eche 460 unit operations presentations the good, the bad

ECHE 460ECHE 460Unit Operations PresentationsUnit Operations Presentations

The Good,The Good,The Bad, andThe Bad, and

The UglyThe Ugly

Ed GatzkeEd GatzkeMarch, 2007March, 2007

IntroductionsIntroductions

Should motivate the topicShould motivate the topic

Should have some broader scopeShould have some broader scope

Use images if possible to get audience engagedUse images if possible to get audience engaged–– Cite Images Cite Images appropriatelyappropriately

ShouldShould prepare audience to some extentprepare audience to some extent

The GoodThe Good

E1-Derek Strange E2-R. Ryan Cox E3-Andrew Davis

Background

� 18th Century: Zeolitesdiscovered by Axel Fredrik Cronstedt

� Found when heated rapidly, causing them to “dance”

� Named zeolite, or “stone that boils”

http://www.bgf.nu/ljus/bilder/cronstedt1.gif


Zeolite Properties

� Porous, crystalline solid with highly ordered microstructure

� Natural and man-made� Function depends on

structure� Work as catalysts, catalyst

supports, and adsorbents

http://www.bojistones.com/crystals/Zeolite-1.jpg

http://www.zeoponix.com/images/zeolite-200.GIF


Gas Chromatography

� Two components: solute gas and carrier gas

� Mobile mixture injected through stationary phase

� Separates solute gas from carrier gas

http://www.b100supply.com/images/products/193.jpg

The BadThe Bad

IntroductionIntroduction• Centrifugal Pumps

- Class of pumps that moves liquids and generates pressure by rotation of

a single or several impellers

- Impellers promote centrifugal force on a liquid causing an increase in

pressure and velocity

- Pump casings help convert kinetic velocity of the fluid into pressure by

directing and containing spiral flow of the liquid

• Pipe Network Flow- Pipes, valves, and fittings combine together to form a network that

allows liquids and gases to be transported

- Each component affects the flow individually through resistance

The The UglyUgly

Group 2, Presentation #2. March 7, 2007

Introduction

� Heat transfer can be used in a variety of applications

� Distillation Columns

� Heat exchangers

� Cooling towers

� Cooling of electronics

SchematicsSchematics

Should represent the physical systemShould represent the physical system–– Not necessarily same layoutNot necessarily same layout

Should have appropriate level of detailShould have appropriate level of detail–– Too much = too complicatedToo much = too complicated

–– Too little = too uselessToo little = too useless

Can use exaggerated Can use exaggerated ““cartoonycartoony”” representationsrepresentations

The GoodThe Good

Univeristy of South Carolina ECHE 460

ApparatusApparatus


Constant Pressure ModeConstant Pressure Mode


Apparatus

Chiller

Heater

Unit

Temperature Bath

Water

Cable

Thermocouple

Solid

Sphere

Infinite Cylinder

Pump


ApparatusK-type

Thermocouple

Cylinder

Cable

Sphere

K-type

Thermocouple

Cable

The BadThe Bad

UO Presentation Spring 2007

Apparatus

Electric Source

Condensing Column

Variac

Inlet Port

Outlet Port

Temperature Reader

Thermocouple

Cold Water Bath

Vapor

Reflux

Vapor CollectionPort

Heating Coil


Apparatus

� Gas Chromatograph:� SRI 8610B with Thermal Conductivity Detector

(TCD)

http://images.google.com/imgres?imgurl=http://www.betatekinc.com/images/SRI/6-MG2.jpg&imgrefurl=http://www.betatekinc.com/SRI_Multiple_Gas_Analyzer_No.2_GC_System.html&h=247&w=200&sz=29&hl=en&start=16&tbnid=oAtD5084lFY7oM:&tbnh=110&tbnw=89&prev=/images%3Fq%3DSRI%2B8610%26svnum%3D10%26hl%3Den%26sa%3DN


Apparatus cont’d

� Gas Chromatograph:� SRI 8610B

Carrier Gas

(Helium)

Zeolite Packed Bed

Injected Gas (Ethane)

P1 P2

Detector

P3

E1 Chris Butch E2 Sherah Aiken E3 Jacob

John

Schematic

10

2

1. othmer still2. heating coil port3. heating coil4. thermometer5. thermocouple6. liquid collection port7. condensate collection port8. filling port9. stopcock10. variac11. cooling bath12. cooling water lines13. vent14. beaker

3

4

5

6 7

8

9

911

12

12

1

13

14

The The UglyUgly

Apparatus

Literature ReviewLiterature Review

Should summarize articleShould summarize article

Should be concise, 1Should be concise, 1--2 pages2 pages

May use images or figures from articleMay use images or figures from article

Should include the full citation Should include the full citation

The GoodThe Good

Literature Review 3Literature Review 3

Improving solar pumping systems by addition of modular centrifugal pumps

• Divided shaft pumps operate more efficiently than stand centrifugal pumps when solar irradiation is low

• The number of impellers or stages operating varied depending on the amount of irradiation during the day

• Pump power demand is proportional to cube of rotational speed

• Pump design should be based on amount of peak power provided by PV cells

Fiaschi, Daniele, et al. Improving the effectiveness of solar pumping systems by using modular centrifugal pumps with variable rotational speed. Solar Energy 79 (2005) 234-244.

ECHE 460 - Group 5 - Project II: Voltammetry - 3/8/07

Literature Review III:

Chronoamperometry to Measure Effectiveness of

Adderall in Dopamine Release

• Adderall results in larger

amounts of dopamine

release (higher amplitude)

• Dopamine release induced by Adderall also has longer

time course of activity

– Shorter rise time, longer clearance time

• Use of each enantiomer singularly is not as effective as

combination of components

The BadThe Bad


Detection of Cavitation Phenomenon in a Centrifugal Pump Detection of Cavitation Phenomenon in a Centrifugal Pump Using Audible Sound [2]Using Audible Sound [2]

►► Studied the onset of cavitation within centrifugal pumpsStudied the onset of cavitation within centrifugal pumps�� Produced by pulsation waves of bubbles and collapse of vapor bubProduced by pulsation waves of bubbles and collapse of vapor bubbles bles upon entering a region of high pressureupon entering a region of high pressure

�� Consequence of insufficient required value for NPSHConsequence of insufficient required value for NPSH

►► Wanted to find specific noise frequencies dependent upon the Wanted to find specific noise frequencies dependent upon the start of cavitationstart of cavitation�� Noise increases linearly with:Noise increases linearly with:

►► FlowrateFlowrate ►►maximum volume of bubblesmaximum volume of bubbles

►► number of bubbles number of bubbles ►►concentration per unit volume of bubblesconcentration per unit volume of bubbles

►► Noise levels of 147 Hz are dependent upon cavitationNoise levels of 147 Hz are dependent upon cavitation�� Frequency can be separated from noise spectraFrequency can be separated from noise spectra

�� Sound signals used to alarm operator of cavitationSound signals used to alarm operator of cavitation�� Alarms can still be used in presence of background noiseAlarms can still be used in presence of background noise

►► NPSH required must be maintained to prevent cavitationNPSH required must be maintained to prevent cavitation

Literature Review Literature Review

The The UglyUgly


Literature Review

�Morrison, et. Al (1990)�Studied various salts (NaCl, NaBr, KBr, KCl) as

MSAs in ethanol/water system

�Orchillés, et. Al (2007)�Studied ionic liquids as MSAs in

acetone/methanol system

�Sapei, et. Al (2007)�Studied VLE for sulfide/hydrocarbon systems to

study more effective separation of sulfur from gasoline

Theory (Working Equations)Theory (Working Equations)

Should include citations when appropriateShould include citations when appropriate

Should include some text summaryShould include some text summary

Should include nomenclatureShould include nomenclature

Can include cartoons to illustrate conceptsCan include cartoons to illustrate concepts

The GoodThe Good


Working EquationsWorking Equations

►► The Bernoulli equation is a generalized energy balance The Bernoulli equation is a generalized energy balance

►► pp = pressure (psi)= pressure (psi) ►► ff = friction factor = friction factor

►► γγ = = specific weight of water (lb/ftspecific weight of water (lb/ft33)) ►► ll = length of tubing (ft)= length of tubing (ft)

►► ZZ = elevation above or below (ft) = elevation above or below (ft) ►► DD = Diameter of tubing (ft)= Diameter of tubing (ft)

►► V V = average liquid velocity (ft/s)= average liquid velocity (ft/s) ►► hhpp = pressure head for = pressure head for

entire entire

►► ggcc = acceleration due to gravity (ft/s= acceleration due to gravity (ft/s22)) system (ft of Hsystem (ft of H22O)O)

►► KK = fitting and valve loss coefficient= fitting and valve loss coefficient

Governing Equation

pcc

hg

VK

D

lf

g

VVZZ

pp =⋅

++⋅−+−+−

∑∑ 22

)()(

)( 221

22

1212

γ


Biot Number

( )( ) Bi

k

Lh

R

R

Ah

AkL

TT

TT

conv

cond

S

SS ≡⋅==⋅⋅=

−−

∞ 12,

2,1,

� Resistance to Conduction/Resistance to Convection

x

T

Ts, 1

T∞h

Fluid

Ts, 2

Ts, 2

Ts, 2

Bi << 1

Bi = 1

Bi>> 1

qconv

Validity of Lumped Capacitance Method

1.0<⋅

=k

LhBi c


Chronoamperometry:

Cottrell Equation

i(t) = nFACo

Do

πt

i = current transient (A)n= number of electrons in analyte half-reactionF= Faraday’s constant (96485 C/mol)A= electrode area (cm2)D0= analyte’s diffusion coefficient (cm2/s)t= time (s)

F.G. Cottrell, Z. Physik. Chem., 42, 385 (1902).

The BadThe Bad


Engineering Principles and Working Equations

� The standard variance is often termed the second moment of the response curve and can be approximated by evaluating the following integrals:

∫

∫∞

−=

0

2

2

)(

cdt

dtttc r

σ (6)

The The UglyUgly


Engineering Principles

LV ff 11ˆˆ =

iiiL

iiV

fxf

Pyf

γ

φ

=

=

1

1

ˆ

ˆ

∫=P

P

li

sati

satii sat

i

dPVRT

Pf1

expφ

∫=P

P

li

sati

satiiiii sat

i

dPVRT

PxPy1

expφγφ

satiiii PxPy γ=

Results and FiguresResults and Figures

Should use solid lines and markers correctlyShould use solid lines and markers correctly

Should have error analysis if possibleShould have error analysis if possible

Should have Should have ““nicenice”” axes rangesaxes ranges

Should have some text explanationShould have some text explanation

Should have a legend when neededShould have a legend when needed

The GoodThe Good


Chronoamperometry 40°C

y = -2.048x

R2 = 0.9533

-3.0

-2.5

-2.0

-1.5

-1.0

0.25 0.45 0.65 0.85 1.05 1.25 1.45

1/Time -.5

(1/sec -.5)

Cur

rent

(Am

ps*1

04 )


Pump EfficiencyPump Efficiency

0

10

20

30

40

50

60

0 2 4 6 8 10 12 14 16

Flowrate (gpm)

Pum

p ef

ficie

ncy

(%)

Pump 1

Pump 2

Pump 1 Mf

Pump 2 Mf

Design Flowrate

►► Pump 1 efficiency is greater than the manufacturer possibly becaPump 1 efficiency is greater than the manufacturer possibly because of use of

a larger impeller installeda larger impeller installed

►► Design flowrate lines give the Design flowrate lines give the bepbep for the pumpfor the pump

The BadThe Bad


Graphical Method to Determine ∆U

lnKi vs. 1/T

y = 3091.9x - 4.8796

R2 = 0.9995

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0.0025 0.00255 0.0026 0.00265 0.0027 0.00275 0.0028 0.00285

1/T (s)

lnK

i Ki

Linear (Ki)

E1 Chris Butch E2 Sherah Aiken E3 Jacob

John

Using Wilson Model with Tavg

The The UglyUgly

(49.5/49.5) Glycerol-Water and (1) Polyacrylamide (unknown molecular weight), at 30 Degrees Celsius

5.16

5.18

5.2

5.22

5.24

5.26

5.28

5.3

0 100 200 300 400

Shear Rate (sec^-1)

Vis

cosi

ty (

cP)

eche 460 unit operations presentations the good, the bad

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