Rapid air drill is the new method for drilling in ice sheets and glaciers to depths of up to 500-600 m, in which cuttings and cores are continually transported by air reverse circulation. The method employs dual wall drill rods. The inner tubes provide a continuous pathway for the chips and cores from the drill bit face to the surface. The original cutter drill bits and air processing devices (air-cooled aftercoolers, air receivers, coalescing filters, desiccant dryers) are used. The airflow velocity for conveying a 60-mm diameter and 200-mm long ice core should not be lower than 22.5 m/s, and the minimal airflow rate for continual chip and cores transport is 6.8 m3/min at 2.3−2.6 MPa. Drilling of a 600-m deep hole can be accomplished within 1.5 days in the case of twenty-four hour drilling operations. The drill system is on the stage of project design.
Rapid air drill