Pneumatic Rock Entry Related Technology Introduction for Rotary Drilling Rigs

Pneumatic rock entry technology for rotary drilling rigs is an efficient drilling method, which is especially suitable for hard rock drilling under complex geological conditions. The following is a detailed introduction of this technology:

I. Overview of pneumatic rock entry technology

Pneumatic rock drilling technology mainly includes two kinds of methods, namely, air-lift backslag and pneumatic impact crushing rock drilling. This way has application cases in foreign countries, but it is relatively rare in the actual construction in China. It is through the use of compressed air as a driving force, drive pneumatic submerged hammer and other devices for drilling, with high drilling efficiency, environmental protection and clean and other advantages.

ll, pneumatic into the rock technology principle

Pneumatic lift back slag:

Pneumatic lift back slagging is to use compressed air to blow up the rock chips from the bottom of the hole and carry them to the surface for discharge through the center channel of the drill pipe.

This process requires a pneumatic swivel to prevent the air line from rotating and to provide a steady flow of compressed air to the drill bucket.

Pneumatic lift back slag can effectively prevent rock chips from clogging the drill bit and improve drilling efficiency.

Pneumatic impact crushing into rock:

Pneumatic impact crushing into rock is through the impact force generated by pneumatic submerged hammer directly transferred to the drill bit, forming a pulsating crushing ability to the rock.

At the same time, the compressed air excluded by the impact is utilized to cool the drill bit and discharge the crushed rock particles.

In the process of pneumatic submerged hammer drilling, the rotary movement of the drill bit is driven by the drilling rig on the ground, thus realizing the continuous drilling of the rock.

III. Pneumatic Rock Entry Technology Equipment

Pneumatic submerged hammer:

Pneumatic down-the-hole hammer is the core equipment of pneumatic rock drilling technology, which is powered by compressed air to produce axial impact movement, driving the hammer to break rock.

Pneumatic down hole hammer is divided into two categories: monobloc type and cluster type, and the cluster type down hole hammer has more advantages in terms of maintenance and caliber adaptability.

Drill pipe and drilling tools:

Drill pipe is an important part for transmitting compressed air and torque, and it usually adopts double-wall drill pipe structure, forming an annular gap between inner and outer pipes and two channels in the center pipe.

Drilling tools include tooth wheel bits, auger bits and so on, which are used to adapt to different stratigraphic conditions. Among them, the tooth wheel bit performs well in hard rock drilling, but it needs to be matched with air-lift anti-slag device to prevent clogging of rock chips.

Auxiliary equipment:

Auxiliary equipments include air compressor, dust removal device, cyclone dust collector, etc., which are used to provide compressed air, collect and treat rock chips, and reduce dust pollution.

Fourth, pneumatic rock technology application cases

In actual construction, pneumatic rock drilling technology has been applied to many hard rock drilling projects. For example, in bridge construction, high-rise building foundations and other infrastructure projects, when encountering complex geological conditions, pneumatic rock drilling technology can provide efficient and environmentally friendly drilling solutions. By optimizing the drilling tool configuration and adjusting the drilling parameters, the drilling efficiency and hole formation quality can be further improved.

Translated with DeepL.com (free version)