Microtunneling - Case #1



Derrick 20’ Modular Separation Plant (20-MSSP)

The performance of a micro-tunneling operation is directly related to the overall cleaning performance of the slurry separation system. Solids that remain within the slurry adversely affect slurry excavation processes. Benefits of proper and efficient separation of the drilled solids from a drilling fluid include:

• Increased Rate of Penetration (Production)
• Reduced Drilling Fluids Costs
• Reduced Water Usage
• Reduced Water Hauling Costs
• Reduced Hauling and Disposal Costs of Dirty Fluid
• Reduced Downstream Wear on Pumps, Plumbing, etc.

All of the above translates to increased production at reduced costs to the contractor.

A contractor based out of Colorado is using a Derrick 20’ Modular Separation Plant to work in conjunction with an Akkerman Microtunneling machine with outer diameter of 78’’.

Primary separation is achieved through the use of two Derrick FLC-2000 4 panel shakers with 7.3 G’s of consistent acceleration that offer up to 800 gpm capacity each. These machines are typically outfitted with Derrick’s patented high open area, long life, and non-blinding polyurethane screen panels.

Underflow from these machines flows into the base tank and is pumped under 35-40 PSI to eight (8) 6” desilter cones that make a fine separation at approximately 30 micron. The centrifugal separation extracts the ultra fine sands and silts greater than 30 micron and discharges them out the underflow. The fines are leaving the hydrocyclones are further dewatered on another FLC-2000 screening machine that is typically outfitted with Derrick’s patented Pyramid screen panels with a corrugated, 3D profile. These screens offer 57% more screen area than conventional flat screens giving the machine an exceptionally high capacity per square foot.

Overflow from the hydrocyclones reports back to the base tank where it eventually overflows out the separation plant and is re-circulated through the MTBM.

The 20’ Modular Separation System with a versatile Platform Strategy for various civil engineering applications is an integrated base tank with centrifugal pumps for feeding hydrocyclones and accommodates a multitude of equipment configurations to meet the given ground conditions on a particular project. Up to three equipment platforms can be mounted on the 20’ base tank providing continuous production. Flexible platform configurations such as an FLC 2000 4-panel Shaker, a FLC 2000 4-panel Mud Cleaner with 6’’ cones, or a DE-1000 Full Hydraulic Driven Centrifuge provide optimal slurry separation. FLC-2000 machines feature Super G® vibrating motors for continuous high G-force linear motion and hydraulic Adjustable While Drilling (AWD) mechanisms achieve maximum solids conveyance. Derrick’s patented, performance enhancing polyurethane screen surfaces or corrugated PyramidTM Screen technology, offering 57% more screening area, result in the most efficient solids removal.