Flexco Grain Transfer Chutes
PRESENTER:
Matthew J. KocaPrincipal Flowpath Engineer
10/9/2015
Flexco Grain Transfer Chutes
Comparative Discrete Element
Model Study of a Typical Grain
Transfer
Flexco Grain Transfer Chutes
210/9/2015
Presentation Outline
• Traditional Grain Chutes vs Flexco Chutes
– Degradation
– Dust
– Central Loading
• Design Methodology
– Continuum Method
– Discrete Element Modeling (DEM)
• Grain Breakage/Degradation White Paper
• Results and Conclusions
• Question & Answers
Flexco Grain Transfer Chutes
310/9/2015
Traditional Grain Chutes
• Traditional Grain Chutes
– Cutoff Gates
– “Dead Boxes”
– High Impact Angles
• Requires material on material
impacts to reduce degradation of
grain shells
• Creates non-uniform material flow
– Non-uniform material flow
• Increased dust levels
• Side loading at load zones
Flexco Grain Transfer Chutes
410/9/2015
Traditional Grain Chutes
• Traditional Grain Chutes
– Impact / stalling at end of incoming
slide
– Impact / stalling at cutoff gate
– Dead Box after cutoff gate
– Material not going in direction of belt
– Contained within Hi-Roller Conveyor
• Out of site, out of mind
• Spillage in Hi-Roller means more
tail pulley clean out
• More maintenance required
Flexco Grain Transfer Chutes
510/9/2015
Flexco Chutes
• Flexco Chutes
– Alternate diverter gate technology
– Low Impact Angles
• Does not require material on
material impacts
• Less degradation of grain shells
due to impacts
– Continuous “ribbon” of material
throughout the chute
– Uniform material stream
• Traps fines & dust inside stream
• Central loading in the direction of
receiving belt
• Highly predictable
Flexco Grain Transfer Chutes
610/9/2015
Flexco Chutes
• Flexco Chutes
– No stalling at impacts
– Low Impact Angles
– Continuous “ribbon” of
material throughout the
chute
– Uniform material stream
– Loads material in the
direction of the receiving
belt
Flexco Grain Transfer Chutes
710/9/2015
Flexco Design Methodology
• Continuum Method
– Takes a macro scale approach to bulk
solids modeling
– Flexco’s Preferred Method
• 30+ years experience
– 2D design based on the centerline of a
uniform stream of material
– Provides predictable, repeatable
results for “free-flowing” bulk materials
– Flexco’s proprietary design manual
including documented case studies
throughout our 30+ years of designs
insure a uniform stream is maintained
throughout the chute
Flexco Grain Transfer Chutes
810/9/2015
Flexco Design Methodology
• Discrete Element Modeling (DEM)
– Takes a micro scale approach to bulk
solids modeling
– Models each individual particle within
the bulk material
• Calculates reaction forces on particles
– Particle on particle
– Particle on chute
• Provides visual of expected material
paths through chute
– Can analyze non-uniform material
streams
– Used to analyze what is going on
“inside” the stream at the particle level
– Much more time intensive vs
Continuum Method
Flexco Grain Transfer Chutes
910/9/2015
Grain Breakage/Degradation White Paper
• Purpose of White Paper
– Provide a method of calculating numerical predictions
for breakage reduction without requiring capital
expenditures from clients
– Justify ROI to the grain industry
– Validate the use of Tasman Warajay Technology in
the grain industry vs traditional handling methods
Flexco Grain Transfer Chutes
1010/9/2015
Grain Breakage/Degradation White Paper
• US Department of Agriculture
Baseline Data
– “Grain Breakage Caused By
Commercial Handling Methods”
(G.H. Foster, L.E. Holman, 1973)
– Pertinent data used was based
on corn kernels
– Provides an actual % of particles
broken in real life tests
• Free fall from 3 different heights
• Impact on concrete at 45
degree angle
• Measured amount of broken
kernels after test
Note: Breakage results at 12.6% moisture at 25oF
Flexco Grain Transfer Chutes
1110/9/2015
Grain Breakage/Degradation White Paper
• DEM Control Analysis
– Replicate historical USDA drop tests
• 40ft drop onto 45deg plate
• 70ft drop onto 45deg plate
• 100ft drop onto 45deg plate
– Record all particle forces from
simulations
– Calibrate DEM particle force outputs
to actual breakage percentages
from USDA research
Flexco Grain Transfer Chutes
1210/9/2015
Grain Breakage/Degradation White Paper
• DEM Chute Analysis
– Use same material properties and
simulation settings from Control
Analysis
– Analyze existing transfers
– Analyze Flexco proposed transfers
– Compare particle forces to theoretical
breakage force limit
– Provides estimated breakage
percentage due to transfer point
Flexco Grain Transfer Chutes
1310/9/2015
Grain Breakage/Degradation White Paper
Flexco Grain Transfer Chutes
1410/9/2015
Results and Conclusions
• There would be an expected 84% decrease in
exposure to theoretical breakage forces
– 2.16% breakage in traditional transfer chute
– 0.34% breakage in Flexco transfer chute
• This analysis represents a single impact within the
chute, and material impacting the receiving belt
– Consider how many impacts and spouts material passes
through in a typical facility
– Cumulative effect of single impact breakage rates could
lead to large loss of product value
– Breakage rates do not decrease as grade of material
drops (as stated in USDA research)
• Currently, before and after sampling is underway at
an installation in the New Orleans vicinity to
validate controlled flow transfers in the grain
industry.
Flexco Grain Transfer Chutes
1510/9/2015
Thank You For Your Time & Attention
Questions & AnswersPRESENTER:
Matthew J. KocaPrincipal Flowpath Engineer