US4132894A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Monitor of the concentration of particles of dense radioactive materials in a stream of air
Assignee: United States Department of Energy
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Filing: 1978-04-04
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Granted: 1979-01-02
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Expires: 1998-04-04
Abstract
Abstract A monitor of the concentration of particles of radioactive materials such as plutonium oxide in diameters as small as 1/2 micron includes in combination a first stage comprising a plurality of virtual impactors, a second stage comprising a further plurality of virtual impactors, a collector for concentrating particulate material, a radiation detector disposed near the collector to respond to radiation from collected material and means for moving a stream of air, possibly containing particulate contaminants, through the apparatus.
Inventors
- 👤 Thomas J. Yule
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:19
CPC Classifications
G; G01; G01T; G01T7/00; G01T7/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
149 words
An apparatus for monitoring the concentration of particles of dense radioactive material in air, the appartus comprising: means for generating a stream of air containing particles of dense radioactive materials; a first separating stage including a first plurality of virtual impactors receiving and separating the stream into a more concentrated stream of larger particles and a first stream of smaller particles; means for exhausting the first stream of smaller particles; a second separating stage including a second plurality of virtual impactors receiving and separating the more concentrated stream of larger particles into a twice concentrated stream of larger particles and a second stream of smaller particles; means for exhausting the second stream of smaller particles; filter means coupled to the twice concentrated stream of larger particles to trap particles from the twice concentrated stream of larger particles; and means for measuring radioactivity of particles trapped by the filter means.
Claim 2
Independent Claim
149 words
An apparatus for monitoring the concentration of particles of dense radioactive material in air, the appartus comprising: means for generating a stream of air containing particles of dense radioactive materials; a first separating stage including a first plurality of virtual impactors receiving and separating the stream into a more concentrated stream of larger particles and a first stream of smaller particles; means for exhausting the first stream of smaller particles; a second separating stage including a second plurality of virtual impactors receiving and separating the more concentrated stream of larger particles into a twice concentrated stream of larger particles and a second stream of smaller particles; means for exhausting the second stream of smaller particles; filter means coupled to the twice concentrated stream of larger particles to trap particles from the twice concentrated stream of larger particles; and means for measuring radioactivity of particles trapped by the filter means.
Claim 3
Dependent Claim
62 words
The apparatus of claim 1 wherein each of the virtual impactors of the first plurality comprises in combination a first nozzle receiving in a cylindrical aperture a portion of the stream of air containing particles of dense radioactive materials and a second nozzle containing a cylindrical aperture coaxial with the cylindrical aperture and separated from the first nozzle by a predetermined distance.
Claim 4
Dependent Claim
38 words
The apparatus of claim 1 wherein the means for exhausting the first and second streams of smaller particles comprises a centrifugal pump connected operatively to apply a reduced pressure to the first and second streams of smaller particles.
Claim 5
Dependent Claim
44 words
The apparatus of claim 1 wherein the filter means comprise a filter paper disposed in the twice concentrated stream and a filter holder to maintain the filter paper in the twice concentrated stream such that the twice concentrated stream passes through the filter paper.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-01-01 | 1982-07-03 | 1983-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-01 | 1986-07-03 | 1987-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-01 | 1990-07-03 | 1991-01-02 | $7700.00 | Window Closed / Lapsed |