product rd session 4 - pushcart case study part 2- jan 2013
TRANSCRIPT
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
1/56
Product Research & DevelopmentSession 4
Case Study of
Pushcart for Vending Ice-Cream
Part 2
Department of Chemical Engineering
2nd
Semester 2012-2013
V. M. Naik
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
2/56
Objectives of the Case Study:
Illustrate the Steps, and Stages Involved in
Product R&D, and the Nonlinear Nature of the
Whole Process
Illustrate the Skills and Competencies Required
to MAKE AN INVENTION AND INNOVATIONHAPPEN
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
3/56
The Background
An MNC Built an Ambitious Modern Plant for Ice-Cream, in
India, and Set up a Unique Supply Chain to Improve
Availability of Quality Ice-Cream to Consumers, in 1990s
CITY COLD
STORES
++ ++
REFRIGERATED
TRUCKS
REGIONAL
COLD
STORES
REFRIGERATED
TRUCKS
RETAIL CABINETS
VENDING PUSHCARTS
FACTORY
COLD STORE
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
4/56
Background Continued.
Ice-Cream Is a Delicately Structured Multiphase CompositeSystem. It Should Be Stored and Served at ~ -18Deg C forConsumers Safety and Delight
Therefore Vending Push CartsWere an Important StrategicBusiness Imperative forIncreasing the Availability ofIce-Cream to Consumers
++
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
5/56
Schematic Design of the Original Push CartDeveloped Jointly by the Indian Business and a Laboratory in The
Netherlands
35 Kg of 35%PG-Water Eutectic Frozen to -25 deg C
Employed as Nontoxic Coolant
Poly Urethane
(PU) Foam
Insulation
Eutectic
CoolantJacket
Freezeron
Wheel++
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
6/56
Market Response
Vendors Complained That the Push Carts Were TooHeavy and Difficult to Push
Consumers Complained That the Ice-Cream Was
Soggy When Purchased in the Afternoon
Ice-cream Sales Were Far Below Break-even Level
An Unrelated Discussion with the Business Head of
CAME Region, Regarding the MAP-DAP Eutectics
Triggered the Subsequent Events
The Needs of Both, the Customers and Consumers
Were not Met
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
7/56
CASE STUDY OF ICE-CREAM VENDING PUSH
CARTS Business Sent a Technical Brief to Research
Develop a Rigorous Theoretical Model of the
Pushcart and Improve the Performance of the
Non-Toxic 35%PG-Water Eutectic Coolant
System So That:
The Pushcarts Can Deliver Non-soggy Ice-
Cream for at Least 10 Hrs
AND, If Possible
The Coolant Quantity Can Be Reduced from
35 Kg to 20 Kg, to Achieve a Reduction in the
Weight of the Push Cart by 15 Kg
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
8/56
CASE STUDY OF ICE-CREAM VENDING PUSH CARTS
The First Step Was to Perform Reality Checks on the
Technical Brief from Business
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
9/56
One Must Learn to Make Quick Back of the Envelop
Estimatesfor Reality Checks
Next Reality Check:
Estimate the Expected Cooling
Capacity of the Eutectic
Reality Check1:
What Could Be the Maximum Extent of Heat Ingress (DH) through
PUF Insulation of the Walls of the Cabinet in 12 Hrs?
DH = A * k * DT * t / l
~ 3600kJoules
Please Note : For a liberal
estimate ofDH, one can neglect
the resistance by air films, and
use the (larger ) outer surfacearea
Tin=-200C
Tout=+300C
0.9 m
0.6m
Insulation:
k = 30 mW/m oC
l = 75 mm
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
10/56
One Must Learn to Make Quick Back of the Envelop
Estimatesfor Reality Checks..
Reality Check 2:
What Is the Expected Latent Heat of Melting for the 35% PG-WaterEutectic System?
DH of Melting = ~ X water* l m Water
= ~ 200 k Joules/kg
Please Note : For a quick
conservative estimate ofDH for
melting, the heat ofmelting/dissolution of the solute
was neglected
Typical melting
curve of eutectics
Temperature
Enthalpy/Kg
MeltingofEuMix
TEu
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
11/56
Findings from Back of the Envelop
Reality Checks 1&2
Latent Heat of Fusion of PG-Water Eutectic
Containing 65% Water~ 200 KJ/Kg
Likely Heat Ingress in to the Box, through
Insulation, over 12 Hrs ~ 3000 KJ
Therefore the Theoretically Estimated Quantity of
Eutectic Coolant Required to Counter the Heat
Ingress for 12 hrs : ~ 15 Kg Maximum (as against 35
Kg Actual)
What Was Likely to Be the Source of Discrepancies?
Next Steps : Verify Data and Assumptions
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
12/56
Conclusions:
1. 35% PGWater Was Not an Eutectic System and Its
Cooling Capacity Was Far Short of Theoretical
Estimates/Requirements
2. There Was Definitely a Need for Improvement of the
Eutectic System.3. Was the Design of Pushcart Acceptable.? Not Sure
D H = < 30 KJ/Kg
Reality Check-3:Experimental Verification of Latent Heat of Melting of 35%PG-Water Eutectic
Using Differential Scanning Calorimetry (DSC)
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
13/56
Case Study Continued.
Next Steps :
Additional Information Gathering, and FirstPerson Observations/Discussions on the
Field, to Better Understand the Issues, as Well
as for Deciding the Way Forward
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
14/56
Visits to Cold Store, Vendors, and Development
Department
Discussions with Customers/Fabricators/Development Team Regarding
New Ideas and Their Feedback:
(i) Electric Supply Unreliable
(ii) Refrigerants in Use Not Suitable for Cooling the Eutectic below 30 Deg C
(iii)Detachable Freezer Couplings not Reliable
(iv) There Is No Better Coolant or Insulation Available in the World (!)
(v) Dry Ice Poses Supply Chain as well as Safety Issues
Field Observations:
(i) Quick Ingress of Hot/Humid Air, When Lid Is Opened(ii) Equilibration of Air Temperature with Surroundings,
in a Short Time
(iii) Steady Ingress of Heat through Insulation,
Heating/Melting of Coolant, and Slow Rise in Ice-Cream
Temperature
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
15/56
New Important Learnings:
Performance of Pushcart Depends on Several Coupled
Factors and Processes. We Must Have a DependableTheoretical Modeling/Simulation Tool to Validate/Rank
Quality of New Candidate Ideas for Performance
Improvement
We Must Co-invent the New Pushcart Design, and
Eutectic System, if We Want to Succeed
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
16/56
Next Step:Build Theoretical Model For Predicting Heat Ingress and Ice-
Cream Melting
How Do You Build a Model for Multiple Coupled Phenomena with Vastly
Different Time-scales within a Short Time and with Limited Resource?
The Physical Model
Enthalpy Temp Diagram
for Cornetto Ice-Cream
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
17/56
17
Building Theoretical Model For Predicting Heat
Ingress and Ice-Cream Melting : The Way-forward
Simplify Model by Decoupling Modeling of the Three Processes Which
Operate at Three Distinct Time-scales, Viz. (i) Quick Ingress of Hot Air
When Lid Is Opened, (ii) Equilibration of Air Temperature with Surroundings,
(iii) Steady Ingress of Heat through Insulation, Heating/Melting of Coolant
and Slow Rise in Ice-Cream Temperature
The Physical Model
Enthalpy Temp Diagram
for Cornetto Ice-Cream
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
18/56
Theoretical Model For Heat Ingress and Ice-Cream
MeltingResult 1..Quick Air Ingress and Its Rapid Equilibration
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
19/56
Theoretical Model For Heat Ingress and Ice-Cream
MeltingResult 2 . Slow Heat Ingress through Walls of Container
Comparison of Result 1&2 with Field Data Confirmed That the
Modeling Methodology
The Model Was Ready for Evaluation of
Alternative Ideas
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
20/56
Generation of New Ideas and Their Evaluation
Using the Theoretical ModelIdeas Generated in the Class Room
Provide Sealed Dispensing System Store Ice-cream in Different Compartments
Provide Cold Air Curtain/Internal Source of Cold Air
Increase Mass of PG-Water
Motorize the Pushcart
Change the Composition of PG-Water
Use a New Genuine Eutectic Coolant
Increase Cooling Surface Area by Putting Frozen
Eutectic in Small Ampoules
Make Cylindrical Pushcarts to Reduce Area/Volume
Ratio
Use Better Insulation
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
21/56
Will Reducing Air-ingress Result in Substantial Performance
Improvement?
Answer : NO
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
22/56
Will Increasing the Weight of PG-Water System
Solve the Problem?
Answer : NO
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
23/56
Will Changing PG-Water Proportion Help?
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
24/56
Will Changing PG-Water Proportion Help?
Answer : NO
http://3.bp.blogspot.com/_JLeMz4WY6MM/TFD9xEDgGhI/AAAAAAAABvg/1pGsHrfHET8/s1600/propyleneGlycolPhaseDiagram.jpg -
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
25/56
Will Use of a Genuine Eutectic with Teu= - 26 Deg Help?
No Success
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
26/56
Will Use of Genuine Eutectics with Much Lower Teu Help?
Option Not Acceptable Due to Refrigeration Constraints
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
27/56
Will Use of Additional Coolant Pads for Increasing Coolant
Surface Help?
No Success
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
28/56
Evaluation of Ideas.
What Next?
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
29/56
A Principle to Remember :
Problems Cannot Be Solved by Thinking Within the
Framework in Which the Problems Were Created
Albert Einstein
O
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
30/56
Important Observations Which Prompted
Conception Of A New Breakthrough Idea
The Push Carts, and Therefore the Model Developed to
Simulate Their Operation, Involved a Competition Between
Two Heat Sinks viz. Ice-Cream and Coolant
In All Alternatives the Coolant Was Not Fully Molten and
Yet Ice-cream Temperatures Rose Above - 18 Deg C
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
31/56
Genesis Of A Novel Breakthrough Idea
Why Not Put The Two Heat Sinks In Series With Each Other
Vs
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
32/56
This Involved Modifying the Model to CheckPracticality of the Idea
Thi I l d Eff t t M dif th M d l
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
33/56
This Involved Efforts to Modify the Model
But the Result Was Worth the Effort
A Novel Design for The Push Cart Was Born
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
34/56
The Magical Result
HEAT SHIELDHEAT SINK
Time (hours)
0 2 4 6 8 10 12 14
Ice-CreamT
emperatu
re(degC)
-21
-20
-19
-18
-17
-16
Heat Sink
Heat Shield
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
35/56
The New Idea Was So Powerful That It Worked with
Even Higher Temperature Eutectics !
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
36/56
What Next ?
File a Patent:
The Idea Is So Simple That It Can Be
Copied Very Easily. But It Is So Useful
That It Has to Be Protected as an
Intellectual Property
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
37/56
What Next ?
File a Patent:
The Idea Is So Simple That It Can Be Copied
Very Easily. But It Is So Useful That It Has to Be
Protected as an Intellectual Property
Search for a Non Toxic, Non Corrosive Pure
Chemical, or Develop a Genuine Eutectic
System with High l, Which Melts between ~ 20
and - 26 Deg C
S h f N T i N C i P Ch i l
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
38/56
Search of a Non Toxic, Non Corrosive Pure Chemical,
or Development of a Genuine Eutectic System with
High l, Which Melts between ~ 20 and - 26 Deg C
Likelihood of Finding an Eutectic Was Higherthan Finding a Pure Chemical
Ice-Cream and Cryogenic Industries All Over theWorld, Had Worked on This Problem WithoutMuch Success.
All Commercially Available Eutectic Coolants
Were Both Corrosive and Not Safe Enough.
S h f N T i N C i P Ch i l
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
39/56
Search of a Non Toxic, Non Corrosive Pure Chemical,
or Development of a Genuine Eutectic System with
High l, Which Melts between ~ 20 and - 26 Deg C
Likelihood of Finding an Eutectic Was Higher thanFinding a Pure Chemical
Ice-Cream and Cryogenic Industries All Over the World,Had Worked on This Problem Without Much Success
All Commercially Available Eutectic Coolants Were BothCorrosive and Not Safe Enough
________________________
How Do We Search for the Right Eutectic System?
S h f N T i N C i P Ch i l
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
40/56
Search of a Non Toxic, Non Corrosive Pure Chemical, or
Development of a Genuine Eutectic System with High l,
Which Melts between ~ 20 and - 26 Deg C
A So Called Rigorous Rational Approach:
C1 C2 .
.
Cm
L1
L2
..
Ln
56 Million Components in
CAS Registry Would Lead to
!256!2
!56
M
M
Binary Combinations
Search of a Non Toxic, Non Corrosive Pure Chemical,
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
41/56
Search of a Non Toxic, Non Corrosive Pure Chemical,
or Development of a Genuine Eutectic System with
High l, Which Melts between ~ 20 and - 26 Deg C
Likelihood of Finding an Eutectic Was Higher than Finding a PureChemical
Ice-Cream and Cryogenic Industries All Over the World, HadWorked on This Problem Without Much Success. All Commercially
Available Eutectic Coolants Were Both Corrosive and Not SafeEnough. Use of Expensive Materials of Construction to Counter the
Issues Was Not a Prudent, and a Viable Option in India. This Was Not a Rational Optimization Problem,
but a Complex Multi-dimensional CreativeChallenge.
Use ofHeuristic Insights about Phenomenologyof Solid-Liquid Phase Equilibria, SimplifiedTheoretical Thumb Rules, and a Hypothetico-Deductive Approach Was the Best Way
Forward.
Some Qualitative Observations on a Simple Binary
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
42/56
Some Qualitative Observations on a Simple Binary
Eutectic System Formed by Two Immiscible Solids
Congruous Melting
Some Qualitative Observations on a Simple Binary
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
43/56
43
Some Qualitative Observations on a Simple Binary
Eutectic System Formed by Two Immiscible Solids
Congruous Melting
Eutectic Temperature of a Binary Mixture Is
Always Lower Than the Melting Point of Either
Component
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
44/56
44
Some Observations On Ternary Eutectic Systems
Three Binary Eutectics
Usually Result in a
Ternary Eutectic, with
Melting Point Lower Than
Those of All Three
Components, and the
Three Binary eutectics
Composition of SuchTernary Eutectic Lies
within the Triangle
Formed by Three Binary
Eutectic Points
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
45/56
If A Is a Solvent, and B a
Solute, The Heat Absorbed
During Eutectic Melting ~
XAlA +
XB D
H
SB-A-----------------------------------
What Do You Do to
Obtain an Eutectic withHigh Heat Absorption
Capacity?
Search For Suitable Eutectic : Our Approach
Congruous Melting
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
46/56
If A Is a Solvent, and B a Solute,
The Heat Absorbed During Eutectic
Melting ~ XAlA + XB DHSB-A---------------------------------------------
What Do You Do to Obtain an
Eutectic with High Heat AbsorptionCapacity?
__________________
Choose a Solvent with High
and a Combination ofComponents Which Forms an
Eutectic Which Is Rich In
Solvent A.
Search For Suitable Eutectic : Our Approach
Congruous Melting
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
47/56
If A Is a Solvent, and B a Solute, the HeatAbsorbed During Eutectic Melting ~ XAlA +XB DHSB-A
---------------------------------------------
Choose a Solvent with High and a
Combination of Components Which Formsan Eutectic Which Is Rich In Solvent.
_________________
Water Is One of the Most Obvious
Choices of Solvent A.
Now How Do We Choose Solute
B ?
Search For Suitable Eutectic : Our Approach
Congruous Melting
H D W Ch S l t B S h Th t It D M lti P i t
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
48/56
How Do We Choose Solute B Such That It Depresses Melting Point
of Ice at Minimal XB & Forms an Eutectic at < - 20 Deg C ?
B
A
A ixRT
AforTl
2
D
Congruous Melting
+
D
+
D
A
A
B
B
A
A
A
mB
B
AA
mB
B
A
A
B
B
B
B
B
mA
A
BB
mA
A
MX
MX
MX
iRT
xiRT
BforT
Similarly
MX
MX
MXi
RT
xiRT
AforT
l
l
l
l
2
2
2
2
ThinkingCreativeeQualitativfor
ThumbrulesveQuantitatiSome
H D W Ch S l t B S h Th t It D M lti
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
49/56
How Do We Choose Solute B Such That It Depresses Melting
Point of Ice at Minimal XB & Forms an Eutectic at < - 20 Deg C ?
B
A
A ixRT
AforTl
2
D
Congruous Melting
BA
BA
mB
BB
B
B
AB
mA
AA
A
A
B
B
B
B
B
mA
A
BB
mA
A
X
M
Mi
RTTBforTLiquidus
Similarly
XM
Mi
RTTAforTLiquidus
MX
MX
MX
iRT
xiRT
AforT
+
D
1
ThinkingCreativeeQualitativfor
ThumbrulesveQuantitatiSome
2
2
2
2
l
l
l
l
H D W Ch S l t B S h Th t It D M lti
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
50/56
50
How Do We Choose Solute B Such That It Depresses Melting
Point of Ice at Minimal XB , & Forms an Eutectic at < - 20 Deg C ?
B
A
A ixRT
AforTl
2
D
Congruous Melting
B
A
BA
mB
BB
B
B
AB
mA
AA
A
A
B
B
B
B
B
mA
A
BB
mA
A
XMMiRTTBforTLiquidus
Similarly
XM
Mi
RTTAforTLiquidus
MX
MX
MX
iRT
xiRT
AforT
+
D
1
ThinkingCreativeeQualitativfor
ThumbrulesveQuantitatiSome
2
2
2
2
l
l
l
l
Look for Small Molecular Weight Well Dissociating Electrolytes Which
Form Eutectics with Water at Temperatures near 20 Deg C
Avoid Halides Corrosive
Avoid Nitrites .Toxic
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
51/56
51
Search For Suitable Eutectic : Our Approach
Employ Water as Solvent for Its Large Latent Heat ofMelting and Low Cost
Look for Low Molecular Weight Electrolytes Which FormEutectics with Water at Temperatures Near 20 oC
Avoid halides..corrosive Avoid Nitrites/Nitratestoxic
This Leaves No Choice from the Inventory ofFreezing Mixtures Reported in Literature
What Next ? Look for Edible Salts of Organic Acids
They are likely to be less corrosive as well
Search For Suitable Eutectic : Our Approach
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
52/56
52
Search For Suitable Eutectic : Our Approach
Employ Water as Solvent for Its Large Latent Heat of Melting and LowCost
Look for Low Molecular Weight Electrolytes Which Form Eutectics withWater at Temperatures Near 20 oC Avoid halides..corrosive
Avoid Nitrites/Nitratestoxic
This Leaves No Choice from the Inventory of Freezing MixturesReported in Literature. What Next ?
Look for Edible Salts of Organic Acids
They are likely to be less corrosive as well
An Encouraging Finding :Sodium AcetateTEu = - 18
oC
What Next ?
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
53/56
53
An Encouraging Finding : Sodium Acetate TEu = - 18oC
What Next ?
Further Lower the Freezing Point Using Other
Non Corrosive Binary-Eutectic Forming Edible
Salts
Eg DiSodium Phosphate, Sodium Carbonate
Adjust Composition Employing Heuristic/
Phenomenological Insights about Multi
Component Eutectic Systems, and Hypothetic-
Deductive Approach, to Obtain Genuine Ternary
or Quaternary Eutectic Point
The Result
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
54/56
The Result
DSC
Temperature
-35 -30 -25 -20 -15 -10
HeatFlow
in
DSC
New MarkI
Eutectic
PG35%
Only the ThirdTrial Produced
the Mark I
Eutectic
Composition!
Was It a Fortuitous Accident?
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
55/56
He Who Catches Plenty of Fish
Knows Where to Throw the Line
..A Chinese Proverb
-
7/29/2019 Product RD Session 4 - Pushcart Case Study Part 2- Jan 2013
56/56
56