SUB-ASSEMBLY FOR DUST SUPPRESSION IN ROCK DRILLING

摘要

This invention concerns an accessory, to be inserted in drillstring behind a drill bit, to provide separation of the liquid and aircomponents of a flushing medium. The accessory comprises aninner housing (36) within an outer housing (34). A liquid/gas mediumenters through opening (50) onto spiral raceway (48). Holes areprovided at intervals along spiral (42). Liquid in the medium iscentrifuged by the spiral (42) and projected into the chamber betweeninner and outer housings (36, 34). The expelled liquid (52) falls to thebase (70) of the housing (34) where it passes through apertures (38)into the drill bore. Once the medium has traversed the spiral (42)essentially only gas remains to pass through the opening (62) to thedrill bit.