| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a hole opening bit for taking out pig iron and the like melted in a furnace from a tap hole of a blast furnace for iron-making or a melting furnace/ash melting furnace of various waste materials, capable of rapidly and uniformly discharging mud granules generated during hole opening so as to achieve efficient tap hole opening operation and effective cooling of bit edge surface and tool bits.SOLUTION: A striking surface 6 is provided with a plurality of tool tips 7 which strike mud at a point of contact, a fluid ejection hole 9 through which a blowing fluid supplied from a hole opening device is ejected, and a mud granule guiding groove 8 which guides mud granules generated by striking. A side peripheral surface is provided with a guide surface 5b that is in contact with the inner wall of the opening hole and guides the striking surface 6 to a normal hole opening position, and a granule discharging notch 5a through which the mud granules guided by the mud granule guiding groove 8 are discharged behind a tap hole opening bit 1, the granule discharging notch 5a being connected to the mud granule guiding groove 8.</p> |
