PSRI is world-renowned for its contribution to the fluidization communities.  Most of our research is proprietary, but PSRI does publish key findings in the open literature in order to promote more discussion of and insight to problems.  We work closely with many universities and national labs throughout the world.  Our recent publications are presented below.

Dynamic Force Sensors and Their Applications in Fluidized Beds Dynamic Force Sensors and Their Applications in Fluidized Beds May 23, 2017 Shyam Sundaram, Allan Issangya,  S.B. Reddy Karri, R.A. Cocco, T.M. Knowlton, B.Freireic- 12th International Conference on Fluidized Bed Technology, Krakow, Poland The internals in fluidized bed... More detail
Hydrodynamics of High Velocity Circulating Fluidized Bed Risers of FCC Catalyst Particles Hydrodynamics of High Velocity Circulating Fluidized Bed Risers of FCC Catalyst Particles May 23, 2017 Allan S. Issangya, S.B. Reddy Karri, Ray A. Cocco, Ted Knowlton, 12th International Conference on Fluidized Bed Technology, Krakow, Poland Fluid catalytic cracking (FCC) risers operate at solids circulation... More detail
Particle Attrition: Mechanisms and Methods to Determine Attrition Indices Particle Attrition: Mechanisms and Methods to Determine Attrition Indices May 23, 2017 Yeook Arrington, S.B. Reddy Karri, Ray Cocco, 12th International Conference on Fluidized Bed Technology, Krakow, Poland Particle attrition can be a major issue in using catalyst particles in fluidized beds and circulating... More detail
Liquid Injections into Fluidized Beds Liquid Injections into Fluidized Beds May 26, 2013 Ray Cocco, Jennifer McMillan, Roy Hays, S.B. Reddy Karri, Fluidization XIV, The Netherlands Many of our fluidized bed unit operations involve liquid injection.  Yet, how the liquid and solids interact in these... More detail
Effect of Bed Diameter, Baffles, Fines Content and Operating Conditions on Pressure Fluctuations in Fluidized Beds Effect of Bed Diameter, Baffles, Fines Content and Operating Conditions on Pressure Fluctuations in Fluidized Beds May 26, 2013   Allan Issangya, S.B. Reddy Karri, Ted Knowlton, Ray Cocco, FluidizationXIV, The Netherlands. Differential pressure fluctuations are routinely measured in fluidized beds to delineate fluidization regimes,... More detail
Reverse Core-Annular Flow of Geldart Group B Particles in Risers Reverse Core-Annular Flow of Geldart Group B Particles in Risers    March 22, 2012 Chew, J. W. , Roy Hays, John G. Findlay, S.B. Reddy Karri, Ted M. Knowlton, Ray A. Cocco, Christine M. Hrenya, Powder Technology 221, 1–12 (2012). Experiments involving monodisperse Geldart... More detail
Species Segregation of Binary Mixtures and a Continuous Size Distribution of Group B Particles in Riser Flow Species Segregation of Binary Mixtures and a Continuous Size Distribution of Group B Particles in Riser Flow      November 30, 2011 Chew, J. W. , Roy Hays, John G. Findlay, S.B. Reddy Karri, Ted M. Knowlton, Ray A. Cocco, Christine M. Hrenya, Chemical Engineering Science 66, 4595–4604 (2011). Experiments... More detail
Cluster Characteristics of Continuous Size Distributions and Binary Mixtures of Group B Particles in Dilute Riser Flow Cluster Characteristics of Continuous Size Distributions and Binary Mixtures of Group B Particles in Dilute Riser Flow    November 13, 2011 J.W. Chew, D.M. Parker, R.A. Cocco C.M. Hrenya, Chemical Engineering Journal 178, 348–358 (2011). Gas–solids circulating fluidized bed (CFB) experiments have been carried out with... More detail
Cluster Characteristics of Geldart Group B Particles in a Pilot-Scale CFB Riser. II. Polydisperse Systems Cluster Characteristics of Geldart Group B Particles in a Pilot-Scale CFB Riser. II. Polydisperse Systems      September 16, 2011 Chew, J.W., R. Hays, J.G. Findlay, T.M. Knowlton, S.B.R. Karri, R.A. Cocco, C.M. Hrenya, Chemical Engineering Science 68, 82-93 (2012). Experiments... More detail
Cluster Characteristics of Geldart Group B Particles in a Pilot-Scale CFB Riser. I. Monodisperse Systems Cluster Characteristics of Geldart Group B Particles in a Pilot-Scale CFB Riser. I. Monodisperse Systems      September 16, 2011 Chew, J.W., R. Hays, J.G.Findlay, T.M. Knowlton, S.B.R.Karri, R.A. Cocco, C.M. Hrenya, Chemical Engineering Science 68, 72–81 (2012). Experiments in a circulating... More detail
Impact of Material Property and Operating Conditions on Mass Flux Profiles of Monodisperse and Polydisperse Group B Particles in a CFB Riser Impact of Material Property and Operating Conditions on Mass Flux Profiles of Monodisperse and Polydisperse Group B Particles in a CFB Riser       August 4, 2011 Chew, J.W., R. Hays, J.G. Findlay,  T.M. Knowlton, S.B.R. Karri,  R.A. Cocco, C.M. Hrenya, Powder Technology 214, 89–98 (2011).   High-speed video... More detail
The Effects of Cohesive Forces on Catalyst Entrainment in Fluidized Bed Reactors The Effects of Cohesive Forces on Catalyst Entrainment in Fluidized Bed Reactors    December 15, 2010 Cocco, R., R. Hays, S. Karri, and T. Knowlton. The Effects of Cohesive Forces on Catalyst Entrainment in Fluidized Bed Reactors. Advances in Fluid Catalytic Cracking: Testing, Characterization and... More detail
Particle Clusters In and Above Fluidized Beds Particle Clusters In and Above Fluidized Beds     October 25, 2010 R. Cocco, F. Shaffer, R. Hays, S.B.R. Karri, T.M. Knowlton, Powder Technology 203 (2010) 3-11.   High-speed video imaging of particle clusters in and above a fluidized bed suggests... More detail
Jet Cup Attrition Testing Jet Cup Attrition Testing    June 28, 2010 R. Cocco, Y. Arrington, R. Hays, J. Findlay, S. Karri, Powder Technology 200 (2010) 224-233. Jet cup attrition testing is a common method for evaluating particle attrition in fixed fluidized beds... More detail
Effects of Imposed Solids Flux and Pressure on Gas Bypassing in Deep Fluidized Beds of Group A Materials Effects of Imposed Solids Flux and Pressure on Gas Bypassing in Deep Fluidized Beds of Group A Materials    May 5, 2010 A.S. Issangya, S.B.R. Karri, T.M. Knowlton, in “Fluidization XIII” (S.D. Kim, Y. Kang, J.K. Lee, Y.C. Seo, eds.) Engineering Conferences International, Gyeong ju, Korea, p. 105. Tests were... More detail
Particle Attrition Measurements Using a Jet Cup Particle Attrition Measurements Using a Jet Cup    May 5, 2010 R. Cocco, S.B.R. Karri, Y. Arrington, R. Hays, J. Findlay, T.M. Knowlton, in “Fluidization XIII” (S.D. Kim, Y. Kang, J.K. Lee, Y.C. Seo, eds.) Engineering Conferences International, Gyeong... More detail
Particle Clusters in Fluidized Beds Particle Clusters in Fluidized Beds     May 5, 2010 R. Cocco, F. Shaffer, S.B.R. Karri, R. Hays, T.M. Knowlton in “Fluidization XIII” (S.D. Kim, Y. Kang, J.K. Lee, Y.C. Seo, eds.) Engineering Conferences International, Gyeong ju, Korea,... More detail
Small Particle Cluster Formation in Fluidized Beds and Its Effect on Entrainment Small Particle Cluster Formation in Fluidized Beds and Its Effect on Entrainment     May 13, 2008 R. Hays, S.B.R. Karri, R. Cocco, T.M. Knowlton in “Circulating Fluidized Bed Technology IX” (J. Wertehr, W. Nowak, K-E Wirth, E-U Hartge eds.) TuTech Innovation GmbH, Hamburg, p. 3... More detail
Effect of Baffles on Jet Streaming in Deep Fluidized Beds of Group A Particles Effect of Baffles on Jet Streaming in Deep Fluidized Beds of Group A Particles     May 13, 2008 A.S. Issangya, S.B.R. Karri, T.M. Knowlton in “Circulating Fluidized Bed Technology IX” (J. Werther, W. Nowak, K-E Wirth, E-U Hartge eds.) TuTech Innovation GmbH, Hamburg, p. 338 ... More detail
Detection of Gas Bypassing Due To Jet Streaming in Deep Fluidized Beds of Group A Particles Detection of Gas Bypassing Due To Jet Streaming in Deep Fluidized Beds of Group A Particles    May 10, 2007   A.S. Issangya, T.M. Knowlton, S.B.R. Karri in “Fluidization XII” (F. Berruti, T. Pugsley eds.) ECI Publications, Harrison Hot Springs, Canada, p. 95.   Tests were conducted... More detail
Hydrodynamic Scale-Up of Circulating Fluidized Beds Hydrodynamic Scale-Up of Circulating Fluidized Beds    May 10, 2007 S.B. Reddy Karri, Ted M. Knowlton, J.S. Smith in “Fluidization XII” (F. Berruti, T. Pugsley eds.) ECI Publications, Harrison Hot Springs, Canada, p. 326. A general procedure that can be... More detail
Scale-up of Fluidized-Bed Hydrodynamics Scale-up of Fluidized-Bed Hydrodynamics      February 16, 2005 Knowlton, T.M., S.B.R. Karri, A. Issangya, Powder Technology 150 (2005) 72-77.   The scale-up of fluidized beds is not an exact science. However, using proven techniques... More detail
Wall Solids Upflow and Downflow Regimes in Risers For Group A Solids Wall Solids Upflow and Downflow Regimes in Risers For Group A Solids       May 28, 2002 S.B. Reddy Karri,  T.M. Knowlton in “Circulating Fluidized Bed Technology VII” (J.R. Grace, J-X. Zhu, H. de Lasa, eds.) Canadian Society of Chemical Engineering, Ottawa... More detail
Simulation of Particles and Gas Flow Behavior in the Riser Section of a Circulating Fluidized Bed Using the Kinetic Theory Approach for the Particulate Phase Simulation of Particles and Gas Flow Behavior in the Riser Section of a Circulating Fluidized Bed Using the Kinetic Theory Approach for the Particulate Phase      August 9, 2000 S. Benyahia, H. Arastoopour, T.M. Knowlton, H. Massah, Powder Technology 112 (2000) 24-33.   Gas/particle flow behavior in the riser section of a circulating fluidized bed CFB was simulated... More detail
Tools and Techniques for Diagnosing and Solving Operating Problems in Fluidized Bed Systems Tools and Techniques for Diagnosing and Solving Operating Problems in Fluidized Bed Systems     May 1, 2000 T.M. Knowlton, Oil and Gas Science and Technology Revue de l’Institut Francais du Petrole, 55 (2000) 209-217.   Two-phase, gas-solid processes are extremely difficult to operate. &n... More detail