GB2391622A - Protecting gas sensors from condensation - Google Patents
Protecting gas sensors from condensation Download PDFInfo
- Publication number
- GB2391622A GB2391622A GB0217680A GB0217680A GB2391622A GB 2391622 A GB2391622 A GB 2391622A GB 0217680 A GB0217680 A GB 0217680A GB 0217680 A GB0217680 A GB 0217680A GB 2391622 A GB2391622 A GB 2391622A
- Authority
- GB
- United Kingdom
- Prior art keywords
- filter
- screen
- mesh
- open
- gas
- 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
- 230000005494 condensation Effects 0.000 title claims abstract description 21
- 238000009833 condensation Methods 0.000 title claims abstract description 21
- 239000006260 foam Substances 0.000 claims abstract description 8
- 239000007769 metal material Substances 0.000 claims abstract description 4
- 239000010935 stainless steel Substances 0.000 claims abstract description 3
- 229910001220 stainless steel Inorganic materials 0.000 claims abstract description 3
- 239000011148 porous material Substances 0.000 claims description 8
- 229920003023 plastic Polymers 0.000 claims description 4
- 239000004033 plastic Substances 0.000 claims description 4
- 229910045601 alloy Inorganic materials 0.000 claims description 3
- 239000000956 alloy Substances 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 2
- 239000002984 plastic foam Substances 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 28
- 238000009434 installation Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/02—Particle separators, e.g. dust precipitators, having hollow filters made of flexible material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/0027—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with additional separating or treating functions
- B01D46/003—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with additional separating or treating functions including coalescing means for the separation of liquid
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/0004—Gaseous mixtures, e.g. polluted air
- G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
- G01N33/0011—Sample conditioning
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Food Science & Technology (AREA)
- Medicinal Chemistry (AREA)
- Combustion & Propulsion (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Sampling And Sample Adjustment (AREA)
Abstract
Condensation build-up on gas sensors is alleviated by a device comprising a filter 1 which at least partially surrounds the sensor 8 and a screen 2 which at least partially surrounds the filter. The filter may comprise a mesh or open cell foam of non-metallic material e.g. open cell plastic foam and the screen may be of stainless steel.
Description
239 1 622
Condensation Filter Description
s This invention relates to condensation filters and especially, but not exclusively, to such filters for use in preventing moisture build-up on gas 10 sensors, for example, by providing a filter around the gas sensors.
Gas sensors, such as those commonly used for detecting environmental gases, for example, methane 15 or other volatile hydrocarbons and carbon dioxide, are often used in areas where there is high humidity. If a gas in the atmosphere is to be detected, 20 there must be a free air passage into the sampling or measuring chamber. An undesirable consequence of this free air passage is that water vapour can also enter the sampling or measuring chamber.
25 In some applications, typically offshore or in coastal installations, the relative humidity can reach 90%=RH, depending on local conditions.
High or changing humidity levels, such as those 30 experienced in offshore installations, cause problems with gas sensors because such sensors generally run at temperatures which are cooler than the ambient environment. The lower temperature of the gas sensor causes water droplets to condense
( thereon, which, in turn, disrupts the optical sensor signals to produce false readings False readings caused by condensation can have 5 serious safety implications, for example, if the sensor is used for flammable gas hazard detection on a safety critical installation, such as an oil or gas production platform offshore, an incorrect reading could lead to a serious accident.
Several solutions to this problem have been sought, for example, the gas sensor can be surrounded with an electric heater or other heating device to warm the sensor to at least the same 15 temperature as the surrounding air so that condensation does not form. Another solution to the problem has been to pass larger currents through the gas sensor than is actually required, this causes the gas sensor to warm up, again tending to prevent 20 condensation build-up.
Although both of these solutions can prevent condensation build-up on gas sensors, therefore preventing false readings, they do have a 25 disadvantage in that the cost of running the equipment is higher than necessary due to the larger amounts of power required.
Accordingly it is an object of the present 30 invention to overcome, or at least substantially reduce, the disadvantages associated with known
types of condensation filter for gas sensors, as claimed above.
Accordingly, the present invention provides 5 apparatus for preventing, or at least substantially reducing, condensation build-up on a gas sensor, comprising: a filter arranged to at least partially surround a gas sensor; and 10 a screen associated with the filter and arranged to at least partially surround the filter.
Preferably, the filter comprises a mesh or open cell foam of non-metallic material, for 15 example, a plastics material such as an expanded, open cell plastics foam. The foam may be of any suitable pore size but preferably the pores are 0.2 mm to 1.8mm, more preferably 0.5 mm to 1.5mm, even more preferably 0.8mm to 1.2mm and most preferably 20 1.Omm.
The screen is preferably a mesh constructed from any suitable metal or alloy, for example stainless steel. The mesh may be open in structure, 25 preferably 20 to 90% open, even more preferably 35 to 80% open and most preferably 40 to 75% open.
The screen may further comprise pliable tabs which, in use, may be used to attach the screen to 30 the filter.
( -4 The screen and/or the filter may be constructed in separate lengths such that they can be applied to existing gas sensors by being wrapped around them.
Preferably, the screen and/or filter further 5 comprises securing means to allow it or them to be i secured around a gas sensor to be protected.
In order that the invention may be more fully understood, a preferred embodiment of condensation 10 filter apparatus in accordance therewith, will now be described by way of example only and with reference to the accompanying drawings, in which; Figure l is a view of the two components 15 of condensation filter apparatus for protecting a gas sensor; Figure 2 is a perspective view of the assembled components of the condensation filter 20 apparatus shown in Figure l; Figure 3 is a perspective view of the condensation filter apparatus being positioned around a gas sensor; and Figure 4 is a perspective view of the condensation filter apparatus wholly positioned around a gas sensor in use.
30 As shown in Figure l, condensation filter apparatus for protecting a gas sensor from
{.. -s condensation build-up comprises a filter pad 1 and a screen indicated generally at 2.
The filter pad 1 comprises an open cell foam 5 structure and is preferably made of a suitable non-
metallic material. The pores of the filter pad 1 are preferably 1.0mm in diameter but any pore size which allows for diffusion of the gas to be sampled and/or measured is suitable.
The screen 2 is made of an open mesh 4 constructed from any suitable metal or alloy.
Preferably, the mesh is 40 to 75% open but this may vary. Pliable tabs 6 are arranged along the edges 15 of the screen 2. This allows the screen 2 and the filter pad 1 to be secured together, as shown in Figure 2, for location around a gas sensor.
The filter pad 1 and screen 2 are wrapped 20 around a gas sensor 8, as shown in Figure 3, such that the gas sensor 8 is at least partially surrounded by the assembled condensation filter apparatus. 25 The screen 2 further comprises securing means 10 to allow its ends to be secured around the gas sensor 8, as shown in Figure 4, thereby enclosing the filter pad 1 between the gas sensor 8 and the screen 4.
Claims (1)
- -6 CLAIMS1. Apparatus for preventing, or at least substantially reducing, condensation build-up on a gas 5 sensor, comprising: a filter arranged to at least partially surround gas sensor; and 10 a screen associated with the filter and arranged to at least partially surround the filter.2. Apparatus according to claim 1, wherein the filter comprises a mesh or open cell foam of non-l' metallic material, for example, a plastics material such as an expanded, open cell plastics foam.3. Apparatus according to claim 2 wherein the foam is of a pore size of 0. 2mm to 1.8mm.4. Apparatus according to claim 3, wherein the pore size is of 0.5mm to 1. 5mm.5. Apparatus according to claim 4, wherein the pore 25 size is of 0.8mm to 1.2mm.6. Apparatus according to claim 5, wherein the pore size is of l.Omm.30 7. Apparatus according to any preceding claim, wherein the screen is a mesh constructed from metal or alloy, for example stainless steel.. -'I( -7- 8. Apparatus according to claim 7, wherein the mesh is open in structure.5 9. Apparatus according to claim 8, wherein the mesh is 20 to 90% open.10. Apparatus according claim 9, wherein the mesh is 35 to 80 open.11. Apparatus according to claim 10, wherein the mesh is 40 to 75% open.12. Apparatus according to any preceding claim, 15 wherein the screen further comprises pliable tabs which, in use, can be used to attach the screen to the filter. ]3. Apparatus according to any preceding claim, 20 wherein the screen and/or the filter are constructed in separate lengths, such that it or they can be applied to existing gas sensors by being wrapped around them.25 14. Apparatus according to any preceding claim, wherein the screen and/or filter further comprises securing means to allow it or them to be secured around a gas sensor to be protected.30 15. Apparatus for preventing, or at least substantially reducing, condensation build-up on a gas-8 sensor, substantially as hereinbefore described with reference to the accompanying drawings.16. A gas sensor when protected by apparatus according to any preceding claim.17. In combination, a gas sensor protected by anti-condensation build-up apparatus, substantially as hereinbefore claimed with reference to the 10 accompanying drawings..
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0217680A GB2391622B (en) | 2002-07-31 | 2002-07-31 | Condensation filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0217680A GB2391622B (en) | 2002-07-31 | 2002-07-31 | Condensation filter |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB0217680D0 GB0217680D0 (en) | 2002-09-11 |
| GB2391622A true GB2391622A (en) | 2004-02-11 |
| GB2391622B GB2391622B (en) | 2005-07-27 |
Family
ID=9941409
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0217680A Expired - Fee Related GB2391622B (en) | 2002-07-31 | 2002-07-31 | Condensation filter |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2391622B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7089781B2 (en) * | 2003-11-04 | 2006-08-15 | Honeywell International, Inc. | Detector with condenser |
| EP1950281A1 (en) * | 2007-01-29 | 2008-07-30 | Fp Sensor Systems GmbH | Measuring device for determining the activity of a fermentation process |
| CN106880992A (en) * | 2017-02-16 | 2017-06-23 | 大连艾科科技开发有限公司 | Laser sensing is popped one's head in and its filtering screen |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63132152A (en) * | 1986-11-21 | 1988-06-04 | Ngk Insulators Ltd | Protective filter for humidity sensor |
| JPS63142253A (en) * | 1986-12-05 | 1988-06-14 | Fujikura Ltd | Waterproof type gas sensor |
| WO2003038421A1 (en) * | 2001-11-01 | 2003-05-08 | Advanced Technology Materials, Inc. | A system and method for detecting hydride gases at low concentrations and in the presence of varying humidity levels |
| WO2003040717A1 (en) * | 2001-10-31 | 2003-05-15 | Robert Bosch Gmbh | Sensor for determining an oxygen concentration in gases |
| WO2003067241A2 (en) * | 2002-02-05 | 2003-08-14 | Stefan Felix Raible | Gas sensor and method for producing the same |
-
2002
- 2002-07-31 GB GB0217680A patent/GB2391622B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63132152A (en) * | 1986-11-21 | 1988-06-04 | Ngk Insulators Ltd | Protective filter for humidity sensor |
| JPS63142253A (en) * | 1986-12-05 | 1988-06-14 | Fujikura Ltd | Waterproof type gas sensor |
| WO2003040717A1 (en) * | 2001-10-31 | 2003-05-15 | Robert Bosch Gmbh | Sensor for determining an oxygen concentration in gases |
| WO2003038421A1 (en) * | 2001-11-01 | 2003-05-08 | Advanced Technology Materials, Inc. | A system and method for detecting hydride gases at low concentrations and in the presence of varying humidity levels |
| WO2003067241A2 (en) * | 2002-02-05 | 2003-08-14 | Stefan Felix Raible | Gas sensor and method for producing the same |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7089781B2 (en) * | 2003-11-04 | 2006-08-15 | Honeywell International, Inc. | Detector with condenser |
| US7360397B2 (en) * | 2003-11-04 | 2008-04-22 | Honeywell International, Inc. | Detector with condenser |
| EP1950281A1 (en) * | 2007-01-29 | 2008-07-30 | Fp Sensor Systems GmbH | Measuring device for determining the activity of a fermentation process |
| CN106880992A (en) * | 2017-02-16 | 2017-06-23 | 大连艾科科技开发有限公司 | Laser sensing is popped one's head in and its filtering screen |
| CN106880992B (en) * | 2017-02-16 | 2019-09-06 | 大连艾科科技开发有限公司 | Laser sensing probe and its filtering screen |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2391622B (en) | 2005-07-27 |
| GB0217680D0 (en) | 2002-09-11 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20100731 |