Abstract: A hole-opening bit that can simplify an operation for opening a tap hole for installing a burner lance for raising the temperature of a furnace bottom of a blast furnace, which allows the blast furnace to be started up in a relatively short time after long-time blast stoppage or after a furnace cooling accident, by efficiently heating the furnace bottom, and a tap hole opening method using the hole-opening bit. A hole-opening bit used to open the tap hole in the furnace bottom of the blast furnace including chips on rear surfaces of a furnace drilling surface of the hole-opening bit such that outermost ends of the chips are located inside of an outermost end of the hole-opening bit.

Abstract: A blast furnace operation method comprising a blast furnace to start up smoothly and perform operation after suspending air blowing by removing as much as possible residual coke that remains inside the furnace during suspension of air blowing and becomes an obstacle to discharging solidified matter. In this blast furnace operation method, air blowing is suspended with the height of a surface of a raw material-filled layer immediately above a blast-furnace tuyere reduced below the height of an upper end of a blast-furnace bosh and then air blowing is resumed. After air blowing into the blast furnace is suspended, oxygen or oxygen and a combustible gas are blown in through a burner inserted into a taphole to combust coke remaining inside the furnace and reduce the volume of residues inside the furnace, and after new coke is charged to a region where the volume decreased, air is blown through a tuyere.

Abstract: A method of heating up a furnace bottom and a burner lance used in the method are proposed. The method of heating up the furnace bottom includes a step of opening, in the tap hole, a burner lance insertion hole having a diameter larger than a diameter of the burner lance so as to penetrate into the furnace, a step of installing the burner lance in the opened burner lance insertion hole, a step of filling a gap between the installed burner lance and a furnace exterior side of the tap hole with a refractory, and a step of blowing in gas for heating into the furnace from the burner lance to heat up the furnace bottom.

Abstract: A hole-opening bit that can simplify an operation for opening a tap hole for installing a burner lance for raising the temperature of a furnace bottom of a blast furnace, which allows the blast furnace to be started up in a relatively short time after long-time blast stoppage or after a furnace cooling accident, by efficiently heating the furnace bottom, and a tap hole opening method using the hole-opening bit. A hole-opening bit used to open the tap hole in the furnace bottom of the blast furnace including chips on rear surfaces of a furnace drilling surface of the hole-opening bit such that outermost ends of the chips are located inside of an outermost end of the hole-opening bit.

Abstract: An acoustic characteristics optimization model analysis apparatus includes a finite element model generation unit; a boundary element model generation unit; an acoustic transfer function calculation unit; a nodal point association unit; and a sound pressure calculation unit that incorporates the plurality of nodal points of the finite element model correlated with the plurality of nodal points of the boundary element model by the nodal point association unit into the acoustic transfer function calculated by the acoustic transfer function calculation unit to calculate a sound pressure transmitted from the finite element model to the predetermined position.

Abstract: An acoustic characteristics optimization model analysis apparatus includes a finite element model generation unit; a boundary element model generation unit; an acoustic transfer function calculation unit; a nodal point association unit; and a sound pressure calculation unit that incorporates the plurality of nodal points of the finite element model correlated with the plurality of nodal points of the boundary element model by the nodal point association unit into the acoustic transfer function calculated by the acoustic transfer function calculation unit to calculate a sound pressure transmitted from the finite element model to the predetermined position.