Bibliografie tematiche / Filter clogging

Letteratura scientifica selezionata sul tema "Filter clogging"

Autore: Grafiati

Pubblicato: 8 giugno 2024

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Articoli di riviste sul tema "Filter clogging":

Liu, Chunye, Rui Wang, Wene Wang, Xiaotao Hu, Wanying Wu e Fulai Liu. "Different Irrigation Pressure and Filter on Emitter Clogging in Drip Phosphate Fertigation Systems". Water 14, n. 6 (9 marzo 2022): 853. http://dx.doi.org/10.3390/w14060853.

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Irrigation pressures and filters have a significant influence on emitter clogging in drip fertigation systems. Exploring the anti-clogging performance of emitters at different irrigation pressures (80, 90, 100 kPa; 40, 50, 60 kPa) and filters (the disc filter with an aperture of 125 μm, the screen filter with an aperture of 125μm, and the screen filter with an aperture of 200 μm) can provide suitable guidance for the design and operation of drip fertigation systems. The average relative discharge (Dra), the Christiansen uniformity coefficient (CU), and the differential pressure (DP) were analyzed to study the anti-clogging performance of flat emitters (FE) and labyrinth emitters (LE). Meanwhile, the scanning electron microscope and energy dispersive spectrometer were used to observe the surface morphology and chemical composition of clogging substances in filters and emitters. Results showed that the irrigation pressure of 90 and 50 kPa did not cause a significant decrease in Dra, and the Dra of two types of emitters were all great than 95.22%. When the irrigation pressure was 80 and 40 kPa, the Dra decreased significantly (73.48–78.71%, 81.3–83.6% for FE and LE). The CU values of emitters were all greater than 90% except for the irrigation pressures of 80 and 40 kPa. The relative Dra and CU of LE were greater than those of FE, indicating that the LE had a better anti-clogging performance compared with the FE. The decrease in DP reflected an increase in the emitter clogging degree. Meanwhile, irrigation pressures and the interaction between irrigation pressures and filters imposed a significant effect on the CU at a significance level of p < 0.05, p < 0.01, respectively. The clogging process was mainly affected by physical and chemical factors, and the generated clogging substances included phosphate fertilizer, silicate, carbonate, and phosphate precipitations. In conclusion, the best operation mode of phosphate fertilizer in drip fertigation systems was to use the disc filter with an aperture of 125 μm and the LE at the irrigation pressure of 50 kPa. An appropriate irrigation pressure combined with effective filters can reduce emitter clogging while saving water and fertilizer.

Bang, Ki Woong, Jin Chul Joo, Jin Ho Kim, Eunbi Kang, Jongsoo Choi, Jung Min Lee e Yonghyok Kim. "Application of Bottom Ash as Filter Media for Construction Site Runoff Control". Water 12, n. 4 (1 aprile 2020): 990. http://dx.doi.org/10.3390/w12040990.

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The potential application of bottom ash (BA) for construction site runoff control as an alternative filter media with high removal efficiency of total suspended solids (TSS) and longer operation period were evaluated. Both lab-scale single-layer and pilot-scale multi-layer filtration experiments were performed using BA filter media with different particle sizes and various volumetric flow rates. Due to the mesoporous, irregular, and spherical shape of gravel-size BA filter media used in this study, relatively low surface area, negligible pore volume, and greater pore size were observed. Both TSS removal efficiencies and clogging of BA filter media were a complex function of particle size of BA filter media and loading rate of TSS. Incoming TSS particles did not significantly penetrate beyond 46-cm BA filter media depth, accumulating on the upper layers and gradually forming a clogging layer to critical thickness, and finally the clogging filtration mechanism dominated the overall removal efficiency of TSS. Accumulation of TSS on BA filter media can be explained by the lumped sigmoidal empirical model, and an exponential decline in accumulation of TSS with depth results in minimal accumulation beneath the clogging layer. As practical implications, BA filter media depth of less than 46 cm is recommended with dual- or multi-media filters using mixtures of gravel-size BA and silt-size fine media, and a combination of detention basins can reduce frequent periodic de-clogging operation and management.

Wu, Zhengguang, Yanjuan Qi, Aihong Kang, Bo Li e Xueling Xu. "Evaluation of Particulate Matter Capture and Long-Term Clogging Characteristics of Different Filter Media for Pavement Runoff Treatment". Advances in Materials Science and Engineering 2020 (27 agosto 2020): 1–15. http://dx.doi.org/10.1155/2020/5012903.

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The removal of particulate matter (PM) by filter media during filtration process can mitigate the pavement runoff pollution effectively. However, this process also makes the filter media prone to clogging. To better understand the size ranges of PM captured by filter media and the subsequent impact on the clogging process, filtration test and clogging test were conducted on five types of filter media. The effect of layer thickness and grain size of different filter media on particle removal efficiency was evaluated, based on the results of PM removal rate and the particle size distribution. The subsequent long-term clogging characteristics of different filter media were also investigated. The results showed that filter media presented different capabilities to capture PM, which could be enhanced by less layer thickness or finer grain size. Normally, PM with the size range of over 49 μm could be captured effectively if proper layer thickness and grain size of filter media were selected. Besides, PM removal rate was not related to the clogging resistance of filter media. Though it can capture a larger amount of PM, Vesuvianite still maintained remarkable clogging resistance. The results will be beneficial to filter media selection and system design optimization for pavement runoff treatment.

Reddi, Lakshmi N., Ming Xiao, Malay G. Hajra e In Mo Lee. "Physical clogging of soil filters under constant flow rate versus constant head". Canadian Geotechnical Journal 42, n. 3 (1 giugno 2005): 804–11. http://dx.doi.org/10.1139/t05-018.

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In this study, the differences in soil filter clogging are evaluated under two operating conditions: constant head and constant flow rate. Whereas filters placed around well screens and leachate collection systems are subjected to a constant flow rate, filters in earth dams and pavement drainage systems operate under constant or slightly varying heads. In this study, the experiments revealed similar permeability reductions with respect to time in both cases; however, the permeability reduction under the condition of constant head occurred in much fewer pore volumes than under the condition of constant flow rate. Self-filtration appeared to be greater under the condition of constant head. The physical clogging model developed for the conditions of constant flow rate and constant head showed good qualitative agreement with experimental observations.Key words: particle, clogging, filter, constant, head, flow.

Lee, Byungsik. "Convolutional Neural Network Model for Estimating Clogging of Ash-Mixed Sand Filters". Journal of the Korean Society of Hazard Mitigation 21, n. 4 (31 agosto 2021): 159–68. http://dx.doi.org/10.9798/kosham.2021.21.4.159.

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A deep learning model was developed to estimate the clogging of voids in bottom-ash-mixed sand filters. Filter clogging is characterized by a decrease in the infiltration ratio with an increase in the outflow. The estimation of clogging for time-series forecasting is a regression problem. Various algorithms for regression problems have been applied through machine learning and deep learning. Despite the various algorithm applications, an application for clogging appears to be emerging. Studies are required to develop dependable models for precisely predicting clogging. A convolutional neural network (CNN) clogging model was developed in this study to estimate the relationship between the infiltration ratio and outflow quantity using features defined by the mixing ratio between sand and ash. Significant clogging data required for the effective maintenance and stable operation of stormwater infiltration filters were obtained using the proposed model. The CNN clogging model is recommended as a supplement to conventional theoretical models and expensive experimental models.

Alimohammadi, Hossein, Kristina Vassiljeva, Eduard Petlenkov, Martin Thalfeldt, Alo Mikola, Tuule Mall Kull e Ahmet Köse. "Gray Box Time Variant Clogging behaviour and Pressure Drop Prediction of the Air Filter in the HVAC System". E3S Web of Conferences 246 (2021): 10002. http://dx.doi.org/10.1051/e3sconf/202124610002.

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Identification and prediction of clogging behavior in heating, ventilation, and air conditioning (HVAC) filters is crucial to avoid issues such as system overheating, energy waste, lower indoor air quality, etc. Researchers are focusing more on the particle loading characteristics of a filter medium in a laboratory environment under steady-state conditions, fixed particle concentrations, area of porosity, dust feed and volumetric flow rate. However, recent research still shows uncertainties in modeling as well as the implementation problems of constructing the HVAC laboratory test bench and equipment. In addition, subjects such as non-uniform particle deposition depreciation of the condition and various type of mechanical filters such as fibrous, fabric, granular, and membrane filter or electrostatic filters which typically used in HVAC systems perform under some assumptions and still need more research. The studies become even more difficult acquiring a large number of time-varying and noisy signals. Another approach among studies is data-driven knowing that Building Automation System (BAS) is not equipped with appropriate sensor measuring the clogging, it is needed to drive the clogging mathematical model from the pressure drop signal. This paper bridges the gap between particle-size study and black box modeling of HVAC filter which has not received much attention from authors. The proposed method assumes that the pressure drop is the result of two time-varying functions; f(t), which represents the dynamics of clogging and, g(t), which refers to dynamics of remained terms. The exponential and polynomial of second order functions are proposed to express the clogging behavior. The software package based on Particle Swarm Optimization Artificial Bee Colony (PSOABC) algorithm, is developed and implemented to estimate the coefficients of the clogging functions based on smallest RMSE, high coefficient of correlation and acceptable tracking. Five Air Handling Unit (AHUs) are selected for practical verification of the model and the results show that the applied method can successfully predict clogging and pressure drop behaviour of HVAC filters.

Alavi Moghaddam, M. R., Y. Guan, H. Satoh e T. Mino. "Filter clogging in coarse pore filtration activated sludge process under high MLSS concentration". Water Science and Technology 54, n. 10 (1 novembre 2006): 55–66. http://dx.doi.org/10.2166/wst.2006.728.

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Coarse pore filtration activated sludge process is a type of hybrid process in which the secondary settling tank of the conventional activated sludge process is replaced by non- woven and coarse pore filter modules. The filter has pores, which are irregular in shape, and much bigger than micro-filtration membrane pores in size. The objective of the study is to find out the effect of the microbial community structure on filter clogging in the coarse pore filtration activated sludge process under high MLSS concentration in aerobic and anoxic/aerobic (A/A) conditions. Filter clogging started from day 65 and 70 in the A/A and aerobic process, respectively, but it was more severe in the A/A process compared to that in the aerobic process. EPS contents of sludge did not change significantly during the operation in both processes, and did not have a crucial effect on the observed filter clogging. There was no strong evidence for direct effect of the type and number of metazoa on filter clogging. The main difference between aerobic sludge and A/A sludge during the filter clogging period was the relative abundance of filamentous bacteria. According to the obtained results, it can be concluded that a higher presence of filamentous bacteria could reduce the severity of filter clogging in a coarse pore filtration activated sludge process.

Dalri, Alexandre B., Gilmar O. Santos, Geffson de F. Dantas, Rogério T. de Faria, José R. Zanini e Luiz F. Palaretti. "Performance of drippers in two filtering systems using sewage treatment effluent". Revista Brasileira de Engenharia Agrícola e Ambiental 21, n. 6 (giugno 2017): 363–68. http://dx.doi.org/10.1590/1807-1929/agriambi.v21n6p363-368.

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ABSTRACT The objective of this study was to evaluate the performance of three models of drippers using treated sewage effluent, pure and diluted, and two types of filters, screen and disc. The treated sewage effluent used in the experiment was collected from the city’s treatment plant. The experiment included 12 lateral lines with three types of emitters to apply pure (100%) and diluted (50%) effluent filtered by screen and disc filters. The combination of those factors set the treatments: T1 (50% effluent diluted in fresh water filtered by a screen filter); T2 (50% effluent diluted in fresh water filtered by a disc filter); T3 (pure effluent filtered by a screen filter); T4 (pure effluent filtered by a disc filter). The results showed that the flat type emitter is less sensitive to clogging, the disc filter is the most suitable to prevent clogging and the use of pure or diluted sewage effluent increases the drippers’ flow rate coefficient of variation.

Shuraits, A. L., A. V. Birykov e A. P. Usachev. "DEVELOPMENT OF A CALCULATION METHODFOR TWO-STAGE NATURAL GAS PURIFICATION PLANTS FROM MECHANICAL IMPURITIES". Russian Journal of Building Construction and Architecture, n. 1(49) (24 febbraio 2021): 54–65. http://dx.doi.org/10.36622/vstu.2021.49.1.005.

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Statement of the problem. Currently, there is no methodology for calculating the degree of clogging of a multilayer filter cartridge taking into account the prevention of deposition of mechanical impurities in the gap between the coarse and fine filter cylindrical filter cartridges. In this regard, the development of such a technique is an urgent task. Results. In this paper, we propose a calculation method for determining the average integral degree of clogging of multilayer cylindrical filter cartridges with mechanical impurities and pressure loss on them which take into account the prevention of sedimentation of mechanical impurities in the gap between the coarse and fine filter cartridges.Conclusions. The results obtained make it possible to determine the pressure loss and the average integral degree of clogging of the multilayer filter cartridge depending on the decrease in the living cross-section of all filter meshes in the process of clogging and to prevent the deposition of solids in the gap between the coarse and fine filter cartridges.

Valmari, Tuomas, Matti Lehtimäki e Aimo Taipale. "Filter Clogging by Bimodal Aerosol". Aerosol Science and Technology 40, n. 4 (aprile 2006): 255–60. http://dx.doi.org/10.1080/02786820500543282.

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Più fonti

Tesi sul tema "Filter clogging":

Biswas, Sharbaree. "Study of cohesive soil-granular filter interaction incorporating critical hydraulic gradient and clogging". Access electronically, 2005. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20060221.100311/index.html.

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Sliwinski, Kristoffer. "A Machine Learning Approach to Predictively Determine Filter Clogging in a Ballast Water Treatment System". Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-263931.

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Since the introduction of the Ballast Water Management Convention, ballast water treatment systems are required to be used on ships for processing the ballast water to avoid spreading bacteria or other microbes which can destroy foreign ecosystems. One way of pre-processing the water for treatment is by straining the water through a filtration unit. When the filter mesh retains particles, it begins to clog and could potentially clog rapidly if the concentration of particles in the water is high. The clog jeopardises the system. The thesis aims at investigating if machine learning through neural networks can be implemented with the system to predictively determine filter clogging by investigating two popular network structures for time series analysis. The problem came down to initially determine different grades of clogging for the filter element based on sampled sensor data from the ballast water treatment system. The data were then put through regression analysis through two neural networks for parameter prediction, one LSTM and one CNN. The LSTM predicted values of variable and clogging labels for the next 5 seconds and the CNN predicted values of variable and clogging labels for the next 30 seconds. The predicted data were then verified through classification analysis by an LSTM network and a CNN. The LSTM regression network achieved an r 2 -score of 0.981 and the LSTM classification network achieved a classification accuracy of 99.5%. The CNN regression network achieved an r 2 -score of 0.876 and the CNN classification network achieved a classification accuracy of 93.3%. The results conclude that ML can be used for identifying different grades of clogging but that further research is required to determine if all clogging states can be classified.
Sedan Ballast Water Management-konventionen introducerades har fartyg behövt använda barlastvattensystem för att behandla barlastvattnet i ett försök att hämma spridningen av bakterier och andra mikrober som kan vara farliga för främmande ecosystem. Ett sätt att förbehandla vattnet innan behandling är genom att låta det passera genom ett filter. När filtret samlar på sig partiklar börjar det att klogga och kan potentiellt klogga igen snabbt när koncentrationen av partiklar i vattnet är hög. Kloggning kan äventyra systemets säkerhet. Det här examensarbetet ämnar att undersöka om maskininlärning genom neurala nätvärk kan implementeras i systemet för att prediktivt bestämma filtrets kloggningsgrad genom att undersöka lämpligheten hos två populära nätverksstrukturer för tidsserieanalys. Problemet handlade initialt om att bedömma olika kloggningsgrader för filterelementet baserat på samplade sensordata från barlastvattensystemet. Datan kördes sedan för regressionsanalys genom två neurala nätverk, ett av typen LSTM och ett av typen CNN för att prediktivt bestämma paramterarna. LSTM-nätvärket uppskattade variabelvärden och kloggningsgrad för de kommande 5 sekundrarna medan CNN:et uppskattade variabelvärden och kloggningsgrad för de kommande 30 sekunderna. Den uppskattade datan verifierades sedan genom klassificering av ett LSTM nätverk och två CNN. LSTM nätverket för regression uppnådde ett r 2 -resultat på 0.981 och LSTM nätverket för klassificering uppnådde en klassificeringsgrad på 99.5%. CNN:et för regression uppn˚adde ett r 2 -resultat på 0.876 och CNN:et för klassificering uppnådde en klassificeringsgrad på 93.3%. Resultatet visar att ML kan användas för att identifiera olika kloggningsgrad men ytterligare forskning krävs för att bestämma om alla kloggningsstadier kan klassificeras.

Andersson, Karolina. "Igensättning av långsamfilter i Östby vattenverk i Kramfors : studie av påverkande faktorer". Thesis, Uppsala University, Department of Earth Sciences, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-9281.

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Östby waterworks in the community of Kramfors has since 2003 had problems of fast clogging of the slow sand filters. As the clogging appears more often, they must be cleaned more frequently which has made the drinking water preparation difficult. Wintertime it has sometimes been impossible to clean the filters which has led to their closing and this has influenced the water quality negatively.

The waterworks is a surface waterworks which takes its raw water from the lake Sjöbysjön. The water is flocculated and filtered in a contact filter with the flocculent EKOFLOCK 91. Thereafter it is alkalinized before it reaches the outdoors placed slow sand filters. After the filters the water is alkalinized and disinfected before it reaches the customers.

This thesis work has looked into which factors influence the clogging and trials have been made in order to optimize the waterworks and thereby reduce the clogging. The raw water has been studied with aspect to biology and chemistry, the filtered water has been studied with aspect to chemistry and also the pressures in the slow sand filters have been studied.

The colour of the raw water from Sjöbysjön and its catchment area has increased since the beginning of the 90-ies and also the bio volume has increased in the lake.

The contents of aluminium before the slow sand filters are far higher than the contents after, which leads to the conclusion that aluminium is accumulated in the filters. The differential pressure over the sand bed increases with time after a cleaning. This indicates an accumulation of particles which increases with the load. Observations of the filter surface before cleaning showed that it was covered by a brown, jelly-like film. The internal resistance in the filter beds increases successively after a cleaning and one month after cleaning it is highest in the upper part of the sand bed. All this points to that flocculated aluminium is gathered in the slow sand filters, on the surface, causing clogging.

While the thesis work has been going on a process of alkalinizing before the contact filters has been reengaged and this has influenced the flocking of organic materials. When raising the pH the dose of flocculent was increased and this combined increased the amount of flocculated material. The contact filters could not bear this increased amount of flock load but showed instead a breakthrough.

In a few lab scale trials the flocking pH was varied as well as the dose flocculent to the raw water and after this the water was filtrated. A tendency was seen that the separation of aluminium, colour and turbidity increased with increasing pH and dose flocculent. At the pH 6.2 and the chemical dose of 60 g/m3 the content of aluminium, the colour and the turbidity showed the lowest values in the filtrate.

Vattenverket i Östby, Kramfors kommun, har sedan 2003 haft problem med för snabba igensättningar i långsamfiltren. Ju oftare de sätter igen desto mer frekvent måste de rensas vilket har försvårat dricksvattenberedningen. Vintertid har rensningar ibland inte kunnat utföras och långsamfiltren har därför stängts av vilket har påverkat vattenkvaliteten negativt.

Verket är ett ytvattenverk som tar sitt råvatten från Sjöbysjön. Vattnet flockas och filtreras i kontaktfilter med fällningskemikalien EKOFLOCK 91. Därefter mellanalkaliniseras det innan det går till de utomhus placerade långsamfiltren. Efter långsamfiltren efteralkaliniseras och desinficeras det innan det når konsumenterna.

I detta examensarbete har faktorer som påverkar igensättningarna undersökts och försök har också gjorts för att optimera driften och därmed minska igensättningarna. Råvattnet har undersökts avseende dess biologi och kemi, filtraten i verken har undersökts med avseende på deras kemi och tryckbildningar i långsamfiltren har studerats.

Färgtalet i råvattentäkten Sjöbysjön och dess tillrinningsområde har ökat sedan början av 90- talet och dessutom har biovolymen i sjön ökat.

Halterna aluminium före långsamfiltren är mycket högre än halterna efter, vilket antyder att aluminium ansamlas i filtren. Differentialtrycket över sandbädden ökar med tiden efter en rensning. Detta tyder på en ansamling av partiklar som ökar med belastningen. Observationer av filterytan innan rensning visade att den täcktes av en brun geléaktig hinna. Motståndet i filtren ökar successivt efter en rensning och är en månad efter rensning störst i den övre delen av sandbädden. Allt detta pekar på att aluminiumflock ansamlas i långsamfiltren, på ytan, och orsakar igensättningarna.

Under examensarbetets gång har en föralkalinisering återinförts i vattenverkets process och den har påverkat fällningen av det organiska materialet. Då pH höjts har också dosen fällningskemikalie ökats vilket har ökat mängden flock. Denna ökade flockmängd har kontaktfiltren inte kunnat bära utan istället släppt igenom.

I några försök i labbskala varierades fällnings-pH och dos fällningskemikalie till råvatten med en efterföljande filtrering. Tendenser som kunde ses var att avskiljningen av aluminium, färg och turbiditet ökade med ökat pH och ökad dos fällningskemikalie. Vid pH 6,2 och kemikaliedos på 60 g/m3 var aluminiumhalterna, färgen och turbiditeten som minst i filtratet.

Mitchell, Ged. "An investigation into the factors affecting the behaviour of Highway Filter Drains, with a particular emphasis on the Scottish Trunk Road Network". Thesis, Abertay University, 2017. https://rke.abertay.ac.uk/en/studentTheses/768779b0-366a-434d-a28d-e9313885d37b.

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Approximately 1500 km (43%) of the strategic Scottish trunk road network drainage asset takes the form of Highway Filter Drains (HFDs). However, despite their popularity, they are prone to clogging, therefore they have an estimated operational life-cycle of ten-years. This research was undertaken to investigate the complex inter-relationship between catchment characteristics, road dynamics and the physical characteristics of the road to establish the key factors that govern the generation and spatial variability of Road-Deposited-Sediment (RDS). The aim being to establish the impact RDS Particle Size Distribution (PSD) has on clogging and the operational life-cycle of HFDs. The research adopted an integrated approach, incorporating: (i) a Field Study to investigate RDS PSD grading envelopes across the Scottish trunk road network, (ii) a HFD Field Survey (HFD-FS) to investigate the current condition of HFDs across a range of catchments, (iii) a HFD Field Study to establish whether, or not, graded stone PSD envelopes comply with specification requirements when first placed in the trench, (iv) 3 HFD Field Studies to assess the level of risk of system failure through evaluating the causes and quantifying the individual, cumulative and influencing factors which contribute to the evolution of clogging in HFDs, and (v) a Field Study utilising Ground Penetrating Radar data to explore why stratified (clogged) layers evolve within some HFDs. Based on the results of this research, design and maintenance procedures were then identified to improve the performance of HFDs. Results established that Scottish trunk roads operate under variable catchment characteristics and road dynamics, with the condition and specification of the road surface, volume of traffic, road geometry, number of running lanes and adjacent land use governing the generation and spatial variability of RDS. Five of the nine trunk road RDS PSD profiles shared a peak particle diameter of 425 μm, two had a peak of 600 μm, one had a peak of 1180 μm and one resulted in a peak of 2120 μm. Particles >1000 μm were mostly mineral or asphalt and it was shown that there is a direct link between the factors that govern the generation and spatial variability of RDS and those that govern the evolution of clogging and actual operational life-cycle of HFDs. The HFD-FS revealed that 69% were assigned Filter Drain Condition Index ratings of 3 or below, which identifies these as having exceeded the ten-year estimated operational life-cycle. 94% of those deemed to have reached the end of their operational life-cycle were over-the-edge (OTE) HFDs, which supports the assertion that pre-treatment would increase their operational life-cycle. Results also established that introducing a kerb-line and gully-pots or grass-strip between the road and the HFD significantly reduced the indices of particle size composition d50 and d90 and percentage of RDS retained at depths spanning 0 - 400 mm, compared to OTE HFDs with comparable catchment characteristics and road dynamics. Based on these results, the operational life-cycle of HFDs with a kerb-line and gully-pots and OTE HFDs with a grass-strip can be expected to exceed twenty-years, if catchment characteristics and road dynamics are representative of those in this study. This research also identified that compacting Type B graded stone with ‘heavy vibrating machinery’ during construction could potentially contribute to clogging. It was also established that HFD harrowing may exacerbate clogging because the process of disintegrating the cake-layer mobilises an otherwise rigid and compacted RDS mass and this is more likely to penetrate deeper into the HFD and inundate the HFD during a storm event. These findings indicate that current HFD construction and maintenance practice could have a detrimental impact on the effective operational life-cycle of HFDs. Overall, this research study has demonstrated that there are considerable uncertainties related to PSD grading envelopes and percentage of RDS migrating from roads to HFDs. It is clear therefore that one of the most notable findings of this research is that given the scale of strategic trunk road networks, assuming a single HFD operational life-cycle profile, for a trunk road or trunk road network, is highly unlikely to be representative of a HFD at the local level. It follows then that the widely accepted estimated ten-year operational life-cycle for HFDs, does not reflect the actual operational life-cycle of HFDs.

Pinto, Marinaldo Ferreira. "Desenvolvimento e avaliação de um sistema de filtragem com reversão de fluxo de alta frequência". Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/11/11143/tde-12072013-082758/.

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A obstrução de emissores tem sido um entrave para a microirrigação. Porém, tem-se notado poucos estudos relativos ao desenvolvimento de equipamentos que auxiliam na prevenção da obstrução de emissores nos últimos anos. Os estudos realizados nesta linha estão geralmente ligados à caracterização dos sistemas em uso. O objetivo deste trabalho foi desenvolver um sistema de filtragem com reversão automática de fluxo, de alta frequência. O sistema foi concebido para operar com água de baixa qualidade, com inversão de fluxo e limpezas automáticas e com volume mínimo de água para realização das limpezas. As decisões do controlador do sistema de filtragem têm como base a perda de carga, obtida por meio de transdutores de pressão instalados na entrada e na saída do sistema. O protótipo final é composto, basicamente, por três filtros de tela e onze válvulas solenoides controladas eletronicamente. Determinou-se a curva de perda de carga em função da vazão, a eficiência de retenção e o volume mínimo de água para limpeza dos filtros. A eficiência de retenção de partículas foi determinada em delineamento experimental inteiramente aleatorizado em esquema fatorial, sendo testados três fatores: tempo de reversão (15 e 30 s); incremento da perda de carga (25 e 50%) e concentração de sólidos (500 e 1000 mg L-1). A eficiência de retenção de sólidos totais foi de 71,7 e 78,3% para as concentrações de 500 e 1000 mg L-1, respectivamente, tendo apresentado diferença significativa a 1% de probabilidade. Entretanto, a eficiência retenção de sólidos maiores que 50 ?m (Ed > 50) foi de 98,6 ± 0,7%, não sendo significante para nenhum dos tratamentos ao nível de significância de 1%. O volume médio de água despendido durante as limpezas foi de 5,39 L por limpeza, que representou um volume de água de limpeza por volume de água filtrada de 8,0 e 12,6 L m-3, para as concentrações de 500 e 1000 mg L-1, respectivamente. Os valores de eficiência energética do sistema de filtragem variaram de 80 a 90% para a vazão de 2 m3 h-1 com pressão de entrada entre 15 a 40 mca. As limpezas do sistema de filtragem não foram totalmente eficazes na retomada da perda de carga, com tendência de aumento com o tempo. A inversão de fluxo com frequências de 11,11 e 22,22 mHz influenciou na evolução da perda de carga do sistema de filtragem, tornando-a mais lenta que a evolução para o sistema funcionando sem inversão de fluxo. Considerou-se que o sistema de filtragem desenvolvido apresentou potencial para filtragem da água de irrigação com baixa qualidade, porém necessita de manutenções periódicas para limpeza do elemento filtrante. A perda de carga admissível do sistema de filtragem deve ser o valor mais restritivo entre o critério de desempenho de retenção de partículas e o de variação de vazão do sistema de irrigação.
Emitters clogging have been a barrier to trickle irrigation. Just a few studies have been performed concerning equipments which assist in preventing emitters clogging in recent years, especially regarding to development equipment. Studies carried out on this issue are usually linked to the characterization of systems in use. The aim of this study was to develop a filtering system with automatic flow reversal of high frequency. The system is designed to operate with low quality water, with reverse flow and automatic cleanings and with minimum volume of water to perform the cleaning. Decisions by the controller of the filtration system are based on head loss, obtained by pressure transducers installed at the upstream and downstream of the system. The final prototype consists of three screen filters and eleven electronically controlled solenoid valves. The curve of head loss was determined as a function of water flow, retention efficiency and minimum volume of water required for cleaning the filters. The efficiency in particle retention was determined following a completely randomized experimental design in a factorial scheme in which three factors were tested: reversal time (15 and 30 s) increase in head loss (25 and 50%) and solids concentration (500 and 1000 mg L-1). The total solids retention efficiency was 71.7 and 78.3% for concentrations of 500 and 1000 mg L-1, respectively, presenting a significant difference at 1%. However, when analyzing the retention efficiency of solids larger than 50 ?m (Ed> 50), none of the treatments was significant at 1%, whose efficiency was 98.6 ± 0.7%. The mean volume of water expended during the cleaning was 5.39 L. It represented a volume of water for cleaning per volume of filtered water from 8.0 and 12.6 L m-3, to concentrations of 500 and 1000 mg L-1, respectively. The energy efficiency values of filtering system ranged from 80 to 90% considering flow rate of 2 m3 h-1 and inlet pressure ranging from 15 to 40 mca. The filtering system cleaning was not totally effective in reestablishing the head loss, with an upward trend over time. The reverse flow with frequency of 11.11 and 22.22 mHz influenced the head loss evolution of the filtration system, making it slower than the trend for the system running without flow reversal. The developed filtration system has potential for filtering low quality irrigation water, but it requires periodic maintenance to clean the filter element. The allowable head loss of the filter system should be the most restrictive value between the criterion of particle retention performance and the flow variation of the irrigation system because of the increase in head loss in the filters.

Boudhan, Rachid. "Performance of pulse-jet bag filter regarding particle removal for nano-waste incineration conditions". Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2017. http://www.theses.fr/2017IMTA0022/document.

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Les performances de filtration d’un filtre à manche vis-à-vis de particules submicroniques et nanométriques ont été évaluées à l’échelle du laboratoire durant plusieurs cycles de colmatage/décolmatage. La distribution granulométrique des particules (aérosol de combustion) était représentative de celle rencontrée en incinération de nano-déchets en sortie de chambre de combustion à l’échelle du laboratoire. Le filtre à manche opérait en conditions réalistes, représentatives de celles rencontrées dans les lignes de traitement des fumées d’incinération de déchets en termes de température, humidité, vitesse de filtration, présence de réactifs et conditions de décolmatage. Le flux d’air et le filtre à manche étaient chauffés à 150°C, la teneur en eau était de 10-12% (soit 3% d’humidité relative HR), et la vitesse de filtration était fixée à 1,9 cm.s⁻¹. Un mélange de particules de taille submicronique de charbon actif et de bicarbonate de sodium, utilisées dans les lignes de traitement des fumées d’incinération pour l’abattement des dioxines/furanes et des gaz acides, était généré simultanément avec l’aérosol de combustion. L’étude s’est centrée sur les performances de filtration au début de la durée de vie du filtre à manche, avant stabilisation de la perte de charge résiduelle du filtre résultant des précédents cycles de filtration. La perte de charge maximale du filtre était fixée à 150 Pa pour tous les cycles de filtration avant décolmatage par rétro-soufflage à air comprimé. Les performances du filtre à manche ont été évaluées en termes d’évolution de sa perte de charge et de son efficacité de collecte (totale et fractionnelle) au cours des cycles de colmatage/décolmatage. De plus, des études expérimentales et théoriques ont été menées afin d’étudier l’influence de divers paramètres sur les performances de filtration du filtre en configuration manche ou plane, tels que l’humidité de l’air (3% HR versus 0% HR à 150°C), la température (150°C versus 24°C), la vitesse de filtration (1,9 cm.s⁻¹ versus 1,4 cm.s⁻¹) et l’influence de l’injection de réactifs. Les principaux résultats de cette étude sont : (i) importante efficacité de capture des particules du filtre à manche en conditions représentatives des lignes de traitement des fumées d’incinération : efficacité minimale de collecte de 98,5% mesurée pour des particules de taille 74 ± 15 nm (diamètre de mobilité électrique), (ii) influence du gâteau résiduel de particules au début de chaque cycle de filtration sur les performances de traitement, (iii) influence significative de l’humidité de l’air sur la structure du gâteau de particules probablement due à l’augmentation des forces d’adhésion entre les particules en présence d’humidité (150°C – 3% HR soit environ 100 g d’eau par kg d’air sec) ; augmentation plus rapide de la perte de charge du filtre à manche en présence d’humidité (150°C – 3% HR) qu’en conditions d’air sec (150°C – 0% HR)
Filtration performance of a pulse-jet bag filter was evaluated at the laboratory-scale regarding submicronic particles with a nanosized fraction during clogging/unclogging cycles. The particle size distribution was representative to those encountered at the outlet of a nano-waste incineration device at laboratory-scale. The bag filter was operated in conditions as similar as possible to those found in flue gas treatment of waste incineration plants, in terms of temperature, humidity, filtration velocity, injection of sorbent reagents and unclogging conditions. The air flow and the bag filter were heated to 150°C, the water content was maintained in the air flow in the range of 10-12% (3% of relative humidity RH), and filtration velocity throughout the bag filter was fixed at 1.9 cm.s⁻¹. A mixture of submicronic suspended particles of activated carbon and sodium bicarbonate, both used in flue gas treatment systems mainly for the removal of dioxins/furans and acid gases, was generated simultaneously with the aerosol representative of combustion emissions.The study focused on the filtration performance at the beginning of the bag filter’s lifetime filter for the 11 first clogging-unclogging cycles before stabilizing the residual pressure drop reached after pulse-jet unclogging. The maximum pressure drop was set at 150 Pa for all filtration cycles. Once the maximum pressure drop was reached, the filter was unclogged using the pulse-jet system. The performance of the bag filter was evaluated in terms of the evolution of pressure drop, fractional and total particle collection efficiencies, during the clogging/unclogging cycles.Moreover, an experimental and theoretical study was carried out on the influence of different parameters on the filtration performance of bag filter and flat filter, such as influence of humidity (3% RH versus 0% RH at 150°C), temperature (150°C versus 24°C), filtration velocity (1.9 cm.s⁻¹ versus 1.4 cm.s⁻¹) and the influence of the injection of sorbent reagents.The main results of this study are: (i) high collection efficiency of the bag filter in representative conditions of flue gas treatment of waste incineration: minimun particle collection efficiency of 98.5% for particle diameter of 74 ± 15 nm (electrical mobility diameter), (ii) influence of residual particle cake at the beginning of the filtration cycles on the bag filter performance, (iii) significant influence of humidity on the porosity of the particle cake due to the capillary condensation of water between the particles in presence of humidity (150°C - 3% RH i.e. almost 100 g of water per kg of dry air). Faster increase of bag filter pressure drop in presence of humidiy (150°C - 3% RH) as compared to the dry conditions (150°C - 0% RH)

Gervais, Pierre-Colin. "Études expérimentale et numérique du colmatage de filtre plissé". Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0007/document.

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L'utilisation de filtres plissés dans le domaine du traitement de l'air est extrêmement fréquente en raison de leur simplicité d'utilisation et de maintenance. Néanmoins, au cours du colmatage, la perte de charge augmente considérablement avec le dépôt de particules. Par conséquent le débit de filtration n'est plus maintenu et une détérioration des médias peut se produire. Il est essentiel de caractériser cette évolution en fonction des conditions opératoires pour mieux concevoir ces équipements. Les travaux ont consisté en une étude expérimentale de l'influence des conditions opératoires sur la géométrie du dépôt par des observations en Tomographie d'Émission MonoPhotonique. Une approche numérique a consisté, dans un premier temps, en une étude de la perméabilité de médias bien caractérisés afin de valider le code GeoDict. Dans un deuxième temps, une étude de la vitesse de l'air a été entreprise sur les médias plissés. La confrontation des résultats numériques avec les données expérimentales nous a permis une validation du code dans les gammes de propriétés des médias et de vitesses typiques. Concernant les médias bimodaux, l'acquisition rapide de données a permis de tester différentes corrélations analytiques afin de classifier les modèles existants d'une manière qui facilite leur utilisation. Si les résultats expérimentaux obtenus sur la localisation du dépôt préférentiel initial dans les filtres plissés sont encourageants, notamment vis-à-vis des simulations d'écoulement réalisées avec GeoDict, ceux issus des acquisitions sur les filtres précolmatés sont à prendre avec prudence et suggèrent d'apporter un certain nombre d'amélioration à notre technique
Pleated filters are widely used in air treatments because of the advantageous effective surface to overall dimension ratio they offer. Their major drawback though resides in their reduced lifetime which still needs to be controlled. Indeed, when clogging, the pressure drop considerably increases, the filtration flow is then no longer maintained which might lead to the deterioration of the media. It is then crucial to characterize the evolution of the pressure drop under operating conditions in order to best design these equipments. Part of our work consisted in studying how the operating conditions influence the geometry of the deposit. To do so, we used Single-Photon Emission Computed Tomography (SPECT), a non-destructive imaging technique that keeps intact the particle structuring. The visualization of aerosol deposit at the beginning of the filtration process allows observing preferential particle deposition on the whole height of the pleat. A numerical approach was used to study the permeability of bimodal fibrous media and we experimentally studied the local velocity as well as the biphasic flow inside pleated filter media. Comparison between experiments and simulations allowed us to validate the Geodict code for a wide range of media properties and velocities. Regarding bimodal fibrous media, the fast data acquisition has allowed testing several existing models which resulted in classifying them in a unique way. If the experimental results on the initial deposition in pleated filters are encouraging, those related to beforehand clogging point to several improvements regarding the technique we used

Japuntich, Daniel A. "Clogging of fibrous filters with monodisperse aerosols". Thesis, Loughborough University, 1991. https://dspace.lboro.ac.uk/2134/7132.

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The clogging of fibrous air filters by solid aerosol particles in the inertial interception capture range was experimentally and theoretically investigated. Flat filters were loaded to particle filter cake formation at 0.10 m/s filter face velocity with monodisperse aerosols. An evaporator-condenser aerosol generator capable of producing a stable 0.6 kg/hr product of monodisperse, solid aerosols in the range 1 to 5 micrometers aerodynamic diameter was designed, fabricated, and optimized. The output aerosol was introduced into a vertical challenge duct, where the mass concentrations upstream and downstream of the filter sample, and thus the filter penetration, were measured using continuous flow sampling through two light scattering photometers. Simultaneous measurements were made of the filter flow resistance during the particle loading process. A discussion of the possible definitions of clogging is given from descriptions of the plots of the experimental filtration responses with mass challenge. The relationship between the clogging point and effective filter pore diameter for different aerosol challenges is given for medium efficiency fibreglass papers and for filters made with 15.5 micrometer diameter monodisperse fibres.

Le, Maout-Alvarez Coralie. "Étude expérimentale des effets chimiques sur le colmatage des filtres dans l’industrie nucléaire". Electronic Thesis or Diss., Université de Lorraine, 2023. http://docnum.univ-lorraine.fr/ulprive/DDOC_T_2023_0015_ALVAREZ.pdf.

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Lors d'un accident de type APRP (Accident de Perte du Réfrigérant Primaire) survenant dans réacteur nucléaire à eau pressurisé (REP), des débris sont générés et ils peuvent être partiellement transportés jusqu'aux filtres des systèmes de secours RIS-EAS des puisards situés dans le fond de l'enceinte de confinement du réacteur. Ces débris peuvent contribuer au colmatage « physique » des filtres. Un autre effet dit « effet chimique » correspond à l'apport de cations en solution de par la corrosion des débris (fibres d'isolant) et la possible corrosion de surfaces métalliques présentes dans le bâtiment réacteur. Ces cations métalliques peuvent former des précipités au sein du lit fibreux formés et accentuer le colmatage physique. En cas d'accident grave avec fusion du cœur, des charges additionnelles de débris sont à considérer comme la présence de particules formées de matériaux de structure, des barres de commande et de produits de fission et des particules de béton résultant d'un interaction corium-béton. Il a été clairement identifié dans la littérature que ces effets chimiques sont à prendre en compte pour s'assurer de la fonction recirculation sur une longue période. La question de recherche est d'être en mesure de comprendre la nature de ces effets chimiques, les paramètres les conditionnant et leurs ampleurs. Le sujet de thèse porte sur l'étude de ces effets chimiques, pour cela une approche paramétrique sera suivie en couplant plusieurs mesures chimiques et en corrélant ces mesures à une perte de charge. Les mesures chimiques en solution se feront principalement par ICP et la caractérisation des précipités potentiellement formés pourra se faire par des analyses type MEB-EDX, DRX et XPS. La boucle de filtration est à concevoir
During a LOCA accident (Loss Of Coolant Accident) occurring to a nuclear Pressurized Water Reactor (PWR), debris are generated and can be partially transported to the RIS-EAS filter in the sumps located in the bottom of the nuclear reactor containment. These debris can contribute to the « physical » clogging of the filters. Another effect called « chemical effects » corresponds to the presence of cations in solution resulting from the debris' corrosion and the possible corrosion of the metal surface present in the reactor containment vessel. In the case of a severe accident with core fuel meltdown, additional loads debris are to be considered as presence of particles formed of structural materials, control rod material, fission products and concrete particles resulting from corium-concrete interaction. To ensure the long term liquid recirculation functionality, the chemical effect have to be understood: nature of these chemical effects, conditioning parameters and potential effect on the clogging. The thesis aims at studying the chemical effects after designing a dedicated experimental loop: a parametric approach , coupled with several chemical and pressure drop measurements. Chemical speciation in solution and precipitate characterizations will/can be respectively performed by ICP and MEB-EDX, DRX and XPS techniques

Grippari, Florence. "Caractérisation et filtration des aérosols nonastructurés : application aux fumées de projection thermique des métaux". Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0158/document.

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Cette étude porte sur la filtration des particules métalliques contenues dans les fumées de métallisation. Des retours d'expériences spécifiques aux dépoussiéreurs filtrants les fumées de métallisation témoignent d'un colmatage des filtres très rapide ainsi que de l'inefficacité des techniques de décolmatage pneumatique habituellement utilisées. Il en résulte une durée de vie des éléments filtrants très réduite. L'objectif de cette étude est de caractériser le colmatage puis le décolmatage afin d'améliorer les performances des dépoussiéreurs à cartouches filtrantes vis-à-vis des fumées de métallisation. Trois axes de recherches ont été exploré sur un banc pilote spécialement équipé : - la caractérisation des fumées de métallisation. Elle a permis de qualifier la structure spatiale de la particule par la dimension fractale et le facteur de forme dynamique grâce au couplage série DMA-ELPI et à une méthodologie originale d'analyse des données validée sur différents aérosols. Les caractéristiques obtenues expliquent les propriétés colmatantes des fumées de métallisation. - La caractérisation du dépôt engendré au cours de la phase de filtration (ou de colmatage). Elle montre une structure incompressible dans la gamme de filtration habituellement pratiquée en industrie. Ces travaux ont permis d'estimer la porosité expérimentale du dépôt formé par les fumées de métallisation. - L'étude sur le décolmatage. Elle décrit et explique l'inefficacité des décolmatages utilisés en industrie. Il ressort que seule une très faible surface du média plissé est décolmatée. L'alternative du precoating se révèle très efficace mais seulement en mode off-line
This study deals with the filtration of metallic particles contained in the metallization fumes. Experience feedback specific to the filtration of metallization fumes by dust collectors report a rapid clogging of filters and the inefficiency of pneumatic cleaning techniques commonly used. This leads to a high reduction in filters lifetime. The objective of this study is characterize clogging then unclogging in order to improve the performance of dust cartridge filter against metallization fumes. Three research axes were explored on a dedicated bench : - Metallization fumes characterization. It allows describing the spatial structure of the particle by the fractal dimension and the dynamic shape factor with the DMA-ELPI serial coupling and thanks to an original data analysis methodology validated on various aerosols. The characteristics obtained explain the clogging properties of metallization fumes. - Characterization of the cake generated during the filtration phase (or clogging). It shows a incompressible structure in the velocities filtration range of industry. The experimental porosity of the cake formed by filtering metallization fumes is estimated thanks to these studies. - Study on cleaning. It describes and explains the inefficiency of pneumatic cleaning techniques employed in industry. It appears that only a very small surface of the pleated media is unclogged. The precoating alternative is shown to be very efficient provided that it is combined with off-line cleaning procedures

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Libri sul tema "Filter clogging":

Koerner, Robert M. Landfill leachate clogging of geotextile (and soil) filters: Project summary. Cincinnati, OH: U.S. Environmental Protection Agency, Risk Reduction Engineering Laboratory, 1991.

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McKnight, Suzanne Jane. The potential causes of clogging of geotextile filters in landfill sites. [London]: Queen Mary and Westfield College, 1992.

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Koerner, Robert M. Leachate clogging assessment of geotextile and soil landfill filters: Project summary. Cincinnati, Ohio: National Risk Management Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 1995.

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Japuntich, Daniel A. Clogging of fibrous filters with monodisperse aerosols. 1991.

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Capitoli di libri sul tema "Filter clogging":

Dudczig, Steffen, Enrico Storti e Christos G. Aneziris. "Registration of Filtration Efficiency of Active or Reactive Filters in Contact with Steel Melt in a Steel Casting Simulator". In Multifunctional Ceramic Filter Systems for Metal Melt Filtration, 489–517. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-40930-1_19.

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AbstractAspecial metal-casting simulator allowed to investigate the behavior of nozzles and filters in contact with a steel melt under controlled atmosphere. First, the clogging of carbon-bonded alumina nozzles with different active or reactive coatings was evaluated by introducing exogenous inclusions while monitoring the changes in melt flow with time. In addition, the microstructure of the nozzles was investigated by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy to assess the coating decomposition and phase transformations. In further approaches, endogenous inclusions were generated in situ by pre-oxidizing and deoxidizing the steel melt. Filters with different active and reactive coatings were immersed for different times in order to investigate the evolution of newly formed phases on the filter surface as well as characterize their cleaning performance based on the analysis of the solidified steel. The inclusions in the frozen steel melt were characterized with the aid of an automatic SEM – ASPEX-system, which identified the chemistry as well as the size and population of the inclusions. In the last approach, investigations of a new combined refining process based on the immersion of reactive filters and a subsequent filtration via carbon-free active filters was investigated, in order to remove the remaining clusters of inclusions.

Wetzig, Tony, Andreas Baaske, Sven Karrasch, Steffen Dudczig e Christos G. Aneziris. "Cleanness of Molten Steel—Active and Reactive, Exchangeable Filter Systems for the Continuous Casting of Steel". In Multifunctional Ceramic Filter Systems for Metal Melt Filtration, 741–68. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-40930-1_29.

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AbstractThe filtration of steel melts in the continuous casting of steel is of special interest in order to meet the ever-increasing purity requirements regarding the metal’s purity. Due to the high mass flow and the high casting duration, the application of in-built filters in the tundish system is rather challenging, especially regarding the filter capacity. In the framework of this contribution, a new concept involving the immersion of filters into the steel melt from above the tundish was investigated. This approach allows for the flexible exchange of used filters without interruption of the underlying process. At the Institute of Ceramics, Refractories and Composite Materials, carbon-bonded alumina filters on the basis of established slurry compositions and modified replication techniques were scaled up for the industrial application in continuous casting of steel. The best property profile was observed for a triple coating approach based on centrifugation, dip coating and spray coating. In the tundish of a steel casting simulator, a lab-scale casting test was conducted in order to check the thermos-mechanical behavior of the filter in contact with molten steel. After the successful evaluation in lab scale, the filters were tested in industrial trials in cooperation with the company thyssenkrupp Steel Europe AG. A ladle casting with immersed filter lasted approximately 45 min with a static casting speed of 8 to 10 t/min and a melt temperature of above 1550 °C. The filters were analyzed for inclusions and potential damage at the Institute of Ceramics, Refractories and Composite Materials. Dense clogging layers on the filter surface were identified as in-situ layers as usually observed in lab-scale steel casting simulator tests in consequence of reactive filtration effects. Furthermore, inclusion clusters which were removed at the filter bottom due to the direct inflow in consequence of the buoyancy were observed as signs of active filtration. A further alternative to foam filters is presented by gel-cast spaghetti filter structures with mechanically robust full-strut structure. In the subproject T01K, the gel casting process was optimized in order to realize the necessary upscaling of the components. With the aid of alginate-based gel casting, spaghetti filter with organized lattice structures were manufactured and tested. Steel casting simulator trials showed favorable behavior in contact with the melt.

Hu, Junlong, Yao Xie, Jing Wang e Deyong Wang. "Anti-clogging performance of coconut fiber filter of drainage body in vacuum preloading". In Urban Construction and Management Engineering IV, 372–78. London: CRC Press, 2024. http://dx.doi.org/10.1201/9781032626444-48.

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Kandra, Harpreet Singh, David McCarthy e Ana Deletic. "Review of clogging processes in stormwater treatment filters". In Sustainable Civil Engineering, 247–79. Boca Raton: CRC Press, 2023. http://dx.doi.org/10.1201/9781003368335-15.

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Yaşar, Fevzi. "Biodiesel Production from Algae Oil". In Algal Biotechnology for Fuel Applications, 59–72. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9789815051001122060006.

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In this study, biodiesel production was investigated by the transesterificationreaction from algae oil. For biodiesel production, the oil obtained from Chlorellaprotothecoides type algae grown in freshwater with 5% thermal water was added tofully automated closed-loop system high-tech pyramid photobioreactors and adaptedfor oil production, which had a low acid value (0.23 mg KOH/g). Because of this, basecatalyst transesterification was applied. For the transesterification reaction, 99.7%purity of methyl alcohol as alcohol and 99.9% purity of potassium hydroxide (KOH)was used as a catalyst. In order to determine the most suitable conditions for theproduction of biodiesel from algae oil, a series of laboratory-scale preliminaryexperiments have been carried out. As a result of the optimization studies, the 6:1methyl alcohol/oil molar ratio, the use of KOH up to 0.75% of the oil by mass, thereaction temperature of 60 °C, and the reaction time of 60 minutes were determined asthe most suitable conditions for biodiesel production. Under these conditions, 96.4%methyl ester yield was obtained, and kinematic viscosity and density values of the finalbiodiesel product were measured as 4.493 mm2/s and 882 kg/m3. As a result of thephysical and chemical analysis of the produced biodiesel, it has been determined that ithas an ester content of over 96% and that the free and total glycerol content withmethanol, mono-, di- and tri-glyceride is well below the maximum values specified inthe EN 14214 and ASTM 6751 biodiesel standards. However, properties such asviscosity, density, flash point, cetane number, acid value, sulfur and water content werefound to be compatible with the specified standards. In addition, besides having thestandard fuel properties of the produced biodiesel, its high cetane number (57) andgood cold filter clogging point (-11 oC), makes it an important alternative diesel enginefuel.

"piggeries increased. In that time limits to farm size were seldom determined by farm waste disposal and air polution. At present there are local regions where is a surplus of slurry. Due to the low value as a fertilizer transport to other regions is too expensive and in some cases over manuring will exceed. Separation of slurry offers the possibility of obtaining solid manure with a high fertilizer value and a liquid with a low value. On this way it becomes more worthwhile to transport the solid manure over longer distances, So it reduces over manuring. However slurry separation with a high efficiency is costly about £4,-/pigplace by adding flocculants and expensive complicated separations (1). Underslat slurry storage also influences environnement as well inside as outside the piggery because gases are released from the slurry. On the other hand anaerobic digestion processes will be avoid by daily removal and separate storage of faeces and urine. That factors were for IMAG a motive to develop a reliable combined manure filter and removal system for piggeries. 2. SEPARATION EFFICIENCY In a preliminary investigation the separation efficiency of different separation techniques under slatted floors was defined. Separation efficiency means which part of the total components in faeces and urine remains in the faeces. This research was carried out in a pen with 8 pigs. The pigs were given wet feed without drinkwaterprovisions. In Fig.l the separation result is mentioned for a filter net of meshsize 0.78x0.78 mm. From Fig.l it is apparent that about 35% of the total faeces and urine is removed as a solid and that about 90% of the total dry matter is in the faeces. Also for a number of minerals, p2°5’ Ca(^ » and Cu> amounts to more than 90%. Nitrogen and potassium were separated in smaller amounts, about 60% and 40% respectively, being retained in the solid. On basis of this result and after comparative research with concern for filtering, clogging and cleaning the above mentioned filternet is now being used for the final mechanized filter and removal system. 3* THE MECHANIZED FILTER INSTALLATION A combined filter and manure system must be completely reliable, since it is not easy to make repairs under “the slats.v After 2-3 years of experience a system which works well has been developed.(2,3,4) In Fig.2 a schematic diagram of the filter system is shown under the slatted floor. In the channel under the slats two angle sections (1) are attached one above the other and fixed over the whole length to both walls. These are covered from above with protective plates (2) joined underneath the slats. The filter net (3) is provided with". In Odour Prevention and Control of Organic Sludge and Livestock Farming, 228–31. CRC Press, 1986. http://dx.doi.org/10.1201/9781482286311-91.

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Atti di convegni sul tema "Filter clogging":

Bonne, Samuel, e Nicolas Arnault. "Oil Filter Clogging Rule - Correlation between Mileage and Lab Test Clogging". In SAE 2012 International Powertrains, Fuels & Lubricants Meeting. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2012. http://dx.doi.org/10.4271/2012-01-1754.

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Youssef, Alilou, Bourrous Soleiman, Thomas Dominique, Bardin-Monnier Nathalie, Nérisson Philippe e Gélain Thomas. "Experimental Characterization of Airflow Within a Clean HEPA Filter Used for the Containment of Radioactive Contamination in Nuclear Facilities". In 2016 24th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/icone24-60901.

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In hazardous industrial activities such as in nuclear facilities, High Efficiency Particulate Air filters (HEPA filters) are essential to ensure the containment of airborne contamination. Most of the filters used in ventilation networks are pleated, in order to offer a larger surface of filtration. For industrial risks likely to lead to an important release of particles (e.g. fire), predicting the evolution of the pressure drop of pleated filters is very important, in order to anticipate any dysfunction, failure or breaking of these devices. Pressure drop variations are linked to airflow rate variations and to clogging process of the medium by airborne particles. Thus, the airflow pattern in a pleat channel is essential for optimizing the filter design and enhancing its lifetime. Particles are transported by the airflow and deposited at the filter surface; hence, the geometry of the dust cake (shape and location) is partially determined knowing the velocity streamlines. The present paper focuses on the characterization of airflows in a clean HEPA filter. The difficulty to perform fine measurement on a real scale filter led us to develop an experimental device, consisting in the reproduction of a single pleat, identical to a real pleat constituting industrial filters. The small dimension of the pleat makes the velocity measurement difficult to establish. That is why μ-PIV method has been adapted to measure the velocity field inside the filter for different filtration velocities at the first moments of the experiment, in order to avoid the impact of clogging by particles used to seed the flow. These particles are DEHS droplets 0.01 < St < 0.05. In the future, these well-characterized airflows will be the basis for CFD computation of particle transport and deposition inside the pleats. Ultimately, the aim is to develop or upgrade physical models predicting the pressure drop evolution of pleated filters, during clogging process in accidental situations.

Ono, Takuya, Koji Watanabe, Shinsuke Tashiro, Yuki Amano e Hitoshi Abe. "HEPA Filter Clogging and Volatile Material Release Under Solvent Fire Accident in Fuel Reprocessing Facility". In 2017 25th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/icone25-67626.

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The new licensing standards were further improved by taking into account of lessons learned from the Fukushima-Daiichi nuclear accident, and countermeasures against severe accidents were newly required as regulatory items, where severe accidents were defined as serious accidents that occur under conditions exceeding design bases. Organic solvent fire in cell was defined as one of the severe accidents in nuclear fuel reprocessing facilities, which should be investigated, in order to establish methods for evaluating effectiveness of the countermeasures. One of the combustibles in the fire accident at reprocessing facilities is the organic solvent composed of 30% tributyl phosphate (TBP) and 70% dodecane. When the solvent burns, aerosol of soot and radioactive substances are released inside the facility. The aerosol causes a clogging of high-efficiency particulate air filters (HEPA filters) in a ventilation system of the facility, which increases a differential pressure of the filters. We have performed combustion tests simulating the fire accident. As one of interesting results of the tests, we observed, when most of dodecane in the solvent was burned out, a rapid increase in a differential pressure of a HEPA filter, which may cause its rupture. We also found a small amount of RuO4 release from the burning solvent, which can pass through HEPA filters due to its volatility. These phenomena should be adapted in the effectiveness evaluations of the countermeasures against the fire accident.

Gupta, Rohit Dev, Paolo Sironi e Luca Della Chisea. "Remote Diagnostics of Air-Filter Clogging in a Network Equipment". In 2021 20th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm). IEEE, 2021. http://dx.doi.org/10.1109/itherm51669.2021.9503243.

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Greenlee, Alison, Timothy Murray, Victor Lesniewski, Mark Jeunnette e Amos G. Winter. "Design and Testing of a Low-Cost and Low-Maintenance Drip Irrigation Filtration System for Micro-Irrigation in Developing Countries". In ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/detc2014-35351.

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The cylindrical filters presently used in <1000 m2 drip irrigation systems are frequently clogged, increasing pressure loss and lowering the flow rate through the filters. This work investigates the mechanisms for this clogging and proposes an alternative filtration design that would enable both more reliable and lower maintenance filtering. This proposed system is compatible with existing drip irrigation systems and could be made inexpensively with plastic bottle manufacturing equipment. To compare the proposed design to off-the-shelf options, a drip irrigation test setup was built to measure the pressure loss across different filters as particles accumulated. These experiments confirmed that pleated cartridge filters, with high effective surface area, incurred lower pressure losses than cylindrical filters. These tests revealed that the greatest reason for clogged performance was that filtered particles (not the cartridge filter itself) eventually restricted the flow of water through the system. This inspired the redesign of the filter housing such that the housing extended far below the filter, providing a catch basin away from the filter for the particles to settle. Fixing the filter independently of the bottom casing significantly improved the overall performance of the filtration system, reduced the maintenance requirement necessary from the user, and would enable inexpensive manufacturing via blow molding. This paper experimentally demonstrates that the cartridge filter inside the redesigned housing can filter out over 2 kg of sand while maintaining less than a .03 bar pressure drop across the filter at a flow rate of 25 l/s.

Yamano, Hidemasa, Hiroyuki Nishino, Kenichi Kurisaka, Yasushi Okano, Takaaki Sakai, Takahiro Yamamoto, Yoshihiro Ishizuka et al. "Development of Risk Assessment Methodology of Decay Heat Removal Function Against Natural External Hazards for Sodium-Cooled Fast Reactors: Project Overview and Volcanic PRA Methodology". In 2016 24th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/icone24-60023.

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This paper describes mainly volcanic probabilistic risk assessment (PRA) methodology development for sodium-cooled fast reactors in addition to the project overview. In the volcanic PRA, only the effect of volcanic tephra (ash) was taken into account because there is a great distance between a plant site assumed in this study and volcanos. The volcanic ash could potentially clog air filters of air-intakes that are essential for the decay heat removal. The degree of filter clogging can be calculated by atmospheric concentration of ash and tephra fallout duration and also suction flow rate of each component. The atmospheric concentration can be calculated by deposited tephra layer thickness, tephra fallout duration and fallout speed. This study evaluated a volcanic hazard using a combination of tephra fragment size, layer thickness and duration. In this paper, each component functional failure probability was defined as a failure probability of filter replacement obtained by using a grace period to a filter failure limit. Finally, based on an event tree, a core damage frequency was estimated about 3 × 10−6/year in total by multiplying discrete hazard probabilities by conditional decay heat removal failure probabilities. A dominant sequence was led by the loss of decay heat removal system due to the filter clogging after the loss of emergency power supply. A dominant volcanic hazard was 10−2 kg/m3 of atmospheric concentration, 0.1 mm of tephra diameter, 50–75cm of deposited tephra layer thickness, and 1–10 hr of tephra fallout duration.

Elrahmani, Ahmed, e Riyadh I. Al-Raoush. "The Dependent Clogging Dynamics and Its Impact on Porous Media Permeability Reduction". In The 2nd International Conference on Civil Infrastructure and Construction. Qatar University Press, 2023. http://dx.doi.org/10.29117/cic.2023.0152.

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The dynamics of fine particle entrapment, transport, and deposition within pore systems, particularly the ability of mobile fines to impair permeability within porous media, are critical to a variety of natural and manmade phenomena, impacting oil and gas recovery, slope stability, filter capacity, and the efficiency of lab-on-chip diagnostics in medical disciplines. According to the research, clogging of pore throats in the porous media is not a random process; clogged throats, in particular, modify flow conditions and promote subsequent clogging nearby which is called dependent clogging. Over the last several decades, significant efforts have been made to identify and parameterize the role of dependent clogging in permeability reduction, with studies applying a combination of physical investigation and numerical simulation to this objective. In this work, we deploy a coupled computational fluid dynamics-discrete element method-based framework to investigate fines migration and consequent pore-throat clogging within a geologically realistic pore system extracted from an x-ray microtomographic image of a sand pack. The analysis of the simulation results revealed a spatial correlation between the clogged throats, implying that throats in close proximity became clogged dependently around the same time. Furthermore, dependent clogging was observed to be more frequent than independent clogging and it impacts system permeability more efficiently. This suggests that the distribution of clogged throats has a significant impact on the system's permeability reduction other than the total number of clogged throats.

Vishal, S. Randive, Katkar Omkar Prataprao, Nashte Adarsh Pravin e A. Rammohan. "Investigation of effect of air filter clogging on performance and emissions from engine". In 2017 International conference on Microelectronic Devices, Circuits and Systems (ICMDCS). IEEE, 2017. http://dx.doi.org/10.1109/icmdcs.2017.8211699.

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Cowart, Jim, Patrick Moore, Harrison Yosten, Leonard Hamilton e Dianne Luning Prak. "Diesel Engine Acoustic Emission Airflow Clogging Diagnostics With Machine Learning". In ASME 2018 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/icef2018-9601.

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A diesel engine electrical generator set (’gen-set’) was instrumented with in-cylinder indicating sensors as well as acoustic emission microphones near the engine. Air filter clogging was emulated by progressive restriction of the engine’s inlet air flow path during which comprehensive engine and acoustic data were collected. Fast Fourier Transforms (FFTs) were analyzed on the acoustic data. Dominant FFT peaks were then applied to supervised machine learning neural network analysis with MATLAB based tools. The progressive detection of the air path clogging was audibly determined with correlation coefficients greater than 95% on test data sets for various FFT minimum intensity thresholds. Further, unsupervised machine learning Self Organizing Maps (SOMs) were produced during normal-baseline operation of the engine. Application of the degrading air flow engine sound data was then applied to the normal-baseline operation SOM. The quantization error of the degraded engine data showed clear statistical differentiation from the normal operation data map. This unsupervised SOM based approach does not know the engine degradation behavior in advance, yet shows clear promise as a method to monitor and detect changing engine operation. Companion in-cylinder combustion data additionally shows the degrading nature of the engine’s combustion with progressive airflow restriction (richer and lower density combustion).

Yamada, Naohiro, Seiichi Nakano, Yusuke Koike, Rika Suzuki, Sachiko Okuda e Shozaburo Konishi. "Low Ash SP/GF-6 Fuel Eco Gasoline Engine Oil". In 2023 JSAE/SAE Powertrains, Energy and Lubricants International Meeting. 10-2 Gobancho, Chiyoda-ku, Tokyo, Japan: Society of Automotive Engineers of Japan, 2023. http://dx.doi.org/10.4271/2023-32-0036.

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<div class="section abstract"><div class="htmlview paragraph">A gasoline particulate filter (GPF) is installed in a passenger vehicle for new exhaust regulation. However, ash in gasoline engine oil has a risk of clogging as well as performance decrease in the GPF. Therefore, new gasoline engine oil whose ash contents decrease to 0.8 mass% was developed in order to avoid the GPF clogging. In addition to this, our developed oil improves fuel efficiency (+0.2% from our SN 0W-16 fuel eco type oil) as well as anti-wear performance for gasoline engine, which resulted in meeting API SP/ILSAC GF-6 0W-16 official certification.</div></div>

Rapporti di organizzazioni sul tema "Filter clogging":

Tien, Chi. Summary of studies on filter clogging. Office of Scientific and Technical Information (OSTI), settembre 1993. http://dx.doi.org/10.2172/10108339.

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Ito, Atsushi, Tsubasa Ishii, Hideaki Ando, Fujio Umebayashi e Keita Kinoshita. Research on Clogging Mechanism of Multilayered Fuel Filters and Extension of Filter Life Span in Ethanol Blended Fuel. Warrendale, PA: SAE International, novembre 2011. http://dx.doi.org/10.4271/2011-32-0570.

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