Condition Monitoring of Orifice in Abrasive Waterjet Cutting System Using High Pressure Sensor

The health of orifice plays an important role in the performance of any abrasive waterjet injection system. The condition of orifice is quasi-static since its geometry changes with time due to the erosive nature of water jet. This results in poor jet quality, ineffective entrainment of abrasives and subsequently poor cutting performance and reduced life of focusing nozzle. In order to assess the health of orifice, an attempt is made to monitor the condition of orifice by monitoring the pressure of water closer to orifice i.e. at the upstream side, employing a high pressure sensor. In this work, the static and dynamic status of pressure inside the mixing chamber is studied for various orifices, including good and bad orifices. Further, the optical examination of orifices and the visualization of jet emerging out of these orifice supplemented this study. At the end, a strategy is evolved for assessing the condition of the orifice.