An abrasive water-jet cutting process is one inwhich water pressure is raised to a very high pressure andforced through a very small orifice to form a very thin highspeed jet beam. This thin jet beam is then directed througha chamber and then fed into a secondary nozzle, or mixingtube. During this process, a vacuum is generated in the chamber,and garnet abrasives and air are pulled into the chamber,through an abrasive feed tube, and mixes with this high speedstream of water. Because of the restrictions introduced by theabrasive feed tube geometry, a vacuum gradient is generatedalong the tube. Although this phenomenon has been recognizedand utilized as a way to monitor nozzle condition andabrasive flowing conditions, yet, until now, conditions insidethe abrasive feed line have not been completely understood. Apossible reason is that conditions inside the abrasive feed lineare complicated. Not only compressible flow but also multiphase,multi-component flow has been involved in inside ofabrasive feed tube. This paper explored various aspects of thevacuum creation process in both the mixing chamber and theabrasive feed tube. Based on an experimental exploration, ananalytical framework is presented to allow theoretical calculationsof vacuum conditions in the abrasive feed tube.
Shijin Zhang Xiaohong Li Yilei Gu College of Resources and Environmental Science,Chongqing University, 400044 Chongqing, China
