| 摘要 |
The invention relates to a method for deep sea mining comprising; - generating an upward flow of valuable matter in a riser line from the bottom of a body of water to a matter processing platform, - processing the matter at the processing platform, - generating a return flow in a return pipe of a mixture of seawater and a non- valuable part of the matter from the processing platform towards the bottom of the body of water, - controlling the pressure in the return pipe for avoiding collapse of the return pipe and/or cavitation of the return pipe, in particular for avoiding collapse of or cavitation in an upper part of the return pipe. |
