Evaluating Transfer Chutes with
Increased Throughput
Bulk Materials Handling Conference 2014
Carrie Hartford
Senior Engine...
SCIENCE ⏐ENGINEERING ⏐DESIGN
WE ARE:
A specialized engineering firm focusing on
providing clients solutions to material
...
SCIENCE ⏐ENGINEERING ⏐DESIGN
COMPANY PROFILE
„ Incorporated in 1966 by Dr.Andrew Jenike
„ World’s largest firm special...
SCIENCE ⏐ENGINEERING ⏐DESIGN
OUR MISSION
To create value by assisting clients to improve
the efficiency, reliability, an...
SCIENCE ⏐ENGINEERING ⏐DESIGN
OUR APPROACH
We use a scientific approach, based on the
characteristics of the materials ha...
SCIENCE ⏐ENGINEERING ⏐DESIGN
OUTLINE
„ Review common transfer chute designs
„ Discuss typical transfer chute problems
...
SCIENCE ⏐ENGINEERING ⏐DESIGN
VARIOUS CHUTE DESIGNS
For free-flowing rocky
material:
„ Rock box
„ Micro ledges
Minimise...
SCIENCE ⏐ENGINEERING ⏐DESIGN
ROCK BOX CONFIGURATIONS
Use rock boxes only if material is free-flowing
8
Cement Clinker Ir...
SCIENCE ⏐ENGINEERING ⏐DESIGN
ROCK BOX CONFIGURATIONS
Rock box with sticky bauxite leads
to frequent head box plugging
He...
SCIENCE ⏐ENGINEERING ⏐DESIGN
HOOD AND SPOON DESIGN
„ Developed in early 1980’s by Jenike & Johanson (US
Patent 4,646,91...
SCIENCE ⏐ENGINEERING ⏐DESIGN
HOOD AND SPOON DESIGN
Sticky fines on impact plate
leading to frequent plugging
Proper stre...
SCIENCE ⏐ENGINEERING ⏐DESIGN
COMMON CHUTE FLOW PROBLEMS
„ Plugging
„ Wear of chute surface
„ Spillage
„ Buildup
„ D...
SCIENCE ⏐ENGINEERING ⏐DESIGN
EXAMPLE CHUTE FLOW PROBLEMS
Wear of chute surface
13
SCIENCE ⏐ENGINEERING ⏐DESIGN
EXAMPLE CHUTE FLOW PROBLEMS
Spillage
Buildup
14
SCIENCE ⏐ENGINEERING ⏐DESIGN
IMPACT ANGLE & SLIDING FRICTION
V2 =Velocity along chute
after impact
V1 = Impact velocity
...
SCIENCE ⏐ENGINEERING ⏐DESIGN
QUESTIONS ASKED TO MAXIMISE USAGE OF
EXISTING PORT INFRASTRUCTURE
„ Can we increase the th...
SCIENCE ⏐ENGINEERING ⏐DESIGN
CASE STUDY
„ Iron ore export terminal in South Africa
„ Belt width: 1650 mm wide
„ Belt ...
SCIENCE ⏐ENGINEERING ⏐DESIGN
CASE STUDY
„ By using rock boxes, the chutes did not wear, but
as the flow rate increased,...
SCIENCE ⏐ENGINEERING ⏐DESIGN
Increase in
fines, mc, &
flow rate
Buildup in
the chute
(eventual
plugging)
Changed
the flo...
TO ANALYSE AND DESIGN CHUTES
•  Bulk density
•  Coefficient of sliding friction
•  Particle size
•  Particle density
•  Ch...
SCIENCE ⏐ENGINEERING ⏐DESIGN
Wear results vary and are dependent on material characteristics such as
particle size, shap...
SCIENCE ⏐ENGINEERING ⏐DESIGN
DEM ANALYSIS OF IRON ORE CHUTE
22
SCIENCE ⏐ENGINEERING ⏐DESIGN
HOOD AND SPOON DESIGN
Proper belt loading
with spoon
Proper stream capture
with hood
23
SCIENCE ⏐ENGINEERING ⏐DESIGN
HOOD AND SPOON DESIGN
Other benefits:
„ Minimal downtown – chute went 2.5
years before cha...
SCIENCE ⏐ENGINEERING ⏐DESIGN
OTHER ISSUES FROM
INCREASED FLOWRATE
„ Example: Material flies over the head chute
25
Head...
SCIENCE ⏐ENGINEERING ⏐DESIGN
CHANGING MATERIAL
„ Example: Using magnetite in hematite handling systems
with rock boxes
...
SCIENCE ⏐ENGINEERING ⏐DESIGN
CONCLUSION
„ Increasing throughput and/or handling different
material through existing inf...
QUESTIONS?
28
Carrie Hartford
Senior Engineer
Perth Western Australia
chartford@Jenike.com
www.jenike.com
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Carrie Hartford, Jenike & Johanson Pty Ltd, Evaluating transfer chutes with increased throughput

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Carrie Hartford delivered the presentation at 2014 Bulk Materials Handling Conference.

The 11th annual Bulk Materials Handling Conference is an expert led forum focusing on the engineering behind the latest expansions and upgrades of bulk materials facilities. This conference will evaluate the latest engineering feats that are creating record levels of throughput whilst minimising downtime.

For more information about the event, please visit: http://www.informa.com.au/bulkmaterials14

Published in: Engineering, Business, Technology

Carrie Hartford, Jenike & Johanson Pty Ltd, Evaluating transfer chutes with increased throughput

  1. 1. Evaluating Transfer Chutes with Increased Throughput Bulk Materials Handling Conference 2014 Carrie Hartford Senior Engineer Perth Western Australia chartford@Jenike.com 1
  2. 2. SCIENCE ⏐ENGINEERING ⏐DESIGN WE ARE: A specialized engineering firm focusing on providing clients solutions to material handling applications 2
  3. 3. SCIENCE ⏐ENGINEERING ⏐DESIGN COMPANY PROFILE „ Incorporated in 1966 by Dr.Andrew Jenike „ World’s largest firm specializing in materials flow „ About 80 personnel world-wide „ Offices in Australia, Brazil, Canada, Chile, USA „ 7,500+ projects world-wide „ Over 11,000 bulk materials tested „ 650+ man-years experience 3
  4. 4. SCIENCE ⏐ENGINEERING ⏐DESIGN OUR MISSION To create value by assisting clients to improve the efficiency, reliability, and safety of their operations by preventing, eliminating, or reducing problems related to bulk materials flow, storage, or processing. 4
  5. 5. SCIENCE ⏐ENGINEERING ⏐DESIGN OUR APPROACH We use a scientific approach, based on the characteristics of the materials handled and process requirements. It is not a trial & error approach! 5
  6. 6. SCIENCE ⏐ENGINEERING ⏐DESIGN OUTLINE „ Review common transfer chute designs „ Discuss typical transfer chute problems „ Evaluate increasing throughput with existing infrastructure „ What about different material handled through an existing system? 6
  7. 7. SCIENCE ⏐ENGINEERING ⏐DESIGN VARIOUS CHUTE DESIGNS For free-flowing rocky material: „ Rock box „ Micro ledges Minimise wear. For fine, sticky material: „ Hood and spoon „ No ledges Prevent plugging and minimise buildup. What if the material is rocky and fine and sticky? „ Prevent plugging and minimise wear 7
  8. 8. SCIENCE ⏐ENGINEERING ⏐DESIGN ROCK BOX CONFIGURATIONS Use rock boxes only if material is free-flowing 8 Cement Clinker Iron Ore
  9. 9. SCIENCE ⏐ENGINEERING ⏐DESIGN ROCK BOX CONFIGURATIONS Rock box with sticky bauxite leads to frequent head box plugging Heavy residual left in head box 9
  10. 10. SCIENCE ⏐ENGINEERING ⏐DESIGN HOOD AND SPOON DESIGN „ Developed in early 1980’s by Jenike & Johanson (US Patent 4,646,910 - August 1985) „ Design reflects novel approach to controlling the material „ Minimises dust generation, centers the load on the receiving belt „ Minimises wear of the receiving belt by giving the load a velocity in the direction of the receiving belt 10
  11. 11. SCIENCE ⏐ENGINEERING ⏐DESIGN HOOD AND SPOON DESIGN Sticky fines on impact plate leading to frequent plugging Proper stream capture with hood (low impact angle) Proper stream control with spoon US Patent 4,646,910 Rhino horn 11
  12. 12. SCIENCE ⏐ENGINEERING ⏐DESIGN COMMON CHUTE FLOW PROBLEMS „ Plugging „ Wear of chute surface „ Spillage „ Buildup „ Dust generation „ Excessive belt wear 12 Plugging
  13. 13. SCIENCE ⏐ENGINEERING ⏐DESIGN EXAMPLE CHUTE FLOW PROBLEMS Wear of chute surface 13
  14. 14. SCIENCE ⏐ENGINEERING ⏐DESIGN EXAMPLE CHUTE FLOW PROBLEMS Spillage Buildup 14
  15. 15. SCIENCE ⏐ENGINEERING ⏐DESIGN IMPACT ANGLE & SLIDING FRICTION V2 =Velocity along chute after impact V1 = Impact velocity θ = Impact angle φ’ = Wall friction angle θ V1 V2 V2 V1 = cosθ −sinθ tan "φ Impact angle and sliding friction is critical in chute design: If θ + φ’= 90°, no resultant velocity 15
  16. 16. SCIENCE ⏐ENGINEERING ⏐DESIGN QUESTIONS ASKED TO MAXIMISE USAGE OF EXISTING PORT INFRASTRUCTURE „ Can we increase the throughput of the same material through the existing design? Consider: „  Belt sizing and speed „  Loads on the belt „  Support structure „  Material flow through the chutes „ Can we put a different material through the existing transfer chutes? „  Example: handling magnetite concentrate in iron ore transfer chutes „ What are the implications? „  Will material flow through the chutes? 16
  17. 17. SCIENCE ⏐ENGINEERING ⏐DESIGN CASE STUDY „ Iron ore export terminal in South Africa „ Belt width: 1650 mm wide „ Belt speed: 5.5 m/s „ Flow rate: 10,000 tph „ Right angle transfer chute „ Rock box used to minimize wear „ Client needed to increase throughput. 17
  18. 18. SCIENCE ⏐ENGINEERING ⏐DESIGN CASE STUDY „ By using rock boxes, the chutes did not wear, but as the flow rate increased, the chute began to plug frequently leading to: „ Cascading shutdown of upstream conveyors „ Belt tracking problems „ Spillage „ Dusting „ Inability to obtain desired throughput 18
  19. 19. SCIENCE ⏐ENGINEERING ⏐DESIGN Increase in fines, mc, & flow rate Buildup in the chute (eventual plugging) Changed the flow path through the chute Changed the way material exited the chute Spillage, dusting, & premature belt wear PROGRESSION OF PROBLEMS Iron Ore 19
  20. 20. TO ANALYSE AND DESIGN CHUTES •  Bulk density •  Coefficient of sliding friction •  Particle size •  Particle density •  Chute tests •  Angle of repose •  Drawdown angle •  Wear tests •  Angle of internal friction Flow properties tests needed: Angle of repose Drawdown angle
  21. 21. SCIENCE ⏐ENGINEERING ⏐DESIGN Wear results vary and are dependent on material characteristics such as particle size, shape, and abrasiveness of particles WEAR TESTS AR 500 Test results are for example only Alumina Ceramic Arcoplate Wear ratio (wear/ distance moved) Pressure Adjustable force Bulk material In hopper Collecting Drum Screw Feeder Wear coupon mounted in rotating head Proprietary J&J wear testing apparatus 21
  22. 22. SCIENCE ⏐ENGINEERING ⏐DESIGN DEM ANALYSIS OF IRON ORE CHUTE 22
  23. 23. SCIENCE ⏐ENGINEERING ⏐DESIGN HOOD AND SPOON DESIGN Proper belt loading with spoon Proper stream capture with hood 23
  24. 24. SCIENCE ⏐ENGINEERING ⏐DESIGN HOOD AND SPOON DESIGN Other benefits: „ Minimal downtown – chute went 2.5 years before changing out the head chute, still not much wear in the spoon. „ Eliminated belt tracking problems „ No spillage „ Reduced dusting significantly „ Obtained desired throughput 24
  25. 25. SCIENCE ⏐ENGINEERING ⏐DESIGN OTHER ISSUES FROM INCREASED FLOWRATE „ Example: Material flies over the head chute 25 Head chute height was set based on cross sectional area of material on belt and material trajectory. Belt speed and cross-sectional area of material on the belt increased to increase throughput. Caused some material to fly over the head chute. Chute was also fuller than designed for. Resulted in increased spillage and higher plugging potential.
  26. 26. SCIENCE ⏐ENGINEERING ⏐DESIGN CHANGING MATERIAL „ Example: Using magnetite in hematite handling systems with rock boxes „ Cycle times of fine, sticky material versus lump ore needs to be evaluated 26
  27. 27. SCIENCE ⏐ENGINEERING ⏐DESIGN CONCLUSION „ Increasing throughput and/or handling different material through existing infrastructure can have significant financial benefits. „ Material testing and DEM are good predictive tools to analyse the feasibility of a usage change. 27
  28. 28. QUESTIONS? 28 Carrie Hartford Senior Engineer Perth Western Australia chartford@Jenike.com www.jenike.com

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