Готові списки джерел за темами / Filtres – Humidité

Добірка наукової літератури з теми "Filtres – Humidité"

Автор: Grafiati
Опубліковано: 8 червня 2024

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Статті в журналах з теми "Filtres – Humidité":

1

Aqueveque, Pablo, Macarena Díaz, Britam Gomez, Rodrigo Osorio, Francisco Pastene, Luciano Radrigan, and Anibal Morales. "Embedded Electronic Sensor for Monitoring of Breathing Activity, Fitting and Filter Clogging in Reusable Industrial Respirators." Biosensors 12, no. 11 (November 8, 2022): 991. http://dx.doi.org/10.3390/bios12110991.

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Millions of workers are required to wear reusable respirators in several industries worldwide. Reusable respirators include filters that protect workers against harmful dust, smoke, gases, and vapors. These hazards may cause cancer, lung impairment, and diseases. Respiratory protection is prone to failure or misuse, such as wearing respirators with filters out of service life and employees wearing respirators loosely. Currently, there are no commercial systems capable of reliably alerting of misuse of respiratory protective equipment during the workday shifts or provide early information about dangerous clogging levels of filters. This paper proposes a low energy and non-obtrusive functional building block with embedded electronics that enable breathing monitoring inside an industrial reusable respirator. The embedded electronic device collects multidimensional data from an integrated pressure, temperature, and relative humidity sensor inside a reusable industrial respirator in real time and sends it wirelessly to an external platform for further processing. Here, the calculation of instantaneous breathing rate and estimation of the filter’s respirator fitting and clogging level is performed. The device was tested with ten healthy subjects in laboratory trials. The subjects were asked to wear industrial reusable respirator with the embedded electronic device attached inside. The signals measured with the system were compared with airflow signals measured with calibrated transducers for validation purposes. The correlation between the estimated breathing rates using pressure, temperature, and relative humidity with the reference signal (airflow) is 0.987, 0.988 and 0.989 respectively, showing that instantaneous breathing rate can be calculated accurately using the information from the embedded device. Moreover, respirator fitting (well-fitted or loose condition) and filter’s clogging levels (≤60%, 80% and 100% clogging) also can be estimated using features extracted from absolute pressure measurements combined to statistical analysis ANOVA models. These experimental outputs represent promising results for further development of data-driven prediction models using machine learning techniques to determine filters end-of-service life. Furthermore, the proposed system would collect relevant data for real-time monitoring of workers’ breathing conditions and respirator usage, helping to improve occupational safety and health in the workplace.
2

Widziewicz-Rzońca, Kamila, Sławomir Janas, Barbara Błaszczak, Monika Błaszczak, Halina Pyta, Patrycja Rogula-Kopiec, Barbara Mathews, and Krzysztof Klejnowski. "ADVANCING THE UNDERSTANDING OF PM FILTER MASS STABILITY: UNVEILING THE INFLUENCE OF HUMIDITY AND TEMPERATURE." Zeszyty Naukowe Pro Publico Bono 1, no. 1 (November 13, 2023): 7–26. http://dx.doi.org/10.5604/01.3001.0053.9741.

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The intricate interplay between humidity and temperature on PM filter performance has remaineda subject of profound scientific interest. By employing fully-automated weighing method anda two-factor regression model, the study aimed to evaluate mass variations of unloaded PM filtersunder diverse humidity and temperature conditions. Existing guidelines, as posited by the USEPA and the European Standard (EN), have demonstrated a pronounced disparity. The US EPAadvocates a narrow humidity range of 30–40% RH, while the EN suggests a broader range of40–50% RH. The results of this investigation confirm the US EPA’s guidelines, which exhibitedsuperior filter mass stability under varying humidity. In controlled stable temperature conditionsof 20C, the research unveiled significant variations in filter mass as RH% increased from 50%to 55%. It has been proven that under stable temperature conditions (20C) inside a weighingrobot, an increase in relative air humidity from 50% to 55% results in filters mass addition by15 μg (Q, quartz fibre filters); by 93 μg (PTFE filters); by 9 μg (G, glass fibre filters); by 112 μg (PA,polyamide filters) and by 20 μg (PC, polycarbonate filters). Further exploration of the conditioningranges prescribed by the EN 12341:2014 standard, the study highlighted glass fibre filters as beingnotably stable, while polyamide membrane filters posed intriguing challenges potentially relatedto ionization insufficiencies during the equilibration stage. These findings bear significance forfilter manufacturing and conditioning protocols, potentially enhancing the precision of air qualitymonitoring practices.
3

Myers, David L., and B. Dean Arnold. "Electret Media for HVAC Filtration Applications." International Nonwovens Journal os-12, no. 4 (December 2003): 1558925003os—12. http://dx.doi.org/10.1177/1558925003os-1200412.

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Air filters produced with charged, or electret, media for HVAC filtration applications have gained significant market share and acceptance over the past few years. While these filters provide the advantage of high initial efficiency and low pressure drop, there are concerns about their ability to maintain efficiency in service. Furthermore, there is a tendency to classify all electret media in the same general category without any consideration of media structure, fiber size, and charging technique. Current research suggests that a variety of factors influence the loss of efficiency in use including humidity, exposure to certain chemicals, aging, temperature, and etc. While this is true of some charged media, the effect of environmental factors on filtration performance is highly dependent upon the media technology itself. This paper provides an overview of current electret media types detailing media structure and charging techniques. Fundamental impact of environmental factors on filtration performance is presented along with field studies detailing in-use performance of filterers manufactured with charged media.
4

Abd Ali, Safaa Abd Zaid, Aurélie Joubert, and Yves Andrès. "Evaluation of Antimicrobial Effect of Zinc Pyrithione against Airborne Fungi and Bacteria Growth Collected onto New and Loaded HVAC Fibrous Filters." Processes 9, no. 9 (August 27, 2021): 1528. http://dx.doi.org/10.3390/pr9091528.

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Microbial growth onto HVAC filters was observed in real conditions with possible degradation of the indoor air quality. The filtration performance of marketed antimicrobial filters containing zinc pyrithione was tested under laboratory conditions and compared to that of similar filters with the same classification, F7 (EN779:2002). The filtration performance of the two tested filters during loading with PM10 particles was quantified in an experimental setup with filter pressure drop measurement and particle counting upstream and downstream of the filters. The microbial growth on the new and loaded filters, both contaminated with a microbial airborne consortium composed of two bacteria (Gram-positive and -negative) and fungi, was quantified by colony-forming units after conditioning the filters for a few days under controlled temperature (25 °C) and humidity (50% or 90% relative humidity). The results reveal that there was no degradation of the filtration performance of the filters treated with the antimicrobial agent. The efficiency of the antimicrobial treatment, i.e., the ability to inhibit the growth of microorganisms during the incubation period, was significant with the new filters regarding the fungal growth, but the results demonstrate that the antimicrobial treatment became inefficient with the loaded filters.
5

Widziewicz-Rzońca, Kamila, and Malwina Tytła. "Water Sorption by Different Types of Filter Media Used for Particulate Matter Collection Under Varying Temperature and Humidity Conditions." International Journal of Environmental Research and Public Health 17, no. 14 (July 17, 2020): 5180. http://dx.doi.org/10.3390/ijerph17145180.

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The present study describes the effects of temperature and humidity on the level of water absorption by filter blanks most popularly used for gravimetric analyzes of particulate matter (PM) and the effects of those on the accuracy of its weight measurements. The main parts of the research quantified the effect of temperature and humidity conditions on water contents quartz fiber (Q), fiberglass (G), PTFE, and nylon (N) filters. Supplementary studies were conducted to estimate the effects of temperature, humidity and material on mass loss/gain and the shape of water retention. All chemical analyses of water contents were performed by the Karl Fischer titration method. The results indicate that quartz filters are the most susceptible to the variations in water contents under changing humidity levels and therefore, less suitable to high accuracy determinations of PM mass compared to nylon or glass filters; PTFE performed the best due to their hydrophobicity. For PM water contents determinations, the best choice of filter media is PTFE. Although many other factors determine the choice of filter type for PM analyses, the present study is an important contribution to knowledge of assessing the suitability of different types of filter material for specific measurements.
6

Dierkes, M., and U. Hilleringmann. "Telemetric surface acoustic wave sensor for humidity." Advances in Radio Science 1 (May 5, 2003): 131–33. http://dx.doi.org/10.5194/ars-1-131-2003.

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Abstract. Surface acoustic wave sensors consist of a piezoelectric substrate with metal interdigital transducers (IDT) on top. The acoustic waves are generated on the surface of the substrate by a radio wave, as it is well known in band pass filters. The devices can be used as wireless telemetric sensors for temperature and humidity, transmitting the sensed signal as a shift of the sensor’s resonance frequency.
7

Chervinskii, Semyon, Ibrahim Issah, Markus Lahikainen, Alireza R. Rashed, Kim Kuntze, Arri Priimagi, and Humeyra Caglayan. "Humidity- and Temperature-Tunable Metal–Hydrogel–Metal Reflective Filters." ACS Applied Materials & Interfaces 13, no. 42 (October 13, 2021): 50564–72. http://dx.doi.org/10.1021/acsami.1c15616.

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8

Chien, Chih-Hsiang, Chufan Zhou, Simon Yang Sing, Benjamin Lopez, Alexandros Theodore, Chang-Yu Wu, and Brian K. Birky. "Effects of Relative Humidity on Impregnated Filters Used in Measurement of Airborne Sulfur Dioxide." Annals of Work Exposures and Health 63, no. 7 (July 6, 2019): 806–13. http://dx.doi.org/10.1093/annweh/wxz053.

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Abstract Impregnated filters treated with alkali and humectant were first used as collection media to assess occupational exposure to sulfur dioxide (SO2), as outlined in the National Institute for Occupational Safety and Health Method 6004 in 1979. Since then, updated treatment protocols have been proposed with decreased amounts of alkali and glycerol, which claim the same filtering capacity. However, there has been no report on how the collection of SO2 on such impregnated media is influenced by relative humidity (RH). This study investigated the role of glycerol (G) amount on impregnated filters (G2 and G10, referring to 2 and 10% glycerol, respectively) in the collection of SO2 (100 l of 10 ppm at 1 l per minute) under low, medium, and high RHs. The testing results show that RH significantly impacted G2 filters with respect to breakthrough time, capacity, and recovery. At low RH, the 5% breakthrough time was less than 10 min and its recovery was merely 42%; at medium and high RHs, although the recovery was satisfactory, the 5% breakthrough time was still less than 100 min. By contrast, G10 filters illustrated nearly 100% recovery and evaluation by analysis of variance showed no significant effect of RH on recovery. In summary, the current treatment protocol of 2% glycerol leads to a significant underestimation of the exposure to SO2 in a low-RH environment; increasing the glycerol content can be an effective alternative to compensating for the effect of RH.
9

Lee, Jinwook, and Jooyoun Kim. "Material Properties Influencing the Charge Decay of Electret Filters and their Impact on Filtration Performance." Polymers 12, no. 3 (March 24, 2020): 721. http://dx.doi.org/10.3390/polym12030721.

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Electret filters as opposed to mechanical filters display the enhanced ability to capture airborne particles with the electrostatic attraction. However, the environmental aging during shelf-life or use may cancel its benefit by dissipating the charges. This work investigates the polymeric attributes influencing the charge decay and the electrostatic filtration of electret filters, employing polymers with different dielectric constants (εr) and wettability. As accelerated aging, high temperature (120 °C) or high humidity (25 °C, 90% RH) was applied to the electret filters for 48 h. For the humidity aging, wetting property of material was a critical factor affecting the charge decay and the filtration performance, as the absorbed water increases the electrical conductivity. For the thermal aging, the material with the highest εr deteriorated the electric potential and the filtration performance by the largest extent, due to the lower band gap energy for charge transfer. The results of this study implicate that εr and wettability are important material parameters influencing the electric conductivity and chain mobility, and they can be used as convenient predictors for charge retention capacity affecting the robust electrostatic filtration performance.
10

Sidheswaran, Meera, Wenhao Chen, Agatha Chang, Robert Miller, Sebastian Cohn, Douglas Sullivan, William J. Fisk, Kazukiyo Kumagai, and Hugo Destaillats. "Formaldehyde Emissions from Ventilation Filters Under Different Relative Humidity Conditions." Environmental Science & Technology 47, no. 10 (May 6, 2013): 5336–43. http://dx.doi.org/10.1021/es400290p.

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Статті в журналах

Дисертації з теми "Filtres – Humidité":

1

Lecoq, Marie. "Étude du colmatage de filtres métalliques par un aérosol liquide." Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0006.

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Le confinement des installations industrielles susceptibles de contenir des matières dangereuses est assuré en grande partie par des filtres à très haute efficacité (THE) intégrés dans les réseaux de ventilation. Dans les procédés, mis en œuvre dans l'industrie nucléaire, certains scénarios accidentels peuvent conduire au dégagement de liquide sous forme de gouttelettes en suspension (aérosol liquide). Dans ce cas de figure, leur présence peut affecter les performances des filtres THE en engendrant une élévation rapide et importante de leur perte de charge pouvant conduire à une diminution notable du débit de ventilation, voire atteindre la limite de leur résistance mécanique et leur capacité à retenir les contaminants aéroportés. Pour pallier ce problème, une des solutions envisagées est l'utilisation d'un préfiltre à fibres métalliques (plus résistant mécaniquement mais moins efficace) pour protéger le filtre THE constituant le dernier niveau de filtration ou pour à minima augmenter sa durée de vie en cas de scénarios accidentels. Afin de valider cette solution, il est nécessaire d'étudier, face à un aérosol liquide, le comportement de ces préfiltres composés par un empilement de plusieurs monocouches de médias de caractéristiques différentes. Les différents médias métalliques testés ont été caractérisés, dans un premier temps, en termes d'épaisseur, de compacité et de distribution granulométrique de fibres. L'évolution de l'efficacité de collecte et de la perte de charge au cours du colmatage par un aérosol liquide DEHS a ensuite été étudiée à différentes vitesses de filtration (0,9 à 18 cm/s). On retrouve l'évolution classique décrite dans la littérature : augmentation quasi-linéaire de la perte de charge avant une croissance exponentielle et une stabilisation. Les médias multicouches présentent, cependant, une phase de stabilisation de la perte de charge plus progressive comparativement aux monocouches. Un scénario de colmatage a été proposé et un modèle simpliste d'évolution de la perte charge en fonction de la masse de liquide accumulé au sein du filtre est présenté pour les médias monocouches. Afin de figer le liquide accumulé au sein du média et permettre une visualisation par micro-tomographie X des médias partiellement ou totalement colmatés, des résines thermodurcissables ont été testées. Les premiers résultats ont mis en évidence une perte de volume des résines trop importante après séchage ce qui rend difficile l'interprétation des clichés obtenus
Industrial installations often contain hazardous materials in aerosol form. High efficiency filters (HEPA) are usually the last barrier that ensure the containment of these airborne particles. In the nuclear industry, a large amount of radioactivity is handled in liquid form, that may release, in few scenarios, liquid aerosols. These particles may affect the performance of HEPA filters with a huge increase of the pressure drop, which lead in return to a significant reduction of the ventilation flowrate. In such scenarios the pressure drop increase may exceed the filter mechanical strength and induce degradations of the media and leading to a deterioration of its capacity to retain aerosol pollutants. To overcome this problem, and to protect HEPA filter, one of the solutions is to use pre-filter (more mechanically resistant but less efficient) made up with metallic fibers. To validate this approach, it is necessary to study the behavior of these prefilters, composed of a stack of different monolayers of media. In my work, I first focused on the clogging of industrial prefilters with liquid aerosol particles. Then, for a more analytical study, I study the clogging each layer separately, in order, to model, on the future, the behavior of the assembly. The microphysical of each media (thickness, packing density, and fiber size distribution) are determined. The evolution of both filter collection efficiency and pressure drop are studied along the clogging by a submicron liquid aerosol DEHS, for different filtration velocity (0,9 à 18 cm/s). For monolayer filters, I measure pressure drops in line with the previous results found in the literature. These experiments first highlight a quasi-linear increase of the pressure drop, associate with a collection of the droplets by the fibers. Then an exponential growth is measures, that corresponds to the clogging of the pores. And finally, an abrupt stabilization is observed corresponding a liquid film formation and its continuous drainage by the airflow. However, I show a more gradual stabilization for multilayer filters. A clogging scenario is proposed, and a simplistic model is established to forecast the pressure drop as a function of the mass of liquid accumulated. To this aim, I develop a new method to freeze the liquid accumulation using resin, that where further analyze using X-ray tomography
2

Godoy, Charlotte. "Filtration d’aérosols de suie en présence de vapeur et/ou de gouttelettes d’eau." Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0287.

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L'épuration de l'air contaminé par les particules générées par de nombreux procédés industriels fait le plus souvent appel à la filtration au moyen de médias filtrants. Ces équipements collectifs de protection des personnes et de l’environnement sont éprouvés en termes d’efficacité initiale mais leur comportement au cours du temps reste difficilement prévisible. Ce constat est d’autant plus vrai lorsque ces dispositifs sont confrontés à un aérosol diphasique constitué de particules solides et liquides. Ces situations peuvent notamment être rencontrées lors de l’usinage de métaux, l’épandage de pesticides ou encore lors d’incendie dans des zones confinées comme les centrales nucléaires. L'étude proposée visera à établir les performances d’un média fibreux vis à vis d’aérosols diphasiques composés de particules solides nanostructurées et de gouttelettes (submicroniques ou microniques). Si la filtration d’aérosols solides ou d’aérosols liquides seuls est relativement bien documentée dans la littérature, aucune étude ne s’est intéressée à cette problématique d’aérosols diphasiques (surtout en termes de colmatage). Pour de forts ratios solide/liquide, l’évolution temporelle de la perte de charge devrait se rapprocher de celle d’un filtre soumis à des aérosols solides, à savoir une augmentation quasi-linéaire au cours du temps. Dans le cas d’un aérosol majoritairement constitué de gouttelettes, une stabilisation de la perte de charge, caractérisée par un état d’équilibre entre le débit massique de gouttelettes collectées et le débit de liquide drainé sur la face aval du filtre, pourrait être envisagée. Mais quid de l’évolution de la perte de charge entre ces deux extremums ? La détermination de l’évolution temporelle de l’efficacité de collecte est tout aussi incertaine et de plus se heurte à un véritable verrou métrologique. Une mesure fine et fiable de la concentration et de la distribution granulométrique d’un aérosol constitué d’agglomérats nanostructurés est déjà relativement complexe. La présence de gouttelettes rendra la mesure d’autant plus difficile car pourrait être à l’origine d’une modification de la distribution granulométrique des particules solides au cours de leur transport (impaction, condensation). De plus, la caractérisation d’un aérosol diphasique nécessitera le couplage de différents granulomètres basés sur des principes de mesure différents de façon à faire la distinction entre les particules liquides et solides. L’objectif de cette thèse a ainsi pour but de pallier l’absence de connaissance sur la filtration d’aérosols diphasiques dans une double optique de protection des personnes et de l’environnement
One of the most frequently used methods to purify air contaminated by particles, in many industrial processes, is filter media. These collective equipment for protecting people and the environment are proven in terms of initial efficiency, but their behavior over time remains difficult to predict. This is all the more noticeable when these devices are confronted with a biphasic aerosol composed of solid and liquid particles. These situations can be encountered during metals machining, pesticides spreading or even during fires in confined areas such as nuclear power plants. The proposed study will aim to establish the performance of a fibrous media with respect to biphasic aerosols with nanostructured solid particles and droplets (submicron or micron-sized). If the filtration of solid aerosols or liquid aerosols is relatively well documented in the literature, no study has been interested in this problem of biphasic aerosols. For high solid / liquid ratios, the time course of the pressure drop should be close to solid aerosols filtration evolution, ie a quasi-linear increase over time. In the case of an aerosol predominantly made up of droplets, a constant pressure drop overtime, characterized by a state of equilibrium between the mass flow rate of collected droplets and the flow rate of liquid drained on the downstream face of the filter, could be considered . But what about the evolution of the pressure drop between these two extremes? The determination of the temporal evolution of the collection efficiency is also uncertain and should be regarded as a real metrological challenge
3

Joubert, Aurélie. "Performances des filtres plissés à Très Haute Efficacité en fonction de l'humidité relative de l'air." Thesis, Vandoeuvre-les-Nancy, INPL, 2009. http://www.theses.fr/2009INPL081N/document.

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Les filtres plissés à Très Haute Efficacité (THE) sont utilisés pour le maintien du confinement des substances radioactives dans les installations nucléaires ; ils constituent ainsi un des éléments sensibles de la sûreté nucléaire. Certains scénarios accidentels, comme l’apparition d’une brèche sur une tuyauterie avec relâchement de vapeur, peuvent conduire à une forte augmentation de l’humidité relative de l’effluent gazeux filtré. Ces travaux permettent de pallier le manque de données analytiques dans la littérature concernant le comportement des filtres plissés THE, en termes de variations de leur perte de charge et de leur efficacité, en cas d’exposition à un débit d’air humide non saturé. Des expériences de colmatage de filtres ont été réalisées sur un banc d’essais à l’aide de deux aérosols : un aérosol non-hygroscopique micronique d’alumine et un aérosol hygroscopique submicronique de chlorure de sodium. Les résultats ont mis en évidence que l’influence de l’humidité durant le colmatage d’un filtre THE dépend de plusieurs paramètres : la géométrie du filtre (plane ou plissée), la granulométrie et la nature hygroscopique de l’aérosol de colmatage et enfin, le temps d’interaction entre l’aérosol et l’air humide. Des mesures d’efficacité des filtres plissés vierges et à différents degrés de colmatage, réalisées avec l’aérosol normalisé d’uranine, se sont également révélées sensibles à la présence plus ou moins importante d’humidité relative dans l’air. Enfin, l’ensemble des résultats a permis d’élaborer une approche empirique d’estimation de l’évolution de la perte de charge d’un filtre THE ; le modèle qui en résulte est applicable durant la formation sous humidité d’un gâteau de particules sans réduction de la surface de filtration
Pleated High Efficiency Particulate Air (HEPA) filters are used for maintaining the containment of radioactive substances in nuclear plants; thus, they are sensitive elements of nuclear safety. Some accidental situations, such as the emergence of a hole on a pipe with release of steam, can lead to a high increase of the air humidity. This work can overcome the lack of analytical data in the literature regarding the behaviour of pleated HEPA filters, in terms of changes in pressure drop and efficiency, in presence of humidity (unsaturated air). Experimental clogging tests have been performed on a test bench with two aerosols: non-hygroscopic micronic alumina particles and hygroscopic submicronic sodium chloride particles. The results showed that the influence of humidity during the clogging of a HEPA filter depends on several parameters: the geometry of the filter (plane or pleated), the size distribution and hygroscopicity of the aerosol clogging and finally the interaction time between the aerosol and humid air. Measurements of efficiency of clean and clogged filters (at different degrees of clogging), performed with the normalized soda fluorescein aerosol, are also sensitive to the presence of more or less relative humidity in the air. Finally, all results helped to develop an empirical model for estimating the evolution of the pressure drop of HEPA filters; this model is applicable during the formation of the particulate cake in presence of humidity without reducing of the surface area filtration
4

Popescu, R̆azvan Ștefan. "Modélisation du comportement des filtres en charbon actif utilisés pour l'épuration de l'air intérieur." La Rochelle, 2008. http://www.theses.fr/2008LAROS238.

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L'épuration par adsorption offre des possibilités intéressantes qui n'ont pas été optimisées, exploitées, voire même simplement explorées. Les systèmes des filtres en charbon actif modélises prennent en compte des mélanges des polluants en faible concentration et composition variable dans le temps, température et humidité fluctuantes, spécificités qui remettent pourtant en cause le principe de fonctionnement comme les règles de dimensionnement ou de maintenance afférentes a ces systèmes. La première partie de la thèse constitue une synthèse bibliographique des phénomènes physico-chimique qui interviennent dans le processus de filtration par adsorption. La deuxième partie présente les modèles développés dans l'environnement Matlab/Simulink sur la base de cette analyse phénoménologique et des hypothèses simplificatrices qui peuvent être faites dans le contexte particulier du traitement de l'air intérieur. Premièrement ont été considères des conditions d'air sec et isotherme et âpres ont a intègre les effets sur la dynamique d'adsorption des variations de température et d'humidité. Enfin la dernière partie présente les simulations qui ont été réalisés avec les modèles développés. Les modèles mono et multi-composes considérant des conditions isothermes et sèches ont été compares avec les donnes expérimentales pour les 6 polluants mesures a Ecole des Mines d'Ales. Le cas d'humidité a été traite séparément en faisant une comparaison des deux modèles développés. Pour terminer, les dernières simulations ont été axées sur la caractérisation du potentiel d'amélioration de la qualité de l'air par l'utilisation des filtres en charbon actif
Indoor air cleaning by adsorption offers interesting solutions which haven’t been optimized, exploited and not even explored. The models of activated carbon filter systems take into consideration the mixture of several pollutants characterized by low concentrations, variable composition in time, temperature and humidity. All these properties are determining the operating criteria like the designing or endurance of those systems. The first part of the paper presents a synthesized biographical study upon the chemical and physical phenomenon which are typical for the filtration processes by adsorption. The second part presents the models developed in Matlab/Simulink software by taking into account the simplified hypothesis applied for the particularities of indoor air cleaning. First isothermal and dry conditions were modeled and then the effects of humidity and temperature influence. Finally the last part describes the simulations realized with the developed models. Mono and multi compound models for dry and isothermal conditions were compared with the experimental data for 6 pollutants measured at Ecole des Mines d’Ales. The influence of humidity was studied separately making a comparison between two models proposed in the present paper. In the end the last simulations show the potential of activated carbon filters to improve the indoor air quality
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Ribeyre, Quentin. "Influence de l'humidité de l'air sur la perte de charge d'un dépôt nanostructuré." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0056/document.

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Dans l’industrie, des systèmes de protection collectifs doivent être mis en œuvre pour protéger aussi bien les travailleurs que l’environnement. Des filtres à fibres sont généralement disposés dans les circuits de ventilation générale pour capter ces particules en suspension dans l’air. Les performances de ces media fibreux en termes d’efficacité de collecte et consommation énergétique sont relativement bien documentées lors de leur fonctionnement dans des conditions standards (humidité et température ambiantes). Cependant, peu d’études s’intéressent à l’interaction de l’humidité de l’air avec un dépôt composé de particules nanostructurées collectées par ces media filtrants et son incidence sur l’évolution de la perte de charge. Le travail de thèse a donc consisté dans un premier temps à la mesure d’isothermes de sorption de quatre poudres nanostructurées. Un modèle semi-prédictif d’adsorption-condensation basé sur le modèle GAB et la loi de Kelvin a ensuite été proposé. La seconde partie de l’étude a permis de décrire expérimentalement la variation de perte de charge et d’épaisseur d’un milieu poreux, formé par ces mêmes particules nanostructurées, pour différentes valeurs d’humidité. Grâce à la variation d’épaisseur du milieu déterminée par trigonométrie laser et au modèle d’adsorption-condensation, la porosité pour chaque valeur d’humidité relative a pu être calculée. En incorporant les valeurs de porosité et d’épaisseur dans trois modèles de perte de charge, il a été possible de représenter de façon satisfaisante les résultats expérimentaux. Enfin, une analyse rhéologique des poudres est proposée pour quantifier leur augmentation de cohésion sous humidité
Air quality has emerged as a major public environmental and health issue. Almost all fine particles in the air are man-made or manufactured and there are many questions regarding the impact of ultrafine (<100nm) particles on human health. Thus, in most cases, institutions use large-scale protection equipment to protect workers. These institutions often use particulate air filters placed within the flow of general ventilation. Almost all of the available data corresponds to standard ambient air conditions. Despite this, few studies focus on the interaction of water moisture on the deposit formed by these accumulated nanoparticles and the impact on the pressure drop. The first part of this study consists of the measurement of sorption isotherms of four nanostructured powders. A semi-predictive sorption model based on the theory of the multimolecular adsorption (described by the GAB equation) and on the capillary condensation (Kelvin’s law) was developed. The second part of the study experimentally describes the thickness and pressure drop variation of a porous medium formed by these nanostructured particles for different values of humidity. Through the thickness variation of the media - determined by laser trigonometry - and adsorption-condensation model, the porosity for each humidity value has been calculated. Following this, three pressure drop models available in the literature have been modified by introducing cake thickness and porosity variation according to relative humidity. This allows us to model the experimental data for all the samples. Finally, a rheological analysis of powders is proposed to quantify the cohesion changes under moisture conditions
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ZUBICKI, ANNE. "Filtres echangeurs de chaleur et d'humidite versus humidificateurs chauffants utilises au cours de la ventilation mecanique prolongee : deux etudes propectives." Montpellier 1, 1992. http://www.theses.fr/1992MON11155.

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7

Chvátal, Michal. "Řízení dodávky vody v rodinném domě." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442453.

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The diploma thesis deals with the design and implementation of the system that will control the water supply for the family house and its garden. The system aslo allows you to store a history that can be viewed via the web interface. The web interface also allows you to set system parameters and monitor the current status.
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Ponkala, Mikko Juha Viljami. "Humidity effects on hygroscopic particles deposited on HEPA filters and silicon wafer surfaces." 2012. http://hdl.handle.net/2152/20008.

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Semiconductor wafer manufacturing facilities (fab) must maintain extremely clean air environments to minimize the number of wafers scrapped due to contamination which would result in reduced yields. The fab air is cleaned bypassing it through either HEPA or ULPA filters. A number of airborne fab contaminants may be hygroscopic causing them to exist as a solid or a liquid when in equilibrium with their environment's relative humidity. The effect of relative humidity on such contaminants is poorly documented whether they were to be captured in a filter or deposited on a wafer. The work presented here experimentally characterizes NaCl evolution within HEPA filters when exposed to humidity fluctuations and the effect of humidity on NH4Cl corrosiveness when deposited on cobalt coated wafers with a TiN layer. Successive deliquescence and efflorescence fluctuations were imposed on particles captured on a glass fiber HEPA filter. Scanning Electron Microscopy (SEM) and Environmental SEM (ESEM) studies of the filters showed that the NaCl, under humidity excursions, did not penetrate deep into the filter but deliquesced and effloresced near the top surface of the filter. Pressure drop measurements for filters containing NaCl particles showed differences in pressure drop associated with relative humidity changes. These pressure drop changes suggested some redistribution particle properties. When exposed to a relative humidity of 20%, the NH4Cl particles did not corrode the cobalt wafer beyond the location of the initial deposit. At 61% relative humidity, the surrounding areas of the particles were corroded with a solid artifact left at the original location. At 76% relative humidity the NH4Cl particles were observed to have deliquesced, which is below the expected deliquescence relative humidity. The corrosion of the cobalt wafer was most extensive when the NH4Cl particles had deliquesced.
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Агафонов, Олексій Андрійович. "Аналіз та вдосконалення технології зневоднення гідроксиду алюмінію". Магістерська робота, 2020. https://dspace.znu.edu.ua/jspui/handle/12345/4683.

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Агафонов О. А. Аналіз та вдосконалення технології зневоднення гідроксиду алюмінію : кваліфікаційна робота магіста спеціальності 136 «Металургія» / наук. керівник Т. М. Нестеренко. Запоріжжя : ЗНУ, 2020. 61 с.
UA : Наведено аналіз сучасних способів зневоднення та факторів, що впливають на технологію зневоднення гідроксиду алюмінію. Експериментально досліджено технологію зневоднення гідроксиду алюмінію, який надходить на кальцінацію, при додаванні зневоднювачів РОLYPAV-С16 (ЕО) виробництва ТДВ «Пологівський хімічний завод «Коагулянт» і іноземного Nalkо 85488. Оптимальні витрати зневоднювачів РОLYPAV-С16 (ЕО) і Nalkо 85488 на 1 т А12О3 становлять 50 г та 40 г відповідно. Погіршення показників роботи печі киплячого шару при використанні реагентів не помічено, основні технологічні параметри зберігалися на заданому рівні. При роботі печі з байпасом витрата газу при застосуванні реагентів знизилася в середньому на 1 м3/т глинозему. Використання зневоднювачів РОLYPAV-С16 (ЕО) і Nalkо 85488 дозволяє зменшити вологість гідроксиду алюмінію на 2 % і стабілізувати роботу вузла фільтрування.
EN : The analysis of modern dehydration methods and the factors influencing to dehydration technology of aluminum hydroxide are given. The dehydration technology of aluminum hydroxide, which enters the calcination, with the addition of РОLYPAV-С16 (ЕО) «Pology Chemical Plant «Coagulant» ALC and foreign Nalko 85488 dehydrators was investigated experimentally. The optimal consumption of РОLYPAV-С16 (ЕО) and Nalko 85488 dehydrators per 1 ton of A12O3 is 50 g and 40 g, respectively. Performance deterioration of the fluid-bed furnace when using reagents was not observed, the main technological parameters were maintained at a given level. Gas consumption per 1 ton of alumina during the operation of the bypass furnace and with using of these reagents decreased by an average of 1 m3. The using of ROLYPAV-C16 (EO) and Nalko 85488 dehydrators allows to reduce the humidity of aluminum hydroxide by 2% and to stabilize the operation of the filtration unit.

Частини книг з теми "Filtres – Humidité":

1

Del Dottore, Emanuela, Alessio Mondini, Davide Bray, and Barbara Mazzolai. "Miniature Soil Moisture Sensors for a Root-Inspired Burrowing Growing Robot." In Biomimetic and Biohybrid Systems, 184–96. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-38857-6_15.

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AbstractThis paper shows the implementation of miniature sensors for soil moisture measurement and their integration in a root-inspired burrowing growing robot. Three kinds of sensors are combined to estimate the water content in soil: a resistivity sensor composed of two brass electrodes, a commercial air humidity sensor interfaced with the soil by a filter membrane of PTFE with polyester scrim, and an RGB sensor used for visible reflectance spectroscopy. We show their integration and embeddability in a burrowing growing robot based on additive manufacturing with a 4 cm probe diameter. The multimodal sensing strategy has been characterized and tested in clay and sand medium at different water content. Results show that the resistive sensor works in all the tested ranges but is prone to failure due to electrode-soil contact issues. The air humidity sensor works accurately in a range of water content less than 5% (dry conditions), and the RGB sensor works in the 5–20% range. We propose a statistical approach for soil moisture estimation that combines all three technologies and demonstrate that we can accurately predict the water content in our experimental soils, clay and sand, with better performance in clay (Root Mean Square Error, RMSE = 0.38). The proposed miniaturized multimodal sensing strategy can enable long-term, in-situ soil moisture monitoring functionalities in self-deployable robots for precision agriculture and forestry applications.
2

Dangsakul, Prachumpong, Nutchanon Siripool, Kraithep Sirisanwannakul, Rachaporn Keinprasit, Khongpan Rungprateeptavorn, Suthum Keerativittayanun, and Jessada Karnjana. "Humidity Sensor Accuracy Improvement Based on Two Nested Kalman Filters for Commercial Cultivation of Tropical Orchids." In Communications in Computer and Information Science, 104–12. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-63823-8_13.

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Siripool, Nutchanon, Kraithep Sirisanwannakul, Waree Kongprawechnon, Prachumpong Dangsakul, Anuchit Leelayuttho, Sommai Chokrung, Jakkaphob Intha, Suthum Keerativittayanun, and Jessada Karnjana. "Relative Humidity Estimation Based on Two Nested Kalman Filters with Bicubic Interpolation for Commercial Cultivation of Tropical Orchids." In Lecture Notes in Computer Science, 201–12. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-62509-2_17.

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Beatriz Cuellar, Hugo, Jesús de la Cruz-Alejo, Ernesto Enciso Contreras, and I. C. Alcocer Guillermo. "Design and Implementation of a LMS Adaptive Filter for Humidity and Temperature Control in a Bioreactor." In Lecture Notes in Electrical Engineering, 123–36. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-72208-1_10.

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Sirisanwannakul, Kraithep, Nutchanon Siripool, Waree Kongprawechnon, Prachumpong Dangsakul, Udom Lewlomphaisarl, Seksun Sartsatit, Thanika Duangtanoo, et al. "Humidity Sensor Drift Detection and Correction Based on a Kalman Filter with an Artificial Neural Network for Commercial Cultivation of Tropical Orchids." In Advances in Intelligent Systems and Computing, 140–49. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-68133-3_14.

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6

Stradling, J. R., and S. E. Craig. "The upper respiratory tract." In Oxford Textbook of Medicine, 3169–72. Oxford University Press, 2010. http://dx.doi.org/10.1093/med/9780199204854.003.180101.

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The upper respiratory tract extends from the anterior nares to the larynx and comprises (1) the nose—with main function as first-line defence against problems with incoming air, acting as a coarse particle filter and a conditioner (temperature and humidity) of the air, and with the sense of smell helping to detect noxious substances that are best avoided. (2) The pharynx—this has to be a rigid tube when used for breathing, but during swallowing it has to be a collapsed tube capable of peristalsis, a combination of functions which is achieved by complex innervation and musculature. Subepithelial collections of lymphoid tissue in the pharynx are ideally suited to process inhaled and swallowed antigens. (3) The larynx—this has three important functions: communication, protection of the airway, and dynamic control of lung volume....
7

Shah, Pallav L., J. R. Stradling, and S. E. Craig. "The upper respiratory tract." In Oxford Textbook of Medicine, edited by Pallav L. Shah, 3933–37. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198746690.003.0396.

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The upper respiratory tract extends from the anterior nares to the larynx and comprises (1) the nose—with the main function as first-line defence against problems with incoming air, acting as a coarse particle filter and a conditioner (temperature and humidity) of the air, and with the sense of smell helping to detect noxious substances that are best avoided. (2) The pharynx—this has to act as a rigid tube when used for breathing, but during swallowing it has to be a collapsible tube capable of peristalsis, a combination of functions which is achieved by complex innervation and musculature. Subepithelial collections of lymphoid tissue in the pharynx are ideally suited to process inhaled and swallowed antigens. (3) The larynx—this has three important functions: communication, protection of the airway, and dynamic control of lung volume.
8

Pretelli, Marco, Leila Signorelli, and Maria Antonietta De Vivo. "Improving the Accessibility of Cultural Sites During Pandemic Through Microclimate Control. The Case of CapsulART Applied to the MANN Museum in Naples." In Studies in Health Technology and Informatics. IOS Press, 2022. http://dx.doi.org/10.3233/shti220880.

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The use of cultural sites has been profoundly altered by the recent pandemic events with relevant consequences on the cultural heritage industry. While before the CoVid-19 pandemic access to Cultural Sites used to involve a simplified form of control, in the transitional period between the pandemic and the post-pandemic, additional steps are required. The research aims to combine seemingly distant aspects: counteracting the spread of contagion and reorganising the admission processes to institutes of culture, such as museums. Based on the literature, it has been shown that the parameters determining air quality (temperature, relative humidity, concentration of pollutants, dust, CO2, etc.) influence the state of conservation of works of art, while their interaction with the spread of the epidemic has been slightly investigated. The research seeks to find innovative technological solutions to allow access and safe visits to the greatest possible number of users. A conscious design, therefore, must be put in place to allow everyone to enjoy works of art, exhibitions and shows. This is how the concept of universal design is declined here, introducing the concept of ‘safe environment accessibility’. The first results of a research carried out on the microclimate and the air quality inside Tyrannicides Hall at the National Archaeological Museum of Naples (MANN) will be presented. A device called ‘CapsulART’ is designed to be placed at the entrance of a specific room, which acts as a filter and as a decompression chamber to lower the level of pollutants present on people’s clothes and shoe soles. Through a reduction in temperature, parameters that may increase the ease of contagion (e.g. sweating) should be decreased.
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Abreu-Harbich, Loyde Vieira de, Giovana Gravellos Dias Starke Rodrigues, Pérola Felipette Brocaneli, Carolina de Rezende Maciel, and Sasquia Hizuru Obata. "Influence of Thermal Comfort provided by Tree Shadows on sidewalks in Downtown São Paulo." In A ERA AMBIENTAL: Do edifício à cidade, 9–20. Even3 Publicações, 2022. http://dx.doi.org/10.29327/5141261.1-1.

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Environmental quality of sidewalks influenced physical activity practices in public areas to prevent diseases related of sedentary lifestyle. Tree and its air thermoregulation capacity can modify microclimate conditions that affect people's daily behavior. To promote the thermal comfort on streets, it is necessary to design urban areas with trees and cool materials that can mitigate effects of heat islands. This work aims to evaluate the influence of thermal comfort in different urban landscapes on pedestrian walkability. Methodology: a) selection of route based on a transect that crosses different types of urban landscape: a park (dense green area) and streets with or not tree planted; b) collection of climate data (air temperature and humidity) and surface temperature by thermal pictures during 13 days in 2019 summer; c) quantification of thermal comfort in terms of Air Temperature; Physiological Equivalent Temperature (PET) and Universal Thermal Comfort Index (UTCI); d) statistical analysis of measured data and mapping of climate variables e) future scenarios using RayMan Pro. Results show air temperature differences between shaded and sun areas is up to 3,1 ° C and 4,5 ° C in terms of PET and 3,5 o C UTCI. It was observed that the features of shade of trees and planting strategies can also influence results. In streets, clusters of trees planted in line can promote more thermal comfort than other analyzed areas (on parks and streets without trees). Considering that people preferred walking on shady places, to plant aligned trees by species as Casealpinia peltophoroides (Sibipiruna) could attenuated 94,8 % of solar radiation and can reduce up to 16o C PET in flat areas. Future scenarios with trees show that São Caetano street can improve air temperatures to 0,5o C in terms of Ta, 1,4 o C PET and 0,9o C UTCI. To reduce heat stress and promote more thermal comfort sensations, it's necessary to modify materials used on façades and pavements. This strategy can improve local commerce due preference of walking on wooded streets by species that can’t filter solar radiation and permits the wind permeability. These results can promote the re-naturalization of commercial areas of Sao Paulo downtown and improve microclimate of urban environments.
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"efficiency. By measurements of total odour strength in a treatment plant the ED values pointed out the sludge press and dewatering process as the predominant odour sources of the plant. In the venting air from this position extremely high ED values were recorded. This air was led through a carbon filter for odour reduction. Olfactometric measurements at the filter revealed poor odour reducing efficiency. It was observed that odour compounds were not destroyed in the filter. They only restrained until the carbon became saturated, and thereafter evaporated into the outlet air contributing to the odour strength. The filter capacity was obviously too small for the heavy load. Attempts to reduce the odour strength before the filter did not succeed, until the air was led through a container filled with saturated lime slurry (pH = 12-14). The slurry was part of a precipitation process in the plant. Dispersion in the alkaline slurry extensively reduced the odour strength of the air, resulting in sufficient capacity of the carbon filter also when handling heavy loads of sewage sludge. Since then the carbon filter has worked well, within the limitation of such filters in general. Neither is it observed signs indicating reduced precipitation properties of the lime slurry. Measurements of total odour strength in combustion processes imply sampling challenges. Beside the chemical scrubber process, combustion of odorous air is the best odour reducing method. The disadvantage of this process is the high energy costs. Treatment at apropriate conditions, however, will destroy the odorous compounds extensively. Temperatures about 850 C and contact time up to 3 seconds are reported (2,3). Olfactometric measurements in combustion processes involve certain sampling problems caused by the temperature difference between inlet and outlet. The humidity of outlet air must also be taken into consideration. Problems may occur when hot outlet air is sampled at low temperatures. In most such cases sampling is impossible without special arrangements. Such conditions are present during odour measurements in fish meal plants with combustion as the odour reducing method. The largest problem turned out to be the temperature differences between outlet air (85-220 C) and outdoor temperatures (0-15 C), causing condensation. The dew point of the outlet air was calculated, and experiments were carried out with dilution of the outlet air to prevent condensation in the sampling bags. Condensation was prevented by diluting the outlet air 5-150 times with dry, purified N gas. Comparison of N -diluted and undiluted samples revealed large differences in ED value. In samples demanding a high degree of dilution to prevent condensation, the measured odour strength was up to 5 times higher than in the undiluted corresponding samples. Samples demanding less dilution showed less deviating results. 4. CONCLUSIONS In the attempt to minimize odour emission, olfactometric measurements of total odour strength give useful informations about the odour reducing efficiency of different processes as a function of parameters like dosage of chemicals in scrubbers, humidity and temperature in packed filters, flow rates, etc. Olfactometric measurements also point out the main odour sources of the plant. From a set of olfactometric data combined with other essential." In Odour Prevention and Control of Organic Sludge and Livestock Farming, 98. CRC Press, 1986. http://dx.doi.org/10.1201/9781482286311-34.

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Тези доповідей конференцій з теми "Filtres – Humidité":

1

Wilcox, Melissa, David Ransom, and Hector Delgado-Garibay. "Filter Failure During High Humidity Conditions." In ASME Turbo Expo 2010: Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-23641.

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The operation of a gas turbine, by its basic design, requires it to ingest enormous quantities of air. Even in relatively clean environments, a gas turbine may ingest hundreds of pounds of foreign matter each year of various sizes. Also, the more advanced the turbine design, the more sensitive it is to the quality of the air ingested. Filtration is applied to the inlet air to provide protection against the effects of contaminated air. Filters used with gas turbines are designed to remove a specified amount of particular contaminants. One type of filter is the high efficiency filter. These are often installed in order to capture particles less than ten microns. These filters are sometimes susceptible to water penetration. If the filter is not designed to remove water, then water can absorb soluble contaminants and carry them through the filter into the inlet of the gas turbine. In the case where harmful contaminants travel through the filter with the water, this can be potentially damaging to the gas turbine. For example, salt is soluble and can lead to hot corrosion in the turbine section. If water is allowed to reach the high efficiency filters then the water may carry contaminants through the gas turbine. In order to mitigate this phenomenon, many filter systems have mist removal systems. Even with a good mist removal system, humidity can reach the high efficiency filters. As humid air flows past the high efficiency filters, the decrease in air pressure can lead to water condensing on the filters. A procedure is presented in this paper which shows that filters that have been fully or near fully loaded with contaminants may experience condensation in an environment with high humidity. This paper reviews a thermodynamic analysis that is used to determine the conditions that must be met in order to experience this phenomenon. The possible occurrence of condensation further demonstrates the criticality of replacing inlet filters as soon as the filter pressure loss shows an upward trend.
2

Schroth, Thomas, Antje Rudolph, and Carl Freudenberg. "Newly Developed Filter Products for Gas Turbine Intake Air Filtration." In ASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1996. http://dx.doi.org/10.1115/96-gt-517.

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The newly developed depth-loading filter types MaxiPleat filter and depth-loading filter cartridge offer gas turbine users numerous advantages in terms of clean air quality in the combustion air, cost-efficiency due to favourable pressure drop, long life and high functional reliability over the entire operating period. The MaxiPleat filters fitted with a paper-like filter medium are produced by using the patented thermal embossing process, distinctive for its solution to the spacing problem. Without using any foreign materials as separators, depths of 250 mm can be achieved in pleating, with V-shaped, flow-optimized pleat geometries. This ensures low pressure drops and high dust holding capacities. The depth-loading filter cartridge is intended as a replacement filter for surface-loading filter cartridges given unsatisfactory results. A conventional pulse-jet system can be converted to a depth-loading filter without any expensive modification. The depth-loading filter cartridge extends substantially the useful life of the filters and significantly improves the pressure drop characteristics, especially when sticky dusts and high humidity locations are involved.
3

Penrod, Samuel L., Pete D. Unger, Ronald P. Rohrbach, Daniel E. Bause, Lixin Xue, and Russ A. Dondero. "Filtration of Aircraft Cabin Air Odors in 100% Relative Humidity, Low Temperature Conditions." In ASME 1998 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/imece1998-0646.

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Abstract Aircraft cabin air is frequently contaminated by low concentration odor causing compounds. Activated carbon has a long history of effective application in gas stream treatment. However, little information is available on removing low concentration odor causing compounds in high humidity, cold air environments. Previous research suggests that high relative humidity would severely reduce the effectiveness of activated carbon filters. Operating conditions in aircraft low pressure water separators typically run at 100% relative humidity and 2°C. Effluent or “breakthrough” curves at 5 ppmv toluene resulted in an adsorption capacity of 0.3 g toluene per gram media at 100% relative humidity compared to a 33% increase at less than 5% relative humidity, i.e. 0.4. Breakthrough analyses were performed at 5 to 40 ppmv toluene at face velocities of 50 to 180 m/min. These results indicate that carbon fiber based filter media hold the promise of effective odor control under conditions of high humidity and low temperature.
4

Gahr, Thomas C., James D. Benson, Kristine Graham, Mark Gogins, and Michael Brown. "Advancements in Electrospun Nanofiber Technology Reduce Gas Turbine Compressor Fouling." In ASME Turbo Expo 2005: Power for Land, Sea, and Air. ASMEDC, 2005. http://dx.doi.org/10.1115/gt2005-68266.

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It is well established that sub-micron ambient aerosol contamination of the intake air can produce fouling of the gas turbine compressor and result in a reduction of power output. Application of electrospun nanofibers of 0.25 micron diameter to a conventional filter media substrate has been demonstrated to improve the efficiency of gas turbine intake filters to remove sub-micron contaminate. The benefits of nanofiber filtration have been proven through use in gas turbine intake air filtration and other industrial and defense filtration applications for over twenty years. Recent advancements in electrospun nanofiber media technology have increased the filtering efficiency of gas turbine intake filters, with minimal differences in filter element pressure loss. These advances have also improved the durability of nanofibers in high temperature and high humidity applications. This paper discusses the laboratory testing that demonstrates these performance and durability improvements. A comparative field test program demonstrates the capability of nanofiber filtration to significantly reduce the fouling of gas turbine compressors.
5

Madsen, Stian, Jørn Watvedt, and Lars E. Bakken. "Gas Turbine Fouling Offshore: Air Intake Filtration Optimization." In ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/gt2018-75613.

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Optimized operation of gas turbines is discussed for a fleet of eleven LM2500PE engines at a Statoil North Sea offshore field in Norway. Three engines are generator drivers while eight engines are compressor drivers. Several of the compressor drive engines run at peak load (T5.4 control), hence production rate is limited by the available power from these engines. The majority of the engines discussed run continuously without redundancy, hence gas turbine uptime is critical for the field’s production and economy. The performance and operational experience with upgraded inlet air filter systems, as well as successful operation at longer maintenance intervals and higher average engine performance are described. For North Sea operation, a key property of the filter system is the ability to handle high humidity and high salt-content, typical of the harsh environment in these waters. The upgraded filter system analyzed in this paper is a 2-stage system (vane separator stage upstream of the high-efficiency filter stage), which is a simplified design versus the old traditional 3-stage systems (louvre upstream and vane separator downstream of the filter stage). These 2-stage systems rely on an efficient upstream vane separator to remove the vast majority of water from the airflow before it reaches the high-efficiency filters. The high-efficiency filters are specially designed to withstand moisture. The effectiveness and contribution of each component in the filtration system are described. Extensive testing of both new and used filter elements, of different filter grade and operated at different intervals, has been performed in a filter test rig facility onshore. Extensive testing of used filters has also been performed at the filter OEM, where filter efficiency is measured as well as destructive testing and analysis of the filter layers. The effect of an optimized air intake filter system for the subject engines, is longer operating intervals, higher power availability and lower engine deterioration. The operating intervals are now extended to six months (4,000 hours), from initially two months (1,500 hours, early 1990s) then four months (3,000 hours, mid 2000s). The HPC efficiency deterioration is reduced by some 3% related to intake filter system, of a total of over 6% in efficiency deterioration over each 6-month operating period.
6

Abdo, Peter, B. P. Huynh, and Vahik Avakian. "Effect of Green Wall Modules on Air Temperature and Humidity." In ASME 2018 5th Joint US-European Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/fedsm2018-83139.

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Green or living walls are active bio-filters developed to enhance air quality. Often, these walls form the base from which plants are grown; and the plant-wall system helps to remove both gaseous and particulate air pollutants. They can be classified as passive or active systems. The active systems are designed with ventilators which force air through the substrate and plant rooting system, therefore the air is purified and filtered through a bio-filtration process which also acts as a natural cooling system. Their benefits include temperature reduction, improvement of air quality and reduction of air pollution, oxygen production as well as the social and psychological wellbeing. They can produce changes in the ambient conditions (temperature and humidity) of the air layers around them which create an interesting insulation effect. The effect of green wall modules on the air temperature and on humidity is investigated in this work. A closed chamber made of acrylic sheets is used to monitor the temperature and humidity variation caused by a green wall module placed at its center. A fan positioned at the back center of the module drives air at ambient conditions and direct it into the module. Temperature and humidity are measured at different locations inside the chamber during operation for different modules with different plant species. The effect of changing the surrounding ambient conditions is also investigated.
7

Pond, B. J., H. Nusbaum, T. C. Du, J. Sobczak, R. A. Schmell, C. K. Carniglia, R. Petty, J. Johnston, and G. B. Charlton. "Measurements of Spectral Shifts and Stress Versus Relative Humidity in Multilayer Coatings." In Optical Interference Coatings. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/oic.1992.ofa3.

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The spectral performance of most multilayer optical coatings varies with changes in relative humidity (RH). The production of humidity-stable coatings is important to many applications where spectral performance is critical. An example of such an application is dichroic filters for multiple wavelength fiber-optic communication systems.
8

Madsen, Stian, and Lars E. Bakken. "Gas Turbine Operation Offshore: Increased Operating Interval and Higher Engine Performance Through Optimized Intake Air Filter System." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-56066.

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Optimized operation of gas turbines is discussed for six LM2500PE engines at a Statoil North Sea offshore field. Three engines are generator drivers whilst three engines are compressor drivers. Two of the compressor drive engines are running at peak load (T5.4 control), hence the production rate is limited by the available power from these engines. All of the six engines discussed run continuously without redundancy, gas turbine uptime is therefore critical for the field’s production and economy. The performance and operational experience with upgraded inlet air filter systems and online water wash at high water-to-air ratio, as well as successful operation at longer intervals and higher average engine performance are described. For North Sea operation, a key property of the filter system is the ability to handle high humidity and high salt-content through the harsh environment in these waters. The upgraded filter systems analyzed in this paper is a 2-stage system (vane separator stage upstream of the high-efficiency-filter stage), which is a simplified design versus the old traditional 3-stage systems (louvre upstream and vane separator downstream of the filter stage). These 2-stage systems rely on an efficient upstream vane separator to remove the vast majority of water from the airflow before it reaches the high-efficiency filters. The high-efficiency filters are especially designed to withstand moisture. Deposit analysis from the downstream side of the filters has been performed. Extensive testing of both new and used filter elements, of different filter grade and operated at different intervals, has been performed on a filter test rig facility onshore. All six engines have historically been operated with 4-month intervals between maintenance stops. Online wash is performed daily between the maintenance stops at full load (i.e. normal operating load for the subject engine). As a result of successful development and pilot testing of new filters and optimized filter change intervals, as well as successful online water wash, the engine operating intervals are now extended to 6 months with very low deterioration rate. Understanding the gas turbine performance deterioration is of vital importance. Trending of its deviation from the engine baseline facilitates load-independent monitoring of the gas turbine’s condition. Instrument resolution and repeatability are key factors in order to get reasonable results from the performance analysis. Improvement of the package instrumentation has been implemented on three of the analyzed engines, for better performance monitoring. As a result of these analyses, a set of monitoring parameters is suggested for effective diagnostics of compressor degradation. Avenues for further research and development are proposed in order to further increase the understanding of the deterioration mechanisms and the gas turbine performance and response.
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Chervinskii, Semyon, Ibrahim Issah, Markus Lahikainen, Alireza R. Rashed, Kim Kuntze, Arri Priimagi, and Humeyra Caglayan. "Humidity- and Temperature- Stimuli-Responsive Tunable Metal-Hydrogel-Metal Reflective Filter." In CLEO: QELS_Fundamental Science. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/cleo_qels.2022.fth5b.6.

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Our work demonstrates a tunable reflectance filter based on a metal-hydrogel-metal structure responsive to humidity and temperature. The filter employs a hydrogel as an insulating layer. Swelling/deswelling and the volume phase transition of the hydrogel allow continuous reversible humidity- and/or temperature-induced tuning of the optical resonance.
10

Herrmann, R., R. Goetzelmann, and R. Schneider. "Stability of Dielectric Multilayer Coatings Produced by Different Coating Technologies." In Optical Interference Coatings. Washington, D.C.: Optica Publishing Group, 1988. http://dx.doi.org/10.1364/oic.1988.thd11.

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Multilayer dielectric filters exhibit a more or less strong shift of their spectral properties when subjected to environmental changes such as changing humidity or temperature. The shift depends on the type of coating materials used and their internal structure. The structure is influenced by the process technology applied for the production of the filters.

Звіти організацій з теми "Filtres – Humidité":

1

Vendel, J., and P. Letourneau. Effect of humidity on the filter pressure drop. Office of Scientific and Technical Information (OSTI), February 1995. http://dx.doi.org/10.2172/95649.

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2

Cheng, Mengdawn, Lee Trowbridge, Glenn A. Fugate, and Jason Richards. Capture of Uranium Particles By Filtration: Effects of Filter Material and Air Humidity. Office of Scientific and Technical Information (OSTI), January 2020. http://dx.doi.org/10.2172/1606911.

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3

Gupta, Ajay. Study of the effect of humidity, particle hygroscopicity and size on the mass loading capacity of HEPA filters. Office of Scientific and Technical Information (OSTI), January 1992. http://dx.doi.org/10.2172/10172571.

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