Kerr-McGee Dredging Case Study

Kerr McGee Dredge Loading into Pond (Model 737)

Application: Clean and dredge paint pigment residuals

Dredge Used: LWT 7MAU Series Pit Hog™ Dredge

Project Summary: Electric manned automated dredge with 3 Krebs cyclones with a capacity of 2,100 gpm, magnetic flow meter to monitor pump performance, slurry density meter to maintain consistent percent solids by varying traverse speed, and Bottom Sense™ (automated system to detect and protect pond bottom) to follow the contour of the pond and protect the liner.

Machinery Specifications: PIT HOG™ DREDGE, 7MAU SERIES MODEL Manned Electric Dredge with On-Board Solids Separation

Flotation:
Catamaran Type Hull--Two Pontoons-56" x 48" x 40' -0" made from 1/4" thick steel plate with Internal Bulkheads and Stiffeners, Polyurethane foam filled.

Cutter:
Auger Type with Shroud

Assembly:
Diameter (HeIix) 18-3/4"
Diameter (Knife Profile) 24-1/4"
Pitch 11"
Flighting 3/8"
Speed Variable to 60 RPM
Cutter Knives Detachable heat-treated blades
Cutter Torque Variable to 17.200 in.-lb.

Working: Cut 13'-6" wide x l8" deep (4.11 m)

Capacity: Digging depth-26' maximum (7.9 m)

Power: 200 HP TEFC Motor - Dredge Pump, Underflow Pump
Service Water Pump and Ancillary Hydraulic Circuits

Pumps:
End Suction Centrifugal with Semi-open Impeller
Dredge Pump ~10" x 8" rubber lined with 22" diameter impeller
Variable speed - 0 to 600 RPM
Design Capacity-2,l00 GPM @. 17 PSIG at cyclone inlet
Underflow Pump 4" x 3" rubber lined with 14" diameter impeller
Variable speed ~ to 1200 RPM
Design Capacity-250 GPM @ 120 ft. head
Service Water Pump 2' x 2' self priming
Variable speed-0 to 2700 RPM
Design Capacity-50 GPM @ 120 ft. head

Solids: Three Krebs Model Dl5LB-T123 Cyclones

Separation: Capacity-2,100 GPM (700 GPM per cyclone)

Hydraulic: Slurry pump - Heavy Duty Hydrostatic Drive
All Other Circuits - Pressure-Volume Gear Pump

Systems:
Fixed Displacement Hydraulic Motor(s)
Capacity-7O GPM @ 1750 RPM Motor Speed
Reservoir-75 Gallons
Circuit One-Auger Drive
Circuit Two-Boom Hoist
Circuit Three-Traverse Winch
Circuit Four-Slurry Pump Drive
Relief Pressure Settings:
Slurry Pump Circuit - 4,500 PSI
All other circuits - 2,700 PSI

Propulsion:
Treble Sheave Hydraulic Winch
Traverse Speed - 0 to 100 FPM
Cutting Speed, Nominal - 8 to 12 FPM

Electrical System: Voltage-480V, 3-phase
Two Control Voltage Transformer(s)
120V Power Supply
4V Power Supply

Automation:
Operation Fully Automated with Monitors feeding Program Logic Control
Dredge Pump - 8" Slurry Flow Meter Monitors Output/Sets Speed
Traverse Winch-8" Slurry Density Meter sets speed
Underfiow Pump -Level Control sets speed; Flow Meter Monitors Output
Service Water Pump - 4" Density Meter starts and stops pump
Cyclone Sump--Level Control signals Underflow Pump
Auger Position--Bottom Sense follows bottom contour--Boom up or down

Coating:
Immersed Surfaces -  epoxy coating, 15 mils min. thickness
All other surfaces - Polyurethane enamel on a corrosion inhibitive primer, 5 mils min thickness