EP1089032B1 - Method and device for avoiding contamination from a gas pipeline system - Google Patents
Method and device for avoiding contamination from a gas pipeline system Download PDFInfo
- Publication number
- EP1089032B1 EP1089032B1 EP00203221A EP00203221A EP1089032B1 EP 1089032 B1 EP1089032 B1 EP 1089032B1 EP 00203221 A EP00203221 A EP 00203221A EP 00203221 A EP00203221 A EP 00203221A EP 1089032 B1 EP1089032 B1 EP 1089032B1
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- Prior art keywords
- gas
- pressure
- pressure value
- pipe
- pression
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- 238000000034 method Methods 0.000 title claims description 17
- 238000011109 contamination Methods 0.000 title claims description 6
- 239000007789 gas Substances 0.000 claims description 61
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 16
- 229910052786 argon Inorganic materials 0.000 claims description 8
- 239000012535 impurity Substances 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 3
- 239000001307 helium Substances 0.000 claims description 2
- 229910052734 helium Inorganic materials 0.000 claims description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 2
- 238000009434 installation Methods 0.000 description 10
- 238000012423 maintenance Methods 0.000 description 6
- 230000003797 telogen phase Effects 0.000 description 5
- 238000003466 welding Methods 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 239000003570 air Substances 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000000356 contaminant Substances 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 238000010926 purge Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 241000894006 Bacteria Species 0.000 description 1
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 1
- 101100536354 Drosophila melanogaster tant gene Proteins 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 239000012080 ambient air Substances 0.000 description 1
- 230000001580 bacterial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000005121 nitriding Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000006213 oxygenation reaction Methods 0.000 description 1
- 238000010422 painting Methods 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 229910000679 solder Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000010025 steaming Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 230000003612 virological effect Effects 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17D—PIPE-LINE SYSTEMS; PIPE-LINES
- F17D5/00—Protection or supervision of installations
- F17D5/02—Preventing, monitoring, or locating loss
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17D—PIPE-LINE SYSTEMS; PIPE-LINES
- F17D1/00—Pipe-line systems
- F17D1/02—Pipe-line systems for gases or vapours
- F17D1/04—Pipe-line systems for gases or vapours for distribution of gas
Definitions
- the present invention relates to a method and an installation to avoid or minimize the entry of gaseous impurities present in the ambient air, in particular water vapor, hydrocarbons or the like, within a gas pipeline or network of where the pipeline or the pipe network is in the stop or rest phase, that is to say when the gas is not consumed by one or more user sites downstream of the pipeline, for example during nights or weekends (weekends).
- industrial gases are stored on site in the form of gaseous or liquefied form in storage containers, such as pressurized cylinders, tanks, capacities or the like; source gas being connected to one or more user sites consuming said gas, via one or more gas pipes conveying said gas.
- the gas can be routed to different sites users either via a single channel, possibly branched, or via several pipes forming a network.
- US-A-5,866,802 proposes a leak detection device in a gas pipeline for measuring the pressure in the pipeline and to determine, from that measure, any pressure drop in the pipe while the gas is not used; such a pressure drop corresponding to a leak.
- the user sites consume gas and therefore the interior of the pipes is swept, almost permanently, by a flow of gas under pressure, that is to say, in general, at a pressure greater than the atmospheric pressure prevailing outside the pipes.
- the pollutants are, in particular, O 2 , N 2 , H 2 O, but also hydrocarbons , paintings suspended in the air ...
- the present invention aims to solve the above problems lectures on harmful inputs of atmospheric compounds undesirable effects in gas pipelines during the shutdown or shutdown phases. rest, during which user sites do not consume or low amounts of gas.
- the means for determining the pressure are chosen among the pressure sensors and / or in that the adjustment means of pressure comprise a valve, preferably a solenoid valve.
- control means comprise a unit of programmable logic controller type.
- the attached figure represents an installation according to the invention, given for illustrative purposes, but not limiting.
- the installation comprises, in pipe head, a device that helps maintain the pipeline main 1 always under a low overpressure between 0.3 and 0.5 bar, when the user site 4 of gas does not consume gas (for example the night or weekends).
- This main line 1 is supplied with gas from the source of gas 14, for example argon, CO2, nitrogen or oxygen, and conveys this gas to the user site 4, the gas being at the outlet of a cold evaporator (not shown) at an outlet pressure (Pef). Moreover, adjustment of the working pressure (P1) of the gas circulating therein is effected by means of regulator 3; usually, the working pressure (P1) is between 2 and 15 bar.
- the solenoid valve 7 is closed by actuating a means of remote control 16, such as a switch.
- the installation furthermore comprises a bypass line 1 'within which has a maintenance pressure (Pbp) whose level is set at means of the expander 11, for example at a pressure (Pbp) of between 0.3 bar and pressure (Pl) work.
- Pbp maintenance pressure
- Pbp is between 0.3 and 0.6 bar.
- the rule of Pbp depends on the type of user site 4, that is to say the type of downstream application using the gas.
- the gas travels source 14 to user 4, via the main line 1.
- line 1 is closed by the valve 7 and, in case of loss of gas, that is to say if the pressure (Pl) becomes less than the maintenance pressure (Pbp) then a flow rate of gas passes in the line 1 'of bypass, so as to ensure a maintenance in pressure of line 1 and thus to avoid the entry of atmospheric impurities in the pipeline circuit.
- Pl pressure
- Pbp maintenance pressure
- the valve 12 makes it possible to guarantee, in line 1 ', a flow rate of adjustable maintenance, for example from 3 to 30 l / min.
- a pressure sensor 6 arranged on the main line 1 detects this sudden drop in pressure, (for example if Pbp ⁇ 0.2 bar) and then triggering an alarm, such as a light signal 17 on a control cabinet 18.
- the operator immediately knows that the impurity inputs in line 1 were important and it is therefore desirable to perform a purge before starting to work, that is, using gas, because it may be impure.
- a pressure sensor can be used to constantly check the pressure and to order a solenoid valve from flow rate of the gas used, when the pressure drops below a preset threshold.
- a flow control valve for example a faucet micrometric, allows to adjust a controlled leakage rate if the sensor detects a pressure drop in the network. This leakage rate is adjustable in function of the process used.
- the leak is signaled either by a control box 17 by a light signal which can be brought back to a certain place, either by a signal transmitted by telemonitoring to an entity providing control and / or supervision of installation to bring the installation back into compliance.
- the system can be controlled by a PLC (Controlleur Programmable Logic) which, depending on the input data, for example the pressure or the rate of pressure decrease in the pipeline, will make an adjustment of the opening or closing, and / or the adjustment of valves proportional flow control.
- PLC Controlleur Programmable Logic
- the system may also include a flowmeter / regulator solid flow with electronic control unit to perform the functions mentioned above for the PLC.
- This solution has the advantage of securing the entire installation and avoid the use of leak detectors on multiple gas plugs present in the workshop, not suitable for remote monitoring.
- the plant and method according to the invention can be applied to various purposes, such as welding of aluminum, or steel.
- the welding can be started, without purging the high flow, even after a long break, like a weekend, and avoids, in addition, the safety problem related to under-oxygenation possible from the working atmosphere.
- welds made from the start have the required quality if the customer has taken precautions the process as a whole: steaming of the wire, etching of sheets just before use ...
- a leakage flow ensures maintenance of the quality of the welding gas, while avoiding an expensive repair of the network that can reach 1 to 2 km total.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
- Pipeline Systems (AREA)
- Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
Description
La présente invention concerne un procédé et une installation permettant d'éviter ou de minimiser les entrées d'impuretés gazeuses présentes dans l'air ambiant, en particulier la vapeur d'eau, les hydrocarbures ou analogues, à l'intérieur d'une canalisation de gaz ou d'un réseau de canalisations de gaz, lorsque la canalisation ou le réseau de canalisations est en phase d'arrêt ou de repos, c'est-à-dire lorsque le gaz n'est pas consommé par un ou des sites utilisateurs situés en aval de la canalisation, par exemple pendant les nuits ou les fins de semaines (week-end).The present invention relates to a method and an installation to avoid or minimize the entry of gaseous impurities present in the ambient air, in particular water vapor, hydrocarbons or the like, within a gas pipeline or network of where the pipeline or the pipe network is in the stop or rest phase, that is to say when the gas is not consumed by one or more user sites downstream of the pipeline, for example during nights or weekends (weekends).
Actuellement, les gaz industriels sont mis en oeuvre dans de nombreux procédés industriels, par exemple dans les domaines du soudage, de l'électronique, de la santé, de la combustion ...Currently, industrial gases are implemented in many industrial processes, for example in the fields of welding, electronics, health, combustion ...
En général, les gaz industriels sont stockés, sur site, sous forme gazeuse ou sous forme liquéfiée dans des récipients de stockage, tels que des bouteilles sous pression, des réservoirs, des capacités ou analogues; la source de gaz étant reliée à un ou plusieurs sites utilisateurs consommant ledit gaz, par l'intermédiaire d'une ou plusieurs canalisations de gaz véhiculant ledit gaz.In general, industrial gases are stored on site in the form of gaseous or liquefied form in storage containers, such as pressurized cylinders, tanks, capacities or the like; source gas being connected to one or more user sites consuming said gas, via one or more gas pipes conveying said gas.
En d'autres termes, le gaz peut être acheminé jusqu'aux différents sites utilisateurs soit via une canalisation unique, éventuellement ramifiée, soit via plusieurs canalisations formant un réseau.In other words, the gas can be routed to different sites users either via a single channel, possibly branched, or via several pipes forming a network.
Dans certains cas, il est nécessaire de contrôler les pertes éventuelles de gaz dans la ou les canalisations. Ainsi, le document US-A-5, 866, 802 propose un dispositif de détection de fuite dans une canalisation de gaz permettant de mesurer la pression dans la canalisation et de déterminer, à partir de cette mesure, toute chute de pression dans la canalisation alors que le gaz n'est pas utilisé ; une telle chute de pression correspondant à une fuite.In some cases, it is necessary to control any gas losses in the pipe or pipes. Thus, US-A-5,866,802 proposes a leak detection device in a gas pipeline for measuring the pressure in the pipeline and to determine, from that measure, any pressure drop in the pipe while the gas is not used; such a pressure drop corresponding to a leak.
Dans certaines applications, il est nécessaire de garantir que le gaz a une pureté ou une qualité prédéterminée, par exemple :
- pour obtenir un joint de soudure exempt de nitrurations ou d'oxydations dans le cas d'un procédé de soudage,
- pour éviter des problèmes de contamination, notamment bactérienne ou virale, lorsque le gaz est mis en oeuvre dans le domaine alimentaire ou médical,
- pour pouvoir être utilisé à des fins d'analyses fines, notamment dans les laboratoires de recherche,
- pour permettre son utilisation en tant qu'atmosphère de refroidissement de circuits comprimés, dans le domaine électronique ...
- to obtain a solder joint without nitriding or oxidation in the case of a welding process,
- to avoid contamination problems, especially bacterial or viral, when the gas is used in the food or medical field,
- to be used for fine analysis, especially in research laboratories,
- to allow its use as a cooling atmosphere of compressed circuits, in the electronic field ...
Or, il a été constaté, en pratique, qu'un problème de contamination de ou des canalisations véhiculant le gaz était susceptible d'apparaítre durant les phases d'arrêt ou de repos des installations, notamment durant les nuits ou les week-ends, c'est-à-dire pendant les périodes de temps durant lesquelles les sites utilisateurs ne consomment pas ou peu de gaz.In practice, however, it has been found that a problem of contamination of or pipelines carrying the gas was likely to occur during the stop or rest phases of the installations, especially during the nights or weekends, that is to say during the periods of time during which user sites do not consume or little gas.
En effet, pendant les phases de travail, les sites utilisateurs consomment du gaz et donc l'intérieur des canalisations est balayé, en quasi-permanence, par un flux de gaz sous pression, c'est-à-dire, en général, à une pression supérieure à la pression atmosphérique régnant à l'extérieur des canalisations.Indeed, during the work phases, the user sites consume gas and therefore the interior of the pipes is swept, almost permanently, by a flow of gas under pressure, that is to say, in general, at a pressure greater than the atmospheric pressure prevailing outside the pipes.
Dès lors, quasiment aucune entrée de contaminants n'est possible.Therefore, almost no entry of contaminants is possible.
Par contre, il en va tout autrement durant les phases de repos ou d'arrêt de l'installation.On the other hand, it is quite different during the phases of rest or stop of the installation.
En effet, durant les phases d'arrêt ou de repos, il a été observé que les canalisations étaient sujettes à des entrées de composés gazeux néfastes ou indésirables, étant donné que, durant ces phases, la pression régnant à l'intérieur des canalisations est susceptible de chuter jusqu'à atteindre environ la pression atmosphèrique (105 Pa) et que, dès lors, des contaminants peuvent s'y infiltrer par différents sites d'entrées potentiels.Indeed, during the shutdown or rest phases, it has been observed that the pipelines were subject to harmful or undesirable gaseous compound entries, since during these phases the pressure inside the pipelines is likely to fall to approximately atmospheric pressure (10 5 Pa) and that, therefore, contaminants may infiltrate through different potential entry sites.
Parmi les sites ou causes possibles d'entrée d'impuretés, on peut citer les robinets qui peuvent rester ouverts, les canalisations pouvant présenter un manque d'étanchéité au niveau de raccords dévissés ou mal vissés, les flexibles branchés aux canalisations présentant des phénomènes de vieillissement devenant ainsi perméables dans une certaine mesure à certaines molécules, les flexibles endommagés ...Among the possible sites or causes of entry of impurities, mention may be made of taps that can remain open, pipes that may have lack of tightness at unscrewed or incorrectly screwed connections, hoses connected to the pipes presenting phenomena of aging thus becoming permeable to some extent to some molecules, the damaged hoses ...
Par exemple, dans le cas d'une canalisation acheminant de l'argon gazeux entre une source d'argon et une machine de soudage, les agents polluants sont, en particulier, O2, N2, H2O, mais aussi les hydrocarbures, les peintures en suspension dans l'air ...For example, in the case of a pipe conveying argon gas between a source of argon and a welding machine, the pollutants are, in particular, O 2 , N 2 , H 2 O, but also hydrocarbons , paintings suspended in the air ...
De manière analogue, dans le cas d'un gaz combustible, tels les GPL, l'acétylène ou l'hydrogène ..., un sérieux problème se pose vis-à-vis des intrusions d'oxygène de l'air dans la canalisation.In the same way, in the case of a combustible gas, such as LPG, acetylene or hydrogen ..., a serious problem arises with regard to oxygen intrusions from the air into the pipeline.
En effet, dans ce cas, à chaque fois que l'on ouvre la ligne de gaz combustible, il apparaít un risque important de formation de mélanges oxycombustibles dangereux dans la canalisation.Indeed, in this case, each time we open the gas line fuel, there is a significant risk of mixing dangerous oxyfuels in the pipeline.
En résumé, la présente invention vise à résoudre les problèmes ci-dessus exposés relatifs aux entrées néfastes de composés atmosphériques indésirables dans les canalisations de gaz, durant les phases d'arrêt ou de repos, pendant lesquelles les sites utilisateurs ne consomment pas ou que de faibles quantités de gaz.In summary, the present invention aims to solve the above problems lectures on harmful inputs of atmospheric compounds undesirable effects in gas pipelines during the shutdown or shutdown phases. rest, during which user sites do not consume or low amounts of gas.
La présente invention concerne alors un procédé pour éviter ou
minimiser une contamination par une ou plusieurs impuretés gazeuses
susceptibles d'être présentes dans l'atmosphère ambiante, pendant au moins
une période de temps durant laquelle un site utilisateur ne consomme pas ledit
gaz, d'au moins une portion d'au moins une canalisation de gaz susceptible de
véhiculer ledit gaz entre au moins une source de gaz et ledit site utilisateur
utilisant ledit gaz, dans lequel :
Selon le cas, le procédé de l'invention peut comprendre une ou plusieurs des caractéristiques suivantes :
- il comporte, en outre, une étape de comparaison de la valeur de pression (Vpd) déterminée à l'étape (a) avec au moins la valeur de pression minimale (Vpo) préfixée.
- il comporte, en outre, une étape de comparaison de la valeur de pression (Vpd) déterminée à l'étape (a) avec au moins la valeur de pression maximale (Vpm) préfixée.
- la valeur de pression minimale (Vpo) est inférieure ou égale à 1,5.105 Pa et la valeur de pression maximale (Vpm) est supérieure ou égale à 1,5.105 Pa et inférieure à 3.105 Pa.
- la plage de valeurs de pressions minimale (Vpo) et maximale (Vpm) est d'environ 1,1.105 Pa à environ 1,8.105 Pa, de préférence de 1,3.105 Pa à environ 1,5.105 Pa.
- le gaz est choisi parmi l'argon, l'hélium ou leurs mélanges.
- on maintient, en outre, un débit de fuite compris entre 3 et 30 l.min-1.
- it further comprises a step of comparing the pressure value (Vpd) determined in step (a) with at least the minimum pressure value (Vpo) prefixed.
- it further comprises a step of comparing the pressure value (Vpd) determined in step (a) with at least the maximum pressure value (Vpm) prefixed.
- the minimum pressure value (Vpo) is less than or equal to 1.5 × 10 5 Pa and the maximum pressure value (Vpm) is greater than or equal to 1.5 × 10 5 Pa and less than 3.10 5 Pa.
- the range of values of minimum (Vpo) and maximum (Vpm) pressures is from about 1.10 5 Pa to about 1.8 x 10 5 Pa, preferably from 1.3 x 10 5 Pa to about 1.5 x 10 5 Pa.
- the gas is selected from argon, helium or mixtures thereof.
- in addition, a leakage rate of between 3 and 30 l.min -1 is maintained.
L'installation susceptible de mettre en oeuvre ce procédé comporte :
- au moins une canalisation de gaz permettant de véhiculer un gaz entre au moins une source de gaz et au moins un site utilisateur,
- des moyens de détermination de la pression régnant à l'intérieur d'au moins une portion de ladite canalisation, pendant ladite période de temps,
- des moyens de pilotage reliés auxdits moyens de détermination de la pression permettant de comparer la valeur de pression mesurée à une valeur de pression minimale (Vpo) préfixée supérieure à 105 Pa et une valeur de pression maximale (Vpm) préfixée supérieure à la valeur de pression minimale (Vpo),
- des moyens d'ajustage de pression permettant d'ajuster ou de maintenir la pression régnant dans au moins ladite portion de canalisation entre lesdites valeur de pression minimale (Vpo) et valeur de pression maximale (Vpm) préfixées, en agissant en réponse auxdits moyens de pilotage de manière à introduire une quantité contrôlée de gaz sous pression dans au moins ladite portion de canalisation.
- at least one gas pipe for conveying a gas between at least one gas source and at least one user site,
- means for determining the pressure prevailing inside at least a portion of said pipe during said period of time,
- control means connected to said pressure determining means making it possible to compare the measured pressure value with a prefixed minimum pressure value (Vpo) greater than 10 5 Pa and a prefixed maximum pressure value (Vpm) greater than the value of minimum pressure (Vpo),
- pressure adjusting means for adjusting or maintaining the pressure prevailing in at least said pipe portion between said minimum pressure value (Vpo) and the predetermined maximum pressure value (Vpm), by acting in response to said pressure means; control to introduce a controlled amount of pressurized gas into at least said portion of pipe.
De préférence, les moyens de détermination de la pression sont choisis parmi les capteurs de pression et/ou en ce que les moyens d'ajustage de pression comprennent une vannes, de préférence une électrovanne.Preferably, the means for determining the pressure are chosen among the pressure sensors and / or in that the adjustment means of pressure comprise a valve, preferably a solenoid valve.
Avantageusement, les moyens de pilotage comprennent une unité de type contrôleur logique programmable.Advantageously, the control means comprise a unit of programmable logic controller type.
La figure ci-jointe représente une installation conforme à l'invention, donnée à titre illustratif, mais non limitatif. The attached figure represents an installation according to the invention, given for illustrative purposes, but not limiting.
Plus précisément, sur la figure, on voit que l'installation comprend, en tête de canalisation, un dispositif qui permet de maintenir la canalisation principale 1 toujours sous une faible surpression comprise entre 0,3 et 0,5 bar, lorsque le site utilisateur 4 de gaz ne consomme pas de gaz (par exemple la nuit ou les week-ends).More precisely, in the figure, it can be seen that the installation comprises, in pipe head, a device that helps maintain the pipeline main 1 always under a low overpressure between 0.3 and 0.5 bar, when the user site 4 of gas does not consume gas (for example the night or weekends).
Cette canalisation principale 1 est alimentée en gaz issu de la source de
gaz 14, par exemple de l'argon, du CO2, de l'azote ou de l'oxygène, et
achemine ce gaz jusqu'au site utilisateur 4, le gaz étant, en sortie d'un
évaporateur à froid (non montré), à une pression de sortie (Pef). Par ailleurs, le
réglage de la pression (Pl) de travail du gaz qui y circule se fait grâce au
détendeur 3; habituellement, la pression (Pl) de travail est comprise entre 2 et
15 bar.This main line 1 is supplied with gas from the source of
Dans ce mode de réalisation, lors des phases de repos, par exemple
durant les nuits, l'électrovanne 7 est fermée par actionnement d'un moyen de
commande à distance 16, tel un interrupteur.In this embodiment, during the rest phases, for example
during the nights, the solenoid valve 7 is closed by actuating a means of
L'installation comporte, en outre, une ligne de bypass 1' au sein de laquelle règne une pression (Pbp) de maintenance dont le niveau est réglé au moyen du détendeur 11, par exemple à une pression (Pbp) comprise entre 0,3 bar et la pression (Pl) de travail.The installation furthermore comprises a bypass line 1 'within which has a maintenance pressure (Pbp) whose level is set at means of the expander 11, for example at a pressure (Pbp) of between 0.3 bar and pressure (Pl) work.
Par exemple, Pbp est compris entre 0,3 et 0,6 bar.For example, Pbp is between 0.3 and 0.6 bar.
Toutefois, si l'on souhaite pouvoir contrôler de petites pertes de gaz, alors on règle Pbp proche de Pl.However, if one wishes to be able to control small losses of gas, then we set Pbp close to Pl.
En général, le règle de Pbp dépend du type de site utilisateur 4, c'est-à-dire du type d'application aval utilisant le gaz.In general, the rule of Pbp depends on the type of user site 4, that is to say the type of downstream application using the gas.
Durant les phases de travail utilisant du gaz, le gaz chemine de la
source 14 à l'utilisateur 4, via la ligne 1 principale.During the working phases using gas, the gas travels
A l'inverse, durant les phases de repos n'utilisant pas de gaz, la ligne 1 est fermée par la vanne 7 et, en cas de perte de gaz, c'est-à-dire si la pression (Pl) devient inférieure à la pression (Pbp) de maintenance alors un débit de gaz passe dans la ligne 1' de bypass, de manière à assurer un maintien en pression de la ligne 1 et à éviter ainsi les entrées d'impuretés atmosphériques dans le circuit de canalisation.Conversely, during rest phases that do not use gas, line 1 is closed by the valve 7 and, in case of loss of gas, that is to say if the pressure (Pl) becomes less than the maintenance pressure (Pbp) then a flow rate of gas passes in the line 1 'of bypass, so as to ensure a maintenance in pressure of line 1 and thus to avoid the entry of atmospheric impurities in the pipeline circuit.
La vanne 12 permet de garantir, dans la ligne 1', un débit de maintenance ajustable, par exemple de 3 à 30 l/min.The valve 12 makes it possible to guarantee, in line 1 ', a flow rate of adjustable maintenance, for example from 3 to 30 l / min.
Toutefois, si les pertes dans la ligne 1 sont plus élevées que le débit de
maintenance, alors un capteur de pression 6 aménagé sur la ligne 1 principale
(en aval de 7) détecte cette chute brutale de pression, (par exemple si Pbp <
0,2 bar) et déclenchant alors une alarme, telle qu'un signal 17 lumineux sur
une armoire de contrôle 18.However, if the losses in line 1 are higher than the
maintenance, then a pressure sensor 6 arranged on the main line 1
(downstream of 7) detects this sudden drop in pressure, (for example if Pbp <
0.2 bar) and then triggering an alarm, such as a
Dans ce cas, l'opérateur sait immédiatement que les entrées d'impuretés gazeuses dans la ligne 1 ont été importantes et qu'il est alors souhaitable de procéder à une purge avant de commencer à travailler, c'est-à-dire à utiliser du gaz, car celui-ci risque d'être impur.In this case, the operator immediately knows that the impurity inputs in line 1 were important and it is therefore desirable to perform a purge before starting to work, that is, using gas, because it may be impure.
De manière alternative, on peut utiliser un capteur de pression pour contrôler, en permanence, la pression et pour commander une électrovanne de débit du gaz utilisé, quand la pression chute en dessous d'un seuil préréglé.Alternatively, a pressure sensor can be used to constantly check the pressure and to order a solenoid valve from flow rate of the gas used, when the pressure drops below a preset threshold.
Une vanne de régulation de débit, par exemple un robinet micrométrique, permet d'ajuster un débit de fuite contrôlé si le capteur détecte une chute de pression dans le réseau. Ce débit de fuite est ajustable en fonction du procédé utilisé.A flow control valve, for example a faucet micrometric, allows to adjust a controlled leakage rate if the sensor detects a pressure drop in the network. This leakage rate is adjustable in function of the process used.
Là encore, dans le cas d'une fuite dépassant le débit de fuite admissible,
la fuite est signalée soit par un boítier de contrôle 17 par un signal lumineux
qui peut être rapporté à un endroit 18 déterminé, soit par un signal transmis par
télésurveillance à une entité assurant le contrôle et/ou la supervision de
l'installation afin de remettre l'installation en conformité.Again, in the case of a leak exceeding the allowable leakage flow,
the leak is signaled either by a
En option, le système peut être commandé par un PLC (Controlleur Logique Programmable) qui, en fonction des données d'entrée, par exemple la pression ou la vitesse de diminution de la pression dans la canalisation, va faire un réglage de l'ouverture ou de la fermeture, et/ou le réglage de vannes proportionnelles de réglage de débit. Ces signaux, commandés par PLC, sont utilisés aussi par le système de télésurveillance.Optionally, the system can be controlled by a PLC (Controlleur Programmable Logic) which, depending on the input data, for example the pressure or the rate of pressure decrease in the pipeline, will make an adjustment of the opening or closing, and / or the adjustment of valves proportional flow control. These signals, controlled by PLC, are also used by the remote monitoring system.
En option, le système peut aussi comprendre un débitmètre/régulateur de débit massif avec centrale électronique pour effectuer les fonctions susmentionnées pour le PLC.Optionally, the system may also include a flowmeter / regulator solid flow with electronic control unit to perform the functions mentioned above for the PLC.
Cette solution présente l'avantage de sécuriser la totalité de l'installation et éviter l'utilisation de détecteurs de fuites sur les multiples prises de gaz présentes dans l'atelier, peu adapté à une télésurveillance.This solution has the advantage of securing the entire installation and avoid the use of leak detectors on multiple gas plugs present in the workshop, not suitable for remote monitoring.
L'installation et le procédé selon l'invention peuvent être appliqués à des fins variées, notamment au soudage de l'aluminium, ou de l'acier.The plant and method according to the invention can be applied to various purposes, such as welding of aluminum, or steel.
En effet, l'aluminium est extrêmement sensible à des agents polluant comme O2 et H2O, qui conduisent à la formation néfaste de porosités dans les soudures.Indeed, aluminum is extremely sensitive to polluting agents such as O 2 and H 2 O, which lead to the harmful formation of porosities in the welds.
En maintenant la canalisation dé gaz, par exemple véhiculant de l'argon ou un mélange d'argon sous pression, en assurant au besoin un léger débit de fuite entre 6 et 30 l/min, le soudage peut être commencé, sans purger la canalisation à grand débit, même après une interruption longue, tel un week-end, et évite, en plus, le problème de sécurité lié à une sous-oxygénation possible de l'atmosphère de travail.By maintaining the gas line, for example conveying argon or a mixture of argon under pressure, providing a slight flow of leakage between 6 and 30 l / min, the welding can be started, without purging the high flow, even after a long break, like a weekend, and avoids, in addition, the safety problem related to under-oxygenation possible from the working atmosphere.
Avec la solution proposée, les soudures effectuées dès le démarrage présentent la qualité requise si pour autant le client a pris les précautions d'usage concernant le procédé en son ensemble : étuvage du fil, décapage des tôles juste avant utilisation ...With the proposed solution, welds made from the start have the required quality if the customer has taken precautions the process as a whole: steaming of the wire, etching of sheets just before use ...
De manière analogue, pour fabriquer de l'acier, il est habituel d'utiliser des canalisations d'acheminement de gaz de longueur importante, c'est-à-dire couramment de plusieurs dizaine de mètres. Or, après une interruption longue, en particulier après les week-ends, il a été observé, un taux de rebuts important dépassant 10 % pendant 2 heures. Ces problèmes sont dus à certaines fuites sur la canalisation faisant entrer l'air dans la canalisation. En particulier, l'azote et l'eau provoquent des porosités débouchant sur les pièces en acier produites.Similarly, to manufacture steel, it is usual to use gas pipelines of considerable length, that is to say commonly several tens of meters. But after a long interruption, especially after the weekends, it was observed a scrap rate greater than 10% for 2 hours. These problems are due to some leaks on the pipe bringing air into the pipe. In In particular, nitrogen and water cause porosities leading to the parts produced steel.
Un débit de fuite assure un maintien de la qualité du gaz de soudage, tout en évitant une réfection onéreuse du réseau pouvant atteindre 1 à 2 km au total. A leakage flow ensures maintenance of the quality of the welding gas, while avoiding an expensive repair of the network that can reach 1 to 2 km total.
Par ailleurs, l'intérêt de l'invention est encore plus grand sur les chantiers navals où le réseau de canalisations de gaz atteint souvent une longueur de plusieurs kilomètres ou dans le domaine agroalimentaire où les réseaux de canalisations doivent respecter, en permanence, des normes hygiéniques très strictes; toute entrée d'air ou d'impuretés pouvant conduire à une formation de nids de bactéries.Moreover, the interest of the invention is even greater on the shipyards where the gas pipeline system often reaches a length of several kilometers or in the agri-food sector where Pipeline networks must always comply with standards very strict hygienic; any entry of air or impurities that may lead to a formation of nests of bacteria.
Claims (7)
- Method for avoiding or minimizing contamination, by one or more gaseous impurities liable to be present in the ambient atmosphere, during at least one period of time when a user site is not consuming the said gas, of at least one portion of at least one gas pipe capable of conveying the said gas between at least one gas source and the said user site using the said gas, in which method:(a) a pressure value (Vpd), corresponding to the pressure inside at least one portion of the said pipe, is determined during the said period of time; and(b) the pressure within at least the said portion of pipe is adjusted in order to maintain the said pressure between a preset minimum pressure value (Vpmin) of greater than 105 Pa and a preset maximum pressure value (Vpmax) above the minimum pressure value (Vpmin), the pressure being maintained or adjusted by introducing pressurized gas into at least the said pipe portion.
- Method according to Claim 1, characterized in that it furthermore includes a step of comparing the pressure value (Vpd) determined in step (a) with at least the preset minimum pressure value (Vpmin).
- Method according to either of Claims 1 and 2, characterized in that it furthermore includes a step of comparing the pressure value (Vpd) determined in step (a) with at least the preset maximum pressure value (Vpmax).
- Method according to one of Claims 1 to 3, characterized in that the minimum pressure value (Vpmin) is equal to 1.5 x 105 Pa or below and in that the maximum pressure value (Vpmax) is equal to 1.5 x 105 Pa or above, but less than 3 x 105 Pa.
- Method according to one of Claims 1 to 4, characterized in that the range of minimum (Vpmin) and maximum (Vpmax) pressure values is about 1.1 x 105 Pa to about 1.8 x 105 Pa, preferably from 1.3 x 105 Pa to about 1.5 x 105 Pa.
- Method according to one of Claims 1 to 5, characterized in that the gas is chosen from argon, helium or mixtures thereof.
- Method according to one of Claims 1 to 6, characterized in that a leakage rate of between 3 and 30 l/min is furthermore maintained.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT1999MI001966A IT1313369B1 (en) | 1999-09-22 | 1999-09-22 | PROCEDURE AND DEVICE TO AVOID THE CONTAMINATION OF A UNCANALIZATION OR OF A RETICLE THAT VEHICLES A GAS. |
ITMI991966 | 1999-09-22 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP1089032A2 EP1089032A2 (en) | 2001-04-04 |
EP1089032A3 EP1089032A3 (en) | 2002-09-11 |
EP1089032B1 true EP1089032B1 (en) | 2005-02-23 |
Family
ID=11383637
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP00203221A Revoked EP1089032B1 (en) | 1999-09-22 | 2000-09-15 | Method and device for avoiding contamination from a gas pipeline system |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP1089032B1 (en) |
DE (1) | DE60018242T2 (en) |
ES (1) | ES2238024T3 (en) |
IT (1) | IT1313369B1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR3091970A1 (en) * | 2019-01-25 | 2020-07-31 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Greenhouse carbon fertilization process |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0232508B2 (en) * | 1984-07-19 | 1990-07-20 | Katsura Seiki Mfg | GASUSHADANBENNOJIDOFUTSUKIHOHO |
DE3907209C1 (en) * | 1989-01-18 | 1990-03-01 | Danfoss A/S, Nordborg | Device for monitoring a fluid piping system for leaks |
SE468775B (en) * | 1991-11-15 | 1993-03-15 | Ventilatorverken Ab | VENTILATION PROCEDURE MAKES COUNTED OR LIKE, EXTRA MOBILE HEALTH DEVICES, AND MEDICAL EFFECTS |
US5225167A (en) * | 1991-12-30 | 1993-07-06 | Clestra Cleanroom Technology, Inc. | Room air sterilizer |
DE19523713C2 (en) * | 1995-06-22 | 1997-04-24 | Mannesmann Ag | Method and device for ensuring the functionality of gas seals in turbocompressors |
JP3105433B2 (en) * | 1995-10-17 | 2000-10-30 | 松下電器産業株式会社 | Piping leak detection device |
-
1999
- 1999-09-22 IT IT1999MI001966A patent/IT1313369B1/en active
-
2000
- 2000-09-15 DE DE60018242T patent/DE60018242T2/en not_active Expired - Fee Related
- 2000-09-15 EP EP00203221A patent/EP1089032B1/en not_active Revoked
- 2000-09-15 ES ES00203221T patent/ES2238024T3/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
DE60018242D1 (en) | 2005-03-31 |
ES2238024T3 (en) | 2005-08-16 |
ITMI991966A1 (en) | 2001-03-22 |
IT1313369B1 (en) | 2002-07-23 |
DE60018242T2 (en) | 2006-01-12 |
EP1089032A2 (en) | 2001-04-04 |
ITMI991966A0 (en) | 1999-09-22 |
EP1089032A3 (en) | 2002-09-11 |
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