State of the Powder Bulk Solids Industry


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

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State of the Powder Bulk Solids Industry

  1. 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. 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. 3. Context of today’s presentation  Will focus primarily on bulk solids handling – hoppers & bins, chutes, pneumatic conveying
  4. 4. Brief History  Coulomb and Rankine (1773 & 1857  Janssen (1895)  Jenike (1960’s)
  5. 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. 6. Direct Shear Testers Ring Jenike Peschl Freeman Brookfield
  7. 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. 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. 9. Economic Trends • Recovering slowly from recession • Aging equipment will have to be upgraded • Provides opportunities for reliable vendors to help their customers
  10. 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. 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. 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. 13. Future Directions
  14. 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. 15. 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
  16. 16. 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
  17. 17. 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.
  18. 18. 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
  19. 19. 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
  20. 20. 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
  21. 21. 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
  22. 22. 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
  23. 23. Testing Flaky Materials  How to test elastic or flaky products  These materials do not shear well  Shear cells too small for large particle flakes
  24. 24. Silo Quaking Issues  Flow of certain materials cause serious vibrations  Typically occurs with incompressible materials  Some possible solutions
  25. 25. Final Thoughts  Still lots of good problems to address  Will need academic/industrial collaboration  Venues like this powder show are a necessity
  26. 26. Find Joe’s Powder Perspectives column online at: