Experimental study on water-jet deicing

The application of water jet in removing ice from river, sea or surface of objects has many advantages, such as no mechanical strike and damage, easy control and portability. While very few investigations have been carried out. So, experimental study of deicing by means of water jet is conducted in this paper. In the experiment, the ice is naturally frozen in a rectangular mold. And the ice is struck directly by water jet at the pressure of 6 MPa from a 1.4 mm-diameter nozzle. Under different target distances, the ice breakdown time, the details of impingement holes including inlet and outlet shapes as well as their diameters, and the cross-sectional shapes are obtained. It was found that at different target distances the inlets and outlets impingement holes were approximately circular, and the cross-sectional shapes didn't display much diversities. The inlets were shaped in cross-sectional direction like a trumpet and subsequently joined by a conical shaped passage. The shapes and the diameters of the outlets were basically unchanged. The inlets are enlarged as the target distance increases, consequently increasing the cross-sectional areas. Experiments indicate that break-through time per unit length will gradually increase with the increase of target distance. And under constant pressure, there exists a threshold value with respect to the distance, which means that the ice will no longer be removed once the jet pressure drops by a certain degree in the air. It is then found that there exists an optimal target distance of vertical jet deicing that maximizes the efficiency under constant pressure.