scholarly journals Development of Needle-Punched Nonwoven Fabrics from Reclaimed Fibers for Air Filtration Applications

2014 ◽  
Vol 9 (1) ◽  
pp. 155892501400900 ◽  
Author(s):  
S. Sakthivel ◽  
Anban J.J. Ezhil ◽  
T. Ramachandran
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Air Permeability ◽  
Filtration Efficiency ◽  
Raw Material ◽  
Fine Tuning ◽  
Physical Parameters ◽  
Air Filtration ◽  
Nonwoven Fabrics

This paper reports an investigative study on the fabrication and measurement of the air permeability, mechanical properties, pore size distribution, and filtration efficiency of different nonwoven fabrics produced from reclaimed fibers by analytically changing the machine variables to manipulate the physical parameters of the nonwoven fabrics. Reclaimed fiber of cotton (60%) and polyester (40%) blend was used, so that the prospect of value addition to an inexpensive source of raw material could be explored. The changes in air permeability were interpreted in terms of fabric density profile and pore size distribution. The filtration parameters of filtration efficiency, dust holding capacity, and pressure drop were also calculated. Additionally, the effects of calendering on pore size and filtration properties were evaluated to discover the opportunity of fine-tuning and the performance of the filters. The outcome in this study reflected an overall development in all filtration characteristics due to the calendering operation.

scholarly journals Air filtration improvement of konjac glucomannan-based aerogel air filters through physical structure design

2021 ◽  
Author(s):  
Hong Qian ◽  
Ying Fang ◽  
Kao Wu ◽  
Hao Wang ◽  
Bin Li ◽  
...  
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Physical Structure ◽  
Structure Design ◽  
Air Filtration ◽  
Air Filters ◽  
Air Filter ◽  
Purification Time

Abstract This study presents two methods to improve the air filtration performance of konjac glucomannan (KGM)-based aerogel air filters through physical structure design by changing the pore-size distribution and the surface area, using an air purifier. Results indicated that KGM-based aerogels had a comparable filtration effect with the commercial air filter with a longer purification time. This purification time could be shortened by over 50%, by changing the pore-size distribution from large size to small size or increase the surface area with the fold structure. This should boost the development of polysaccharide-based aerogel used as the air filter.

scholarly journals Review of Formation and Gas Characteristics in Shale Gas Reservoirs

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5427
Author(s):  
Boning Zhang ◽  
Baochao Shan ◽  
Yulong Zhao ◽  
Liehui Zhang
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Shale Gas ◽  
Physical Parameters ◽  
Gas Reservoirs ◽  
Shale Formations ◽  
Adsorbed Gas ◽  
Shale Gas Reservoirs ◽  
Longmaxi Shale

An accurate understanding of formation and gas properties is crucial to the efficient development of shale gas resources. As one kind of unconventional energy, shale gas shows significant differences from conventional energy ones in terms of gas accumulation processes, pore structure characteristics, gas storage forms, physical parameters, and reservoir production modes. Traditional experimental techniques could not satisfy the need to capture the microscopic characteristics of pores and throats in shale plays. In this review, the uniqueness of shale gas reservoirs is elaborated from the perspective of: (1) geological and pore structural characteristics, (2) adsorption/desorption laws, and (3) differences in properties between the adsorbed gas and free gas. As to the first aspect, the mineral composition and organic geochemical characteristics of shale samples from the Longmaxi Formation, Sichuan Basin, China were measured and analyzed based on the experimental results. Principles of different methods to test pore size distribution in shale formations are introduced, after which the results of pore size distribution of samples from the Longmaxi shale are given. Based on the geological understanding of shale formations, three different types of shale gas and respective modeling methods are reviewed. Afterwards, the conventional adsorption models, Gibbs excess adsorption behaviors, and supercritical adsorption characteristics, as well as their applicability to engineering problems, are introduced. Finally, six methods of calculating virtual saturated vapor pressure, seven methods of giving adsorbed gas density, and 12 methods of calculating gas viscosity in different pressure and temperature conditions are collected and compared, with the recommended methods given after a comparison.

scholarly journals Physical parameters of Fluvisols on flooded and non-flooded terraces

2017 ◽  
Vol 31 (1) ◽  
pp. 73-82 ◽  
Author(s):  
Milena Kercheva ◽  
Zofia Sokołowska ◽  
Mieczysław Hajnos ◽  
Kamil Skic ◽  
Toma Shishkov
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Mercury Intrusion Porosimetry ◽  
Water Retention Curve ◽  
Anthropogenic Factors ◽  
Physical Parameters ◽  
Water Desorption ◽  
Mercury Intrusion ◽  
The Impact

Abstract The heterogeneity of soil physical properties of Fluvisols, lack of large pristine areas, and different moisture regimes on non-flooded and flooded terraces impede the possibility to find a soil profile which can serve as a baseline for estimating the impact of natural or anthropogenic factors on soil evolution. The aim of this study is to compare the pore size distribution of pristine Fluvisols on flooded and non-flooded terraces using the method of the soil water retention curve, mercury intrusion porosimetry, nitrogen adsorption isotherms, and water vapour sorption. The pore size distribution of humic horizons of pristine Fluvisols on the non-flooded terrace differs from pore size distribution of Fluvisols on the flooded terrace. The peaks of textural and structural pores are higher in the humic horizons under more humid conditions. The structural characteristics of subsoil horizons depend on soil texture and evolution stage. The peaks of textural pores at about 1 mm diminish with lowering of the soil organic content. Structureless horizons are characterized by uni-modal pore size distribution. Although the content of structural pores of the subsoil horizons of Fluvisols on the non-flooded terrace is low, these pores are represented by biopores, as the coefficient of filtration is moderately high. The difference between non-flooded and flooded profiles is well expressed by the available water storage, volume and mean radius of pores, obtained by mercury intrusion porosimetry and water desorption, which are higher in the surface horizons of frequently flooded Fluvisols.

scholarly journals Prediction of Relative Air Permeability of Porous Media With Weibull Pore Size Distribution

2019 ◽  
Vol 55 (11) ◽  
pp. 10037-10049
Author(s):  
Zhenlei Yang ◽  
Binayak P. Mohanty ◽  
Yalchin Efendiev ◽  
Zhuping Sheng
Keyword(s):  
Porous Media ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Air Permeability

scholarly journals The Pore Size Distribution of Naturally Porous Cigarette Paper and its Relation to Permeability and Diffusion Capacity

2015 ◽  
Vol 26 (7) ◽  
Author(s):  
Bernhard Eitzinger ◽  
Maria Gleinser ◽  
Stefan Bachmann
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Filler Content ◽  
Air Permeability ◽  
Size Distributions ◽  
Diffusion Capacity ◽  
Pore Size Distributions ◽  
Cigarette Paper ◽  
And Diffusion

SummaryThe pore size distribution of cigarette paper determines its air permeability and diffusion capacity and thereby has a significant influence on the gas exchange of a cigarette through the cigarette paper during smoking and during smouldering. For the design of cigarettes and in particular of cigarette papers it is important to understand how the pore size distribution of the cigarette paper is affected by the paper composition and paper properties and how it influences air permeability and diffusion capacity.It was the aim of this study to investigate how the composition of the cigarette paper such as filler content, fibre type and burn additive content qualitatively influenced the pore size distribution and how the pore size distribution and, in particular, which pore size range is correlated with air permeability and diffusion capacity, respectively. To this end eight naturally porous cigarette papers were selected which differed in air permeability, diffusion capacity, fibre type, filler content and burn additive content. The pore size distributions of these papers were measured by mercury porosimetry before and after the papers had been heated to 230 °C for 30 min. The pore size distributions were investigated for qualitative differences when air permeability, fibre type and filler content of the cigarette paper are modified. Furthermore by appropriate weighting of the pore size distributions optimal correlations between a weighted pore volume and air permeability or diffusion capacity were determined. The results show a good correlation with correlation coefficients greater than 0.9 for air permeability as well as for diffusion capacity. The results indicate that large pores are better correlated with changes in air permeability, while small pores are more strongly correlated with changes in diffusion capacity and support previous theoretical results obtained from flow and diffusion models. They also demonstrate the tight relationship between pore size distribution, air permeability and diffusion capacity, which makes the pore size distribution a tool to further optimize cigarette papers, for example, with respect to carbon monoxide yields in the smoke of a cigarette. [Beitr. Tabakforsch. Int 26 (2015) 312-319]

Evaluation of Pore Size Distribution for Controlled Permeability Formwork Liner

2014 ◽  
Vol 534 ◽  
pp. 53-62
Author(s):  
Zheng Hong Tian ◽  
Xiao Dong Wang
Keyword(s):  
Experimental Data ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Good Accuracy ◽  
Functional Material ◽  
Nonwoven Fabrics ◽  
The Matrix ◽  
Accuracy And Repeatability ◽  
Good Agreement

Controlled permeability formwork liner (CPFL) is the functional material similar to nonwoven fabrics and its filtration and drainage performance is dominated by the pore size distribution (PSD) of matrix. In this paper, suction table method, generally used to measure soil pore diameter, is improved for testing PSD of CPFL and experimental data was compared to the results from four other normal experimental methods, i.e., wet sieving method, bubble point method, mercury intrusion porosimetry (MIP) method and image analysis. The comparison indicates that PSD of CPFL obtained from suction table show good accuracy and repeatability. Furthermore, a modified mathematical model derived from Rawal model and Fature model is proved to be suitable for determinating PSD of the matrix of CPFLwith bilayer structure, and have a good agreement with the experimental data from suction table.

scholarly journals Cell wall microstructure, pore size distribution and absolute density of hemp shiv

2018 ◽  
Vol 5 (4) ◽  
pp. 171945 ◽  
Author(s):  
Y. Jiang ◽  
M. Lawrence ◽  
M. P. Ansell ◽  
A. Hussain
Keyword(s):  
Cell Wall ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Middle Lamella ◽  
Primary Cell Wall ◽  
Physical Parameters ◽  
Absolute Density ◽  
Hemp Shiv ◽  
Helium Pycnometry

This paper, for the first time, fully characterizes the intrinsic physical parameters of hemp shiv including cell wall microstructure, pore size distribution and absolute density. Scanning electron microscopy revealed microstructural features similar to hardwoods. Confocal microscopy revealed three major layers in the cell wall: middle lamella, primary cell wall and secondary cell wall. Computed tomography improved the visualization of pore shape and pore connectivity in three dimensions. Mercury intrusion porosimetry (MIP) showed that the average accessible porosity was 76.67 ± 2.03% and pore size classes could be distinguished into micropores (3–10 nm) and macropores (0.1–1 µm and 20–80 µm). The absolute density was evaluated by helium pycnometry, MIP and Archimedes' methods. The results show that these methods can lead to misinterpretation of absolute density. The MIP method showed a realistic absolute density (1.45 g cm −3 ) consistent with the density of the known constituents, including lignin, cellulose and hemi-cellulose. However, helium pycnometry and Archimedes’ methods gave falsely low values owing to 10% of the volume being inaccessible pores, which require sample pretreatment in order to be filled by liquid or gas. This indicates that the determination of the cell wall density is strongly dependent on sample geometry and preparation.

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