US4024407A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for measuring the dust content of a gas stream
Assignee: Centre dEtudes et de Recherches de lIndustrie des Liants Hydrauliques
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Filing: 1975-05-15
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Granted: 1977-05-17
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Expires: 1995-05-15
Abstract
Abstract A device for measuring dust content in a gas stream comprising a light soe, a photosensitive receiver, and means to direct an essentially dust free stream against the main gas stream to form a dust curtain into which the beam penetrates and reflects to the receiver.
Inventors
- 👤 Jean-Paul Meric
- 👤 Raymond Peltier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:58
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/53
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
144 words
In a device for measuring the dust content of a gas stream, which may contain dust and has a given average circulation velocity in a given direction, the device including a source arranged to emit a beam of electromagnetic radiation, and a photosensitive receiver placed near the source, on the same side as the source with respect to the gas stream, to measure radiation from the source backscattered by dust in the gas stream, the improvement comprising means for directing a stream of relatively dust-free gas in front of said source and said receiver in a direction having at least a component opposite to said given direction of said average circulation velocity of said gas stream so as to cause accumulation of dust in form of a curtain in front of the device and an increasing output from said receiver with increasing dust content.
Claim 2
Dependent Claim
144 words
In a device for measuring the dust content of a gas stream, which may contain dust and has a given average circulation velocity in a given direction, the device including a source arranged to emit a beam of electromagnetic radiation, and a photosensitive receiver placed near the source, on the same side as the source with respect to the gas stream, to measure radiation from the source backscattered by dust in the gas stream, the improvement comprising means for directing a stream of relatively dust-free gas in front of said source and said receiver in a direction having at least a component opposite to said given direction of said average circulation velocity of said gas stream so as to cause accumulation of dust in form of a curtain in front of the device and an increasing output from said receiver with increasing dust content.
Claim 3
Dependent Claim
27 words
A device according to claim 1, wherein the radiation beam makes an angle of about 30° with the direction of the mean velocity of the gas stream.
Claim 4
Dependent Claim
21 words
Device according to claim 1, further comprising means for modulating the radiation beam located by the receiver including a synchronous detector.
Claim 5
Dependent Claim
19 words
Device according to claim 1, further comprising an interference filter placed in front of the source and the receiver.
Claim 6
Dependent Claim
12 words
Device according to claim 1, wherein the radiation source is a laser.
Claim 7
Dependent Claim
19 words
Device according to claim 1, wherein the receiver is annular in shape and is disposed coaxially to the source.
Claim 8
Dependent Claim
24 words
Device according to claim 1, further comprising means for causing the beam to pivot such as to sweep a section of the gas stream.
Claim 9
Dependent Claim
30 words
A device according to claim 1, wherein said means for directing comprise means for directing a stream of relatively dust-free air in a direction substantially opposite to said given direction.
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) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |