Blast hole drill rigs, also known as drilling rigs, are sophisticated pieces of heavy gear used for drilling blast holes in quarrying and mining activities. Proper drilling is necessary for effective blasting and excavation. To understand how blast hole drill rigs work, it’s vital to be familiar with their main components.
The Mast or Derrick
The mast, also called the derrick, is the main vertical support structure of the drill rig. It holds up the drill head assembly and provides height for drilling. Masts can extend upwards of 100 feet to reach drilling depths. They are composed of robust steel beams or tubes to withstand the tremendous loads and vibrations of drilling. Hydraulic cylinders or rack and pinion mechanisms are utilized to raise and lower the mast.
Drill Head Assembly
Mounted at the top of the mast is the drill head assembly. This holds the critical drilling components including the rotary drive, drill steel, and drill bit. The rotary blast hole drilling uses hydraulic motors and gears to spin the drill steel and bit at high RPMs for drilling into rock. Sensors offer feedback on drill parameters like RPM, pressure, and depth. Rotational power is transferred from the drive to the drill bit by the drill steel.
Drilling Pipe or Steel Processing Equipment
Drill steel lengths must be increased as holes go deeper. This process is overseen by the drill pipe/steel handling system. It has a pipe/steel elevator to grip and move sections, a rack to hold extra drill steel, and a cathead or spin table to join sections. When drilling and in between holes, hydraulic cylinders assist with the insertion and removal of drill steel.
Feed or Hoist System
The entire drill head assembly and attached drill steel are moved up and down in a vertical motion by the hoist/feed system in order to drill deeper. For drilling and steel removal, hydraulic cylinders offer strong pushing and pulling forces. Throughout the drilling cycle, feed rates and depths are precisely controlled by electronic sensors. The drill head, steel, and any cuttings in the hole must all weigh a significant amount, which the system must sustain.
Cab or Control Unit
The operator has a commanding view of the drill site and is enclosed in an elevated cab or control station. This is where all of the drilling functions, including feed, auxiliary systems, rotary drive, and mast movement, are controlled. Digital monitors provide real-time readings on drill settings. Switches, levers, and joysticks enable exact operation control. For precision, high-tech taxis also incorporate 3D modeling and GPS.
Underbelly
Mounted beneath the rig is the undercarriage system which contains the chassis, tracks or wheels, suspension, and hydraulic motors. The undercarriage offers movement across difficult terrain at job locations. Tracks offer more traction than wheels on soft or uneven ground. Hydraulic drive motors power the rails or wheels. Outriggers are also supplied for stability while drilling.
Auxiliary Systems
Additional systems on blast hole drill rigs include hydraulic power packs, lubrication, cooling, lighting, and more. Hydraulic power packs supply pressurized fluid to operate components like the mast, feed, and undercarriage. Lubrication and cooling systems keep components working smoothly. Lights illuminate the work area for nighttime operations. Electronic monitoring tracks service intervals and preventative maintenance needs.
Conclusion
In summary, while blast hole drill rigs may look complex on the exterior, understanding the purpose and function of its primary systems and components provides insight into how they efficiently and precisely drill blast holes for quarrying and mining applications. Drilling performance is maximized and safety is ensured by proper part maintenance and operation.
