The invention discloses a multiple step type drilling and protecting integrated
system and a process for a soft
coal seam. The
system mainly comprises an
air compressor, a high-pressure rubber hose, a hole protecting drilling
machine, a rack, a hole protecting drilling rod, a guider and a simple
drill. The process comprises the steps of firstly drilling a hole by using a common drilling rod and a common
drill and pulling the common drilling rod and the common
drill out of the hole after the hole is formed; then performing second drilling of the formed
drill hole by using the hole protecting drilling rod and the simple drill in a matching mode, and simultaneously performing wind-power auxiliary slagging, when an end hole point is drilled, the hole protecting drilling rod is not withdrawn, the
whole body is left inside the hole, and hole wall supporting and gas extraction functions are achieved; and finally pulling out and recycling the hole protecting drilling rod through the hole protecting driller after the gas extraction is completed. According to the
system and the process, the process is unique, a hole protecting
pipe can transmit high-pressure air and can extract gas, the
coal dust discharging performance is strong, the hole protecting
pipe moves forwards along the
drill hole easily, the hole protecting
pipe diameter is large, the hole protecting length is long, the problems that the soft
coal seam is small in hole protecting pipe
diameter and short in feeding distance are solved, and the system and the process are particularly suitable for soft high gas coal seams with a value of a sturdiness coefficient f, which ranges between 0.3 and 0.8.