High Lifting Capacity Engineering Drilling Rig With Mud Reverse Circulation

The reverse circulation drilling technology using sand and gravel pump ( centrifugal pump ) to create negative pressure in the inner cavity of drill pipe to make the liquid j 2 litres in the inner cavity of drill pipe is called pump suction reverse circulation drilling. The pressure of the driving liquid is generally less than one atmosphere pressure ( 0.1 MPa ), so it is efficient in shallow holes. When the hole depth is more than 80m, the suction efficiency decreases rapidly. Bored piles are generally shallow, and the strata are mostly quaternary loose soil, sand layer and gravel layer. Reverse circulation drilling is performed by pumping, and the drill bit presses people and rotates. once the formation is stirred, the drilling residue is quickly carried out of the hole by the circulation medium. therefore, the drilling efficiency is very high, the quality of the hole formation is good, the drill bit has a long life, low power consumption and low cost. In bedrock strata, it is also easy to discharge slag and has high efficiency. The diameter of bored piles in China's pumping reverse circulation drilling construction can reach 0.6 - 25 meters, and a record of 6 meters in diameter has been set.

GF200C is a crawler-chassis type mud-reverse-circulation drilling rig. It uses high-power impeller pump to pump mud and stone from hole end which can increase the work efficiency a lot. This model is suitable for infrastructure pile of road, bridge, railway, building, and farm water well as well. it can work in soil, sand, gravel layer and soft rock.

truck chassis is DONGFENG brand 4*2 drive.168mm diameter rod is equipped.2 sets of electric motor to drive spindle and pump.Gantry tower up-down is controlled by hydraulic system.

In the pumping reverse circulation drilling, the circulation medium is maintained by the vacuum degree of the pump. The commonly used pump is a sand pump, which requires to be able to discharge rock debris and have a relatively large vacuum degree. In order to allow rock debris to pass smoothly, the free passage in the pump body should be consistent with the inner diameter of the drill pipe. The gap between the blades of sand pump should be large, the effective vacuum degree should not be lower than 8m water column, and the pump body and blades should have better wear resistance. The flow rate of sand pump depends on the inner diameter of drill pipe in the hole, generally 120 ~ 240 m3 / h, with a maximum of 500 m3 / H.