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EVALUATION OF A FILTRATION SYSTEM FOR PRESSURIZED AIRCRAFT.
Operation TUMBLER-SNAPPER.
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Frank G. Ort and Michael J. Schumchyk, November 1952.
CONFIDENTIAL
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Cherical Corps particulate filters for test were installed in
the air ducts from turbosuperchargers of the engines on B-29 aircraft,
_which supply heated and pressurized air to the cabin, with the object of
determining filter efficiencies in removing radioactive aerosols from
influent air while passing through radioactive clouds.
Filtration
efficiencies in excess of 99.9% were obtained under the specified conditions.
Preliminary tests indicated that type 7 filter material was superior to
type 6 under the conditions of temperature and pressure in the air ducts.
These conditions necessitated changes in the specifications for certain
filter components of standard particulate filters.
Operational test
results were obtained by sampling filter influent and effluent air and
monitoring the sampling filters for radioactivity.
This procedure involved
careful calibration of the sampling orifices at the varying temperatures
and pressures incident to the varying speeds and altitudes attained by the
aircraft.
Such calibration was essential in the determination of the
ratio of air-volume sampled to the total air-volume passing through the
filters.
WT-536
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EVALUATION OF AIR MONITORING INSTRUMENTS.
Operation TUMBLER-SNAPPER.
Luther M. Hardin and D'Arcy Littleton, Jr., November 1952.
CONT IDENTIAL
The CmlC Portable Air Sampler, E22, and the modified Tracerlab
Continuous Air Monitor were tested for adequacy and applicability to
radiological air-monitoring problems.
Tests were made in the aerosols
caused by shots 5, 6, 7, and 8 of Gperation SNAPPER, and aerosols due to
the redispersion of contamination from Operation JANGLE.
that:
It was shown
(1) the E22 portable air sampler is a soundly designed instrument
worthy of further consideration, but requires additional modification and
tests before standardizing for this application; (2) the modified Tracer-
lab continuous air monitor is not suitable for field use, since it is
bulky, fragile, complex, and not easily shielded from background radiation
due to faliout; and (3) millipore filter material is very efficient in
the removal of particles from the air-stream, but less efficient than
CmlC type 6 filter material in retaining the separated particles on its
surface.
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