GB2226401A - Gas analysis apparatus - Google Patents
Gas analysis apparatus Download PDFInfo
- Publication number
- GB2226401A GB2226401A GB8829047A GB8829047A GB2226401A GB 2226401 A GB2226401 A GB 2226401A GB 8829047 A GB8829047 A GB 8829047A GB 8829047 A GB8829047 A GB 8829047A GB 2226401 A GB2226401 A GB 2226401A
- Authority
- GB
- United Kingdom
- Prior art keywords
- gas
- radiation
- sampling means
- analysis
- source
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000004868 gas analysis Methods 0.000 title claims description 15
- 230000005855 radiation Effects 0.000 claims abstract description 35
- 238000005070 sampling Methods 0.000 claims abstract description 20
- 239000002245 particle Substances 0.000 claims abstract 3
- 238000004458 analytical method Methods 0.000 claims description 10
- 238000000034 method Methods 0.000 claims description 6
- 239000011148 porous material Substances 0.000 claims 1
- 239000007789 gas Substances 0.000 description 22
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- QGJOPFRUJISHPQ-UHFFFAOYSA-N Carbon disulfide Chemical compound S=C=S QGJOPFRUJISHPQ-UHFFFAOYSA-N 0.000 description 2
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 2
- GQPLMRYTRLFLPF-UHFFFAOYSA-N Nitrous Oxide Chemical compound [O-][N+]#N GQPLMRYTRLFLPF-UHFFFAOYSA-N 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- LELOWRISYMNNSU-UHFFFAOYSA-N hydrogen cyanide Chemical compound N#C LELOWRISYMNNSU-UHFFFAOYSA-N 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 239000004291 sulphur dioxide Substances 0.000 description 2
- 235000010269 sulphur dioxide Nutrition 0.000 description 2
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 1
- YGYAWVDWMABLBF-UHFFFAOYSA-N Phosgene Chemical compound ClC(Cl)=O YGYAWVDWMABLBF-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 210000004027 cell Anatomy 0.000 description 1
- 210000002421 cell wall Anatomy 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 1
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 1
- 238000011545 laboratory measurement Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 1
- 239000001272 nitrous oxide Substances 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 238000005201 scrubbing Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910001868 water Inorganic materials 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3504—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
- G01N21/03—Cuvette constructions
- G01N21/031—Multipass arrangements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
- G01N21/03—Cuvette constructions
- G01N21/031—Multipass arrangements
- G01N2021/0314—Double pass, autocollimated path
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/47—Scattering, i.e. diffuse reflection
- G01N21/49—Scattering, i.e. diffuse reflection within a body or fluid
- G01N21/53—Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
- G01N21/534—Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke by measuring transmission alone, i.e. determining opacity
- G01N2021/536—Measurement device mounted at stack
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/85—Investigating moving fluids or granular solids
- G01N2021/8578—Gaseous flow
- G01N2021/8585—Gaseous flow using porous sheets, e.g. for separating aerosols
Abstract
The apparatus comprises a radiation source and radiation sensor means together with gas sampling means 10 through which the radiation passes lengthwise, and focusing reflection means 32, 34, 36 being provided to cause multiple passes of said radiation through the sampling means. Both the radiation source and sensor means are at the same end 16 of the apparatus, and the whole is adapted to be mounted directly on a gas stack through an anti-vibration mounting. Porous panels exclude particles in the gas from the apparatus. <IMAGE>
Description
GAS ANALYSIS
This invention relates to gas analysis. More particularly, but not exclusively, the invention relates to the analysis of low concentrations of emissions, on a continuous basis, in such gas flows as incinerator exhausts and other stack gas situations.
The measurement of low concentrations of gases such as pollutants in situations such as those mentioned above have hitherto been achieved by means of removal of gas samples and laboratory analysis of these.
There is disclosed in EP 0 243 139 A gas analysis apparatus capable of providing continuous analysis of stack gases. However, although that apparatus provides significant advantages over previous such apparatus, it is not capable of analysing the content in a gas stream of gases present only in a few tens of parts per million.
Accordingly, an object of the present invention is to provide gas analysis apparatus, and a method of using same, offering improvements in relation to one or more of these matters, or generally.
According to the invention there is provided gas analysis apparatus, and a method of gas analysis as defined in the accompanying claims.
In a preferred embodiment, a method and apparatus is provided to make on-line analysis of concentrations as low as 100 parts per million, and lower, without the need to take a sample for laboratory measurement. Multiple highly reflective surfaces in a sampling cell provide up to 10 metres of infra-red path lengths which permit the analysis of very low component concentrations. The apparatus enables the monitoring and checking of the performance of gas scrubbing plant. Among many components which can be analysed are hydrogen chloride, carbon monoxide, sulphur dioxide, ammonia and oxides of nitrogen. Up to 3 gases can be measured simultaneously.
In apreferred embodiment, apparatus providing a radiation source and radiation sensor means together with optical signal processing means enables cross-sensitivity, caused by interference from non-measured components in the gas stream to be largely eliminated. The apparatus also compensates for temperature-induced changes in gas volumes, a major problem in flue gas analysis. A robust casing enables use in aggressive environments.
Also in a preferred embodiment, using ultra-violet or infra-red absorption techniques, analysis at concentrations as low as 5 parts per million at an accuracy of up to plus or minus 2 per cent on a full scale deflection are obtainable. The apparatus can be flange-mounted directed into a stack or duct. A porous filter system allows the gas to diffuse through the cell walls, while preventing ingress of particulates to the optical components. The increased path length provided by the mirror system is an important contributor to the increased sensitivity.
Continuous measurement of up to 3 gases on one set of apparatus can be achieved. Gases which can be analysed include carbon monoxide, carbon dioxide, sulphur dioxide, nitric oxide, nitrogen dioxide, hydrogen cyanide, carbonyl chloride, carbon disulphide, ammonia, water and nitrous oxide.
An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:
Fig 1 shows a plan view of a gas analysis apparatus, including ray diagrams;
Fig 2 shows a longitudinal section through the apparatus of Fig 1, taken on the line II-II in Fig 1; and
Fig 3 shows a section on the line III-III in Fig 2, on a slightly larger scale.
As shown in the drawings, gas analysis apparatus 10 is adapted to be mounted on a stack 12 by means of rubber anti-vibration mountings 14. On the external side of stack wall 12 is a control unit 16. On the interior side of the stack wall is a sampling unit 18.
Control unit 16 is constructed and arranged as described in EP 0 243 139 A to which reference is hereby directed. The entire disclosure of the aforesaid specification is hereby incorporated in the present application as a part hereof. The control unit includes an ultra-violet or infra-red radiation source arranged to transmit radiation through the gas or gases to be analysed.
It also includes radiation sensor means.
The gas sampling unit 18 comprises a rectangular assembly including porous metallic side walls 20 positioned in relation to the direction D of gas flow through stack 12, so that the gas diffuses into the apparatus for analysis. The entire assembly is of a rugged and robust construction, as shown in Figs 1 and 3, comprising a generally rectangular framework 22 including tensioners 24, top and bottom plates 26, 28 and associated structures which need no further description. The entire assembly is mounted by means of resilient mountings 14 so as to be uninfluenced by vibration in use.
A main lens 30 directs radiation from control unit 16 through sampling unit 18 to mirrors 32, 34 and 36 in turn.
Fig 1 shows a part of the paths followed by the radiation as it passes between these mirrors. The result of the arrangement of mirrors is that the radiation describes a stepwise sequential series of paths lengthwise of unit 18, these paths being spaced apart across the width of mirror 34. Also, the mirrors 32 and 36 are set so as to reflect the radiation alternately up and down so that the points of reflection on mirror 34 are arranged in two paths of 5 points, one path above the other. The mirrors are position-adjustable so as to alter the attitude and exact location of each mirror to achieve the aforesaid path sequence. Adjustment is provided by means of inclined slots and fasteners. The mirrors themselves have concave reflective surfaces to provide optical focussing. The arrangement of the mirrors is such that a path length of about 10 metres is achieved. The exit beam of radiation passing through a portion of lens 30 slightly spaced, vertically, from the inlet beam.
In use, the above apparatus enables continuous monitoring of gas concentrations by means of the radiation intensity measurements provided by control unit 16. As will be understood, the construction is of considerable economy, and enables the advantages of the unit 16 to be considerably extended to the measurement of low gas concentrations without the attendant disadvantages of known prior apparatus for such purposes which has required separate laboratory processing of extracted gas samples.
Claims (10)
1 Gas analysis apparatus comprising:
a) a radiation source arranged to transmit radiation through a gas to be analysed;
b) gas sampling means positionable in relation to said radiation source to receive said radiation;
c) radiation sensor means arranged to receive radiation from said sampling means and to provide an output signal providing means for obtaining an analysis of said gas;
d) said gas sampling means being adapted to be mounted on or in a gas conduit so that gas within the conduit is received directly for sampling;
e) said radiation source and said radiation sensor means being located at the same inlet end of said gas sampling means with respect to the lengthwise direction of passage of said radiation therethrough; and
f) reflection means being provided at the other end of said gas sampling means with respect to said lengthwise direction to reflect radiation from said source to said sensor whereby said radiation passes lengthwise of said sampling means twice between said source and said sensor;
characterised by
g) further reflection means at said inlet end of said gas sampling means and co-operating with said reflection means to cause multiple passes of said radiation lengthwise of said gas sampling means before the radiation passes to said radiation sensor means.
2 Apparatus according to claim 1 characterised in that said reflection means comprise mirrors adapted to focus said radiation.
3 Apparatus according to claim 2 characterised in that said reflection means comprises concave mirrors.
4 Apparatus according to any one of claims 1 to 3 characterised in that said reflection means at said other end of said gas sampling means comprises a pair of mirrors, and at least some of said mirrors being positionadjustable to enable said radiation to describe a stepwise sequential series of paths lengthwise of said gas sampling means, said steps of said paths being spaced apart across at least one dimension of said reflection means at said inlet end.
5 Apparatus according to any one of the preceding claims characterised in that said gas sampling means comprises a gas permeable porous material serving to restrict ingress of particles contained in said gas to be analysed of 20 microns or larger particle size.
6 Apparatus according to any one of the preceding claims characterised by anti-vibration means to mount said apparatus directly on a gas stack or the like.
7 Gas analysis apparatus substantially as described herein with reference to and as shown in the accompanying drawings.
8 Gas analysis apparatus comprising a radiation source, radiation sensor means and gas sampling means, characterised in that multiple path reflection means transmits said radiation between said source and said sensor means, and said gas sampling means is adapted to be mounted directly on a gas stack or the like.
9 A method of gas analysis comprising:
a) providing apparatus according to any one of the preceding claims; and
b) using said apparatus to determine an analysis of said gas
characterised by the step of
c) mounting said apparatus directly on a gas stack or the like to analyse gas contained in or passing therethrough.
10 A method of gas analysis substantially as described herein with reference to the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8829047A GB2226401B (en) | 1988-12-13 | 1988-12-13 | Gas analysis |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8829047A GB2226401B (en) | 1988-12-13 | 1988-12-13 | Gas analysis |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8829047D0 GB8829047D0 (en) | 1989-01-25 |
| GB2226401A true GB2226401A (en) | 1990-06-27 |
| GB2226401B GB2226401B (en) | 1992-11-25 |
Family
ID=10648391
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8829047A Expired - Fee Related GB2226401B (en) | 1988-12-13 | 1988-12-13 | Gas analysis |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2226401B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2262338A (en) * | 1991-07-02 | 1993-06-16 | Stephen William Goom | Infra red gas detector |
| EP1106990A2 (en) * | 1999-12-10 | 2001-06-13 | Showa Denko Kabushiki Kaisha | Method for measuring water concentration in ammonia |
| GB2381579A (en) * | 2001-06-29 | 2003-05-07 | Draeger Safety Ag & Co Kgaa | Measuring instrument for determining the percentage of a component in a fluid |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3792272A (en) * | 1973-01-12 | 1974-02-12 | Omicron Syst Corp | Breath test device for organic components, including alcohol |
| GB1460612A (en) * | 1973-04-06 | 1977-01-06 | Perkin Elmer Corp | Confocal cavity optical gas sensor |
| GB1538833A (en) * | 1977-11-28 | 1979-01-24 | Adrian W | Device for measuring the concentration of gas |
| GB2035552A (en) * | 1978-11-29 | 1980-06-18 | Land Pyrometers Ltd | Radiation detection of gas compositions |
| EP0094706A2 (en) * | 1982-05-14 | 1983-11-23 | Combustion Developments Limited | Gas analyser |
| EP0123458A2 (en) * | 1983-04-05 | 1984-10-31 | Edinburgh Sensors Limited | An infrared absorption gas detector |
| US4560873A (en) * | 1983-06-17 | 1985-12-24 | Lear Siegler, Inc. | Situ multi-channel combustion gas analyzer |
| EP0203767A2 (en) * | 1985-05-20 | 1986-12-03 | Rosemount Analytical Inc. | Improved automated acousto-optic infra-red analyzer system for monotoring stack emissions |
| US4632563A (en) * | 1983-02-28 | 1986-12-30 | The Syconex Corporation | In-situ gas analyzer |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8609619D0 (en) * | 1986-04-19 | 1986-05-21 | Procal Analytics | Gas analysis |
-
1988
- 1988-12-13 GB GB8829047A patent/GB2226401B/en not_active Expired - Fee Related
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3792272A (en) * | 1973-01-12 | 1974-02-12 | Omicron Syst Corp | Breath test device for organic components, including alcohol |
| US3792272B1 (en) * | 1973-01-12 | 1986-07-22 | ||
| GB1460612A (en) * | 1973-04-06 | 1977-01-06 | Perkin Elmer Corp | Confocal cavity optical gas sensor |
| GB1538833A (en) * | 1977-11-28 | 1979-01-24 | Adrian W | Device for measuring the concentration of gas |
| GB2035552A (en) * | 1978-11-29 | 1980-06-18 | Land Pyrometers Ltd | Radiation detection of gas compositions |
| EP0094706A2 (en) * | 1982-05-14 | 1983-11-23 | Combustion Developments Limited | Gas analyser |
| US4632563A (en) * | 1983-02-28 | 1986-12-30 | The Syconex Corporation | In-situ gas analyzer |
| EP0123458A2 (en) * | 1983-04-05 | 1984-10-31 | Edinburgh Sensors Limited | An infrared absorption gas detector |
| US4560873A (en) * | 1983-06-17 | 1985-12-24 | Lear Siegler, Inc. | Situ multi-channel combustion gas analyzer |
| EP0203767A2 (en) * | 1985-05-20 | 1986-12-03 | Rosemount Analytical Inc. | Improved automated acousto-optic infra-red analyzer system for monotoring stack emissions |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2262338A (en) * | 1991-07-02 | 1993-06-16 | Stephen William Goom | Infra red gas detector |
| EP1106990A2 (en) * | 1999-12-10 | 2001-06-13 | Showa Denko Kabushiki Kaisha | Method for measuring water concentration in ammonia |
| GB2381579A (en) * | 2001-06-29 | 2003-05-07 | Draeger Safety Ag & Co Kgaa | Measuring instrument for determining the percentage of a component in a fluid |
| GB2381579B (en) * | 2001-06-29 | 2005-02-02 | Draeger Safety Ag & Co Kgaa | An optical absorptiometer |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2226401B (en) | 1992-11-25 |
| GB8829047D0 (en) | 1989-01-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20071213 |