Abrasive water jet cutting system for deep sea use over 100m was developed experimentally. This report outlines the system composition and its possibility for practical use underwater. Two major problems which occur in underwater application were examined and solved. In order to avoid the rust problem of tube plugging in an abrasive feeding hose and unstable feeding of abrasive to nozzle bead, dry abrasive was slurried with high polymer and water. Slurry feeding rate was regulated by tube pump which located near the nozzle bead underwater. Abrasive transportation in slurry form enabled either batch of real-time loading to bopper even from the surface. Remotely and real-time supervising of the cutting results. i.e. cutting through or just kerfing is the second problem to be solved. Underwater sound pressure level and acoustic frequency by water jet were found to change significantly and immediately depending on the cutting results. Such acoustic characteristics was recognized to be very useful for developing the Simple. low cost and reliable supervising device.
Several types of abrasive water jet cutting system for underwater use have been surveyed and estimated for practical application (1. 2. 3). In those previous studies. two major problems were extracted (4). Transporting the abrasive with water cannot be a solution either because the stoppage of abrasive flow causes immediate abrasive settling and plugging in feeding bose. Second problem is the need of supervising devices of cutting results - cutting through perfectly or just kerfing - even in any cutting systems. This report outlines the newly designed underwater abrasive water jet cutting system which enabled smooth. continuous and regulated feeding of abrasive in deep sea over 100m. Underwater sound pressure level and acoustic frequency by water jet activity were also studied for developing the remotely supervising device of cutting results.