Experimental investigation and statistical analysis of operational parameters on temperature rise in rock drilling

Abstract

Heat generated during rock drilling, due to friction at the bit-rock interface. Due to which temperature increases, which can influence the thermal stress and subsequent rock failure. In this paper, an attempt is made to present results related to the temperature assessment during rotary drilling of rocks on medium-grained sandstone under controlled laboratory conditions. The experiments were conducted by using embedded thermocouple technique, the thermocouple was placed at a distance of 0.5mm (horizontal) from the bit-rock interface. The influence of operational parameters, i.e., the diameter of the drill bit, spindle speed and rate of penetration of rise in temperature was studied using multiple regression and data analysis was carried out using analysis of variance (ANOVA). The temperature was measured by using embedded thermocouple technique at a depth of 6mm, 14mm, 22mm and 30mm respectively. Regression models were developed for the prediction of temperature at the bit-rock interface. It was observed that the increase in temperature for medium-grained sandstone was from 49 0 C to 74 0 C (51.08%) with an increase in the diameter of the drill bit, spindle speed and rate of penetration.