SLIDE 1 High Performance Foil Rotor Improves De-Ink Pulp Screening
Cameron Pflueger1
James A. Olson, Sean Delfel, Carl Ollivier-Gooch, Pat Martin2, Frederic Vaulot1 and Robert W. Gooding1 Department of Mechanical Engineering, Pulp and Paper Centre, University of British Columbia, Canada
1Advanced Fiber Technologies, Montreal, Canada 2Catalyst Paper, Paper Recycling Division, Coquitlam, Canada
SLIDE 2 Our Goal
To help our customers by:
(efficiency / fractionation)
- increasing capacity
- reducing power consumption
- reducing the overall cost of
pulp screening
SLIDE 3
Pulp Screening Basics
Pressure screens are essential for contaminant removal and fibre fractionation Cylinders and rotors are the key performance parameters
SLIDE 4 Negative Peak, Pmin Pulse Width Positive Peak, Pmax
Nomenclature
2 3D
V P C
t Power
ρ = Pressure Coefficient: Power Consumption:
2 2 1 t P
V P C ρ =
SLIDE 5 Previous Work
Wall Cp vs. foil camber (numerical, Feng et al. 2005).
1 2
0.0 0.1
NACA 0012 (0% Camber)
NACA 4312 (4% Camber) NACA 8312 (8% Camber)
Perssure Coefficient, Cp Position, x/Chord
SLIDE 6
CFD Single foil
SLIDE 7
CFD Single foil
Wall Cp vs. angle-of-attack for a NACA 0012 foil (numerical, Feng et al. 2005).
2 2 1 t P
V P C ρ =
SLIDE 8
New Developments
Foil Parameters Studied: Angle-of-attack (α) Flap Angle (δ) Flap positioning
Anderson, 1991 Canadian Forces C-130
SLIDE 9
Results
Flap angle was varied at a constant α : δ = 7°:
SLIDE 10
Results
δ = 15°: Flap angle was varied at a constant α :
SLIDE 11
Results
δ = 22°: Flap angle was varied at a constant α :
SLIDE 12
Results
δ = 29°: Flap angle was varied at a constant α :
SLIDE 13
Results
δ = 36°: Flap angle was varied at a constant α :
SLIDE 14 Results
The α- and δ- sweep data was combined to create surfaces of max. and min. wall CP.
- Min. CP vs. α and δ. The ‘x’ marks the optimum of
CP = -0.82 at α = 1.2 deg. and δ = 16 deg.
SLIDE 15 Results
Surfaces were constructed of min. and max. wall CP vs. x- and y- position of the flap LE:
- Min. CP vs. x and y positions of the flap LE. The optimum of
CP = -0.82 is at x = -0.05*c and y = -0052*c.
SLIDE 16
Mill Trial – De-Ink Fine Screen
SLIDE 17
Mill Trial – De-Ink Fine Screen
Catalyst Paper, Paper Recycling Division Flowsheet
SLIDE 18
Mill Trial – De-Ink Fine Screen
10 15 20 25 30 35 40 45 50 55 11 12 13 14 15 16 17 Tip Speed (m/s) Power (kW) DEF Rotor OEM Rotor 42%
SLIDE 19
Mill Trial – De-Ink Fine Screen
1.0 1.2 1.4 1.6 1.8 2.0 12 13 14 15 16 17 Tip Speed (m/s) Thickening Factor DEF Rotor OEM Rotor
SLIDE 20
Mill Trial – De-Ink Fine Screen
40% 50% 60% 70% 80% 12 13 14 15 16 17 Tip Speed (m/s) Stickies Removal Efficiency DEF Rotor OEM Rotor
SLIDE 21 Mill Trial – De-Ink Fine Screen
0% 20% 40% 60% 80% 100%
1 2
Stickies Removal Efficiency OEM Rotor DEF Rotor Area Count
SLIDE 22 Mill Trial – De-Ink Fine Screen
1 2 3 4 5 6 7 8 0.21 0.3 0.4 0.5 0.75 1 1.5 2 2.5 3 Stickies Distribution (mm2)
Accept Stickies Concentration (number per gram)
OEM Rotor DEF Rotor <
SLIDE 23 Conclusions
Multi-element foil technology allows for greater control of pressure pulse.
- Wider, stronger pulse can be obtained
Reducing Rotor Speed Increases Stickies Removal Efficiency Power savings of 42% have been shown thus far with equivalent OEM rotor capacity Preliminary mill trials extremely promising.
SLIDE 24
Thank you! Questions?
