Study On The Change Law Of Drilling Index Of Mining Drill And Its Chip Removal Performance

Along with the continuous increase of coal mining intensity in China,the recoverable amount of shallow coal seams is decreasing year by year,and deep mining has become an inevitable trend of coal mining in mining areas.However,with the increasing frequency of impact dynamic disasters encountered in the deep mining of coal seams,the recovery of deep coal seams has great potential safety hazards.In this context,this paper proposes the drilling process through mining rigs.The research on the change law of some related indicators to predict the possibility of the occurrence of impact dynamic disasters has a strong practical guiding significance.Aiming at the problems studied in this paper,on the basis of the analysis and research on the mechanics mechanism of coal drilling rock drilling,the changes of the two drilling indexes of the drill pipe speed and the cuttings volume and the internal part of the coal and rock mass are analyzed by theoretical means.The relationship between the magnitude of the stress,and the influence of the drilling speed on the variation of the two,and the laboratory tests and field drilling experiments were carried out on the basis of the developed drilling equipment,and the different factors were fully studied.The variation law of the drill pipe speed and the amount of drill cuttings is affected.At the same time,this paper fully considers the influence of low drilling efficiency and other problems on the continuity of the borehole during the actual drilling process,and in order to improve the internal stress of the coal and rock mass and the degree of concentration in order to improve the drilling rod rotation speed and the cuttings amount index when drilling.Accuracy,the necessity of researching the chip removal performance of the drill pipe is proposed,and the research content of the variation law of the drilling index is supplemented.On the basis of analyzing the theory of chip removal characteristics of drill pipe,the coal body model was reconstructed by EDEM,and the influence of drill pipe speed and drill pipe pitch on the chip removal performance of drill pipe was studied.The research results show that under certain conditions :The coal body stress and the drill pipe speed are roughly negatively correlated;there is a roughly positive correlation between the coal body stress and the cuttings amount;the drilling speed has a greater influence on the drill pipe speed,and the two are basically negative.The relationship of the exponential distribution;the amount of cuttings and the drilling speed approximate a power function relationship within a certain range.It can be seen that in the actual drilling process,the internal stress of the coal and rock mass and the degree ofconcentration can be reflected side by the change rule of the two indexes of the drill pipe speed and the cuttings amount,so as to show the possibility of dynamic disasters.Sex size is predicted,but this process requires a limit on the drilling speed of the rig.At the same time,it is also proposed that within a certain range,appropriately increasing the rotational speed and pitch of the drill pipe can increase the chip removal performance of the drill pipe,so the entire drill process needs to select the appropriate drill pipe speed and pitch.By studying the chip removal performance of the drill pipe,not only the drilling efficiency can be improved,but also the variation law of the measured drilling index can more accurately reflect the magnitude and concentration of the coal body stress in different regions of the coal rock body to reduce The prediction error on the probability of the occurrence of an impact dynamic disaster.This thesis has 72 figures,13 tables and 78 references.