Background
Hydropower is central to energy development in southwest China, and more large projects are moving higher and deeper into remote mountain gorges. On these sites compressed air powers drilling, anchoring and grouting, and reliable supply directly affects progress.
Challenge
The project lies in a high mountain gorge. Dam foundation and slope treatment required anchor drilling and consolidation grouting at the same time, with many air points over a long schedule. The site is far from towns, so diesel had to be hauled in at high and uncertain cost; some faces were underground, where diesel exhaust adds to ventilation load; and diesel engines lose power at altitude.
Solution
With site power available, M Series electric portable units were chosen: the DM250-31/25 (31 m³/min @ 25 bar) for high-pressure anchor drilling and DM185 units for medium-pressure grouting and hole cleaning. Motor output is unaffected by altitude and no fuel is needed.
Results
All units run on the site grid, so diesel storage and haulage were eliminated; no exhaust in the caverns eased ventilation; and output was unaffected by thin air, avoiding the derating diesel units suffer at altitude. The units ran steadily through the main construction period and met the air demand for foundation and slope treatment.
