The Experts below are selected from a list of 3123 Experts worldwide ranked by ideXlab platform
Gernot Krammer - One of the best experts on this subject based on the ideXlab platform.
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influence of operating parameters on cake formation in pilot scale pulse jet Bag Filter
Powder Technology, 2012Co-Authors: Mahmood Saleem, Gernot Krammer, Rafi Ullah Khan, Suleman M TahirAbstract:Bag Filters are commonly used for fine particles removal in off-gas purification. There dust laden gas pervades through permeable Filter media starting at a lower pressure drop limit leaving dust (called Filter cake) on the Filter media. The Filter cakeformation is influenced by many factors including filtration velocity, dust concentration, pressure drop limits, and Filter media resistance. Effect of the stated parameters is investigated experimentally in a pilot scale pulse-jet Bag Filter test facility where lime stone dust is separated from air at ambient conditions. Results reveal that filtration velocity significantly affects Filter pressure drop as well as cake properties; cake density and specific cake resistance. Cake density is slightly affected by dust concentration. Specific resistance of Filter cake increases with velocity, slightly affected by dust concentration, changes inversely with the upper pressure drop limit and decreases over a prolonged use (aging). Specific resistance of Filter media is independent of upper pressure drop limit and increases linearly over a prolonged use.
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effect of filtration velocity and dust concentration on cake formation and Filter operation in a pilot scale jet pulsed Bag Filter
Journal of Hazardous Materials, 2007Co-Authors: Mahmood Saleem, Gernot KrammerAbstract:Bag Filters are used for the removal of fine solid particles from process gases. Thus, understanding the Filter cake build up and its properties is a subject of interest. The Filter cakes properties may depend on many factors like, for example, filtration velocity and dust concentration. The effect of dust concentration and filtration velocity on filtration time, specific cake resistance and mean cake density is investigated in a pilot scale jet pulsed Bag Filter. An in situ optical system is used to measure cake thickness distributions on the Filter surface. Additionally, the operation is simulated using a one-dimensional model and results are compared with experiments. The experimental results indicate that cake density and specific resistance increase with increasing velocity at constant dust concentration. The effect of dust concentration on Filter cake density and specific resistance is small.
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optical in situ measurement of Filter cake height during Bag Filter plant operation
Powder Technology, 2007Co-Authors: Mahmood Saleem, Gernot KrammerAbstract:Abstract A pilot scale jet pulsed Bag Filter test facility is operated at conditions similar to those of the industrial Bag Filters. The facility is equipped with a stereo vision based optical system for in-situ cake height distribution measurements on the Bag Filter surface. Experimental data are presented and data evaluation procedures are discussed to elaborate the features of the measuring system. The results show that the cake height distribution becomes narrower towards the end of filtration cycles. A steep pressure drop rise is observed at the start of a filtration cycle in the absence of re-attachment and a non-uniform Bag cleaning, which may be attributed to different cake properties. The specific cake resistance remains constant over the linear part of the pressure drop curve indicating a non-compressible cake formation. The analysis of residual cake patches shows a large number of small sized cake patches and a few large sized cake patches on the Filter surface. The cake patch size increases with the cake formation. The fractal analysis of patches boundary indicates preferential cake formation at the boundary of the residual cake patches shortly after regeneration.
Hyun Seol Park - One of the best experts on this subject based on the ideXlab platform.
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Non-uniform filtration velocity of process gas passing through a long Bag Filter
Journal of Hazardous Materials, 2018Co-Authors: Sangcheol Park, Joonmok Shim, Yun Haeng Joe, Hyun Seol Park, Weon Gyu ShinAbstract:Filtration velocity is one of the dominant parameters that determine the pressure drop through a Bag Filter. Experimental investigation of the air flow pattern around a Bag Filter inside a Bag house is very difficult because of the complexity of the 3-D air flow. For this reason, we numerically investigated flow characteristics along a Bag Filter in detail. We newly found that the filtration velocity is non-uniform along the axial direction of a long Bag Filter when the height of the Filter is greater than 10 m. The filtration velocity is very small at the bottom of the Bag Filter but very large at the top. For Bag Filter lengths of over 10 m, 70% of total inlet flow is Filtered in just the top 30% of the long Bag Filter. This indicates that the top section of the long Bag Filter could deteriorate faster than the bottom section, making it necessary to develop a new method to avoid the problem. We developed an equation that can help predict the initial pressure drop across long Bag Filters with different heights, but identical filtration characteristics.
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Influence of air injection nozzles on Filter cleaning performance of pulse-jet Bag Filter
Powder Technology, 2017Co-Authors: Joonmok Shim, Yun Haeng Joe, Hyun Seol ParkAbstract:The Filter cleaning performance of different air injection nozzles installed in a pulse-jet Bag Filter dust collector were compared. The examined nozzles were a hole nozzle, a nipple nozzle, and a dual-slit injector. The latter is an air injection nozzle with two circumferential slits, which was newly designed in this study to introduce large volumes of cleaning air with a small amount of compressed air, thereby significantly improving the Filter cleaning efficiency. When the dual-slit injector was applied under a 2.0 m/min filtration velocity, superior Filter cleaning performance and lower dust emission were observed compared to those for the hole and nipple nozzles. In addition, there was little difference in Filter cleaning efficiency according to pulsing air pressure, indicating that low and high pulse pressures can yield similar levels of Filter cleaning performance when the dual-slit injector is employed; thus, the pulsing energy for Filter regeneration can be reduced. Under a 4.0 m/min filtration velocity, neither the hole nor nipple nozzle yielded effective Filter cleaning, generating a higher pressure drop and a significantly reduced pulse-jet cleaning interval. On the other hand, the dual-slit injector applied to the pulse-jet Bag Filter maintained stable Filter cleaning performance, even under the high filtration velocity.
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Evaluation of the can velocity effect on a Bag Filter
Powder Technology, 2017Co-Authors: Yun Haeng Joe, Joonmok Shim, Hyun Seol ParkAbstract:In this study, the effects of can velocity on the performance of a pilot-scale Bag Filter dust collector were examined. Test Bag Filters were made of polyester fabric and had a 156 mm diameter and a 3 m length. The cleaning interval of the pulse-jet cleaning system and the effects of inlet particle concentration with various can velocities were considered. When the dust collector was operated with insufficient can velocity, an unreasonable increase in the cleaning interval was observed. The cleaning interval decreased with the increased can velocity. Furthermore, under the unsuitable can velocity condition, the increasing tendencies of the cleaning interval and dust emission by decreased inlet particle concentration deviated from the expected theoretical tendency. Therefore, the appropriate can velocity should be selected in a pilot-scale experiment for improving the prediction of actual-scale dust collector performance.
Mahmood Saleem - One of the best experts on this subject based on the ideXlab platform.
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influence of operating parameters on cake formation in pilot scale pulse jet Bag Filter
Powder Technology, 2012Co-Authors: Mahmood Saleem, Gernot Krammer, Rafi Ullah Khan, Suleman M TahirAbstract:Bag Filters are commonly used for fine particles removal in off-gas purification. There dust laden gas pervades through permeable Filter media starting at a lower pressure drop limit leaving dust (called Filter cake) on the Filter media. The Filter cakeformation is influenced by many factors including filtration velocity, dust concentration, pressure drop limits, and Filter media resistance. Effect of the stated parameters is investigated experimentally in a pilot scale pulse-jet Bag Filter test facility where lime stone dust is separated from air at ambient conditions. Results reveal that filtration velocity significantly affects Filter pressure drop as well as cake properties; cake density and specific cake resistance. Cake density is slightly affected by dust concentration. Specific resistance of Filter cake increases with velocity, slightly affected by dust concentration, changes inversely with the upper pressure drop limit and decreases over a prolonged use (aging). Specific resistance of Filter media is independent of upper pressure drop limit and increases linearly over a prolonged use.
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effect of filtration velocity and dust concentration on cake formation and Filter operation in a pilot scale jet pulsed Bag Filter
Journal of Hazardous Materials, 2007Co-Authors: Mahmood Saleem, Gernot KrammerAbstract:Bag Filters are used for the removal of fine solid particles from process gases. Thus, understanding the Filter cake build up and its properties is a subject of interest. The Filter cakes properties may depend on many factors like, for example, filtration velocity and dust concentration. The effect of dust concentration and filtration velocity on filtration time, specific cake resistance and mean cake density is investigated in a pilot scale jet pulsed Bag Filter. An in situ optical system is used to measure cake thickness distributions on the Filter surface. Additionally, the operation is simulated using a one-dimensional model and results are compared with experiments. The experimental results indicate that cake density and specific resistance increase with increasing velocity at constant dust concentration. The effect of dust concentration on Filter cake density and specific resistance is small.
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optical in situ measurement of Filter cake height during Bag Filter plant operation
Powder Technology, 2007Co-Authors: Mahmood Saleem, Gernot KrammerAbstract:Abstract A pilot scale jet pulsed Bag Filter test facility is operated at conditions similar to those of the industrial Bag Filters. The facility is equipped with a stereo vision based optical system for in-situ cake height distribution measurements on the Bag Filter surface. Experimental data are presented and data evaluation procedures are discussed to elaborate the features of the measuring system. The results show that the cake height distribution becomes narrower towards the end of filtration cycles. A steep pressure drop rise is observed at the start of a filtration cycle in the absence of re-attachment and a non-uniform Bag cleaning, which may be attributed to different cake properties. The specific cake resistance remains constant over the linear part of the pressure drop curve indicating a non-compressible cake formation. The analysis of residual cake patches shows a large number of small sized cake patches and a few large sized cake patches on the Filter surface. The cake patch size increases with the cake formation. The fractal analysis of patches boundary indicates preferential cake formation at the boundary of the residual cake patches shortly after regeneration.
Joonmok Shim - One of the best experts on this subject based on the ideXlab platform.
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Non-uniform filtration velocity of process gas passing through a long Bag Filter
Journal of Hazardous Materials, 2018Co-Authors: Sangcheol Park, Joonmok Shim, Yun Haeng Joe, Hyun Seol Park, Weon Gyu ShinAbstract:Filtration velocity is one of the dominant parameters that determine the pressure drop through a Bag Filter. Experimental investigation of the air flow pattern around a Bag Filter inside a Bag house is very difficult because of the complexity of the 3-D air flow. For this reason, we numerically investigated flow characteristics along a Bag Filter in detail. We newly found that the filtration velocity is non-uniform along the axial direction of a long Bag Filter when the height of the Filter is greater than 10 m. The filtration velocity is very small at the bottom of the Bag Filter but very large at the top. For Bag Filter lengths of over 10 m, 70% of total inlet flow is Filtered in just the top 30% of the long Bag Filter. This indicates that the top section of the long Bag Filter could deteriorate faster than the bottom section, making it necessary to develop a new method to avoid the problem. We developed an equation that can help predict the initial pressure drop across long Bag Filters with different heights, but identical filtration characteristics.
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Influence of air injection nozzles on Filter cleaning performance of pulse-jet Bag Filter
Powder Technology, 2017Co-Authors: Joonmok Shim, Yun Haeng Joe, Hyun Seol ParkAbstract:The Filter cleaning performance of different air injection nozzles installed in a pulse-jet Bag Filter dust collector were compared. The examined nozzles were a hole nozzle, a nipple nozzle, and a dual-slit injector. The latter is an air injection nozzle with two circumferential slits, which was newly designed in this study to introduce large volumes of cleaning air with a small amount of compressed air, thereby significantly improving the Filter cleaning efficiency. When the dual-slit injector was applied under a 2.0 m/min filtration velocity, superior Filter cleaning performance and lower dust emission were observed compared to those for the hole and nipple nozzles. In addition, there was little difference in Filter cleaning efficiency according to pulsing air pressure, indicating that low and high pulse pressures can yield similar levels of Filter cleaning performance when the dual-slit injector is employed; thus, the pulsing energy for Filter regeneration can be reduced. Under a 4.0 m/min filtration velocity, neither the hole nor nipple nozzle yielded effective Filter cleaning, generating a higher pressure drop and a significantly reduced pulse-jet cleaning interval. On the other hand, the dual-slit injector applied to the pulse-jet Bag Filter maintained stable Filter cleaning performance, even under the high filtration velocity.
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Evaluation of the can velocity effect on a Bag Filter
Powder Technology, 2017Co-Authors: Yun Haeng Joe, Joonmok Shim, Hyun Seol ParkAbstract:In this study, the effects of can velocity on the performance of a pilot-scale Bag Filter dust collector were examined. Test Bag Filters were made of polyester fabric and had a 156 mm diameter and a 3 m length. The cleaning interval of the pulse-jet cleaning system and the effects of inlet particle concentration with various can velocities were considered. When the dust collector was operated with insufficient can velocity, an unreasonable increase in the cleaning interval was observed. The cleaning interval decreased with the increased can velocity. Furthermore, under the unsuitable can velocity condition, the increasing tendencies of the cleaning interval and dust emission by decreased inlet particle concentration deviated from the expected theoretical tendency. Therefore, the appropriate can velocity should be selected in a pilot-scale experiment for improving the prediction of actual-scale dust collector performance.
Laurent Le Coq - One of the best experts on this subject based on the ideXlab platform.
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Influence of air humidity on particle filtration performance of a pulse-jet Bag Filter
Journal of Aerosol Science, 2019Co-Authors: Rachid Boudhan, Sylvain Durécu, Aurélie Joubert, Kamal Gueraoui, Laurent Le CoqAbstract:Abstract A pulse-jet Bag Filter, representative of those implemented in waste incineration plants for flue gas treatment, was studied at laboratory scale to evaluate the influence of air humidity on the filtration performance. Several cycles of clogging/unclogging were performed with non-hygroscopic submicronic particles with a nanosized fraction with on-line cleaning at operating conditions as similar as possible to those found in the flue gas treatment of waste incineration plants (150 °C – 73 g/m3 of absolute humidity), and in dry conditions (150 °C). The results revealed a significant influence of air humidity on the Bag Filter performance: faster increase of Bag Filter pressure drop during clogging in presence of humidity due to water capillary condensation, lower efficiency of particulate cake unclogging and better collection efficiency of particles between 110 and 300 nm in diameter.
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Pulse-Jet Bag Filter Performances for Treatment of Submicronic and Nanosized Particles from Waste Incineration
Waste and Biomass Valorization, 2018Co-Authors: Rachid Boudhan, A. Joubert, Danielle Venditti, D. T. Tran, Sylvain Durécu, Kamal Gueraoui, Laurent Le CoqAbstract:The main objectives of this study were to develop an experimental set-up to perform clogging/unclogging tests on a single Baghouse fabric Filter, and to evaluate its filtration performance regarding submicronic and nanosized particles, for operating conditions as close as possible to those found in real-scale waste incineration facilities in terms of gas flowrate, temperature and humidity, inlet concentrations for both the dust and the sorbent, the pressure and duration of the cleaning pulse-jet. The performances of a Bag Filter during several clogging/unclogging cycles were evaluated regarding the filtration of a submicronic aerosol whose particle size distribution is representative of nanowaste incineration emissions at the boiler outlet. In order to reproduce the real operating conditions in the flue gas treatment line, the airflow and the Bag Filter were heated to 150 °C and the filtration unit was insulated. The water content was maintained in the airflow in the range of 10–12% (i.e. 3% relative humidity) by water injection and the filtration velocity throughout the Bag Filter was 2 cm/s. Moreover, a mix of suspended particles of activated carbon and sodium bicarbonate, used in flue gas treatment lines mainly for dioxin/furan and acid gas removal, were generated simultaneously with the submicronic aerosol. The results showed a high total particle collection efficiency of the Bag Filter, which increased rapidly with clogging from 98 to 99.99%. Particles with a diameter of 90 nm were the most penetrating across the Filter, for which the fractional efficiency reached a minimum value of 97.5%. These results demonstrated the effectiveness of Bag Filters for submicronic and nanosized particle filtration in industrial conditions for the treatment of waste incineration fumes.
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INFLUENCE OF OPERATING CONDITIONS ON Bag Filter PERFORMANCES FOR INCINERATION FUMES TREATMENT
2016Co-Authors: Rachid Boudhan, Danielle Venditti, Sylvain Durécu, Aurélie Joubert, Kamal Gueraoui, Laurent Le CoqAbstract:Filtration performances of a Bag Filter implemented for the flue gas treatment of waste incineration plant were studied at laboratory scale in order to evaluate the influence of filtration cycles (clogging/unclogging). The filtration performances were evaluated during clogging with a submicronic aerosol with nano-size fraction, at a filtration velocity of 1.9 cm.s-1. Investigations of the influence of Filter washing and filtration velocity on the filtration performances were performed with the same Filtering media in flat configuration. Experimental results showed an influence of filtration velocity on fractional filtration efficiency in particular for particle diameter close to the Most Penetrating Particle Size of the Filter. Moreover, results indicated that new Filters were significantly less efficient than washed Filters at the beginning of the clogging. Finally the influence of clogging/unclogging cycles on Bag Filter performances was demonstrated both for pressure drop and filtration efficiency evolutions during clogging.
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Nanowaste incineration: performances of a Bag Filter in a pilot scale device under real operating conditions
2014Co-Authors: Aurélie Joubert, Danielle Venditti, D. T. Tran, Sylvain Durécu, Olivier Le Bihan, Thierry Meunier, Emmanuel Fiani, Laurent Le CoqAbstract:Up to now, there is no peculiar approved procedure for the waste management of nanoobjects at their end of life, mainly because the current regulation does not consider the typical nanospecificity of such emerging products. The French project “NANOFlueGas” (2011-2014) aims to provide data and to assess nanosafety aspects during the final destruction of nanomanufactured products by incineration. The two main objectives of this project are firstly, to better understand possible mechanisms of nanoparticle release during the incineration of nanowastes, and secondly, to evaluate the efficiency of the current pollution control processes and procedures implemented on waste incineration facilities. This study deals with the evaluation of the performances of a Bag Filter regarding its clogging with a representative nanosized aerosol emitted from nanowaste incineration in boiler output. A laboratory-scale filtration unit was developed, where a single Bag Filter was implemented (reduced height to 0.44 m). The aerosol used for clogging tests was a condensation aerosol generated from graphite monoliths (generator DNP 2000, Palas). Its particle size distribution and shape were accurately chosen in order to be representative of the aerosol emission profile previously determined from incineration tests performed on a nanowaste mainly composed of black carbon within a laboratory-scale furnace [1] In order to meet with the real operating conditions in the flue gas treatment line, the airflow and the Bag Filter were heated to 150°C, the filtration unit was insulated, and 10-12% moisture was maintained in the airflow by water injection. Filtration velocity throughout the Bag Filter was set to 2 cm/s. Moreover, the influence of upstream sorbent injection (typically sodium bicarbonate with activated carbon) was also tested in our small-scale device. The evolution of performances were evaluated throughout the clogging in terms of both pressure drop generated by the hot gaseous flowrate through the Filter, and particle collection efficiency evaluated from particle concentration measurements upstream and downstream to the Filter using an ELPI impactor (Dekati) after hot sampling and dilution.
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Filtration performances of a lab Bag-Filter unit under specifications of incineration fluegas treatment
2014Co-Authors: Aurélie Joubert, Danielle Venditti, D. T. Tran, Sylvain Durécu, Olivier Le Bihan, Bruno Debray, Thierry Meunier, Emmanuel Fiani, Laurent Le CoqAbstract:Up to now, there is no peculiar approved procedure for the waste management of nanoobjects at their end of life, mainly because the current regulation does not consider the typical nanospecificity of such emerging products. The French project “NANOFlueGas” aims to provide data and to examine nanosafety aspects at the destruction stage of nanomanufactured products by incineration. One part of the project deals with the evaluation of the performances of a Bag Filter unit regarding its clogging with a characteristic nanosize aerosol emitted from nanowaste incineration in boiler output. A laboratory-scale filtration unit was developed where a single Bag Filter was implemented (reduced height to 0.44 m). The porous media was constituted from Teflon fibers. The main structural parameters of the media are presented in Table 1. The aerosol used for clogging tests was formed by a mix of suspended particles of activated carbon and sodium bicarbonate (SAG 420, TOPAS), mainly introduced in the flue gas treatment line for dioxin/furan and acid gas removal, and a condensation aerosol from graphite monoliths (DNP 2000, Palas) whose particle-size distribution and shape were chosen in order to be representative of the aerosol emissions determined from preliminary tests with a laboratory-scale incineration unit and a nanowaste (Tran et al., 2012). In order to be consistent with the real operating conditions in flue gas treatment lines, the airflow and the Bag Filter were heated to 150°C, the filtration unit was insulated and 10-12% of water content was maintained in the airflow by water injection. Filtration velocity through the Bag Filter was 1.9 cm/s. Figure 1 represents the particle size distribution of the aerosol upstream the Bag Filter. The performances were evaluated throughout the clogging in terms of Filter pressure drop and particle collection efficiency from hot sampling and dilution before particle counting (ELPI, Dekati at 150°C). Three experimental tests were carried out. The evolutions of the Filter performances are displayed in Figure 2. Results showed a high particle collection efficiency of the filtration unit whatever the level of clogging. The study of fractional efficiency led to the same conclusions whatever the particle size. As expected, the Filter pressure drop increased with the clogging. Initial pressure drop values increased with the tests which can be explained by the off-line cleaning procedure implemented.