Application of Triangular Drilling Rod to Gas Drainage Borehole Drilling in Medium Soft Seam

In order to solve the drilling bit jammed,drilling bit buried,low drilling cuttings discharging,serious gas outburst,low mechanization level and others occurred when the conventional drilling rods applied to the borehole drilling in the medium soft seam or coal and gas outburst seam,a new triangular drilling rod was researched and developed.The new triangular drilling rod could have three half round clearances and increase the channel to discharge the coal dust and gas.With the stirrings around the drilling rods,the drilling cuttings would be suspended by the pressurized air and could be transmitted to the drilling mouth at the function of the air quantity and air velocity.According to the great site experiments in Dingji Mine,the disadvantages of the triangular drilling rods designed and applied were improved.The results showed that the triangular drilling rod could have high efficient borehole drilling completed along in medium soft seam.