| 摘要 |
PROBLEM TO BE SOLVED: To attenuate tube wave in a mine shaft. SOLUTION: The attenuator has a body 10 composed of a permeable substance including a rigid basic material saturable with fluid. In the simplest form, the attenuator has one or more tubular bodies 10 constituting a part of a mine shaft sound wave detection layer system. The shape can be modified, especially in the area of end part, to reduce refection of tube wave in mine shaft. An alternative attenuator has a body 10 mode of an attenuating substance being disposed in mine shaft and shaped such that the impedance of sound wave in mine shaft varies not abruptly but gradually. One especially suitable body 10 has diameter increasing toward the center and formed of two conical bodies arranged while connecting the bases or of a tube having conically tapered end parts. |
