Depending on the application, hole size and available space and equipment, a number of different drilling methods are used in Underground Mining, including Top-Hammer, DTH (or ITH) or simpler equipment like jackleg drills. Whatever the drilling method, they have one thing in common, they all need compressed air at enough volume and pressure to flush the hole during drilling or actuate the percussion mechanism or for both actions.
Down-The-Hole (DTH) or In-The-Hole (ITH) drilling is used normally when larger diameters and longer holes are needed. It may be used to blast and cut holes or for service holes in underground mines like ventilation or drain holes at quite larger diameters which consume much more compressed air.
National Compressed Air (NCA) offers electric driven, rotary screw air compressors and booster air compressors suitable for operation in underground mines, capable of operating different drilling methods and using all sizes of DTH hammers. NCA also offers lightweight, small sized compressors with easy portability in tightly spaced underground mines.