Mass Transfer Coefficients (MTC) and Correlations II
|
|
- Emery Lawrence
- 5 years ago
- Views:
Transcription
1 Mass Transfer Mass Transfer Coefficients (MTC) and Correlations II 7.2-
2 Correlations of Mass Transfer Coefficients Mass transfer coefficients (MTCs) are not physical properties like the diffusion coefficient. They differ from case to case and even within a system, depending on their definition. With the help of experimental observations, correlations for mass transfer coefficients have been developed for standard cases (e.g. fluid flow through a packed bed of particles, gas bubbles rising in a tank, falling films, flow over surfaces and within tubes, ). Such MTC correlations are typically expressed with dimensionless numbers, frequently in the following form: kd D C dv X D Y or X Y Sh C Re Sc
3 Convective Sh Nu Conductive heat transfer heat transfer h l Equivalent in heat transfer h: convective heat transfer coefficient λ: thermal conductivity diffusivity of momentum thermal diffusivity Pr is the equivalent to Sc in heat transfer α: thermal diffusivity Dimensionless numbers Table 8.3- from Cussler, 3 rd ed
4 Selected mass transfer correlations for fluid-fluid interfaces a Table from Cussler
5 Selected mass transfer correlations for fluid-solid interfaces a 5 Table from Cussler 7.2-5
6 MTC Correlations Excellent for preliminary design of small pilot plants. For design of full scale equipment you must supplement them with data of the SPECIFIC chemical system. Fluid-Fluid interface MTC error at best 30% The MTC is expressed mostly as Sherwood-# kl D or a Stanton-# k The Sh is typically expressed by powers of Re and Sc corresponding to convection and diffusion, respectively. When the convection is not a typical forced one but one generated by density gradients, it is free convection and the Re is replaced by the Grashof-#. Fluid-Solid interface The error is about 0% and as low as % especially when dealing with laminar flow in a single tube. This high accuracy is attributed to the heat transfer origin of these correlations and the fact that SIMPER geometries are involved. Also heat transfer is an older subject than mass transfer. For example, laminar flow of one fluid in a tube is much better understood than turbulent flow of gas and liquid in a packed tower! Again the MTC is written in the Sh- or St-notation
7 Example: Dissolution rate of a spinning disk Remember from Generalized Mass Balances : A solvent flow approaches a spinning disk made out of a sparingly soluble solute. Calculate the diffusioncontrolled rate at which the disk slowly dissolves at steady state. The diffusion flux is: 2/ 3 / 2 c D j D z 0 z c(sat) z / 6 j j / 2 2 D d 0.62 d D / Re Sc d D / 3 c / 3 (sat) c (sat)
8 Now: A solid disc of benzoic acid (BA) 2.5 cm in diameter is spinning at 20 rpm and 25 C. How fast will it dissolve in a large volume of a) water and b) air? -5 2 D BA/W=0 cm /s 2 D BA/A=0.233cm /s Solubility of benzoic acid in water is g/cm 3. Equilibrium vapor pressure of benzoic acid in air is 0.3 mmhg at 25 C. The molecular weight of BA is 22 g/mol. Will the mass transfer be faster in air or in water?
9 From Table : /2 /3 k 0.62D D a) For water /3 /2 and N kc (sat) cm 20 / 60 2 / s 0.0cm / s s 0.0cm / s 0 cm / s k N cm / s 0.003g / cm b) For air /2 2 cm 20 / 60 2 / s 0.5cm / s ka s 0.5cm 2 / s 0.233cm 2 / s / cm / s g / cm s 0.47cm / s N 0.3mmHg mol g 0.47cm / s 760mmHg cm 298 mol g / cm s The flux in air is /3 of that in water even though the k in air is 500 times that in water
10 Mass Transfer across Interfaces (very important) Often we encounter the following scenario: Bulk interface Bulk Basic equation: N Kc where K is the overall MTC and c an APPROPRIATE concentration difference and most notably the equilibrium or asymptotic concentration. Case a: Heat transfer Hot benzene on cold water. The benzene cools while the water warms until they reach the same T. Equal T is the criterion for equilibrium. The amount of energy transferred is always equal to the T. No problem!
11 Case b: Bromine extraction A benzene solution of bromine is placed on top of a water solution containing the SAME concentration of bromine. ater the initially equal concentrations have CHANGED and the Br concentration in C 6 H 6 is higher than in H 2 O. Why? Bromine is more soluble in C 6 H 6 than in H 2 O. Now the c here should be: c = c (in benzene) - Hc (in water) Otherwise the initial c is zero and we still have flux. The partition coefficient H is: Bromine concentration: concentration of Br in benzene H= concentration of Br in water at equilibrium 7.2-
12 Case c: Bromine vaporization Initially Br evaporates from water into air. Initially the Br concentration in water is higher than that in air; at the end it is lower. This might be a problem of units: Concentrations in the liquid are expressed in mol/ and those in air by the partial pressure?? Mass transfer should be described in terms of the more fundamental chemical potentials. If this was done, the concentration difference would disappear
13 7.4 The Overall MTC The flux in the gas is: N k (p p ) p 0 i (4) Because the interfacial region is thin, it is at steady state. Thus, the flux will be equal to that in the liquid. N k (c c ) (5) i 0 where k P and k are the gas and liquid MTC s! So, k p p k c c P 0 i i
14 Always we must remove the dependency on the interfacial concentration or partial pressures, as these are difficult to determine. Usually there is equilibrium at the interface: c i p i H c i k P p k P k c H k 0 0 H is Henry s constant or the partition coefficient in the simplest case (6) So the flux N from equation (5) should be derived as: N (p Hc ) 0 0 / k H / k p (7) K P k p H k is the overall gas-side MTC
15 Analogy with electric circuits: Current N p k 0 P Hc H k 0 Voltage difference 2 resistances in series Many times the engineer s job is to determine which is the rate limiting resistance: in the gas or the liquid??
16 Now we can write the flux equation in two ways: A) B) N K (p p *) p 0 N K (c * c ) 0 where where K K p / k H / k / k / k H p and c * 0 p / H K is called the overall liquid-side mass transfer coefficient and c * is the hypothetical liquid concentration in equilibrium with the bulk gas concentration. p p * Hc 0 K P is the overall gas-side mass transfer coefficient and p * is the hypothetical gas-phase concentration that would be in equilibrium with the bulk liquid concentration. and
17 Example : Oxygen Mass Transfer Estimate the overall liquid-side MTC for O 2 transfer from water into air assuming that each MTC is k = D/0.0 cm, Henry s law constant is H = atm, D air = 0.23 cm 2 /s and D water = cm 2 /s. Goal: Calculate k and k P and substitute in the appropriate equation. k D 0.0cm cm / s cm / s 0.0cm Finding k P and H is more difficult for unit conversion k p k D G G RT (0.0cm)RT cm / s 3 (0.0cm)(82cm atm / (mol K))(298K) mol / (cm s atm)
18 From the way H is given (unit consistency) H H` c atm mol / 8 cm atm cm 3 / mol Insert these values into the equation for K K / k / k H p / (2. 0 cm / s) / (9.4 0 mol / cm s atm cm atm / mol) cm / s The mass transfer is dominated by the liquid-side resistance!!
19 Example : Perfume Extraction Jasmone (C H 6 O) is a valuable aroma from jasmine flowers that is used in soaps and cosmetics. We are recovering this from its water solution (jasmine flowers in water) with benzene drops the k B =3.0 x 0-4 cm/s while k W = 2.4x0-3 cm/s However, jasmone is 70 times more soluble in C 6 H 6 than in H 2 O. What is the overall MTC? Assuming steady state N = k (c - c ) = k (c - c ) (8) W 0 W iw B ib 0B The interfacial concentration is in equilibrium, so: c ib H ciw (9)
20 Eliminate the interfacial concentration using equations 8 and 9: k c k c k Hc k c W 0 W W iw B iw B 0B k c k c ( k k H) c W 0 W B 0B W B iw Replace this in the N for benzene c iw c k c k c ib H k k H W 0 W B 0B W B (0) k c k c W 0W B 0B N k H c B - 0B k k H W B Hk c Hk c k c Hk c kk k k H k k H W B W B W 0 W B 0B W 0B B 0B B W k (Hc c ) B 0 W 0B / k H / k B W (Hc c ) 0 W 0B
21 The overall MTC, K is K' 4 3 / (3.0 0 cm / s) 70 / (2.4 0 cm / s) cm / s Again the mass transfer in water controls the process because jasmone is more soluble in C 6 H
Convective Mass Transfer
Convective Mass Transfer Definition of convective mass transfer: The transport of material between a boundary surface and a moving fluid or between two immiscible moving fluids separated by a mobile interface
More informationTheories for Mass Transfer Coefficients
Mass Transfer Theories for Mass Transfer Coefficients Lecture 9, 5..7, r. K. Wegner 9. Basic Theories for Mass Transfer Coefficients Aim: To find a theory behind the empirical mass-transfer correlations
More informationChemical Reactions II
Mass Transfer Chemical Reactions II Lecture, 6..7, r. K. Wegner . Homogeneous chemical reactions Chemical reactions can alter mass fluxes by orders of magnitude. Recall NH 3 absorption into water: log(c
More informationIntroduction to Heat and Mass Transfer. Week 12
Introduction to Heat and Mass Transfer Week 12 Next Topic Convective Heat Transfer» Heat and Mass Transfer Analogy» Evaporative Cooling» Types of Flows Heat and Mass Transfer Analogy Equations governing
More informationMass Transfer Operations I Prof. Bishnupada Mandal Department of Chemical Engineering Indian Institute of Technology, Guwahati
Mass Transfer Operations I Prof. Bishnupada Mandal Department of Chemical Engineering Indian Institute of Technology, Guwahati Module - 2 Mass Transfer Coefficient Lecture - 4 Boundary Layer Theory and
More informationMass Transfer Fundamentals. Chapter#3
Mass Transfer Fundamentals Chapter#3 Mass Transfer Co-efficient Types of Mass Transfer Co-efficient Convective mass transfer can occur in a gas or liquid medium. Different types of mass transfer coefficients
More informationModule 9: Mass Transfer Lecture 40: Analysis of Concentration Boundary Layer. The Lecture Contains: The concentration boundary layer
The Lecture Contains: The concentration boundary layer Heat and Mass Transfer Analogy Evaporate Cooling file:///d /Web%20Course%20(Ganesh%20Rana)/Dr.%20gautam%20biswas/Final/convective_heat_and_mass_transfer/lecture40/40_1.html[12/24/2014
More informationGas transfer rates If either phase concentration can not be predicted by Henry's law then there will be a transfer of mass across the interface until
Gas transfer rates If either phase concentration can not be predicted by Henry's law then there will be a transfer of mass across the interface until equilibrium is reached. The mechanisms and rate expressions
More informationMASS TRANSFER AND GAS ABSORPTION EQUIPMENT
MASS TRANSFER AND GAS ABSORPTION EQUIPMENT Mark J McCready University of Notre Dame Indiana, USA TOPICS Review of heat transfer and heat exchangers Some fundamental aspects of mass transfer Analysis of
More informationInterphase Mass Transfer see Handout. At equilibrium a species will distribute (or partition ) between two phases.
Interphase Mass Transfer see Handout At equilibrium a species will distribute (or partition ) between two phases. Examples: 1. oxygen (species) will partition between air (gas phase) and water (liquid
More informationSteady-State Molecular Diffusion
Steady-State Molecular Diffusion This part is an application to the general differential equation of mass transfer. The objective is to solve the differential equation of mass transfer under steady state
More informationBAE 820 Physical Principles of Environmental Systems
BAE 820 Physical Principles of Environmental Systems Inter phase mass transfer Dr. Zifei Liu Mass transfer between two phases For a two phase system not at equilibrium (concentrations in the two phases
More informationOutline. Definition and mechanism Theory of diffusion Molecular diffusion in gases Molecular diffusion in liquid Mass transfer
Diffusion 051333 Unit operation in gro-industry III Department of Biotechnology, Faculty of gro-industry Kasetsart University Lecturer: Kittipong Rattanaporn 1 Outline Definition and mechanism Theory of
More informationTransport processes. 7. Semester Chemical Engineering Civil Engineering
Transport processes 7. Semester Chemical Engineering Civil Engineering 1 Course plan 1. Elementary Fluid Dynamics 2. Fluid Kinematics 3. Finite Control Volume nalysis 4. Differential nalysis of Fluid Flow
More informationChapter 2 Mass Transfer Coefficient
Chapter 2 Mass Transfer Coefficient 2.1 Introduction The analysis reported in the previous chapter allows to describe the concentration profile and the mass fluxes of components in a mixture by solving
More informationForced Convection: Inside Pipe HANNA ILYANI ZULHAIMI
+ Forced Convection: Inside Pipe HANNA ILYANI ZULHAIMI + OUTLINE u Introduction and Dimensionless Numbers u Heat Transfer Coefficient for Laminar Flow inside a Pipe u Heat Transfer Coefficient for Turbulent
More informationHeat and Mass Transfer Unit-1 Conduction
1. State Fourier s Law of conduction. Heat and Mass Transfer Unit-1 Conduction Part-A The rate of heat conduction is proportional to the area measured normal to the direction of heat flow and to the temperature
More informationIntroduction to Mass Transfer
Introduction to Mass Transfer Introduction Three fundamental transfer processes: i) Momentum transfer ii) iii) Heat transfer Mass transfer Mass transfer may occur in a gas mixture, a liquid solution or
More informationMODULE 3: MASS TRANSFER COEFFICIENTS
MODULE 3: MASS TRANSFER COEFFICIENTS LECTURE NO. 4 3.4.3 Correlation of mass transfer coefficients for single cylinder Bedingfield and Drew (1950) studied the sublimation from a solid cylinder into air
More informationMYcsvtu Notes HEAT TRANSFER BY CONVECTION
www.mycsvtunotes.in HEAT TRANSFER BY CONVECTION CONDUCTION Mechanism of heat transfer through a solid or fluid in the absence any fluid motion. CONVECTION Mechanism of heat transfer through a fluid in
More informationHeat processes. Heat exchange
Heat processes Heat exchange Heat energy transported across a surface from higher temperature side to lower temperature side; it is a macroscopic measure of transported energies of molecular motions Temperature
More informationMass Transfer Operations
College of Engineering Tutorial # 1 Chemical Engineering Dept. 14/9/1428 1. Methane and helium gas mixture is contained in a tube at 101.32 k Pa pressure and 298 K. At one point the partial pressure methane
More informationMechanical Engineering. Postal Correspondence Course HEAT TRANSFER. GATE, IES & PSUs
Heat Transfer-ME GATE, IES, PSU 1 SAMPLE STUDY MATERIAL Mechanical Engineering ME Postal Correspondence Course HEAT TRANSFER GATE, IES & PSUs Heat Transfer-ME GATE, IES, PSU 2 C O N T E N T 1. INTRODUCTION
More informationContents. 1 Introduction 4. 2 Methods Results and Discussion 15
Contents 1 Introduction 4 2 Methods 11 3 Results and Discussion 15 4 Appendices 21 4.1 Variable Definitions................................ 21 4.2 Sample Calculations............................... 22
More informationAir-Water Gas Exchange of Chemicals
Air-Water Gas Exchange of Chemicals terry.bidleman@ec.gc.ca Centre for Atmospheric Research Experiments Science & Technology Branch, Environment Canada Photo: Thule Bay, Alaska Jim Milne, DRDC Why? Air-Water
More informationPrinciples of Convection
Principles of Convection Point Conduction & convection are similar both require the presence of a material medium. But convection requires the presence of fluid motion. Heat transfer through the: Solid
More informationDEMONSTRATION OF MASS TRANSFER USING AERATION OF WATER
DEMONSTRATION OF MASS TRANSFER USING AERATION OF WATER Sultana R. Syeda *, B.M. S. Arifin, Md. M. Islam and Anup Kumar Department of Chemical Engineering, Bangladesh University of Engineering and Technology
More informationCHAPTER 3 MODELLING AND ANALYSIS OF THE PACKED COLUMN
37 CHAPTER 3 MODELLING AND ANALYSIS OF THE PACKED COLUMN Absorption in a chemical process refers to a mass transfer between gas and liquid which transfers one or more components from the gas phase to the
More informationConvection. forced convection when the flow is caused by external means, such as by a fan, a pump, or atmospheric winds.
Convection The convection heat transfer mode is comprised of two mechanisms. In addition to energy transfer due to random molecular motion (diffusion), energy is also transferred by the bulk, or macroscopic,
More informationHeat Transfer with Phase Change
CM3110 Transport I Part II: Heat Transfer Heat Transfer with Phase Change Evaporators and Condensers Professor Faith Morrison Department of Chemical Engineering Michigan Technological University 1 Heat
More informationChapter 9 NATURAL CONVECTION
Heat and Mass Transfer: Fundamentals & Applications Fourth Edition in SI Units Yunus A. Cengel, Afshin J. Ghajar McGraw-Hill, 2011 Chapter 9 NATURAL CONVECTION PM Dr Mazlan Abdul Wahid Universiti Teknologi
More informationStudies on flow through and around a porous permeable sphere: II. Heat Transfer
Studies on flow through and around a porous permeable sphere: II. Heat Transfer A. K. Jain and S. Basu 1 Department of Chemical Engineering Indian Institute of Technology Delhi New Delhi 110016, India
More informationPHYSICAL MECHANISM OF CONVECTION
Tue 8:54:24 AM Slide Nr. 0 of 33 Slides PHYSICAL MECHANISM OF CONVECTION Heat transfer through a fluid is by convection in the presence of bulk fluid motion and by conduction in the absence of it. Chapter
More informationChapter 3 NATURAL CONVECTION
Fundamentals of Thermal-Fluid Sciences, 3rd Edition Yunus A. Cengel, Robert H. Turner, John M. Cimbala McGraw-Hill, 2008 Chapter 3 NATURAL CONVECTION Mehmet Kanoglu Copyright The McGraw-Hill Companies,
More informationERT 216 HEAT & MASS TRANSFER SEM2, 2013/2014
ERT 16 HET & MSS TRNSFER SEM, 01/014 Tutorial: Principles of Mass Transfer (Part 1) gas of CH 4 and He is contained in a tube at 10 kpa pressure and 98 K. t one point the partial pressure of methane is
More informationFORMULA SHEET. General formulas:
FORMULA SHEET You may use this formula sheet during the Advanced Transport Phenomena course and it should contain all formulas you need during this course. Note that the weeks are numbered from 1.1 to
More informationLevel 7 Post Graduate Diploma in Engineering Heat and mass transfer
9210-221 Level 7 Post Graduate Diploma in Engineering Heat and mass transfer 0 You should have the following for this examination one answer book non programmable calculator pen, pencil, drawing instruments
More informationPart I.
Part I bblee@unimp . Introduction to Mass Transfer and Diffusion 2. Molecular Diffusion in Gasses 3. Molecular Diffusion in Liquids Part I 4. Molecular Diffusion in Biological Solutions and Gels 5. Molecular
More informationDifferential equations of mass transfer
Differential equations of mass transfer Definition: The differential equations of mass transfer are general equations describing mass transfer in all directions and at all conditions. How is the differential
More informationPX-III Chem 1411 Chaps 11 & 12 Ebbing
PX-III Chem 1411 Chaps 11 & 12 Ebbing 1. What is the name for the following phase change? I 2 (s) I 2 (g) A) melting B) condensation C) sublimation D) freezing E) vaporization 2. Which of the following
More informationMOMENTUM TRANSPORT Velocity Distributions in Turbulent Flow
TRANSPORT PHENOMENA MOMENTUM TRANSPORT Velocity Distributions in Turbulent Flow Introduction to Turbulent Flow 1. Comparisons of laminar and turbulent flows 2. Time-smoothed equations of change for incompressible
More informationChapter 6 Fundamental Concepts of Convection
Chapter 6 Fundamental Concepts of Convection 6.1 The Convection Boundary Layers Velocity boundary layer: τ surface shear stress: s = μ u local friction coeff.: C f y y=0 τ s ρu / (6.) (6.1) Thermal boundary
More information2 THEORY OF TRANSPORT IN MEMBRANES
2 THEORY OF TRANSPORT IN MEMBRANES 2.1 Driving forces for transport mechanisms A membrane process is a separation process that covers a broad range of problems from particles to molecules and a wide variety
More informationSummary of Dimensionless Numbers of Fluid Mechanics and Heat Transfer
1. Nusselt number Summary of Dimensionless Numbers of Fluid Mechanics and Heat Transfer Average Nusselt number: convective heat transfer Nu L = conductive heat transfer = hl where L is the characteristic
More informationUNIT II CONVECTION HEAT TRANSFER
UNIT II CONVECTION HEAT TRANSFER Convection is the mode of heat transfer between a surface and a fluid moving over it. The energy transfer in convection is predominately due to the bulk motion of the fluid
More informationCHEMISTRY Topic #2: Thermochemistry and Electrochemistry What Makes Reactions Go? Fall 2018 Dr. Susan Findlay See Exercises in Topic 8
CHEMISTRY 2000 Topic #2: Thermochemistry and Electrochemistry What Makes Reactions Go? Fall 208 Dr. Susan Findlay See Exercises in Topic 8 Vapour Pressure of Pure Substances When you leave wet dishes on
More informationPHYSICAL MECHANISM OF NATURAL CONVECTION
1 NATURAL CONVECTION In this chapter, we consider natural convection, where any fluid motion occurs by natural means such as buoyancy. The fluid motion in forced convection is quite noticeable, since a
More informationUnit OperatiOn. Table 1: List of some unit operations
Unit OperatiOn What is chemical engineering? Chemical Engineering is a group of industrial processes in which row materials are changed or separated into useful products What are "Unit Operations"? Every
More informationCHEN 7100 FA16 Final Exam
CHEN 7100 FA16 Final Exam Show all work and state all assumptions for full credit. The exam is closed book, notes, and homework. Only the course reader and your mind should be open. No electronic devices
More informationHEAT TRANSFER 1 INTRODUCTION AND BASIC CONCEPTS 5 2 CONDUCTION
HEAT TRANSFER 1 INTRODUCTION AND BASIC CONCEPTS 5 2 CONDUCTION 11 Fourier s Law of Heat Conduction, General Conduction Equation Based on Cartesian Coordinates, Heat Transfer Through a Wall, Composite Wall
More informationPhone: , For Educational Use. SOFTbank E-Book Center, Tehran. Fundamentals of Heat Transfer. René Reyes Mazzoco
8 Fundamentals of Heat Transfer René Reyes Mazzoco Universidad de las Américas Puebla, Cholula, Mexico 1 HEAT TRANSFER MECHANISMS 1.1 Conduction Conduction heat transfer is explained through the molecular
More informationNUMERICAL STUDY OF HEAT AND MASS TRANSFER DURING EVAPORATION OF A THIN LIQUID FILM
THERMAL SCIENCE, Year 2015, Vol. 19, No. 5, pp. 1805-1819 1805 NUMERICAL STUDY OF HEAT AND MASS TRANSFER DURING EVAPORATION OF A THIN LIQUID FILM by M hand OUBELLA a, M barek FEDDAOUI b *, and Rachid MIR
More informationA drop forms when liquid is forced out of a small tube. The shape of the drop is determined by a balance of pressure, gravity, and surface tension
A drop forms when liquid is forced out of a small tube. The shape of the drop is determined by a balance of pressure, gravity, and surface tension forces. 2 Objectives 3 i i 2 1 INTRODUCTION Property:
More informationHeat Transfer Convection
Heat ransfer Convection Previous lectures conduction: heat transfer without fluid motion oday (textbook nearly 00 pages) Convection: heat transfer with fluid motion Research methods different Natural Convection
More informationFluid Flow, Heat Transfer and Boiling in Micro-Channels
L.P. Yarin A. Mosyak G. Hetsroni Fluid Flow, Heat Transfer and Boiling in Micro-Channels 4Q Springer 1 Introduction 1 1.1 General Overview 1 1.2 Scope and Contents of Part 1 2 1.3 Scope and Contents of
More informationLecture 8. Mole balance: calculations of microreactors, membrane reactors and unsteady state in tank reactors
Lecture 8 Mole balance: calculations of microreactors, membrane reactors and unsteady state in tank reactors Mole alance in terms of oncentration and Molar low Rates Working in terms of number of moles
More informationHeat Transfer Modeling using ANSYS FLUENT
Lecture 1 - Introduction 14.5 Release Heat Transfer Modeling using ANSYS FLUENT 2013 ANSYS, Inc. March 28, 2013 1 Release 14.5 Outline Modes of Heat Transfer Basic Heat Transfer Phenomena Conduction Convection
More informationLecture 5: Diffusion Controlled Growth
Materials Science & Metallurgy Master of Philosophy, Materials Modelling, Course MP6, Kinetics and Microstructure Modelling, H. K.. H. Bhadeshia Lecture 5: iffusion Controlled Growth Rate Controlling Processes
More informationHEAT TRANSFER BY CONVECTION. Dr. Şaziye Balku 1
HEAT TRANSFER BY CONVECTION Dr. Şaziye Balku 1 CONDUCTION Mechanism of heat transfer through a solid or fluid in the absence any fluid motion. CONVECTION Mechanism of heat transfer through a fluid in the
More informationELEC9712 High Voltage Systems. 1.2 Heat transfer from electrical equipment
ELEC9712 High Voltage Systems 1.2 Heat transfer from electrical equipment The basic equation governing heat transfer in an item of electrical equipment is the following incremental balance equation, with
More informationCONVECTIVE HEAT TRANSFER
CONVECTIVE HEAT TRANSFER Mohammad Goharkhah Department of Mechanical Engineering, Sahand Unversity of Technology, Tabriz, Iran CHAPTER 5 NATURAL CONVECTION HEAT TRANSFER BASIC CONCEPTS MECHANISM OF NATURAL
More informationA) sublimation. B) liquefaction. C) evaporation. D) condensation. E) freezing. 11. Below is a phase diagram for a substance.
PX0411-1112 1. Which of the following statements concerning liquids is incorrect? A) The volume of a liquid changes very little with pressure. B) Liquids are relatively incompressible. C) Liquid molecules
More informationPRINCIPLES AND MODERN APPLICATIONS OF MASS TRANSFER OPERATIONS
PRINCIPLES AND MODERN APPLICATIONS OF MASS TRANSFER OPERATIONS Jaime Benitez iwiley- INTERSCIENCE A JOHN WILEY & SONS, INC., PUBLICATION Preface Nomenclature xiii xv 1. FUNDAMENTALS OF MASS TRANSFER 1
More informationOutlines. simple relations of fluid dynamics Boundary layer analysis. Important for basic understanding of convection heat transfer
Forced Convection Outlines To examine the methods of calculating convection heat transfer (particularly, the ways of predicting the value of convection heat transfer coefficient, h) Convection heat transfer
More informationMembrane processes selective hydromechanical diffusion-based porous nonporous
Membrane processes Separation of liquid or gaseous mixtures by mass transport through membrane (= permeation). Membrane is selective, i.e. it has different permeability for different components. Conditions
More informationCENG 5210 Advanced Separation Processes. Reverse osmosis
Reverse osmosis CENG 510 Advanced Separation Processes In osmosis, solvent transports from a dilute solute or salt solution to a concentrated solute or salt solution across a semipermeable membrane hich
More informationUniversity School of Chemical Technology
University School of Chemical Technology Guru Gobind Singh Indraprastha University Syllabus of Examination B.Tech/M.Tech Dual Degree (Chemical Engineering) (4 th Semester) (w.e.f. August 2004 Batch) Page
More information1 Model for gas-liquid reactions Based on film model
1 Model for gas-liquid reactions Based on film model A(g >l) +νb(l) Products Governing equations are as follows: d 2 C A dx 2 = k 2 C A C B (1) D B d 2 C B dx 2 = νk 2 C A C B (2) Here x is the actual
More informationTechnological design and off-design behavior of heat exchangers 26
Technological design and off-design behavior of heat exchangers 26 2.2 MODELING OF HEAT TRANSFER The overall heat transfer coefficient U depends on the distribution of thermal resistances in the exchanger.
More informationLiquids and solids are essentially incompressible substances and the variation of their density with pressure is usually negligible.
Properties of Fluids Intensive properties are those that are independent of the mass of a system i.e. temperature, pressure and density. Extensive properties are those whose values depend on the size of
More informationTOWARDS A BETTER UNDERSTANDING OF SIMULATING THE MULTICOMPONENT SOLUBILITY OF NATURAL EXTRACTS IN SUPERCRITICAL CARBON DIOXIDE
TOWARDS A BETTER UNDERSTANDING OF SIMULATING THE MULTICOMPONENT SOLUBILITY OF NATURAL EXTRACTS IN SUPERCRITICAL CARBON DIOXIDE S. Maharaj *, D. R. McGaw, M.Watson, R.Skeene and B. Sellier * Sharad.Maharaj@sta.uwi.edu
More informationRank the following in order from lowest to highest boiling point. Lowest 1 < 2 < 3 < 4 Highest. Which sketch shows the strongest hydrogen bond?
Posting ID: 453368 Course: CHE_107_General_Ch emistry_2 Instructor: Blue Course Name: CHE_107_General_Chemistry_2 Question #: 1 Fill in one of the three common phases of matter for each one of these descriptions.
More informationME-662 CONVECTIVE HEAT AND MASS TRANSFER
ME-66 CONVECTIVE HEAT AND MASS TRANSFER A. W. Date Mechanical Engineering Department Indian Institute of Technology, Bombay Mumbai - 400076 India LECTURE- INTRODUCTION () March 7, 00 / 7 LECTURE- INTRODUCTION
More informationAnalyzing Mass and Heat Transfer Equipment
Analyzing Mass and Heat Transfer Equipment (MHE) Analyzing Mass and Heat Transfer Equipment Scaling up to solving problems using process equipment requires both continuum and macroscopic knowledge of transport,
More informationLecture 30 Review of Fluid Flow and Heat Transfer
Objectives In this lecture you will learn the following We shall summarise the principles used in fluid mechanics and heat transfer. It is assumed that the student has already been exposed to courses in
More informationMass Transfer and Separation Processes
Principles of Mass Transfer and Separation Processes Binay K. Dutta Universiti Teknologi Petronas Malaysia New Delhi-110001 2009 PRINCIPLES OF MASS TRANSFER AND SEPARATION PROCESSES Binay K. Dutta 2007
More informationPrinciples of Convective Heat Transfer
Massoud Kaviany Principles of Convective Heat Transfer Second Edition With 378 Figures Springer Contents Series Preface Preface to the Second Edition Preface to the First Edition Acknowledgments vii ix
More informationIntroduction to Heat and Mass Transfer. Week 14
Introduction to Heat and Mass Transfer Week 14 HW # 7 prob. 2 Hot water at 50C flows through a steel pipe (thermal conductivity 14 W/m-K) of 100 mm outside diameter and 8 mm wall thickness. During winter,
More informationThermal Systems. What and How? Physical Mechanisms and Rate Equations Conservation of Energy Requirement Control Volume Surface Energy Balance
Introduction to Heat Transfer What and How? Physical Mechanisms and Rate Equations Conservation of Energy Requirement Control Volume Surface Energy Balance Thermal Resistance Thermal Capacitance Thermal
More informationCircle one: School of Mechanical Engineering Purdue University ME315 Heat and Mass Transfer. Exam #2. April 3, 2014
Circle one: Div. 1 (12:30 pm, Prof. Choi) Div. 2 (9:30 am, Prof. Xu) School of Mechanical Engineering Purdue University ME315 Heat and Mass Transfer Exam #2 April 3, 2014 Instructions: Write your name
More informationPhysical & Interfacial Electrochemistry 2013.
Physical & Interfacial Electrochemistry 13. Lecture 8 Hydrodynamic Voltammetry Hydrodynamic voltammetry Hydrodynamic voltammetry deals with voltammetric measurements conducted under conditions where there
More informationAGITATION AND AERATION
AGITATION AND AERATION Although in many aerobic cultures, gas sparging provides the method for both mixing and aeration - it is important that these two aspects of fermenter design be considered separately.
More informationNatural Convection Systems
C H A P T E R 6 Natural Convection Systems 6.1 Physical Mechanism Of Natural Convection Many familiar heat transfer applications involve natural convection as the primary mechanism of heat transfer. Some
More informationUnit operations of chemical engineering
1 Unit operations of chemical engineering Fourth year Chemical Engineering Department College of Engineering AL-Qadesyia University Lecturer: 2 3 Syllabus 1) Boundary layer theory 2) Transfer of heat,
More informationCHEMISTRY. CHM202 Class #2 CHEMISTRY. Chapter 10. Chapter Outline for Class #2
CHEMISTRY Fifth Edition Gilbert Kirss Foster Bretz Davies CHM202 Class #2 1 Chemistry, 5 th Edition Copyright 2017, W. W. Norton & Company CHEMISTRY Fifth Edition Gilbert Kirss Foster Bretz Davies Chapter
More informationMASS TRANSPORT Macroscopic Balances for Multicomponent Systems
TRANSPORT PHENOMENA MASS TRANSPORT Macroscopic Balances for Multicomponent Systems Macroscopic Balances for Multicomponent Systems 1. The Macroscopic Mass Balance 2. The Macroscopic Momentum and Angular
More informationEngineering and. Tapio Salmi Abo Akademi Abo-Turku, Finland. Jyri-Pekka Mikkola. Umea University, Umea, Sweden. Johan Warna.
Chemical Reaction Engineering and Reactor Technology Tapio Salmi Abo Akademi Abo-Turku, Finland Jyri-Pekka Mikkola Umea University, Umea, Sweden Johan Warna Abo Akademi Abo-Turku, Finland CRC Press is
More informationRecap: Introduction 12/1/2015. EVE 402 Air Pollution Generation and Control. Adsorption
EVE 402 Air Pollution Generation and Control Chapter #6 Lectures Adsorption Recap: Solubility: the extent of absorption into the bulk liquid after the gas has diffused through the interface An internal
More informationConvection Heat Transfer. Introduction
Convection Heat Transfer Reading Problems 12-1 12-8 12-40, 12-49, 12-68, 12-70, 12-87, 12-98 13-1 13-6 13-39, 13-47, 13-59 14-1 14-4 14-18, 14-24, 14-45, 14-82 Introduction Newton s Law of Cooling Controlling
More informationME 331 Homework Assignment #6
ME 33 Homework Assignment #6 Problem Statement: ater at 30 o C flows through a long.85 cm diameter tube at a mass flow rate of 0.020 kg/s. Find: The mean velocity (u m ), maximum velocity (u MAX ), and
More informationAxial profiles of heat transfer coefficients in a liquid film evaporator
Axial profiles of heat transfer coefficients in a liquid film evaporator Pavel Timár, Ján Stopka, Vladimír Báleš Department of Chemical and Biochemical Engineering, Faculty of Chemical and Food Technology,
More informationINSTRUCTOR: PM DR MAZLAN ABDUL WAHID
SMJ 4463: HEAT TRANSFER INSTRUCTOR: PM ABDUL WAHID http://www.fkm.utm.my/~mazlan TEXT: Introduction to Heat Transfer by Incropera, DeWitt, Bergman, Lavine 5 th Edition, John Wiley and Sons Chapter 9 Natural
More informationHomework Set 4. gas B open end
Homework Set 4 (1). A steady-state Arnold ell is used to determine the diffusivity of toluene (speies A) in air (speies B) at 298 K and 1 atm. If the diffusivity is DAB = 0.0844 m 2 /s = 8.44 x 10-6 m
More information1 Matlab solution to diffusion-reaction problems
1 Matlab solution to diffusion-reaction problems Diffusion-Reaction problems are very common in chemical reaction engineering and often numerical solutions are needed. Here we look at using matlab to obtain
More information6. Laminar and turbulent boundary layers
6. Laminar and turbulent boundary layers John Richard Thome 8 avril 2008 John Richard Thome (LTCM - SGM - EPFL) Heat transfer - Convection 8 avril 2008 1 / 34 6.1 Some introductory ideas Figure 6.1 A boundary
More informationSpecific heat capacity. Convective heat transfer coefficient. Thermal diffusivity. Lc ft, m Characteristic length (r for cylinder or sphere; for slab)
Important Heat Transfer Parameters CBE 150A Midterm #3 Review Sheet General Parameters: q or or Heat transfer rate Heat flux (per unit area) Cp Specific heat capacity k Thermal conductivity h Convective
More informationUNIT 5 Readiness Assessment Quiz
UNIT 5 Readiness Assessment Quiz Name: Vanden Bout/LaBrake UTEID: Spring 2013 CH302 I. MYTH BUSTERS: Soda Freezing Demonstration. Sometimes when you purchase a bottle of soda from a vending machine, the
More informationConvective Heat and Mass Transfer Prof. A. W. Date Department of Mechanical Engineering Indian Institute of Technology, Bombay
Convective Heat and Mass Transfer Prof. A. W. Date Department of Mechanical Engineering Indian Institute of Technology, Bombay Module No.# 01 Lecture No. # 41 Natural Convection BLs So far we have considered
More informationDiffusion and Adsorption in porous media. Ali Ahmadpour Chemical Eng. Dept. Ferdowsi University of Mashhad
Diffusion and Adsorption in porous media Ali Ahmadpour Chemical Eng. Dept. Ferdowsi University of Mashhad Contents Introduction Devices used to Measure Diffusion in Porous Solids Modes of transport in
More informationSolids, liquids and gases
Solids, liquids and gases Solids, liquids, and gases are held together by intermolecular forces. Intermolecular forces occur between molecules, not within molecules (as in bonding). When a molecule changes
More information