On the Airlift Experiment Using 200 m-Depth Vertical Water Tank

In this paper, the study on the performance of a 200 m airlift pump for water and highly-viscous shear-thinning slurry is introduced, mainly following the published paper [1]. The experiment was conducted using the facility in Advanced Institute of Science and Technology, Tsukuba, which had been used for the project of polymetallic nodule about 30 years ago. Here, in the present study, we investigate the airlift performance for the shear-thinning slurry which imitates the rare-earth mud water in the deep ocean. The experimental results showed that the airlift pump can work properly not only for water but also highly viscous slurry. It was confirmed that actual airlift performance obtained with the experiments does not show the reduction of the lifted liquid with increasing the gas flow rate, which the numerical results show the some deviation of the predicted value for high gas flow rate.