Overview
All-Pumps supplied a compact, skid-mounted system that reliably meters dry polymer into a TBM conveyor process. The package integrates a micro-batch screw feeder and a side channel blower on a heavy-duty PFC base frame, with dedicated VSDs for easy adjustment of feed rate and airflow. The pre-assembled design simplifies installation and provides accurate, consistent polymer dosing.
Application
Real-time drying of excavated spoil by dosing a superabsorbent polymer (SAP) into the blower airstream and distributing it across the TBM conveyor.
Process
As the TBM excavates, wet spoil drops onto the conveyor. The side channel blower entrains the SAP powder and spreads it evenly across the belt. The polymer absorbs free water, producing drier, more stable spoil by the time it reaches the portal—reducing mess, carryback, and downstream water handling.
Customer Goals
Cleaner belts, reduced housekeeping, easier spoil handling and tipping, and lower demand on the dewatering plant.
System Design & Technical Overview
This integrated skid package delivers controlled polymer dosing and contained powder transfer for TBM spoil drying.
How it Operates
- Polymer is loaded into the hopper.
- The micro-batch screw feeder delivers powder at the set dosing rate via its VSD.
- The side channel blower provides airflow to entrain and convey the powder to the discharge point and through a spreader nozzle onto the conveyor.
- A 4″ isolation valve allows safe maintenance without disturbing upstream equipment.
Key Technical Features
- Conveyor belt transporting material inside TBM tunnelling system for powder dosing and processing.
- Approx. envelope: 1500 mm (L) × 1243 mm (W) × 1936 mm (H)
- Six Ø24 mm base mounting holes
- Ø30 mm lifting holes for safe handling
- 4″ discharge connection with ball valve
- Polymer Summary (MaxiFlox® 821)
- Organic superabsorbent polymer (SAP) in dry granular form
- Absorbency: typically 50–200× its weight in water
- Approx. 10 kg can absorb >1000 L depending on conditions
- Particle size: 0.5–3.0 mm
- Bulk density: ~0.75 g/cm³
- pH (0.1% solution): 5–8
- Shelf life: 24 months at 0–35 °C
The Results
- Drier spoil at the portal
- Cleaner conveyors with less carryback
- Reduced housekeeping requirements
- Less free water entering bins, trucks, and dewatering systems
- Stable, predictable dosing via micro-batch feeder
- Fast installation with pre-aligned equipment and clear lifting/mounting points
- Straightforward maintenance with isolation at discharge
