Heat and Mass Transport Processes

This subject is not offered in 2014.

Estimated 170 hours

Students must have completed the following subjects prior to enrolling in this subject:

AND the following subject:

CHEM20018 Reactions and Synthesis can be taken concurrently

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For the purposes of considering applications for Reasonable Adjustments under the Disability Standards for Education (Cwth 2005) and Students Experiencing Academic Disadvantage Policy, this subject requires all students to actively and safely participate in laboratory activities. Students who feel their disability may impact upon their participation are encouraged to discuss this with the Subject Co-ordinator and the Disability Liaison Unit http://www.services.unimelb.edu.au/disability/

AIMS

This subject aims to extend the fundamental concepts of heat transfer from that covered in CHEN20009 Transport Processes to include natural and forced convection and two phase systems. Mass transfer concepts are extended to unsteady state mass transfer and Fick's Second Law, prediction of diffusivity and of mass transfer coefficients. These fundamental concepts are then applied to the design of processes and equipment including shell and tube, air-cooled and plate heat exchangers, evaporator systems, membrane devices, binary distillation systems, gas absorbers and cooling towers. Experience in the use of appropriate simulation packages such as HYSYS for exchanger and distillation column design are included. This simulation work builds on the skills developed in CHEN20009 Chemical Process Analysis 2.

INDICATIVE CONTENT

• Forced Convection: Use of heat transfer correlations to predict coefficients;
• Heat Exchange: concept of an overall heat transfer coefficient, fouling factors; determination of the area required for a given heat duty, Heat exchanger design. Use of simulation packages such as HYSYS and ASPEN.
• Free convection: discussion and application of Grashof Number and other dimensionless groups.
• Condensation and Boiling: Fundamentals. Evaporation: various evaporator types and their advantages and disadvantages (forced circulation, film types); multiple and single effects; backward and forward feed; boiling point elevation; mechanical recompression; evaporator energy balances.
• Mass Transfer: Unsteady state mass transfer and Fick's Second Law; prediction of diffusivity; dimensional analysis and equations of change for mass transfer.
• Distillation: single-stage separations, equilibrium flash, differential distillation; multistage separations, operating lines, reflux; binary distillation, varying reflux ratio, minimum reflux, total reflux, optimum reflux, feed plate location, side streams, open steam; tray efficiency via overall and Murphree efficiencies. Use of simulation packages such as HYSYS.
• Gas absorption: basic mass transfer mechanism; material balances, co-current and countercurrent flow, limiting L/G ratio; multistage absorption and the absorption factor method; continuous contact, transfer units, height of a transfer unit, calculation of number of transfer units. Humidification and cooling tower height calculation.
• Membrane Systems: Microfiltration, ultrafiltration, nanofiltration and reverse osmosis. Gas separation systems. Robeson’s bound. Electrodialysis and pervaporation. Membrane selection.

INTENDED LEARNING OUTCOMES (ILO)

On completion of this subject the student is expected to:

1. Be able to apply the principles of heat transfer to solve heat transfer problems, particularly those involving two phase systems
2. Be able to assess quantitatively the performance of heat exchanger and evaporation equipment
3. Be able to apply the principles of mass transfer to solve mass transfer problems and to membrane separation processes
4. Be able to describe the concepts of equilibrium stage and continuous contactor analysis and apply these concepts to simple distillation and gas absorption problems
5. Be able to assess quantitatively the performance of simple, conventional distillation, gas absorption, membrane and cooling tower equipment
6. Be able to use simulation and spreadsheet software for the basic design of heat exchangers, absorption equipment, cooling towers and distillation columns

• A written 3-hour end-of-semester examination (70%)
• A 90-minute written class test one third of the way through the semester (15%).
• Three assignments, one involving laboratory work and two involving computer based simulation, expected to take about 10 hours outside of class, due in Weeks 8, 10 and 12 (15%). Formal reports are not required for these assignments, only a summary of the calculations made and the results generated.

Hurdle requirement: A mark of greater than 40% in the end-of-semester examination is required to pass the subject

The examination paper will consist of problems designed to test whether the student has acquired the ability to apply fundamental principles to the solutions of problems involving heat and mass transfer; and whether they can complete the process design of a range of heat and mass transfer equipment. The problems set for the exam will be similar in style to those undertaken in the tutorial classes, but will require the student to show that they can extend themselves beyond the level of the simpler tutorial problems.

Intended Learning Outcomes (ILOs) 1 and 2 are addressed in the MS test, the assignments and the examination.

ILOs 3, 4 and 5 are addressed in the assignments and the examination

ILO 6 is addressed in one of the assignments.

This subject potentially can be taken as a breadth subject component for the following courses:

• Bachelor of Arts
• Bachelor of Commerce
• Bachelor of Environments
• Bachelor of Music

You should visit learn more about breadth subjects and read the breadth requirements for your degree, and should discuss your choice with your student adviser, before deciding on your subjects.

• Ability to apply knowledge of basic science and engineering fundamentals
• In-depth technical competence in at least one engineering discipline
• Ability to undertake problem identification, formulation and solution
• Ability to use a systems approach to design and operational performance

LEARNING AND TEACHING METHODS

The subject will be delivered through a combination of lectures, self managed assignments, and self managed work on tutorial questions supported by tutorial classes. The assignments will focus on:

1. Development of HYSYS simulation skills through a computer-based exercise
2. Development of skills in MS Excel through a computer-based exercise
3. A laboratory based excercise which will reinforce the material covered in lectures.

INDICATIVE KEY LEARNING RESOURCES

Coulson, J.M.; Richardson, J.F.; Backhurst, J.R.; Harker, J.H. (1999). Coulson and Richardson's Chemical Engineering Volume 1 - Fluid Flow, Heat Transfer and Mass Transfer (6th Edition). Elsevier

Richardson, J.F.; Harker, J.H.; Backhurst, J.R. (2002). Coulson and Richardson's Chemical Engineering Volume 2 - Particle Technology and Separation Processes (5th Edition).. Elsevier.

CAREERS / INDUSTRY LINKS

The skills gained in this subject are crucial to the career of a process engineer. They will be important for students wishing to progress to jobs in engineering design offices and in operational roles within a wide range of industries including petrochemicals, food processing, wastewater treatment and pulp and paper manufacture.