powerpoint presentation...2/28/2018 5 separation at discharge pulley at discharge, top particles...
TRANSCRIPT
2/28/2018
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Conveyors 301John Garrison
John Garrison
▪ Vice President of Sales
▪ Superior Industries
▪ Previous experience
▪ Terex MPS
▪ Motion Industries
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Stockpile Segregation
What is segregation?
▪ Separation of material by particle size
▪ Uneven concentration of coarse and fine
▪ Poor structural and textual characteristics
▪ Shorter life expectancy of final product
Effects of Segregation
▪ Penalties of > 50¢ per ton
▪ Decreased value of product
▪ Rejection of entire stockpile
▪ Labor to rebuild is prohibitive
▪ Degraded company reputation
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Stockpile Segregation
▪ Stockpiling Problems
▪ Causes of Stockpile Segregation
▪ Preventing Segregation
▪ Telescoping Radial Stacking Conveyor
▪ Desegregated Stockpiles
▪ Conveyor Automation
Where does segregation occur?
▪ After product is crushed, screened, blended
▪ Likely locations:
▪ Stockpile
▪ Handling and transport
▪ Storage (bins and hoppers)
▪ During application of final mix
Problems Caused by Segregation
▪ Fluctuating gradation makes it impossible to
produce acceptable asphalt or concrete
▪ Too many fines? Shortage of concrete paste
or asphalt mix (stiff consistency)
▪ Too many large particles? Excess amount of
paste or asphalt (runny consistency)
▪ Roads have poor structural integrity and
shorter lifespan
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Causes of Stockpile Segregation
Degree in Variation of Particle Size
Ratio less than 2:1
Minimal segregation
Ratio greater than 2:1
Higher degree of segregation
Bouncing on Belting
Most stockpiles created by conveyors
Belt bounces when crossing idlers
(Due to belt sag between idlers)
Finer particles settle to bottom
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Separation at Discharge Pulley
▪ At discharge, top particles travel
at greater velocity than bottoms
▪ Larger particles travel further
from conveyor, smaller closer
▪ Fine materials cling to belt and
end up in front side of pile
Effect of Overrun
Fine
Medium
Course
Wind Effect on Falling Material
▪ Wind effects trajectory
▪ Greater effect on fine material
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Preventing Segregation
Building with Trucks
▪ Dump into separate piles...minimize overrun
▪ If loader, raise material to full bucket height
▪ Better blends the material
▪ Never drive on material...degrading
Building with Dozers
▪ Allows layers, minimizes segregation
▪ If material comes by truck, inclined layers
▪ If by conveyor, horizontal layers
▪ Avoid pushing material over pile
▪ This results in overrun
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Disadvantages of Dozers
▪ Heavy equipment compacts and crushes
▪ Degradation and contamination
▪ Dealing with segregation upon reclaim
▪ Extra labor and equipment is costly
Fixed Height Radial Stackers
▪ Moves left to right (radially)
▪ Blended more than conical pile
▪ Discharge height = degree of segregation
▪ Fines separated more as height increases
Telescoping Chute
▪ Minimizes effect of wind
▪ Extends from pulley to pile
▪ Limits free fall of material
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Variable Height Radial Stackers
▪ Distance from head pulley minimized
▪ Reduces free falling material
Windrow Concept
Windrow Concept
▪ Building stockpiles in layers
▪ Each layer consists of series of windrows
▪ Segregation pattern is repeated
▪ When reclaiming, no need to blend
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Conical Stockpile
Fine
Medium
Course
Windrow Stockpile
Fine
Medium
Course
Methods of Building Windrows
Tripper Conveyor Telescopic Stacking Conveyor
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Tripper Conveyor System
▪ Stationary applications
▪ Fixed height
▪ Segregation by wind
Telescoping Conveyors
Telescoping Conveyors
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Telescoping Conveyors
Manual Control
Limit Switch Automation
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PLC Controlled
▪ Computer receives data from inputs
▪ Controls various components
▪ Encoder mounting positions:
▪ Winch cable to monitor stinger
▪ Wheel to monitor radial position
▪ Discharge point to monitor pile height
▪ Everything is customizable
Partially Desegregated Stockpile
▪ Overrun can still be a problem
▪ Ends of piles subject to segregation
▪ 40% of final pile is overrun
▪ Prevent material from rolling over edges
Overrun
No Overrun
Fully Desegregated Stockpile
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Aggregate Industries
▪ Littleton Quarry
▪ 35-miles northeast of Boston
▪ Project to reduce cost per ton
▪ Relocate plants closer to quarry face
▪ (2) 36” x 150’ TeleStacker® Conveyors
▪ Cut footprint by 43%
▪ Eliminate 2,200’ of overland conveyor
Aggregate Industries
▪ “Material handling delivered quick returns
and is the biggest efficiency factor.”
Chad Abramson, Plant Manager
▪ Eliminated:
▪ Double handling of material
▪ Loaders and haul trucks
▪ 8,000 ton capacity fixed stackers
▪ 28¢ per ton savings
Before
Aggregate Industries
▪ Creating fully desegregated, kidney bean
shaped stockpiles
▪ Stockpiling 70,000 tons under each
TeleStacker® Conveyor (+89%)
▪ “Environmentally friendly alternative that
makes our neighbors happy.”
After
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Conveyors vs Rolling Stock
Factors to Consider
▪ Cost benefit
▪ Product quality
▪ Topography
▪ Environmental concerns
Conveyor Advantage
▪ Limited inflationary effect
▪ Improved product quality
▪ Continuous flow
▪ Environmentally friendly
▪ Design flexibility
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CalPortland - Santosh Plant
▪ Material handling from extraction to plant
▪ 2-miles of overland conveyor
▪ Replaced multiple haul trucks
▪ Robert Hostettler, plant manager:
▪ Less harmful chemicals released
▪ Electricity prices more stable than fuel
▪ Smaller operational footprint
▪ Much less manpower required
▪ Components can be reused when finished
Overland Conveyor vs Haul TruckHaul Trucks Conveyors
Capital Purchase Price $300,000 Capital Purchase Price $250,000
Length of Haul 1,050-feet Conveyor Length 1,050-feet
Number of Trucks 2 Trucks Net Elevation Change 40-feet
Load/Truck 40 Tons Belt Width 42-inches
Truck Cycle Time 10 minutes Estimated Horsepower 50 HP
Depreciation Schedule 7 years Number of Sections 1
Expected Life 30,000 hours Site Preparation $10,500
Operation/Days 10 hours Operation/Days 10 hours
Days of Operation/Week 5 days Days of Operation/Week 5 days
Labor w/ Benefits $25.00 per hour Labor w/ Benefits (Per Hour) $25.00 per hour
Maintenance/Fuel $56.00 per hour Electricity Cost per kW $0.08 per hour
Lifetime Capital Maintenance $70,000 per truck Tons Per Hour 480
Overland Conveyor vs Haul Truck
Haul Trucks Conveyors
Cost Per Ton $ 0.43 $ 0.03
Conveyor Savings/Ton $ 0.40
Savings Per Day $ 1,920
Savings Per Week $ 9,600
Savings Per Month $ 41,600
Savings Per Year $ 449,200
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QUESTIONS?