Energy saving analysis of the hydrostatic drives used in the rotary head system of the blast hole drill rig

Abstract

Blast hole drill rigs are used for drilling the soft and the medium-hard rocks in open-pit mines. In such rigs, the drill bit is rotated by a hydrostatic drive. In this respect, two different type hydrostatic drives have been considered. In the first drive, the rotation of the drill bit takes place by a variable displacement pump and two low-torque high-speed hydro-motors along with a step-down gear unit (i.e. LTHS drive), whereas in the second drive an identical pump and a high-torque low-speed hydro-motor (i.e. HTLS drive) rotate the drill bit. In this study, the energy saving analysis of the above mentioned hydrostatic drives has been performed with respect to the load profile of the blast hole drilling. In this respect, the modelling, simulation and the experimentation of the drives have been carried out. Simulations have been performed in MATLAB–Simulink environment and it has been verified through experiments. The proportional-integral-derivative control algorithm has been used to control the drives speed in various loading stages. Results show that the high-torque low-speed drive save more energy compares to the low-torque high-speed drive for the usual operating range of the blast hole drilling.