Nature and areas of occurrence of multiphase flows in the processing of materials and biomaterials. Fundamental properties of the dispersed phase.

Sizes and shapes of particles, droplets, and bubbles. Determination of viscosity and interfacial contact area in multiphase systems.

Flow of liquid–solid particle mixtures. Fluid–solid particle systems. Fundamentals of sedimentation theory.

Methods for the separation of fluid–solid systems: filtration, centrifugation, and dust removal (dedusting).

Liquid–gas systems. Models of gas bubble formation and growth, flow regimes, phase fractions and flow resistance in liquid–gas mixtures, and the theory of gas sparging (bubbling).

Fluidization processes and pneumatic conveying.

Liquid–liquid systems. Methods of emulsion generation and stability of emulsions. Flow of liquid–liquid and liquid–gas systems in microchannels, including flow regimes and mechanisms of droplet and bubble formation.

Investigation of the shape and size of gas bubbles formed in different liquids, as well as the study of gas bubble flow velocities.

Investigation of phase fractions in liquid–gas and liquid–solid particle mixtures, determination of sedimentation velocities of dispersed systems, and phase separation kinetics using turbidimetry.

Fluidized bed dynamics and pneumatic conveying.

Analysis of industrial processes combined with the identification of multiphase flow regimes occurring within them. Preparation of a presentation related to an industrial process and the methodology for determining process parameters.

Written examination based on the lecture. The requirement for passing is obtaining a positive grade, i.e. achieving at least 60% of the total available points.

Obtaining a positive grade requires:

• Delivery of a multimedia presentation / seminar paper on an assigned topic, which constitutes 60% of the seminar grade;
• Active participation in the discussion of presentations delivered by other students, as assessed by the academic instructor, which constitutes 40% of the seminar grade.

The requirement for passing the course is obtaining a positive grade from:

• Oral assessments for all laboratory exercises performed. The averaged grade from the oral tests constitutes 20% of the final course grade (66% of the laboratory grade).
• A positive grade for a substantive laboratory report prepared in laboratory groups, which constitutes 10% of the final course grade (34% of the laboratory grade). The instructor may differentiate the final report grades by taking into account ongoing observation of the student’s performance during laboratory classes, including, among others, active participation in laboratory work and contribution to the processing and analysis of results.

Obtaining a positive grade requires that the student is able to:

• define fundamental quantities and concepts of multiphase flow used in chemical and biochemical engineering, and discuss methods for determining phase fractions and flow resistances in two-phase and multiphase mixtures;
• analyze the mechanisms of multiphase flows in macro- and microchannels;
• characterize and compare different aeration techniques, and perform measurements of basic multiphase flow parameters using appropriate equipment, including bubble shape, size, and velocity in a liquid layer, phase fractions and flow resistance of two-phase mixtures, sedimentation velocity, and aeration kinetics in liquid–gas systems;
• characterize and compare fluidized beds, calculate parameters of fluidization and pneumatic conveying processes, conduct experiments related to fluidization and pneumatic transport, and analyze the obtained results;
• analyze industrial processes with respect to the occurrence of multiphase flows.

Processing and analysis of experimental results
A positive grade is awarded when the student:

• is able to work effectively in a group and, through joint discussion, interprets the results with respect to the aim and hypothesis, indicating their significance;
• actively participates in laboratory classes as well as in the processing of the obtained results and the preparation of the report, as assessed on the basis of the instructor’s observation.