Simulation of the Chip Removal Process for Anchor Rod Drilling Rigs and Influencing Factors Analysis

The process of rock debris discharge from the drill hole is a dynamic process, which was influenced by multiple factors. Research on the rock debris discharge process and its influencing factors is significant for the design of anchor drill machines. In this paper, the CFD software was used to simulate the rock debris discharge process in the anchor drill machine by the multi-phase coupling method, and the influence mechanism of the inlet and outlet pressure changes on the discharge process was analyzed. The results show that under the same conditions, the smaller size of rock debris will obviously influenced by the gas phase, and it can move to the outlet position quickly. And the retention time in the drill hole will longer, when the particle size of the rock debris is larger. There will be a critical value for the inlet and outlet pressure. When the inlet pressure reaches a certain pressure, the discharge rate of the rock debris particles will reach a relatively large value and remain relatively stable over time. When the outlet maintains a high negative pressure state, the flow velocity at the outlet will be higher than that of the fluid in the drill hole, and the rock debris discharge efficiency will also increase. When the outlet pressure is equal to or higher than the operating pressure, the discharge speed of the rock debris will significantly decrease, and the accumulation of rock debris particles will occur at the bottom.