Reverse Circulation Drill

Reverse Circulation Drill is also called central sample collection or double wall reverse circulation drilling pipe. This type of drilling usually uses double-walled drill pipe. Drilling power is high wind pressure gas. The compressed air enters the hammer through the gap between the outer tube and the inner tube, so that the hammer hits the drill bit to break the rock formation. The rod inner tube collects rock samples.

Advantages of reverse circulation drilling hammer bit：
1. No pollution
The reverse circulation air drilling hammer can quickly extract samples on the drill bit face at the moment of rock breaking. The sample does not need to travel the length of the hammer, thus avoiding sample contamination and loss.

2. High productivity
In broken and fractured rock formations, reverse circulation hammers are stronger than ordinary impactors in terms of penetration speed.
 

3. Dried samples
Even in the presence of water, dry samples can be collected because cuttings are collected as soon as they are produced on the bit face.

4. High sample recovery rate
Because the sample is taken from the bit face, sample loss is avoided in fractured and fractured rock formations. Because the diameter of the drill bit and the outer diameter of the wear sleeve are almost equal, the recovery rate of sample collection can reach 98%.