Slurry returning from the tunnel face enters the coarse shale shaker, where large soil particles, stones, and other coarse solids are screened out. The slurry then moves to the hydrocyclone section for further separation.
The desander uses 12-inch hydrocyclones to remove sand-sized particles. Smaller 4-inch hydrocyclones handle finer solids that remain in the slurry. The separated solids are discharged through the cyclone underflow and sent to the shale shaker for dewatering before collection.
The treated slurry flows into the clean-slurry tank and returns to the TBM circulation system. A decanter centrifuge can be added when further fine-solids removal is needed.