Flight-Testing of the FAA Onboard Inert Gas Generation System on ...
Flight-Testing of the FAA Onboard Inert Gas Generation System on ...
Flight-Testing of the FAA Onboard Inert Gas Generation System on ...
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Bleedair Flow (SCFM)<br />
50<br />
45<br />
40<br />
35<br />
30<br />
25<br />
20<br />
15<br />
10<br />
5<br />
Ascent<br />
0<br />
0 100 200 300 400 500 600 700 800 900 1000<br />
Atmo Pressure (mBar)<br />
FIGURE 13. CORRELATION OF BLEED AIRFLOW AND ATMOSPHERIC PRESSURE<br />
FOR A SINGLE-MEMBRANE TEST<br />
5.1.4 Membrane Performance Degradati<strong>on</strong>.<br />
An ASM can be sensitive to c<strong>on</strong>taminents in <str<strong>on</strong>g>the</str<strong>on</strong>g> air source. These c<strong>on</strong>taminents can decrease<br />
<str<strong>on</strong>g>the</str<strong>on</strong>g> effectiveness or even damage <str<strong>on</strong>g>the</str<strong>on</strong>g> fibers in <str<strong>on</strong>g>the</str<strong>on</strong>g> ASM, degrading <str<strong>on</strong>g>the</str<strong>on</strong>g> ASM performance over<br />
time exposure to <str<strong>on</strong>g>the</str<strong>on</strong>g>se c<strong>on</strong>taminents. As previously stated, <str<strong>on</strong>g>the</str<strong>on</strong>g> <str<strong>on</strong>g>FAA</str<strong>on</strong>g> OBIGGS has a filter to<br />
remove particulate, but how effective this type <str<strong>on</strong>g>of</str<strong>on</strong>g> filter is at protecting <str<strong>on</strong>g>the</str<strong>on</strong>g> ASM is unknown.<br />
Most hollow fiber is intollerant <str<strong>on</strong>g>of</str<strong>on</strong>g> hydrocarb<strong>on</strong> vapor in general and <str<strong>on</strong>g>the</str<strong>on</strong>g> amount <str<strong>on</strong>g>of</str<strong>on</strong>g> hydrocarb<strong>on</strong><br />
vapor in <str<strong>on</strong>g>the</str<strong>on</strong>g> bleed air and <str<strong>on</strong>g>the</str<strong>on</strong>g> filter’s ability to remove it is in questi<strong>on</strong>.<br />
To determine <str<strong>on</strong>g>the</str<strong>on</strong>g> effect <str<strong>on</strong>g>of</str<strong>on</strong>g> aircraft bleed air systems <strong>on</strong> an ASM, a single-ASM used during<br />
ground and flight tests was subjected to a single test point before and after <str<strong>on</strong>g>the</str<strong>on</strong>g> tests. The NEA<br />
and ASM inlet (bleed) flow were measured for a given NEA purity at a specific inlet pressure<br />
and temperature at sea level. Table 2 shows <str<strong>on</strong>g>the</str<strong>on</strong>g> difference in ASM performance before and after<br />
<str<strong>on</strong>g>the</str<strong>on</strong>g> test. The 14 percent drop in NEA produced is more than <str<strong>on</strong>g>the</str<strong>on</strong>g> expected decrease in<br />
productivity due to normal break-in <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> ASM over <str<strong>on</strong>g>the</str<strong>on</strong>g> first hours <str<strong>on</strong>g>of</str<strong>on</strong>g> service.<br />
TABLE 2. AIR SEPARATION MODULE PERFORMANCE DATA BEFORE AND AFTER<br />
100 HOURS OF AIRCRAFT OPERATION<br />
Membrane<br />
State<br />
ASM Inlet<br />
Temperature<br />
ASM Inlet<br />
Pressure Altitude<br />
NEA<br />
Purity NEA Flow<br />
ASM Inlet<br />
Flow<br />
Before 172°F 25 psig Sea Level 5% 0.36 lbs/min 1.48 lbs/min<br />
After 169°F 25 psig Sea Level 5% 0.31 lbs/min 1.25 lbs/min<br />
Difference 0.05 lbs/min 0.23 lbs/min<br />
17