DEVICE FOR JUDGING HOLE-OPENING CONDITION OF IRON TAPPING HOLE IN BLAST FURNACE

PROBLEM TO BE SOLVED: To provide a hole-opening condition judging device for executing the normal hole opening while surely judging a lateral hole opening and continuing the hole-opening work. SOLUTION: This hole-opening condition judging device is composed of a rotational angle detector 21 fitted to a chain feed motor 13 in a drilling machine 10 for iron tapping hole, a torque measuring instrument 22 for measuring the rotational torque of a drilling rod 12 fitted to a drifter 11, a computing element 25 for judging whether the opening is the lateral hole or the normal hole based on the result comparing the feeding speed of the drilling rod 12 calculated based on the information of the rotational angle detector 21 and a pre-inputted threshold value of the feeding speed, and the result comparing the measured value of the torque measuring the instrument 22 and a pre-inputted threshold value of the torque and means 29, 30 for displaying, printing or alarming the calculated result.