Sachpazis Costas: Geotechnical Engineering: A student's Perspective Introduction
State of the Powder Bulk Solids Industry
1. The State of the
Powder Handling
Industry
Presented by:
Joe Marinelli of Solids Handling Technologies
Karl Jacob of The Dow Chemical Company
Joe Florkowski of Powder & Bulk Solids
2. About Joe and Karl
Joe Marinelli –President of Solids
Handling Technologies with 42
years in solids handling
Karl Jacob – 32 years with Dow,
founder of Solids Processing Lab
5. Flowability measurements
• Jenike Shear Tester
Standard in Europe and US
• Rotational Shear Testers
Schulze RST, Brookfield,
Freeman, Peschl
• Rotational testers have increased
productivity and reproducibility
7. Need for understanding of
shear testing measurements
• How to use flow properties test
results
• Practical designs to ensure
reliable flow
• Need to consider special designs
for difficult materials like elastic
solids, stick-slip, flaky, etc.
8. Current situation in bulk
solids handling
• Power plants shutting down
• Recognition by pharma sector of the
importance of solids handling
• Alternative energy strategy
bringing new solids handling
problems like batteries, biomass,
etc.
• New polymeric materials are
different than previous materials
like PS, PE, PC, Nylon, etc.
9. Economic Trends
• Recovering slowly from recession
• Aging equipment will have to be
upgraded
• Provides opportunities for reliable
vendors to help their customers
10. Education – still a
problem!
• Solids handling not consistently
taught at university level
• Most new engineers not aware of the
science of solids handling
• International universities involved
with solids handling applications –
Australia and Germany for example
• Lack of familiarity with Bulletin 123
11. Education
Only a few institutions teach an
elective course in particle technology
– Akron, Purdue, Texas A&M, CCNY,
Cooper Union, Colorado, Florida
Industry needs to push for this topic
to taught and seen as equal as other
mechanical and chemical operations
Students need to understand the
importance of the area and how they
can add value by knowing about
solids
12. Research
• Fundamental research in bulk solids
handling still lacking in the USA
• Research tends to focus on the
“new” ideas – making and using
nanoparticles for example.
• Recent AIChE Plenary Session
underscored the industrial need for
particle technology expertise in both
research and manufacturing
14. Computational Tools
• Considerable progress in the last decade
for a variety of computational tools –
DEM, DEM/CFD, Solids Flowsheeting
tools
• Allow examination of geometries not
solved analytically
• Combination of computer science and
engineering science will only make
these tools better
• Validation essential!!!!
15.
16. Pneumatic Conveying
Still a lot more work to do in dense
phase to move from empirical
approach to more fundamental
approach
Is there a way to correlate pickup
velocity or line pressure drop to
flow properties?
Helpful values are: particle density,
particle size distribution and shape
17. Retrofits vs. New Equipment
• More companies fixing existing
equipment
• May be more practical to replace
with new equipment
• Requires knowledge of solids
handling and a practical approach
18. Biomass Handling
• Alternative and renewable energy
critical
• Wood pellets or chips for heat
• Soy, animal fats for biofuels
• Sugarcane, corn starch, switchgrass,
bamboo, palm
• Agricultural and municipal waste
• Estimated at 146 billion tons/yr used
Most folks forget about the “messy front end”
of biomass and grossly underestimate the
complexities of the situation.
19. A Better Understanding of flow
Promoting Devices
• Need much more understand of the
transmission of pressure and
vibrational waves in bulk solid as
function of solids properties
• Vibration
Vibrators, bin dischargers, etc
• Aeration
Aeration nozzles, air blasters
20. Segregation Problems
Segregation problems are common
Several mechanisms that cause it
Excellent work done by Lueptow at
Northwestern and McCarthy at Pitt
beginning to shed fundamental
light on the problem
21. Northwestern Work
Stratified Segregated Mixed
W = 69 cm
Q = 1 cm3/s Q = 24 cm3/s Q = 420 cm3/s
q = Q/T
vr
Large
Particles
Small
Particles
Mixed
ParticlesStratified
22. Rathole Calculations
Rathole calculations are too conservative
Jenike found conservative approach
necessary
An approach to determine stresses acting
on solids in funnel flow is required
23. Ratholing
“Dead” or non-
flowing region
Very simple
question: how big
should the hole be to
prevent the
formation of a stable
rathole?
• Approaches thus far
• Jenike ff=1.7
• Johanson, JR,
effective head approach
• Arnold and Roberts,
average the above
• Schwedes
•So what do we do?
• experienced practitioners
know what bound to choose
• consider the economic
consequence of a 6 ft outlet
size
24. Testing Flaky Materials
How to test elastic or flaky products
These materials do not shear well
Shear cells too small for large
particle flakes
25. Silo Quaking Issues
Flow of certain materials cause
serious vibrations
Typically occurs with
incompressible materials
Some possible solutions
26. Final Thoughts
Still lots of good problems to address
Will need academic/industrial
collaboration
Venues like this powder show are a
necessity