動吸振器と段付管によるマンガン団塊採鉱用揚鉱管の縦振動と軸応力の抑制

抄録

In order to reduce the longitudinal vibration and axial stress of the pipe string for mining manganese nodules from deep-sea floors by a pump-lift system, the string is assumed to be a two-stepped pipe string with larger diameter in the upper part. Moreover, a buffer and two pump-modules attached to the string are equipped with a vibration absorber. Then, the longitudinal vibration and axial stress caused in the string by the heave-motion of the mining ship are analyzed theoretically for practical cases. The result indicates that the maximum amplitude and axial stress in the uniform pipe string could be reduced by about 55 % and 42 %, respectively if the string were replaced by the two-stepped pipe string with the same mass and with the buffer having a vibration absorber.