Development of Impact Test System for Waterjet Descaling Nozzles with LabVIEW

High-pressure water jet technology is widely used in hot-rolling billet descaling process. Impact force and behavior of jets play a vital role on effect of water jet billet descaling. The parameters of nozzles and jet determine the characteristics of jetting. Some of these parameters, however, can only be obtained through experimentation. The mechanism of high-pressure water jet billet descaling was analyzed in this paper. The factors affecting billet descaling were also discussed. Furthermore, theoretical formula accounting for water jet impact force was derived from the discussion. An indoor test set-up investigating impact properties of water jet descaling nozzles was established. Virtual instrument Lab VIEW was combined with mathematics software MATLAB to develop a measuring system of the test set-up. The real-time test of descaling nozzles parameters can be achieved through the system. The measuring system included three modules: pressure-flow curve, three-dimensional platform movement track and jet impact force measurement. Various parameters of the nozzles and jet can be obtained by means of the modules. Experimental results were compared with theoretical ones and observations were made regarding the variation of parameters. Results showed that variation of the parameters yielded by experiments agreed well with theoretical prediction. Variation of each parameter was visually depicted. The impact force and behavior of the jet were accurately measured. It contributes to descaling nozzle design improvement and descaling system structure optimization.