Patent DE323738C successfully refreshed from Google Patents.
Patent US3652227A successfully refreshed from Google Patents.
US3652227A
Expired / Lapsed
US
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Nitric oxide analysis
Assignee: Beckman Coulter Inc
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Filing: 1969-12-15
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Granted: 1972-03-28
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Expires: 1989-12-15
Abstract
Abstract Method and apparatus for determining the nitric oxide content of a sample gas stream. The nitric oxide in the gas stream is reacted with an excess amount of ozone so as to completely convert the nitric oxide into nitrogen dioxide. The resulting gas containing nitrogen dioxide and residual ozone is passed through a scrubber which removes the ozone and does not affect the nitrogen dioxide content of the gas. The resulting gas is then analyzed for its NO2 content, which is a function of the nitric oxide content of the sample gas. The method and apparatus may also be utilized for determining the total amount of nitrogen dioxide and nitric oxide in a sample gas. The invention is particularly applicable to the monitoring of air for air pollution control.
Inventors
- 👤 John N Harman
- 👤 Radhakrishna M Neti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:16
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/002; Y; Y10; Y10T; Y10T436/00; Y10T436/17; Y10T436/177692; Y10T436/179228
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
38 words
A method as set forth in claim 1 wherein: the nitric oxide in said gas stream is reacted with an excess amount of ozone so that said resulting gas stream will contain ozone as well as nitrogen dioxide.
Claim 2
Dependent Claim
22 words
A method as set forth in claim 1 wherein: said ozone is produced by reacting ultraviolet radiation with an oxygen bearing gas.
Claim 3
Dependent Claim
23 words
A method as set forth in claim 1 wherein: said ozone is produced by generating an electric discharge in an oxygen bearing gas.
Claim 4
Dependent Claim
14 words
A method as set forth in claim 1 wherein: said scrubber means contains AgO.
Claim 5
Dependent Claim
74 words
A method as set forth in claim 1 wherein said sample gas stream contains interferents other than ozone and including the additional steps of: providing second scrubber means capable of scrubbing said interferents from said sample gas stream without appreciably affecting the nitric oxide content thereof; and passing said sample gas stream through said second scrubber means prior to reacting the stoichiometric amount of ozone with the nitric oxide in the sample gas stream.
Claim 6
Dependent Claim
25 words
A method as set forth in claim 6 wherein said second scrubber means contains a material selected from the group consisting of Ca(OH)2 and KOH.
Claim 7
Dependent Claim
15 words
A method as set forth in claim 6 wherein said first-mentioned scrubber means contains AgO.
Claim 8
Dependent Claim
19 words
A method as set forth in claim 6 wherein said first-mentioned scrubber means scrubs ozone by thermal decomposition thereof.
Claim 9
Independent Claim
96 words
A method of continuously monitoring the nitric oxide content of an air sample stream containing interferents comprising the steps of: scrubbing the interferents from the air sample stream; reacting the nitric oxide in the air sample stream with an excess amount of ozone so as to completely convert the nitric oxide to nitrogen dioxide and also provide ozone in the resulting gas stream; scrubbing the ozone from said resulting gas stream; and thereafter determining the nitrogen dioxide content of the scrubbed gas stream as a measure of the nitric oxide content of said air sample stream.
Claim 10
Dependent Claim
24 words
A method as set forth in claim 10 wherein said ozone is scrubbed from said resulting gas stream by passing the stream over AgO.
Claim 11
Dependent Claim
31 words
A method as set forth in claim 11 wherein: said interferents are scrubbed by passing the air sample stream over a material selected from the group consisting of Ca(OH)2 and KOH.
Claim 12
Dependent Claim
63 words
A method as set forth in claim 11 wherein said excess amount of ozone is provided by: passing a second air stream through an activated charcoal scrubber so that interferents are absorbed and a mixture consisting essentially of nitrogen and oxygen is emitted from the scrubber as an effluent; and reacting the oxygen bearing effluent from the activated charcoal scrubber with ultraviolet radiation.
Claim 13
Independent Claim
103 words
A method of determining the total nitric oxide and nitrogen dioxide content of a sample gas stream containing interferents comprising the steps of: reacting the nitric oxide in the sample gas stream with at least the stoichiometric amount of ozone so as to completely convert the nitric oxide into nitrogen dioxide; passing the resulting gas stream through a scrubber containing AgO to scrub said interferents and any ozone present in the gas stream; and thereafter determining the nitrogen dioxide content of the effluent emanating from said scrubber whereby the total nitric oxide and nitrogen dioxide content of the sample gas stream is determined.
Claim 14
Independent Claim
154 words
An apparatus for determining the nitric oxide content of a sample gas stream comprising: means for providing a supply of ozone; a reaction chamber; means for conveying ozone from said first-mentioned means and the sample gas stream to said reaction chamber whereby the nitric oxide in said sample gas stream will be converted into nitrogen dioxide in the chamber so that a nitrogen dioxide and ozone containing gas stream is emitted from the reaction chamber as an effluent; scrubber means for scrubbing ozone from said gas stream witHout appreciably affecting the nitrogen dioxide content of the gas stream so that a nitrogen dioxide containing gas stream is emitted from the scrubber means as an effluent; means for conveying the effluent from said reaction chamber to said scrubber means; analyzer means for determining the nitrogen dioxide content of said gas stream; and means for conveying the effluent from said scrubber means to said analyzer means.
Claim 15
Dependent Claim
18 words
An apparatus as set forth in claim 15 wherein said scrubber means contains AgO as a scrubber material.
Claim 16
Dependent Claim
27 words
An apparatus as set forth in claim 15 wherein said scrubber means contains means capable of thermally decomposing ozone thereby scrubbing the ozone from said gas stream.
Claim 17
Dependent Claim
28 words
An apparatus as set forth in claim 15 wherein said means for providing a supply of ozone includes a source of ultraviolet radiation for photo-oxidizing oxygen to ozone.
Claim 18
Dependent Claim
30 words
An apparatus as set forth in claim 15 wherein said means for providing a supply of ozone includes means for generating an electric discharge sufficient to convert oxygen into ozone.
Claim 19
Dependent Claim
81 words
An apparatus as set forth in claim 15 including: second scrubber means capable of scrubbing interferents from the sample gas stream without appreciably affecting the nitric oxide content thereof so that a nitric oxide containing gas stream is emitted from the second scrubber means as an effluent; and said sample gas conveying means includes means for introducing the sample gas stream into said second scrubber means and means for delivering the effluent from said second scrubber means to said reaction chamber.
Claim 20
Dependent Claim
29 words
An apparatus as set forth in claim 20 wherein said second scrubber means contains a material selected from the group consisting of Ca(OH)2 and KOH as a scrubber material.
Claim 21
Dependent Claim
259 words
In an apparatus for continuously monitoring the nitric oxide content of a sample air stream containing interferents, the combination of: first scrubber means capable of scrubbing interferents from an air stream containing nitric oxide without appreciably affecting the nitric oxide content of the stream so that a nitric oxide containing gas stream is emitted from the first scrubber means as an effluent; means for introducing the sample air stream into said first scrubber means; a first reaction chamber wherein nitric oxide in the sample air stream is converted to nitrogen dioxide so that an air stream containing nitrogen dioxide is emitted from the first reaction chamber as an effluent; means for conveying the effluent from said first scrubber means into said first reaction chamber; second scrubber means capable of scrubbing both nitric oxide and interferents from an air stream so that an air stream with nitric oxide and interferents removed is emitted from the second scrubber means as an effluent; means for introducing an air stream into said second scrubber means; a second reaction chamber containing means for converting oxygen into ozone; means for conveying the effluent from said second scrubber means through said second reaction chamber into said first reaction chamber; third scrubber means capable of scrubbing ozone in a gas stream containing nitrogen dioxide without appreciably affecting the nitrogen dioxide content of the gas stream; analyzer means for determining the nitrogen dioxide content of said gas stream; and means for conveying the effluent from said first reaction chamber through said third scrubber means to said analyzer means.
Claim 22
Dependent Claim
19 words
An apparatus as set forth in claim 22 wherein said third scrubber means contains AgO as a scrubber material.
Claim 23
Dependent Claim
29 words
An apparatus as set forth in claim 23 wherein said first scrubber means contains a material selected from the group consisting of Ca(OH)2 and KOH as a scrubber material.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-28 | 1975-09-27 | 1976-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-28 | 1979-09-27 | 1980-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-28 | 1983-09-27 | 1984-03-28 | $7700.00 | Window Closed / Lapsed |