Solid-Fluid Operations
Code
10681
Academic unit
Faculdade de Ciências e Tecnologia
Department
Departamento de Química
Credits
6.0
Teacher in charge
Manuel José Teixeira Carrondo, Rui Manuel Freitas Oliveira
Weekly hours
5
Total hours
91
Teaching language
Português
Objectives
In this course several classical unit operations in the chemical/biochemical industries involving fluids and solids will be studied. Examples of such unit operations are filtration, centrifugation, gas cleaning, settling and fluidization. The course will focus on the phenomelogical understanding of such processes, on mathematical modelling and process optimization and process design.
Prerequisites
none
Subject matter
- Particle characterization: size distributions based on weight, number and surface area. Averages based on number or weight data. Effect of shape. Methods for particle size measurement.
- Size reduction of solids: Mechanisms for size reduction. Dynamics of size distribution. Energy for size reduction. Equipment for size reduction.
- Motion of particles in a fluid. Characterization of flow around a sphere: laminar and turbulent flow, Stokes law, skin and form drag friction, terminal settling velocities. Extension to non-spherical particles. Transient motion of particles: vertical acceleration under gravity.
- Sedimentation: free and hindered settling, the thickening process, settlers sizing.
- Flow in packed columns. Characterization of flow in packed columns. Characterization of packings. Calculation of friction factors and pressure drop. Extension to vacuum columns. Economical design of packed bed columns. Heat and mass transfer.
- Fluidization: description of fluidization phenomena; Gas and liquid fluidization, Bubbling behavior, Elutriation, Calculation of minimum fluidizing velocity, Calculation of bed expansion, Estimation of required heat transfer surface area.
- Centrifugation: Types of centrifuges. Mechanical design. Fluid pressure and liquid surface form. Separation of two liquids. Separation between suspension solids and liquids. Filtration using centrifuges. Prediction of separation efficiency.
- Filtration: Filtration theory The general filtration equation. Cake and filter resistance. Compressible and incompressive cakes. Filtration equipment. Design of plate and frame filters and design of rotary vacuum filters
- Gas cleaning: Cyclone design. The theoretical cut model. Recovery efficiency. Pressure drop in cyclones. Electrostatic separators.
Bibliography
- J.M. Coulson and J.F. Richardson, Chemical Engineering, II Vol., 2ª Ed., 1965, Pergamon Press, London
- J. P. K. Seville, U. Tüzün and R. Clift, Processing particulate solids, 1ª Ed., 1997, Blackie Academic & Professional, London, UK, ISBN: 0751403768
- Philip A Schweitzer, Handbook of Separation Techniques for Chemical Engineers, 3ª Ed, 1996, McGraw-Hill, New York, NY, ISBN: 0070570612
- Albert Rushton, Anthony S. Ward, Richard G. Holdich, Solid-Liquid Filtration and Separation Technology (Hardcover), 2ª Ed, 2000, Wiley-VCH, Germany
Teaching method
In this course the theoretical matters are given in two lessons a week of 1 hour each. In the practial lessons (1 lesson a week of 2,5 hours) and tutorial (2 hours/week) the study is problem-oriented.