According to whether the excavation surface is closed, the shield machine can be divided into two types: closed type and open type. According to the principle of balancing the earth pressure and water pressure of the excavation surface, the closed shield machine can be divided into: earth pressure type and mud water type. According to the excavation method, the open shield machine is divided into: hand excavation, semi-mechanical excavation, and mechanical excavation.
In the shield machine, the mud-water separation treatment is required for the mud-water balance shield machine. The mud-water balance shield machine uses mud-water to resist the water pressure and earth pressure of the excavation surface to maintain the stability of the excavation surface, control the deformation of the excavation surface and the settlement of the foundation; form a weakly permeable mud film on the excavation surface to maintain the water pressure Effective on the excavation face. The effect of the mud-water separation is achieved by the mud-water treatment system related to the shield machine.
The mud pumped by the mud pipeline during the tunneling of the mud-water shield machine is transported to the mud-water separation station for separation:
- Through the primary screening, most of the solid stones and mud blocks are separated;
- After the first-stage separation, most of the clods above 3mm are separated, and the separated mud flows into the slurry collection tank, and then is pumped to the second-stage cyclone by the mud pump for separation;
- The accuracy of the secondary separation is 70~74μm. After the secondary separation, the mud is pumped to the tertiary flow device again for separation ;
- The separation accuracy of the three-stage cyclone is 20-25 μm. After the three-stage separation, the mud flows back to the pulping tank, and after pulping, it is transported to the knife excavation by the mud pump for placement.
- After the waste slurry is filtered and separated by a filter press as required, the slurry particles larger than 5 μm in the slurry are basically separated, and then the sedimentation can meet the discharge requirements.
KOSUN- China Solids Control Leader&Drilling Waste Management Expert
Contact person: Lily Wang