scholarly journals High-Performance Washable PM2.5 Filter Fabricated with Laser-Induced Graphene

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5551
Author(s):  
Anh-Phan Nguyen ◽  
Won-Kyu Kang ◽  
Jung-Bae Lee ◽  
Jung-Bin In
Keyword(s):  
Particulate Matter ◽  
Pressure Drop ◽  
Removal Efficiency ◽  
High Performance ◽  
Tap Water ◽  
Air Cleaning ◽  
Cleaning Agents ◽  
Single Side

This study demonstrates a novel application of laser-induced graphene (LIG) as a reusable conductive particulate matter (PM) filter. Four types of LIG-based filters were fabricated based on the laser-induced pyrolysis of thin polyimide (PI) sheets, each pyrolyzed on either a single side or both sides, with or without densification. The LIG filters exhibited a high removal efficiency while maintaining minimal pressure drop compared to a commercial fiberglass filter. The densified LIG (dLIG) filters displayed a higher PM2.5 removal efficiency (>99.86%) than regular LIG filters. The dLIG filters also exhibited excellent durability when tested for washability by ultrasonication in tap water. After being cleaned and left to dry, the structures of the dLIG filters were well-maintained; their filtration efficiencies were also well-maintained (less than a 7% change in PM2.5 removal efficiency), and their resistances only marginally increased (less than a 7% increase after five uses). These results demonstrate the robustness and reusability of the dLIG filters and the accessibility of their cleaning (not requiring aggressive cleaning agents). These promising features will enable the application of LIG in economical, scalable, and high-performance air cleaning.

A lottery draw machine-inspired movable air filter with high removal efficiency and low pressure drop at a high flow rate

2019 ◽  
Vol 7 (11) ◽  
pp. 6001-6011 ◽  
Author(s):  
Nara Han ◽  
Yo Seph Lee ◽  
Byung Kwon Kaang ◽  
Wooree Jang ◽  
Hye Young Koo ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Pressure Drop ◽  
Electric Field ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Low Pressure ◽  
High Flow ◽  
High Electric Field ◽  
High Flow Rate ◽  
Air Filter

A lottery draw machine-inspired novel movable air filter (MAF) system is presented in which MAFs are vigorously moved or rotated to form a high electric field and capture particulate matter (PM) particles.

Effective removal of particulate matter from air by using zeolite-coated filters

2020 ◽  
Vol 8 (35) ◽  
pp. 17960-17968 ◽  
Author(s):  
Dong Kyu Yoo ◽  
Ho Chul Woo ◽  
Sung Hwa Jhung
Keyword(s):  
Particulate Matter ◽  
Pressure Drop ◽  
Removal Efficiency ◽  
Effective Removal ◽  
Pm Removal ◽  
Better Than

Zeolites are very effective (much better than MOFs) in removal of particulate matter (PM) from air; NaX/cotton showed 3.6-times the PM removal efficiency of bare cotton with a small increase in the pressure drop of 9 Pa.

The assessment of particulate matter (PM2.5) removal efficiency on air cleaner products through full scale test in Korea

2019 ◽  
Vol 18 (1) ◽  
pp. 76-80 ◽  
Author(s):  
Kichul Kim ◽  
Pil-Ju Park ◽  
Soomi Eo ◽  
Seungmi Kwon ◽  
Kwangrae Kim ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Removal Efficiency ◽  
Full Scale ◽  
Full Scale Test ◽  
Air Cleaner ◽  
Scale Test

scholarly journals Honeycomb wet scrubber for acidic gas control: modeling and long-term test results

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Thi-Cuc Le ◽  
Gung-Hwa Hong ◽  
Guan-Yu Lin ◽  
Ziyi Li ◽  
David Y. H. Pui ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Removal Efficiency ◽  
Treatment Method ◽  
Acidic Gases ◽  
Potential Applications ◽  
Wet Scrubber ◽  
Predicted Height ◽  
Long Term Performance ◽  
Term Performance

AbstractA laboratory scale, 1.0 CMM (m3 min− 1) wet scrubber packed with water-absorbing honeycomb material (HWS) with a very large geometric surface area of 480 m2 m− 3 and a low pressure drop developed in our previous study was shown to achieve a very high removal efficiency for acidic gases but there were no long-term test data. In this study, the HWS scaled up to operate at a 100 CMM flow rate was tested for removing mixed acidic gases at a semiconductor fab for a very long period of 3.5 yr. Results showed that the removal efficiency for the mixed gases emitted from the fab always maintained as high as > 95% for HF, CH3COOH, HCl, HNO3, HNO2, and H2SO4 with the inlet concentrations ranging from supper-ppmv to sub-ppmv, during a 3.5-yr period. With water jet cleaning of the honeycomb modules once per year, the pressure drop of the HWS remained to be low at 0.5–0.8 cm H2O, indicating minimal scaling in the HWS. Additionally, the predicted height and removal efficiencies of the HWS were very close to the experimental data. The excellent long-term performance of the HWS warrants its potential applications in many areas in which liquid absorption is the preferred treatment method and the theoretical equations can facilitate the design of the HWS.

scholarly journals Optimization and Modeling of Microcystin-LR Degradation by TiO2 Photocatalyst Using Response Surface Methodology

2020 ◽  
Author(s):  
Negar Jafari ◽  
Afshin Ebrahimi ◽  
Karim Ebrahimpour ◽  
Ali Abdolahnejad
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Contact Time ◽  
High Performance ◽  
Operating Variables ◽  
Effective Removal ◽  
Positive Effect ◽  
Harmful Effects ◽  
Maximum Removal

Introduction: Microcystin-leucine arginine (MC-LR) is a toxin with harmful effects on the liver, kidney, heart, and gastrointestinal tract. So, effective removal of MC-LR from water resources is of great importance. The aim of this study was to remove microcystin-LR (MC-LR) from aqueous solution by Titanium Dioxide (TiO2). Materials and Methods: In the present study, TiO2, as a semiconductor, was used for photodegradation of MC-LR under ultraviolet light (UV). The Response Surface Methodology was applied to investigate the effects of operating variables such as pH (A), contact time (B), and catalyst dose (B) on the removal of MC-LR. The MC-LR concentration was measured by high-performance liquid chromatography (HPLC). Results: The results showed that single variables such as A, B, and C had significant effects on MC-LR removal (pvalue < 0.05). In other words, increase of the contact time and catalyst dose had a positive effect on enhancing the removal efficiency of MC-LR, but the effect of pH was negative. The analysis of variance showed that BC, A2, and C2 variables had a significant effect on the MC-LR removal (pvalue < 0.05). Finally, the maximum removal efficiency of MC-LR was 95.1%, which occurred at pH = 5, contact time = 30 minutes, and catalyst dose = 1 g/l. Conclusion: According to the findings, TiO2, as a photocatalyst, had an appropriate effect on degradation of the MC-LR.

Drag Reduction of Polymer Solutions in a Pipe With a Highly Water-Repellent Wall

1999 ◽  
Author(s):  
Keizo Watanabe ◽  
Hiroshi Udagawa
Keyword(s):  
Pressure Drop ◽  
Laminar Flow ◽  
Drag Reduction ◽  
Polymer Solutions ◽  
Tap Water ◽  
Acrylic Resin ◽  
Water Repellent ◽  
Number Range ◽  
Surfactant Solutions ◽  
Laminar And Turbulent Flow

Abstract By applying a highly water-repellent wall pipe in the drag reduction of polymer solutions, a flow system in which drag reduction is obtained in both laminar and turbulent flow ranges has been realized. Experiments were carried out to measure the pressure drop in pipes with a highly water-repellent wall and an acrylic resin wall by means of a pressure transducer. The diameter of the pipe was 6mm. The polymer solutions tested were PE015 aqueous solutions in the concentration range of 30ppm∼1000ppm. The drag reduction ratio for laminar flow was about 11∼15%. To understand this effect, the pressure drop was measured by using surfactant solutions and degassed water, and by pressurizing tap water in the pipeline. It was shown that the laminar drag reduction does not occur in the case of surfactant solutions although degassed water and pressurizing tap water in the pipeline have no effect on the reduction. In the laminar flow range, the friction factor of a power-law fluid with fluid slip was analyzed by applying the modified boundary condition on fluid slip at the pipe wall, and the analytical results agree with the experimental results in the low Reynolds number range.

scholarly journals The Concentrations and Removal Effects of PM10 and PM2.5 on a Wetland in Beijing

2019 ◽  
Vol 11 (5) ◽  
pp. 1312 ◽  
Author(s):  
Chunyi Li ◽  
Yilan Huang ◽  
Huanhuan Guo ◽  
Gaojie Wu ◽  
Yifei Wang ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Removal Efficiency ◽  
Land Surface ◽  
Nature Reserve ◽  
Metropolitan Areas ◽  
Average Concentration ◽  
Pm10 And Pm2.5 ◽  
Bare Land ◽  
Land Surfaces ◽  
The Relationship

Particulate matter (PM) is an essential source of atmospheric pollution in metropolitan areas since it has adverse effects on human health. However, previous research suggested wetlands can remove particulate matter from the atmosphere to land surfaces. This study was conducted in the Hanshiqiao Wetland National Nature Reserve in Beijing during 2016. The concentrations of PM10 and PM2.5 on a wetland and bare land in the park, as well as metrological data, were collected during the whole year. Based on the observed data, removal efficiency of each land use type was calculated by empirical models and the relationships between concentrations and metrological factors were also analyzed. The results indicated that: (1) In general, the PM10 and PM2.5 concentrations on the bare land surface were higher than those on the wetland surface, in both of which the highest value appeared at night and evening, while the lowest value appeared near noon. In terms of season, the average concentration of PM10 was higher in winter (wetland: 137.48 μg·m−3; bare land: 164.75 μg·m−3) and spring (wetland: 205.18 μg·m−3; bare land: 244.85 μg·m−3) in general. The concentration of PM2.5 on the wetland surface showed the same pattern, while that on the bare land surface was higher in spring and summer. (2) Concentrations of PM10 and PM2.5 were significantly correlated with the relative humidity (p < 0.01) and inversely correlated with wind speed (p < 0.05). The relationship between PM10 and PM2.5 concentrations and temperature was more complicated—it showed a significantly negative correlation (p < 0.01) between them in winter and spring, however, the correlation was insignificant in autumn. In summer, only the correlation between PM10 concentration and temperature on the wetland surface was significant (p < 0.01). (3) The dry removal efficiency of PM10 was greater than that of PM2.5. The dry removal efficiencies of PM10 and PM2.5 followed the order of spring > winter > autumn > summer on the wetland. This study seeks to provide practical measures to improve air quality and facilitate sustainable development in Beijing.

Charged graphene aerogel filter enabled superior particulate matter removal efficiency in harsh environment

2020 ◽  
Vol 395 ◽  
pp. 125086 ◽  
Author(s):  
Kaiying Zhao ◽  
Jianying Huang ◽  
Jiajun Mao ◽  
Zewei Bao ◽  
Zhong Chen ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Removal Efficiency ◽  
Harsh Environment ◽  
Graphene Aerogel

An Analytical Study of the Optimized Performance of an Impingement Heat Sink

2004 ◽  
Vol 126 (4) ◽  
pp. 528-534 ◽  
Author(s):  
S. B. Sathe ◽  
B. G. Sammakia
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Sink ◽  
High Performance ◽  
Cross Flow ◽  
High Heat ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
High Heat Transfer ◽  
Flow Through

The results of a study of a new and unique high-performance air-cooled impingement heat sink are presented. An extensive numerical investigation of the heat sink performance is conducted and is verified by experimental data. The study is relevant to cooling of high-power chips and modules in air-cooled environments and applies to workstations or mainframes. In the study, a rectangular jet impinges on a set of parallel fins and then turns into cross flow. The effects of the fin thickness, gap nozzle width and fin shape on the heat transfer and pressure drop are investigated. It is found that pressure drop is reduced by cutting the fins in the central impingement zone without sacrificing the heat transfer due to a reduction in the extent of the stagnant zone. A combination of fin thicknesses of the order of 0.5 mm and channel gaps of 0.8 mm with appropriate central cutout yielded heat transfer coefficients over 1500 W/m2 K at a pressure drop of less than 100 N/m2, as is typically available in high-end workstations. A detailed study of flow-through heat sinks subject to the same constraints as the impingement heat sink showed that the flow-through heat sink could not achieve the high heat transfer coefficients at a low pressure drop.

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