
UF Chemical Engineering > People > Faculty > Kerry D. Johanson
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Kerry D. Johanson
Ph.D., 1994, Brigham Young University
(Chemical Eng.) |
| Courtesy Faculty |
Ph : 352-303-9123
Fax : 352-846-1196
matflowsol@bellsouth.net
205 Particle Sci. & Tech. |
| Faculty
Web Page |
| Areas |
| Reduction of segregation in process plants
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| Effect of cohesion on flow profiles and
solids wall loads |
| Effect of bulk solid strength on hang-ups
in bins and hoppers |
| Effect of air injection on overcoming cohesive
hangups and limiting flow rates |
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Our current research addresses key problems of cohesive
powder flows. Pharmaceutical, food, and nutraceutical
industries must produce consistent products which are
often a mixture of cohesive and non-cohesive materials
of varying particle size. Blending is a primary unit operation.
However, blender scale-up is currently impossible. Scale-up
requires separating the influence of material properties
from that of blender geometry and operation mode. The
key to predictive capability is to determine the influence
of material properties on local velocity profiles, and
the relationship between velocity profile and blender
residence time distribution functions. Current research
focuses on unraveling these relationships.
Pharmaceuticals and foods tend to gain cohesive strength
when stored, resulting in extensive flow problems during
handling. These problems cause significant unscheduled
process/plant downtimes. Current research includes determining
key relationships between cohesive powder behavior and
particle scale events such as caking (growth of crystalline
structures between particles) or cohesive strength caused
by capillary and van der Waal’s forces between particles.
Our research scope extends to determining the coherence
length of bulk solid materials as they shear. This work
examines how the structure of bulk mixtures may affect
bulk properties. The goal is to build a link between bulk
behavior, powder structure, and the inter-particle forces
that can be controlled by modifying surface characteristics.
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| Recent Publications |
| 1. |
Johanson, K, “Predicting cone-in-Cone
Blender Efficiencies from Key Material Properties,”
Powder Technology, 170 (2006) 108. |
| 2. |
Johanson, K., Eckert, C., Ghose, D.,
Djomlija, M. and Hubert, M., “Quantitative Measurement
of Particle Segregation Mechanisms,” Powder Technology,
159 (2005) 1. |
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Johanson, K and Francis, T., “Chapter
13: Powder Flow Properties”, Encapsulated and Powdered
Foods, Ed. C. Onwulata (2005) 331. |
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Bilgili, E., Yepes, J., Stephenson, L.,
Johanson, K. and Scarlett, B., “Stress Homogeneity
in Powder Specimens Tested in the Jenike Shear Cell:
Myth or Fact,” Part. Syst. Charact., 21 (2004)
293. |
| 5. |
Johanson, K. “Rathole Stability
Analysis for Aerated Powder Materials,” Powder
Technology, 141 (2004) 161. |
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