Core Drilling Equipment-Drilling Rig
1. Which are the disadvantages of a mechanical core drill as compared to a hydraulic core drill?
* Very bad control of the rpm
* Bad control of the feed force
* Extremely bad rod handling
2. What limits the depth capacity of a core drill?
* The drill rigs lifting force
* The torque
3. Which are the main components of an underground core drill?
* Feed frame
* Rotation head
* Rod holder
* Skid frame with positioning arm
* Wire-line winch
* Control panel
* Power unit
4. Describe the advantages of APC drilling as compared to manual drilling.
* Supervision of all drilling parameters:
- Less risk for getting stuck with the drill string
- Better penetration rate and bit life
- Less hole deviation
* Drilling during breaks
- Higher productivity
- Possibility for one-man operation
- Lower drilling costs.
5. Which are the advantages, from a driller point of view, with a long feed stroke as compared to a short feed stroke?
* Less re-chucking operations
* Less risk for a core blockage
6. Describe the function of a mechanized rod handling system on an underground core drill.
* The rotation head is in its front position on the feed frame
* The chuck closes and grips the drill rods while the rod holder opens.
* The feed cylinder makes a full backward stroke placing the rotation head in its rear position on the feed frame.
* The rod holder closes and grips the drill rods while the chuck opens and releases the drill rods.
* The feed cylinder makes a full forward stroke returning the rotation head to its front position on the feed frame.
* Point 1 – 5 is repeated until a threaded coupling is placed in between the chuck and the rod holder.
* The chuck as well as the rod holder grips a drill rod on each side of the threaded coupling.
* The chuck is rotated clockwise until the thread is opened.
* The lose drill rod is manually lifted from the feed frame to the rod rack.
7. Why is a rigid set up especially important for core drills?
* To avoid harmful vibrations
* For a correct alignment of the core drill.
Source: https://www.cgegtech.com/
Geo Equip Tech Wuxi, CGET Wuxi
*Without permission, it cannot be reproduced, and the source of the reprint must be indicated.*
