substance: TinO2n-1 (n 3)
property: optical properties
Diffuse reflectance spectra of TinO2n1: Fig. 1. A very broad peak that shifts steadily to the red with increasing n
is apparent, and a linear relationship between log n and (/c)max is found (Fig. 2).
CHEM-ENG 120
Introduc)on to Engineering Calcula)ons
Units and Dimensions
Force and Weight
Dimensional Homogeneity
Numerical Calcula@ons
2015 David M. Ford
1
Units and Dimensions
Most quan@es of interest to engineers have two
parts
a numerical
Flow Rate
Material usually (although not always) ows through
some type of conduit or pipe
Cross-sec.onal area
perpendicular to ow
Flowrate: amount of material passing through the cross-sec.on per unit .me.
2015 David M. Ford
7
Types of Flow Rates
Chemical Composi.on
Moles and molecular weight
Why moles instead of mass?
Chemistry tells us that chemical reac.ons lead to
propor.onal changes in numbers of molecules, not mass
N2 + 3H2 2 NH3
2015 David M. Ford
15
Moles and Molecular Weight
Process Variables
Describe the condi.ons in the streams and units
Examples
mass, volume, and their corresponding ow rates
density
chemical composi.on whats there, and how much?
temperature
pressure
2015 David M. Ford
1
Mass and Volume
CHEM-ENG 120
Processes and Process Variables
2015 David M. Ford
1
Processes
Process: an operaAon, or combinaAon of operaAons, to
accomplish an objecAve
Input Streams
Feed
Process
2015 David M. Ford
Output Streams
Products
2
Unit OperaAons
A
CHEM-ENG 120
Introduc)on to Engineering Calcula)ons
Sta/s/cs & Data Plo7ng/Fi7ng
2015 David M. Ford
1
Basic Sta/s/cs - Mo/va/on
Youll be dealing with numerical data from processes
measurements of temperature, pressure, concentra/on,
ow rate, pro
CHEM-ENG 120
Course Introduc6on
2015 David M. Ford
1
What is Chemical Engineering?
2015 David M. Ford
2
What is Chemical Engineering?
raw materials
transforma6on process
physical, chemical, biological
products
when the products are more valuab
Ethan Liu
CHEM-ENG 120
1/28/14
Homework #1
I hope to gain a better grasp of the basic concepts that provide the basis for Chemical
Engineering. I want to become more competent at doing mass balances and designing process
flowsheets. I also want to become
Ethan Liu
Chem-Eng 120
Homework 3
2/10/14
1. Two thermocouples are tested by inserting their probes in boiling water The results of five
measurements are as follows.
(a) Set A: 72.4, 73.1, 72.6, 72.8, 73
Mean = (72.4 + 73.1 + 72.6 + 72.8 + 73) / (5) = 72.
Ethan Liu
CHEM-ENG 120
Professor Ford
2/5/2014
1. You are trying to decide which two automobiles to buy how many miles would you have to
drive for the lower fuel consumption of the second car to compensate for the higher cost of this
car?
Car A: $14,500,
Ethan Liu
Homework 4
Chem-Eng 120
2/18/14
1. Liquid benzene and liquid n-hexane are blended to form a stream flowing at a rate of 700
lbm/h. Using specific gravities from GTable B.1, estimate the mass and volumetric feed rate s
of the two hydrocarbons to
Ethan Liu
Chem-Eng 120
HW 5
2/25/14
1. Water enters a 2.00-m3 tank at a rate of 6.00 kg/s and is withdrawn at a rate of 3.00 kg/s. The
tank is initially half full.
(a) This is a continuous, transient process.
(b) Accumulation = 6.00 kg/s 3.00 kg/s = 3.00
Ethan Liu
Chem-Eng 120
Homework 7
3/14/14
1. Overall: 3 balances
Unit 1: 2 balances
Mixer: 3 balances
Unit 2: 3 balances
Overall balance to find m3, mass balance around Unit 1 to find m1, mass balance around Unit 2 to
find m2, A balance around Unit 1 to f
Ethan Liu
Chem-Eng 120
Homework 6
3/4/14
1. Shown below is a flowchart of a process in which acetic acid (A) is extracted from a
mixture of acetic acid and water (B) into 1-hexanol (C), a liquid immiscible with water.
(a) There are 3 independent balances,
Annie Burton
CHEM-ENG 120
1/23/14
Homework #1
From this course I expect to learn more about mass balances, where Chemical Engineers
work, more about solving problems in Matlab, and more about energy. This course will
expand on everything taught in the fal
PROBLEM 4.40
KNOWN: Nodal point on boundary between two materials. FIND: Finite-difference equation for steady-state conditions. SCHEMATIC:
ASSUMPTIONS: (1) Steady-state conditions, (2) Two-dimensional conduction, (3) Constant properties, (4) No internal
PROBLEM 4.39
KNOWN: Nodal point configurations corresponding to a diagonal surface boundary subjected to a convection process and to the tip of a machine tool subjected to constant heat flux and convection cooling. FIND: Finite-difference equations for th
PROBLEM 4.38
KNOWN: Heat generation and thermal boundary conditions of bus bar. Finite-difference grid. FIND: Finite-difference equations for selected nodes. SCHEMATIC:
ASSUMPTIONS: (1) Steady-state conditions, (2) Two-dimensional conduction, (3) Constant
PROBLEM 4.37
KNOWN: Two-dimensional cylindrical configuration with prescribed radial (r) and angular () spacings of nodes. FIND: Finite-difference equations for nodes 2, 3 and 1. SCHEMATIC:
ASSUMPTIONS: (1) Steady-state conditions, (2) Two-dimensional con
PROBLEM 4.36
KNOWN: Conduction in a one-dimensional (radial) cylindrical coordinate system with volumetric generation. FIND: Finite-difference equation for (a) Interior node, m, and (b) Surface node, n, with convection. SCHEMATIC:
(a) Interior node, m (b)
PROBLEM 4.35
KNOWN: Boundary conditions that change from specified heat flux to convection. FIND: The finite difference equation for the node at the point where the boundary condition changes. SCHEMATIC:
q s
m -1,n y/2 y q1 q3 q5 x x m, n-1 m,n q2
h, T m
PROBLEM 4.34
KNOWN: External corner of a two-dimensional system whose boundaries are subjected to prescribed conditions. FIND: Finite-difference equations for these situations: (a) Upper boundary is perfectly insulated and side boundary is subjected to a
PROBLEM 4.33
KNOWN: Plane surface of two-dimensional system. FIND: The finite-difference equation for nodal point on this boundary when (a) insulated; compare result with Eq. 4.42, and when (b) subjected to a constant heat flux. SCHEMATIC:
ASSUMPTIONS: (1
PROBLEM 4.32
KNOWN: Internal corner of a two-dimensional system with prescribed convection boundary conditions. FIND: Finite-difference equations for these situations: (a) Horizontal boundary is perfectly insulated and vertical boundary is subjected to a