Research on cooling technology of shredder cutting tool with ultrasonic vibration-assisted cutting

Abstract

To improve service life of shredder cutters, new technologies such as ultrasonic vibration-assisted cutting and cooling technology (jet and spray) are introduced into the design of the cutter for a two-axis horizontal shredder. Ultrasonic vibration-assisted cutting technology is theoretical analyzed, and result shows that the effect of friction reduction only happens when the speed of cutting is less than vibration speed. Therefore, the vibration-assisted cutting get a friction reduction of 52.5% and a cutting temperature reduction of 10.5% when the vibration-assisted cutting with an amplitude of 25μm and a frequency of 20 kHz is performed on the shredder with the rotational speed of 60 r/min. Three cooling methods are proposed to lower the temperature of shredder tools such as air jet cooling, water jet cooling, and spray cooling. They are all simulated with Ansys-fluent software on the basis of the Lagrangian model. Simulation results show that water jet cooling can realize better cooling effect, whereas its cooling effect will not improve obviously until the jet diameter increases to around 4 mm. In addition, the cooling effect of the spray with vibration cutting which has less coolant consumption is very close to that of the water jet without vibration cutting. Therefore, the mode of spray cooling with vibration cutting can be used instead of the mode of water jet cooling for higher coolant utilization. By comparing with the traditional cutting of shredder, the spray cooling with vibration cutting has a cutting temperature reduction of 65%.