Transport phenomena III

Year
3
Academic year
2019-2020
Code
01009481
Subject Area
Chemical Engineering
Language of Instruction
Portuguese
Mode of Delivery
Face-to-face
Duration
SEMESTRIAL
ECTS Credits
6.0
Type
Compulsory
Level
1st Cycle Studies

Recommended Prerequisites

Calculus I, II and III, Transport Phenomena I and II, Chemical Thermodynamics, Mass and Energy Balances.

Teaching Methods

There are theoretical (T) and theoretical-practical (TP) lectures. In the first, theoretical concepts are presented followed by their applications through the presentation of case studies that are discussed and solved in class. The main way of teaching is in the form of handouts, using also small demonstration movies. Students are encouraged to solve exercises in TP class where discussions with their colleagues are allowed. Some problems are also proposed for autonomous solving which are then discussed in following TP class. The use of the LABVIRTUAL platform is also stimulated.

Learning Outcomes

Students should: 1. identify and mathematically describe the mechanisms of mass transfer; 2. identify the transport of a solute between phases in contact and quantify the total resistance; 3. establish mass balances in steady state and in transient conditions with different geometries; 4. know the methodology for calculating the mass transfer coefficients; 5. design packed absorption/stripping towers; 6. identify simultaneous heat and mass transfer processes and establish the corresponding energy and mass balances to be applied in water cooling towers and dryers.

The students should develop the ability to understand and relate knowledge of the contents taught, to acquire knowledge independently and to formulate and solve problems. They should also demonstrate a well-structured and integrated way of thinking by applying their knowledge and understanding in a manner that indicates a professional approach to their work.

Work Placement(s)

No

Syllabus

Mass transfer: mechanisms (diffusion, convection), empirical correlations for the mass transfer coefficients. Dimensional analysis. Internal and external flow (flow over spheres, cylinders and plates). Analogies between momentum, heat and mass transfer. Concentration variation with time and position (microscopic balances in plane walls, cylinders and spheres) – Heisler and Gurney-Lurie charts.

Absorption of gases in liquids: mass resistances in contacting phases (two-film theory), overall mass transfer coefficient, design of packed absorption /stripping towers. Calculation of the packing height (HTU, NTU and rigorous calculation); case of dilute mixtures; definition of HETP (height equivalent of a theoretical plate).

Simultaneous heat and mass transfer. Humidity chart. Brief reference to the operation and design of water cooling towers as well as of humidification towers and dryers of solids.

Head Lecturer(s)

Maria da Graça Videira de Sousa Carvalho

Assessment Methods

Continuous assessment
Frequency: 100.0%

Final assessment
Exam: 100.0%

Bibliography

- Bergman, T.L.; Lavine, A.S.; Incropera, F.P.; de Witt, D.P. Fundamentals of Heat and Mass Transfer. 7th ed, J. Wiley & Sons, N.Y., 2011.

- Çengel, Y.; A.Ghajar, A. Heat and Mass Transfer: Fundamentals and Applications. McGraw-Hill Inc., N.Y. , 2010.

- Welty, J.R; Wicks, C.E.; Wilson, R.E.; Rorrer G.L. Fundamentals of momentum, heat and mass transfer. 5th ed. John Wiley &Sons, Inc, N.Y., 2010.

- Geankoplis, C.J. Transport Processes and Separation Process (Includes Unit Operations), 4th ed., Prentice-Hall, 2003

- McCabe, W.; Smith, J.; Harriott, P. Unit Operations of Chemical Engineering. 7th ed. McGraw-Hill Book Co., NewYork, 2005.

- Figueiredo, M.M. Absorção – Colunas de Enchimento. Cadernos de Eng. Química, 1, Dep. Engenharia Química, Universidade de Coimbra, 1987

- Wankat, P.C. Separation Process Engineering. Prentice Hall, 2007.

- Azevedo, E.G.; Alves, A.M. Engenharia dos Processos de Separação. IST Press, Lisboa, 2009.