Patent US3909204A successfully refreshed from Google Patents.
US3909204A
Expired / Lapsed
US
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Gas pollution monitor
Assignee: British Gas PLC
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Filing: 1973-09-04
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Granted: 1975-09-30
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Expires: 1993-09-04
Abstract
Abstract Apparatus for monitoring low concentrations of nitrogen oxides and carbon monoxide in gas streams, in which carbon monoxide is determined by passing gas over iodine pentoxides to liberate quantative amounts of iodine vapour which are measured by means of a Pt-Act C or Ag/buffered halide cell associated with a galvanic cell, and nitrogen oxides are measured by passing gas through Pt-Act C or Ag/halide cells. Interfering gases are removed by known means prior to passage of gas through cell. NO concentrations may be determined in the presence of NO2, thus NO2 concentration may be determined by difference.
Inventors
- 👤 John Douglas Allen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:08
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/404; G01N27/4045; Y; Y10; Y10T; Y10T436/00; Y10T436/17; Y10T436/177692; Y10T436/20; Y10T436/204998; Y10T436/205831
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
154 words
APPARATUS FOR MEASURING LOW CONCENTRATIONS OF NITROGEN OXIDES AND CARBON MONOXIDE IN A GAS WHICH APPARATUS INCLUDES MEANS FOR RECEIVING THE GAS TO BE TREATED, MEANS FOR PROVIDING TWO SEPARATE STREAMS OF THE GAS TO BE TESTED, MEANS FOR REMOVING INTERFERING GASES FROM A FIRST OF THE TWO STREAMS, MEANS FOR REACTING THE CARBON MONOXIDE PRESENT IN THE FIRST STREAM WITH A IODINE PENTOXIDE COMPOUND TO PRODUCE CORRESPONDINGLY QUANTITATIVE AMOUNTS OF IODINE, A GALVANIC CELL ASSOCIATED WITH EACH STREAMS AND COMPRISING A PLATINUM CATHODE IN CONTACT WITH A NEUTRAL BUFFERED HALIDE ELECTROLYTE IN WHICH IS IMMERSED AN ACTIVE CARBON OR SILVER ANODE, MEANS FOR CAUSING SAID IODINE PENTOXIDE CONTAINING FIRST STREAM AND SAID SECOND STREAM TO FLOW OVER THE CATHODE OF ITS ASSOCIATED CELL, MEANS FOR MEASURING THE RATE OF FLOW OF EACH STREAM THROUGH ITS ASSOCIATED CELL AND MEANS FOR MEASURING THE CURRENT FROM EACH CELL WHEN ITS ASSOCIATED STREAM PASSES THROUGH IT.
Claim 2
Dependent Claim
154 words
APPARATUS FOR MEASURING LOW CONCENTRATIONS OF NITROGEN OXIDES AND CARBON MONOXIDE IN A GAS WHICH APPARATUS INCLUDES MEANS FOR RECEIVING THE GAS TO BE TREATED, MEANS FOR PROVIDING TWO SEPARATE STREAMS OF THE GAS TO BE TESTED, MEANS FOR REMOVING INTERFERING GASES FROM A FIRST OF THE TWO STREAMS, MEANS FOR REACTING THE CARBON MONOXIDE PRESENT IN THE FIRST STREAM WITH A IODINE PENTOXIDE COMPOUND TO PRODUCE CORRESPONDINGLY QUANTITATIVE AMOUNTS OF IODINE, A GALVANIC CELL ASSOCIATED WITH EACH STREAMS AND COMPRISING A PLATINUM CATHODE IN CONTACT WITH A NEUTRAL BUFFERED HALIDE ELECTROLYTE IN WHICH IS IMMERSED AN ACTIVE CARBON OR SILVER ANODE, MEANS FOR CAUSING SAID IODINE PENTOXIDE CONTAINING FIRST STREAM AND SAID SECOND STREAM TO FLOW OVER THE CATHODE OF ITS ASSOCIATED CELL, MEANS FOR MEASURING THE RATE OF FLOW OF EACH STREAM THROUGH ITS ASSOCIATED CELL AND MEANS FOR MEASURING THE CURRENT FROM EACH CELL WHEN ITS ASSOCIATED STREAM PASSES THROUGH IT.
Claim 3
Dependent Claim
34 words
Apparatus as claimed in claim 1 in which means are provided for supplying gas free from carbon monoxide for the purpose of zeroing the means for measuring the current across the associated galvanic cell.
Claim 4
Dependent Claim
41 words
Apparatus as claimed in claim 1 in which means are provided for supplying a gas free from nitrogen dioxide to the galvanic cell associated with the second stream for the purpose of zeroing the current measuring means associated with that cell.
Claim 5
Dependent Claim
49 words
Apparatus as claimed in claim 1 in which means are provided in said second stream for converting nitric oxide to nitrogen dioxide and means are provided for passing, at separate times, stream containing residual nitrogen dioxide and streams containing residual nitrogen dioxide and nitrogen dioxide formed from nitric oxide.
Claim 6
Dependent Claim
32 words
Apparatus as claimed in claim 4 in which said means for converting nitric oxide to nitrogen dioxide is a bed comprising a solution or moist solid of a permanganate or a dishromate.
Claim 7
Dependent Claim
17 words
Apparatus as claimed in claim 1 in which means are provided for the removal of interfering compounds.
Claim 8
Dependent Claim
59 words
Apparatus as claimed in claim 6 wherein beds of acidified chromium trioxide and activated charcoal are provided to remove nitric oxide nitrogen dioxide, acetylene, ethylene, sulphur dioxide, hydrogen sulphide, mercaptans and ozone from the carbon monoxide stream and a bed of silver peroxide is provided to remove ozone, sulphur dioxide, hydrogen sulphide and mercaptans from the nitrogen oxides stream.
References Cited (Backward Citations)
US3589868A
Cited
US3764269A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |