A down-the-hole drill, usually called DTH by most professionals, is basically a jackhammer screwed on the bottom of a drill string. The fast hammer action breaks hard rock into small cuttings and dust that are evacuated by a fluid (air, water or drilling mud). The DTH hammer is one of the fastest ways to drill hard rock. The system is thought to have been invented independently by Stenuick. Origin of the nameDTH is short for “down-the-hole”. Since the DTH method was originally developed to drill large-diameter holes downwards in surface-drilling applications, its name originated from the fact that the percussion mechanis. .
In DTH drilling, the percussion mechanism – commonly called the hammer – is located directly above the drill bit. The drill pipes transmit the necessary feed force and rotation to the hammer and the bit, along with the flui.
[pdf] (2) Elimination measures: First, adjust the pipeline to eliminate air leakage, increase the diameter of the air supply pipe, and reduce the gas consumption equipment; and whether the reversing valve is lost, damaged or stuck; the third is to add oil to the lubricator, replace the polluted lubricating oil, clean or blow through the small holes of the oil circuit; the fourth is to replace the broken water needle and replace the brazing rod that blocked the center hole The fifth is to knock off the condensed ice cubes; the sixth is to replace the worn parts in time; the seventh is to reduce the water pressure and overhaul the water injection system.
[pdf] (2) Elimination measures: First, adjust the pipeline to eliminate air leakage, increase the diameter of the air supply pipe, and reduce the gas consumption equipment; and whether the reversing valve is lost, damaged or stuck; the third is to add oil to the lubricator, replace the polluted lubricating oil, clean or blow through the small holes of the oil circuit; the fourth is to replace the broken water needle and replace the brazing rod that blocked the center hole The fifth is to knock off the condensed ice cubes; the sixth is to replace the worn parts in time; the seventh is to reduce the water pressure and overhaul the water injection system.
[pdf] 
