Joseph Marinelli, President, Solids Handling Technologies, Inc. Karl Jacob, Fellow, The Dow Chemical Company

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

3. Context of today’s
presentation
 Will focus primarily on bulk
solids handling – hoppers & bins,
chutes, pneumatic conveying

4. Brief History
 Coulomb and Rankine (1773 & 1857
 Janssen (1895)
 Jenike (1960’s)

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

6. Direct Shear Testers
Ring
Jenike
Peschl
Freeman
Brookfield

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

13. Future Directions

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!!!!

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

27. Find Joe’s Powder Perspectives column online at:
http://www.powderbulksolids.com/powder-perspectives