temperature of the foundation;
• a heat-insulating layer interposed between said first group and said second group of cooling fluid passages permitting said first and second groups of cooling passages to respectively control the temperatures of the hearth bottom and foundation independently;
• means for measuring the temperature inside the hearth bottom using a plurality of temperature measuring elements disposed therein;
• means for computing, based upon the measured temperature, and the heat conductivity and thickness of the hearth bottom bricks, the thickness of any deposit that may have formed on the top surface of the hearth bottom;
• and
• means for either or both (a) changing the kind and (b) adjusting the flow rate of a cooling fluid passed through the cooling fluid passages so that the deposit does not exceed a predetermined thickness.

A blast furnace having a cooling apparatus for controlling the temperature of the furnace's hearth bottom and foundation comprising:

• a foundation;
• a hearth bottom;
• a first group of cooling fluid passages horizontally disposed between said hearth bottom and said blast furnace foundation for controlling the temperature of the hearth bottom;
• a second group of cooling fluid passages horizontally disposed adjacent to or in the blast furnace foundation for directly controlling the temperature of the foundation;
• a heat insulating layer interposed between said first group and said second group of cooling fluid passages permitting said first and second groups of cooling passages to respectively control the temperatures of the hearth bottom and foundation independently;
• means for measuring the temperature at a predetermined point within the hearth bottom;
• means for computing, based upon the measured temperature and known parameters including the heat conductivity of the hearth and its thickness, the thickness of a deposit formed on the top surface of the hearth bottom;
• means for comparing the thickness, so computed, with a predetermined desired maximum thickness, and
• means for controlling, via said cooling apparatus, the temperature of the furnace's hearth bottom so as to control the thickness of the deposit so that it does not exceed the predetermined maximum thickness.