With 70,000 lb pullback and 28,000 lb pulldown, the water well drilling rig MARK70 proves its strength among the Versa-Drill fleet. Its exceptional, easy-to-use technology makes its compressor air drilling.
[pdf] 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] Continuous full-load operation (load rate>90%) accelerates component wear and may shorten life to 6-8 years. Reasonably control the load rate (recommended 70%-85%), and avoid frequent starts and stops through frequency conversion control or air tank adjustment.
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