US4471220A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for monitoring trace gaseous ammonia concentration in flue gases
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1981-12-21
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Granted: 1984-09-11
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Expires: 2001-12-21
Abstract
Abstract A system is disclosed for monitoring the concentration of gaseous ammonia in flue gases by simultaneously measuring the temperature and optical transmission of a flue gas-ammonia mixture.
Inventors
- 👤 Bruce N. Perry
- 👤 Alexander Stein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:00
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/39; G01N33/00; G01N33/0004; G01N33/0009; G01N33/0027; G01N33/0036; G01N21/84; G01N21/85
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
205 words
A system for monitoring gaseous ammonia concentration in flue gases comprising: (a) a first laser means which emits radiation at about 927.30 cm -1 which is selectively absorbed by ammonia but not spectrally selectively absorbed by any substance in said flue gases said flue gases including more than about 10% CO 2 and more than about 8% H 2 O; (b) a second laser means which emits radiation which is not spectrally selectively absorbed by ammonia or by said flue gases; (c) means to measure the temperature of said flue gases; (d) means to modulate the output radiations of each of said first and second laser means; (e) means to measure each of the powers of the output radiations of said first and second laser means; (f) means to combine and direct a portion of each of said output radiations onto a common optical path through said flue gases; (g) means to measure the powers of each of said portion of said radiations after passing through said flue gases; (h) means to electronically measure the absorption of said radiations; and (i) means for computing the absolute concentration of said ammonia from said measurements of said absorption of said radiation and said measurements of said temperature.
Claim 2
Independent Claim
205 words
A system for monitoring gaseous ammonia concentration in flue gases comprising: (a) a first laser means which emits radiation at about 927.30 cm -1 which is selectively absorbed by ammonia but not spectrally selectively absorbed by any substance in said flue gases said flue gases including more than about 10% CO 2 and more than about 8% H 2 O; (b) a second laser means which emits radiation which is not spectrally selectively absorbed by ammonia or by said flue gases; (c) means to measure the temperature of said flue gases; (d) means to modulate the output radiations of each of said first and second laser means; (e) means to measure each of the powers of the output radiations of said first and second laser means; (f) means to combine and direct a portion of each of said output radiations onto a common optical path through said flue gases; (g) means to measure the powers of each of said portion of said radiations after passing through said flue gases; (h) means to electronically measure the absorption of said radiations; and (i) means for computing the absolute concentration of said ammonia from said measurements of said absorption of said radiation and said measurements of said temperature.
Claim 3
Dependent Claim
13 words
The system of claim 1 wherein said laser means are CO 2 lasers.
Claim 4
Dependent Claim
17 words
The system of claim 1 wherein said second laser means emits radiation at 924.53 cm -1 .
References Cited (Backward Citations)
US3766380A
Cited
US3958122A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-09-11 | 1988-03-12 | 1988-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-11 | 1992-03-12 | 1992-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-11 | 1996-03-12 | 1996-09-11 | $7700.00 | Window Closed / Lapsed |