What is the process of DTH drilling?

Downhole hammer drilling is an efficient drilling method commonly used in medium to hard rock formations, and is widely used in mining, engineering blasting, water well construction, and other fields. Its core features are: the impactor is located at the bottom of the hole, directly acting on the rock, with low energy loss and high pore forming efficiency.

DTH drilling process flow

1、Installation and commissioning of DTH rock blasting drill rig

Before starting the homework, the connection and fixation of the DTH rock blasting drill rig, down the hole hammer, drill rod, and drill bit should be completed, and the gas supply system should be checked to adjust the pressure and exhaust volume of the air compressor according to the working conditions.

2、Activate the gas supply system

After the air compressor is running, high-pressure air enters the inside of the down the hole hammer through the drill rod, providing power for the impact operation of the DTH  rock blasting drill rig, while also undertaking the role of rock slag discharge.

3、Rock breaking by down the hole hammer impact

The down the hole hammer driven by compressed air will drive the internal piston to perform high-speed reciprocating motion during operation. The continuous impact energy generated by this motion will be directly transmitted to the drill bit, effectively crushing the rock at the bottom of the hole and completing the crushing operation.

4、Drilling tool rotation and propulsion

Crawler pneumatic DTH drilling rig can provide stable rotational torque and axial reciprocating thrust, enabling the drill bit to achieve continuous and efficient downward drilling under the combined action of impact and rotation.

5、Discharge of rock debris

The rock debris formed after rock fragmentation is carried out of the hole through the annular gap between the drill rod and the hole wall under the action of airflow, thereby maintaining the cleanliness of the hole bottom, which is conducive to the continuous drilling process and improving drilling efficiency.

6、Extension of connecting rod

When the crawler pneumatic dth drilling rig reaches the depth of a single rod, pause the operation first, connect a new drill rod, and continue drilling until the design hole depth is reached.

7、End and Inspection

After the dth rock blasting drill rig drilling operation is completed, the gas supply system should be turned off first, and then the drilling tool should be removed from the hole. Next, it is necessary to check the depth, diameter, and integrity and flatness of the borehole wall. Based on the inspection results, determine whether the drilling conditions meet the standards and requirements for subsequent construction.

Basic principle of down the hole hammer drilling

The core of down the hole hammer drilling is that the impact device is located at the bottom of the borehole. During the dth rock blasting drill rig construction process, compressed air enters the inside of the down the hole hammer through the drill rod, driving the piston to perform high-speed reciprocating motion, thereby generating sustained impact force that directly acts on the drill bit to break the rock. This method effectively reduces the loss of energy during transmission.

Technical advantage

Down the hole hammer drilling has the characteristics of high impact efficiency, stable drilling quality, and small deviation in hole orientation, making it particularly suitable for deep hole operations and high hardness rock environments. In addition, compressed air has both power and slag discharge functions, simplifying the construction process and helping to improve overall operational efficiency.