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PowerPoint Presentation - Aerospace Engineering and Engineering

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PowerPoint Presentation - Aerospace Engineering and Engineering Powered By Docstoc
					Carbon Dioxide and Moisture
     Removal System
         NASA ECLSS
         July 17, 2002
  Team Organization

• Jessica Badger           • Dennis Arnold
  – Project Coordinator        – Team Leader
  – Honeycomb structures       – Aerogels




• April Snowden            • Julia Thompson
  – Researcher                 – Researcher
  – Carbon nanotubes           – Honeycomb structures


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 Overview

• Space Launch Initiative Program
• Current RCRS Design
   – Solid Amine Technology/Ion Resin Beads
• Carbon Dioxide/Moisture Removal System
  (CMRS) Design Requirements
• Coeus Engineering’s Design Process
• Possible Designs
   – Honeycomb structures
   – Carbon nanotubes
   – Aerogels
• Future Work
07-17-02          Coeus Engineering           3
 Space Launch Initiative Program

                      • Focuses on the future of
                        exploration and
                        development of space
                      • Creation of 2nd Generation
                        Reusable Launch Vehicle
                        (RLV)
                           – Reduce risk of crew loss to
                             1 in 10,000 missions
                           – Lower payload cost to less
                             than $1,000 per pound
                           – Incorporate latest
                             technology for CO2 removal


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 Current RCRS Design

                  • 11 layered CO2 adsorbent “beds”
                  • Alternating active and inactive beds
                       – Active beds remove CO2
                       – Inactive beds exposed to vacuum
                         release CO2
                  • Dimensions: 3 ft x 1 ft x 1.5 ft
                       – 70% beds
                       – 30% controls/valving
                  • Removes ≈ 0.62 lbs CO2/hour
                       – 7 member crew
                       – Requires 26 lbs of solid amine
                         chemical
                       – Requires flow rate of 40 cfm

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 Current RCRS Design

                      • Ion resin beads
                           – Copolymer of
                             polystyrene and
                             divinylbenzene
                           – Sometimes made from
                             Acrylic
                           – ≈ 3mm diameter
                           – Extremely porous
                           – Coated surface area:
                               250-350 m2/cm3

07-17-02   Coeus Engineering                6
 Current RCRS Design

• Hamilton Standard produces solid amines
  used in RCRS
• Solid amine chemicals
    – CO2 and H2O “loosely” bond to solid amines
    – Reaction produces heat
    – Common alkanolamine CO2 adsorbents:
           – monoethanolamine (MEA)
           – diethanolamine (DEA)
           – methyldiethanolamine (MDEA)




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 Current RCRS Design

                   • Active/Inactive beds inter-
                     layered
                        – Active beds pressurized and
                          heated
                        – Inactive beds cold and
                          exposed to vacuum
                        – Large pressure and
                          temperature gradients


                   • Aluminum Puffed Duocell
                     Foam
                        – Houses ion-resin beds
                        – Structural rigidity
                        – Heat transfer properties
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 Current RCRS Design

                        • Channeled air flow
                               – Each bed contains 4
                                 bead-filled foam
                                 chambers
                        • Retaining screens
                               – Prevent beads from
                                 entering main air
                                 stream
                               – 8 screens per layer
                               – Create large pressure
                                 drop

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 CMRS Design Requirements

• Maximize solid-amine surface area
• Minimize pressure drop through each
  bed
• Maximize structural rigidity
• Maximize heat transfer from active to
  inactive beds



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 Design Process




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 Honeycomb Structures

                       • Packed or joined
                         together in hexagonal
                         manner
                       • Lightweight
                       • High strength and
                         rigidity to weight ratios
                       • Commonly used in
                         sandwiched structures
                               – Airliner floors
                               – Airplane wings
                               – Motorcycle helmets


07-17-02   Coeus Engineering                      12
 Honeycomb Structures

                       • Applied in directional
                         air/fluid flow control
                         and/or energy absorption
                       • Available in 5052 and
                         5056 Aluminum alloys
                       • Varied cell sizes
                           – 1/16” - 3/8”
                       • Can be perforated
                           – Allows air flow
                           – Improves heat removal



07-17-02   Coeus Engineering                   13
 Honeycomb Structures

• Various grades can be exposed to
  temperatures up to 430 oF
• 5 lbs/ft3
• .0015 nominal thickness
• Provides for about 30.38 in2 surface area per
  cubic inch




07-17-02         Coeus Engineering         14
 Honeycomb Structures

                       • If coated with chemical,
                         surface area not
                         comparable to that of
                         beads
                       • Would provide
                         structural rigidity
                       • Would provide heat
                         transfer




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 Carbon Nanotubes

     Enter the World of




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  What is it?

• Discovered by              • Fullerene-related
  Sumio Iijima in 1991         structures
• High-resolution            • Consists of
  transmission                 graphene cylinders
  electron microscopy          closed at either end




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 Types of Carbon Nanotubes

• Single-walled
  carbon nanotube
   – Single sheet of
     carbon atoms
   – 1 < d < 3 nm.
• Multi-walled carbon
  nanotube
   – Multiple sheets of
     carbon atoms
   – d > 3 nm.


07-17-02               Coeus Engineering   18
  Attributes of Carbon Nanotubes

• Diameter                         • Super strength
    – Size of nanometers
    – 1/50,000th of a human        • Low weight
      hair
                                   • Stability
• Length
    – Several micrometers          • Flexibility
    – Largest is ~ 2 mm            • Good heat
• Each nanotube is a                 conductance
  single molecule
    – Hexagonal network of         • Large surface area
      covalently bonded
      carbon atoms                         – 300-800 m2/cm3


 07-17-02              Coeus Engineering                  19
 Mechanical Properties

• Extremely strong
   – 10-100 times stronger than steel per unit weight
• High elastic moduli
   – About 1 TPa
• Flexible
   – Can be flattened, twisted, or bent around sharp
     bends without breaking
• Great performance under compression
• High thermal conductivity


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     Possible Uses

•     Transistors and diodes
•     Field emitters for flat-panel displays
•     Cellular-phone signal amplifiers
•     Ion storage for batteries
•     Materials strengthener
       – Polymer composites
       – Low-viscosity composite


    07-17-02         Coeus Engineering         21
 Potential Use for CMRS

• Coat nanotubes with solid amine
   – Maximize surface area
• Eliminate mesh retaining screen
   – Carbon nanotubes fixed to housing structure
   – No need for beads
   – Minimize pressure drop
• Nanotube structure to channel air
   – Replace aluminum Duocell foam with
     aluminum/carbon nanotube composite
   – Coat carbon nanotubes with solid amine and fit
     into honeycomb or Versacore structure
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 What is an Aerogel?

• Critically evaporated gel
• Lightest solid known
• Almost transparent
  solid
• Great insulator




07-17-02        Coeus Engineering   23
     The History of Aerogels

•     Samuel Stephens Kistler
•     A friendly little wager
•     First publication: Nature 1931
•     Little done until late 1970’s




    07-17-02       Coeus Engineering   24
 Aerogels as Support Structures

• Young’s modulus:                  106 – 107 N/m2
• Tensile strength:                 16 Kpa
• Density:                          ≥ 0.003 g/m3



• Support 1500 times
  their own weight



07-17-02        Coeus Engineering                25
 Aerogels as Insulation

• Examples of use:
   – Modern refrigerators
   – Mars rover
• 39 times better than best
  fiberglass insulation




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 Aerogels as High Surface
 Area Materials

• Up to 99% air
• Pore size
   – Range from
   3 nm to 50 nm
   – Average about 20 nm
• Effective surface area:
           300 – 400 m2/cm3

07-17-02        Coeus Engineering   27
 Aerogels and Coeus Engineering

• Recap
   –   Strong
   –   Lightweight
   –   High surface area
   –   Does not require a screen
• Can the aerogel be coated?
• Different base materials
• Place inside honeycomb

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 Carbon Nanotubes / Aerogels

  Properties   Ion Resin        Carbon      Aerogels
                 Beads         Nanotubes
Surface Area   250-350           300-800    300-400
               m2/cm3            m2/cm3     m2/cm3
Young's          N/A          1 TPa        106-107 Pa
Modulus
Tensile          N/A          30 GPa       16 kPa
Strength                      (max)
Cost              ?                    ?       ?

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 Future Plans

• Wrap-up research
   – Nanotubes
   – Aerogels
   – Carbon nanofoam
• Prepare cost analysis
• Compare and contrast research findings
   – Confer with John Graf
• Decide on a final recommendation
• Final presentation and final report

07-17-02           Coeus Engineering       30
 Special Thanks!!

• Dr. John Graf
• Dr. Ronald O. Stearman
• Marcus Kruger




07-17-02      Coeus Engineering   31
     Questions?

•     Preguntas?
•     Questionne?
•     Bопрос?
•     Kwestie?
•     Ninau?
•     Swali?
•     Spørsmål?
•     Förhöra?

    07-17-02        Coeus Engineering   32

				
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