In Down The Hole (DTH) hammer drilling works, when the piston inside the hammer hits the bit, the power produced creates a shock wave on the rock. When a pressure is applied with the bit under load, a connection surface is created between the bit and the rock due to this pressure. The counter reaction shown by the rock against this pressure, depends on the characteristic feature and pressure load of the rock.
Tungsten carbide tips inserted on the bit, apply a load in each stroke of the piston inside the rock drill. This whole process is realized depending upon the rock drill working at a very high frequency. During this process, between 1000 and 2400 impacts are created. At each impact, the propagation of buttons inside the rock is 1mm in average at each impact, depending upon the hardness degree of the rock.
The hammer should be selected in accordance with the compressor capacity used currently. It must be known that the hammer compressor would use average 85% of air production capacity. The bit should be selected in the manner that would be suitable for making the most effective drilling in accordance with the rock type. The compressor, on the machine or as a separate unit, makes the air conveyed into the system. The purpose here, is to convey the air into the hammer with minimum loss. The air flow is compressed and reinforced inside the hammer, and it activates the hammer whose mode of operation has been adjusted as a cycle. During one cycle of the piston, the air is swung from the hammer twice and this gets the water and rock fractures carried away, which are created during the drilling. The purpose here, is to spend the air in the most effective way. DTH (Down The Hole) drilling process, approximately 85% of the energy coming from the piston, reaches the connection surface between the rock and the bit.