FINAL PRESENTATION P13681
Dec 22, 2015
FINAL PRESENTATION
P13681
2
The Team• Austin Frazer
• Role: Lead Engineer - Analysis• Major: Mechanical Engineering
• Eileen Kobal• Role: Lead Engineer – Mixtures of
Gas Fluids• Major: Chemical Engineering
• Ana Maria Maldonado• Role: Team Manager• Major: Industrial Engineering
• Marie Rohrbaugh• Role: Project Manager• Major: Mechanical Engineering
3
Concept Summary
To mass spectrometer
Valve
High pressure helium
High pressure helium
Fixturing/leakage similar to other side
Fixtures interface between AGT can and valve
Fixture leakageValve leakage
Leakage from valve
Leakage from Fixture
Leakage from room through lid and baseplate
Moog’s Problem Statement:
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Concept Summary ContinuedMoog’s current means of fixture leakage reduction: Vented Double O-ring
3000 psi
Valve
0 psi (Vacuum)
• Vent open to ambient. Leakage past 1st O-Ring is meant to dissipate out of can
• MSD team is able to modify vent conditions
5
Concept Summary Continued
• Moog already has “constant N2 flow” subsystem implemented on bottom large O-ring
• Similar subsystem could be applied to top large O-ring
• This was listed as lower priority
Constant N2 flow during test
Moog’s current means of fixture leakage reduction: Large O-rings
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Customer Specifications and Requirements
Ran
king
Voice of the Customer
to Voice of the
EngineerNumbers represent how well the engineering specification meets the customer requirement .
The Ranking describes how important the customer need is.
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Project Overview
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Simulink Model• System was modeled in Simulink to help select a concept
• Only vented double O-ring was modeled. Not large O-rings• Model was built with a perfectly mixed assumption. This would prove to be a
poor assumption• Results of the Simulation indicated that a pulse-purge vent condition
would most drastically reduce the fixture leakage. This was the basis for the system design of MSD I
0 50 100 150 200 250 300 350 4000
0.2
0.4
0.6
0.8
1x 10
-11
Time (seconds)
He
Can
Lea
kage
(cc
/s)
Volumetric Flow Rate of Helium into the Can Over Time
Case 3
Case 1 (Baseline)
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Initial Project Design – End of MSD I
Permanent Subsystem Required:• Modification of baseplate• Robust Labview programming by Moog
supplier• System was required to operate
independent of operator input• Multiple circle seal valves• Robust and space - efficient mounting of all
required components• Hardlines capable of safely handling high
pressures
Cost: Approximately $7,500 per AGT
The initial design (per the detailed design review) was intended to be a permanent system. Due to budget cuts this was eliminated as a viable concept Design accounts for large O-ring and
vented double O-ring leakage
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Initial Project Design Continued
High Pressure Inlet
All vents connected to one system
Modifications to baseplate necessary
Access port to Vent
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Initial Project Design - Continued
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Actual System Design – Portable System• Due to budget cuts, a portable “proof of concept” system was
created to test the validity of the pulse purge vented double O-ring
• Most design criteria from MSD I remained intact. Changes include• Valves, regulators, electrical components donated by Moog• All parts machined and assembled by the MSD team• Electrical subsystem to control valve(s) to be designed/implemented
by MSD team• Operator input into system OK
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Actual System Design - Schematic
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Actual Project Design – Portable System
Tube represents valve. Typically the Fixture system is on both the inlet and outlet of the valve.
High Pressure Helium into Fixture System
Vented Helium
Seals have two o-rings with a vent between. Gas moves freely between the seals.
Helium Leakage from Fixture
Welded to minimize leakage
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Bill of Materials
Total cost ~$1000
Total cost after donated/borrowed items ~$40
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System Architecture
Flexline goes to next slide
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System Architecture Continued
Helium InletVent Port
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Results• 4 hours of continuous leakage data was acquired under
varying vent conditions. Sample plot is given below:
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Results Continued
0 100 200 300 400 500 600 700 800-5
-4
-3
-2
-1
0
1
2
3
4
5x 10
-6 Constant 30psi Nitrogen
He Pressure (psi)
Cor
rect
ed L
eaka
ge (s
cc/s
ec)
0 100 200 300 400 500 600 700 800-1
-0.5
0
0.5
1
1.5
2
2.5
3x 10
-5
He Pressure (psi)
Co
rre
cte
d L
ea
kag
e (
scc/
sec)
Pulse-Purge
30psi N2
Low P N2
0 100 200 300 400 500 600 700 800-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5x 10
-7 Constant Vacuum
He Pressure (psi)
Co
rre
cte
d L
ea
kag
e (
scc/
sec)
Duty cycle varies within this plot. No correlation between duty cycle and leakage rate*
Proves to increase fixture leakage (as expected)
*It is concluded that the N2 pulse actually pushes the Helium out of the vent. Uniform mixing does not occur
Not strong enough correlation to draw conclusions (see order of magnitude)
Analysis of the test data produces the following plots:
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Results Continued
Constant N2 flow around large O-rings significantly reduces fixture leakage
1 sec of pressure followed by 50 sec of vacuum
Cycled 14 times 14 peaks
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Conclusions• Proof-of-concept design was successfully designed and
assembled. Reliable test data was collected• Test data indicates that pulsing/purging the vented double
O-ring volume does not reduce fixture leakage adequately• Test data indicates that constant flow of N2 past the lower
large O-ring significantly reduces leakage results• A constant flow through the vent is expected to significantly reduce
fixture leakage
• Project output is consistent with current Moog priorities• Data was collected and the concept was tested. Relatively few un-
returnable company resources were used. A conclusive answer has been acquired
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Our Recommendation• Do not pursue pulse purge vent condition
• If modifying selected fixturing was a possibility, allowing a constant flow through the vent is expected to significantly reduce fixture leakage
• Implement the constant N2 flow system on the upper large O-ring• Designs have already been completed for the modification of the can
and manufacturing of addition required components
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MSD II Schedule
We finished on time!!!
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Acknowledgements• Robert Bauer & Moog Space and Defense Group• Michael Zona• Dr. Jason Koldziej• Dr. Karuna Koppula• Dr. Elizabeth DeBartolo• Prof. John Wellin
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QUESTIONS?
Thank you for coming!