Explain construction of blast hole drill
BLAST HOLE DRILL: Roller bit drill cuttings are flushed out by compressed air is known as blast hole drill.In our country 150,260and310mm dia.electric blast hole drills are commonly used in opencast mines.Blast hole drill are crawler mounted.By adding drill rods one after another deep holes can be drilled.For dragline benches 40m or even longer holes are required.Feed mechanism of the drill is by hydraulic pumps.Drill rood is fitted in a long mast.For adding drill rods or for bit changing rod changer or carousel of the machine is used.Rod length is generally 10-12m Depending on the model,the machine can drill holes of upto 3-5rods.Blast hole drills are equipped with 3hydraulic jack for leveling the m...