Shaft sinking companies are showing an increasing interest in the use of shaft drill rigs equipped with high-performance hydraulic rock drills. Therefore dhms has developed all-hydraulic shaft drill rigs with three or four-drill booms now.
The rigs are available in flameproof or non-flameproof versions.
The first all-hydraulic shaft drill rig with four booms will be delivered to the China Coal Mine Construction Group Corporation (CCMCGC) in Hefei, Anhui province, China later this year.
It is planned for use during sinking of new shafts for development of new mines or mine extensions.
The new all-hydraulic shaft drill rig dh SDH4 provides a number of benefits compared with conventional pneumatic or semi-hydraulic versions regarding following aspects:
- Increased drilling speed during blasthole drilling
- Increased drilling speed and drill depth during extension drilling (eg. injection holes)
- Simple and quick change between rotary or rotary percussive drilling mode and therefore easy adaption to varying rock conditions
- Improved drilling control (collaring, anti-jamming system)
- Avoiding of lubrication oil mist
- Reduced noise level
- Reduced compressed-air consumption (compressed air is only needed for drifter lubrication or flushing)
The high drilling speed achieved by using hydraulic rock drills means that the rig can operate with fewer drill booms. Thus time for erecting at shaft bottom and number of operators can be reduced.
The drill feeds fitted to the new rig feature a cylinder system that delivers high-thrust and pull-back forces. They also come with a hose reel and can be equipped with a hydraulic clamping device for extension drilling and a dust suction hood for air flushing.
A choice of rock drills is available and clients can opt for the powerful dh DP15 drifters or rotary drills of the dh DR series. Rock drills can be changed with very little effort.
One or two tailor-made, electro-hydraulic power packs are installed on the shaft platform to provide the drive energy. Special measures have been put in place to protect the power packs from water ingress.
The drive station can be coupled to the drill rig after the latter has passed through the lower shaft platform and then uncoupled again for the return trip. The connections comprise two hydraulic pressure lines, one return line and one oil drain line, plus the supply lines for flushing water or air. Zero-leakage hydraulic quick-couplers are used.
The electrical connections comprise a power cable for the 24V DC supply and a data transmission cable. Special connectors are used for the interconnection points, while control commands are sent from wireless remote controls. A separate console is provided for each drill boom and each control console can be switched over between the different booms.
Similar to the compressed-air equipment the rigs can be folded up umbrella-like for in-shaft transport and are designed for a maximum transport diameter of only 1,900mm.
After reaching the shaft bottom the dh SDH4 is positioned in the shaft center and braced by three struts to the shaft wall. Then the drill booms are brought into drilling position. To match uneven shaft floor conditions the tripod can be adjusted hydraulically.
Image: The new hydraulic shaft drill rig dh SDH4. Photo: courtesy of dhms.