US3870468A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nitrogen dioxide analysis
Assignee: Rosemount Inc
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Filing: 1972-06-16
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Granted: 1975-03-11
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Expires: 1992-06-16
Abstract
Abstract A method and apparatus for converting nitrogen dioxide to nitric oxide for the ultimate reaction with ozone to cause a chemiluminescent reaction, the intensity of which is a function of the nitric oxide concentration. The method comprises passing the nitrogen dioxide through a small, confined volume and applying concentrated heat to the volume in the presence of suitable amounts of vitreous carbon. In one preferred embodiment the apparatus includes a quartz container and a filament constructed of vitreous carbon. In an alternative embodiment, loose vitreous carbon or a vitreous carbon rod is confined within the quartz container, and heat is applied by a heated stainless steel or nichrome filament surrounding the quartz container.
Inventors
- 👤 Radhakrishna M Neti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:48
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/20; C01B21/24; C01B21/26; C01B21/262; G; G01; G01N; G01N21/00; G01N21/75; G01N21/76; G01N21/766; G01N31/00; G01N33/00; G01N33/0004; G01N33/0009; G01N33/0011; G01N33/0013; Y; Y10; Y10T; Y10T436/00; Y10T436/17; Y10T436/177692; Y10T436/178459
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
70 words
A method of treating nitrogen dioxide comprising: passing said nitrogen dioxide through a small, confined volume containing a catalytic agent selected from the group of vitreous carbon, and a carbon and ceramic mixture, and applying heat to said confined volume to heat said nitrogen dioxide to a temperature in the range of from 200*-600*C. whereby the nitrogen dioxide is substantially fully converted to nitric oxide during application of said heat.
Claim 2
Independent Claim
70 words
A method of treating nitrogen dioxide comprising: passing said nitrogen dioxide through a small, confined volume containing a catalytic agent selected from the group of vitreous carbon, and a carbon and ceramic mixture, and applying heat to said confined volume to heat said nitrogen dioxide to a temperature in the range of from 200*-600*C. whereby the nitrogen dioxide is substantially fully converted to nitric oxide during application of said heat.
Claim 3
Independent Claim
70 words
A METHOD OF TREATING NITROGEN DIOXIDE COMPRISING: PASSING SAID NITROGEN DIOXIDE THROUGH A SMALL, CONFINED VOLUME CONTAINING A CATALYTIC AGENT SELECTED FROM THE GROUP OF VITREOUS CARBON, AND A CARBON AND CERAMIC MIXTURE, AND APPLYING HEAT TO SAID CONFINED VOLUME TO HEAT SAID NITROGEN DIOXIDE TO A TEMPERATURE IN THE RANGE OF FROM 200*-600*C. WHEREBY THE NITROGEN DIOXIDE IS SUBSTANTIALLY FULLY CONVERTED TO NITRIC OXIDE DURING APPLICATION OF SAID HEAT.
Claim 4
Independent Claim
70 words
A METHOD OF TREATING NITROGEN DIOXIDE COMPRISING: PASSING SAID NITROGEN DIOXIDE THROUGH A SMALL, CONFINED VOLUME CONTAINING A CATALYTIC AGENT SELECTED FROM THE GROUP OF VITREOUS CARBON, AND A CARBON AND CERAMIC MIXTURE, AND APPLYING HEAT TO SAID CONFINED VOLUME TO HEAT SAID NITROGEN DIOXIDE TO A TEMPERATURE IN THE RANGE OF FROM 200*-600*C. WHEREBY THE NITROGEN DIOXIDE IS SUBSTANTIALLY FULLY CONVERTED TO NITRIC OXIDE DURING APPLICATION OF SAID HEAT.
Claim 5
Dependent Claim
25 words
A method according to claim 1 wherein said nitrogen dioxide is passed continuously through said volume and wherein said heat is alternately applied and removed.
Claim 6
Dependent Claim
46 words
Apparatus for converting nitrogen dioxide to nitric oxide comprising: means defining a small, confined volume containing vitreous carbon, said means having an inlet and an outlet for the conduction of said nitrogen dioxide therethrough; and means for generating and applying to said confined volume concentrated heat.
Claim 7
Dependent Claim
46 words
Apparatus for converting nitrogen dioxide to nitric oxide comprising: means defining a small, confined volume containing vitreous carbon, said means having an inlet and an outlet for the conduction of said nitrogen dioxide therethrough; and means for generating and applying to said confined volume concentrated heat.
Claim 8
Dependent Claim
32 words
Apparatus according to claim 3 wherein said means defining a small, conFined volume comprises an elongated container having an inlet at one end thereof and an outlet at the other end thereof.
Claim 9
Dependent Claim
43 words
Apparatus for converting nitrogen dioxide to nitric oxide comprising: a container having an inlet and an outlet for the conduction of nitrogen dioxide therethrough, a vitreous carbon filament within said container, and means for energizing said filament to apply heat to said container.
Claim 10
Dependent Claim
43 words
Apparatus for converting nitrogen dioxide to nitric oxide comprising: a container having an inlet and an outlet for the conduction of nitrogen dioxide therethrough, a vitreous carbon filament within said container, and means for energizing said filament to apply heat to said container.
Claim 11
Dependent Claim
22 words
The apparatus of claim 5 including means for heating the contents of the container to a temperature of 200* to 600* C.
Claim 12
Dependent Claim
20 words
The apparatus of claim 6 wherein the container is elongate in form and is also packed with vitreous carbon particles.
Claim 13
Dependent Claim
12 words
The apparatus of claim 7 wherein the container is fabricated of quartz.
Claim 14
Dependent Claim
67 words
Apparatus for converting nitrogen dioxide to nitric oxide comprising: an elongate tube having an inlet at one end thereof and an outlet at the other end thereof, porous screens closing the ends of said tube, and said tube being at least partially filled with vitreous carbon; a filament in heat transmitting relation to said tube; and means for energizing said filament to apply heat to said tube.
Claim 15
Dependent Claim
67 words
Apparatus for converting nitrogen dioxide to nitric oxide comprising: an elongate tube having an inlet at one end thereof and an outlet at the other end thereof, porous screens closing the ends of said tube, and said tube being at least partially filled with vitreous carbon; a filament in heat transmitting relation to said tube; and means for energizing said filament to apply heat to said tube.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |