(291b) An Academics View On Mixing Education At the University of Alberta

Suzanne Kresta (BSc, UNB (1986), MSc, Leeds (UK, 1987), PhD, McMaster (1992)) teaches Mass and Energy Balances (CME 265), design (ChE 464) and Mixing (ChE 420 and 620), and serves as co-editor of the Handbook of Industrial Mixing. Her principle research contributions are related to understanding turbulence and mixing in stirred tanks (measurement of turbulence, the use of spatial statistics to define mixing and length scales, nano-particle production, solids suspension, and reactor design) and she has collaborated with colleagues in a wide variety of industries (including oils sands extraction and froth treatment, photographic film, drinking water treatment, mineral processing and metals refining, polymer reactor design, cosmetics, mixing equipment design, fish processing, clean-up of nuclear waste, and fertilizer production). Many of her papers are both widely cited in the research literature and used for industrial design calculations.

Her teaching interests include visual problem solving tools, the use of story telling and case studies, active learning, and explicit use of cognitive levels with learning objectives. She has served as an Iron Ring Warden since 1999, as a Peer Consultant at the University of Alberta since 2004, and has won a number of national and international awards.

Research Interests

The mixing unit operation is far broader than the classical well mixed continuous stirred tank reactor, and is present in most chemical processes. Tightly designed mixing equipment is needed to meet the demanding process specifications of products ranging from Corianä countertops, through pharmaceutical and photographic crystals, cosmetics, fine chemicals, water treatment, and extraction of metals from ore.

Our group is currently exploring the theory of spatial statistics and how it can be applied to mixing problems to provide a rigorous definition of well mixed. The equations underlying the modelling of mixing sensitive reactions are being revisited in this context. Applications projects include the production of nanoscale metal powder, the distribution and suspension of multi-modal particle mixtures, drawdown of floating solids, and dissolution kinetics of partially soluble liquids.

Current Projects

• Continuous production of nanoscale metal precipitates; Shad Siddiqui, Alena Kukukova, Peter Unwin; Umicore, NSERC
• Drawdown of floating solids; Oscar Khazam, Lightnin
• Modelling equations for mixing sensitive reactions; Imran Shah, NSERC
• Segregation dimensions and the characterization of mixing; Suzanne Kresta, Alena Kukukova, Joelle Aubin; NSERC, CNRS
• Multimodal solids suspension and distribution; Inci Ayranci, Lightnin