Filtration performance of biaxial circular seamless knitted filter material based on electrostatic adsorption

2021 ◽  
pp. 152808372110017
Author(s):  
Haiwen Mao ◽  
Zhijuan Pan
Keyword(s):  
Numerical Simulation ◽  
Research And Development ◽  
Electrostatic Field ◽  
Filter Material ◽  
Filtration Efficiency ◽  
Electrostatic Adsorption ◽  
Filtration Performance ◽  
Filter Materials ◽  
Active Filtration ◽  
The Relationship

In order to solve the problem of dust accumulation at the joints of traditional filter materials and the reduction of filtration efficiency, weft knitting was selected to make the fabric cylindrical unwinding machine. The cylindrical filter material was formed by cylindrical needling machine in the later period. This type of novel seamless filter material was compared with the traditional one on the filtration performance and numerical simulation of filtration performance. The results show that when the warp and weft lining yarns in the seamless filter material were PTFE monofilaments containing tourmaline particles, the filtration efficiency was the optimal due to the presence of the surface static voltage. The filtration efficiency could greatly be improved by 7.24%. The relationship between the surface static voltage and distance was exponential. The filter material with electrostatic field on the surface increased the active filtration of electrostatic adsorption in addition to the passive filtration. This type of seamless filter material provided research and development ideas and theoretical guidance for the development and application of filter materials.

scholarly journals Experimental study on filtration effect of oilfield sewage based on new polyurethane modified materials

2020 ◽  
Vol 82 (10) ◽  
pp. 2039-2050
Author(s):  
Bingcheng Liu ◽  
Hongsong Li ◽  
Ning Liu ◽  
Wenguang Jia
Keyword(s):  
Filter Material ◽  
Filtration Efficiency ◽  
Practical Significance ◽  
Micro Computed Tomography ◽  
Adsorption Effect ◽  
Filtration Performance ◽  
Quality Of Water ◽  
Solids Concentration ◽  
Computed Tomography Scanning ◽  
The Difference

Abstract In the process of oilfield wastewater treatment, the polymer-modified materials with special wettability have been recognized by many scholars for their high filtration efficiency and good adsorption effect. In this paper, we used micro-computed tomography scanning and infrared scanning technology to further explore the internal structure and surface chemistry of polyurethane modified materials and then established an experimental platform for the filtration performance of polyurethane modified materials. The change of suspended solids concentration and oil content in the sewage was tested under different filtration rate, filter layer thickness, and water quality. The results showed that the porosity of the filter material and the oil-absorbing material was 65.85% and 56.03% respectively, and the difference in the number of oxygen-containing functional groups on the surface of these two materials indicated different adsorption force for sewage impurities. And the polyurethane modified materials had good filtration performance. Through these experiments, we demonstrated that the quality of water filtrated by the polyurethane modified materials met the requirements of the ‘National Comprehensive Wastewater Discharge Standards’, and the filtration efficiency for suspended particles and oils in oily sewage was higher than 80%. These materials have important practical significance for the harmless treatment of oily sewage.

scholarly journals Experimental Study of Filtration Materials Used in the Car Air Intake

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3498
Author(s):  
Tadeusz Dziubak ◽  
Sebastian Dominik Dziubak
Keyword(s):  
Flow Resistance ◽  
Initial Period ◽  
Filter Material ◽  
Filtration Efficiency ◽  
Structure Parameters ◽  
Air Filtration ◽  
Resistance Increase ◽  
Filter Materials ◽  
Engine Component ◽  
Dust Absorption

Traditional cellulose filter media used for air filtration in vehicle engines are characterized by 99.9% filtration efficiency and accuracy above 2–5 µm. The highest engine component wear is caused by dust grains above 1 µm. Filter media with nanofiber additions provide greater filtration efficiency of dust grains below 5 µm. Filter material selection for vehicle engine air filter is a problem because their manufacturers mainly provide only the structure parameters: pore size, air permeability, and thickness. There is no information about material filtration properties using polydisperse test dust. The manuscript presents methodology and experimental test results of five samples A, B, C, D and E, filter materials differing in their chemical composition and structure parameters. In the first stage, efficiency characteristics φw, filtration accuracy dzmax and the flow resistance Δpw depending on the dust absorption coefficient km of three filter cartridges of each material, A, B, C, D and E, were determined. Then, from each material characteristics of one piece was selected in order to compare their initial and initial period efficiencies as well as changes in the flow resistance depending on the dust absorption coefficient km. Obtained results showed that the filter materials differ significantly in efficiency and accuracy values in the initial filtration period. Initial period duration is also different, i.e., filtration efficiency increasing time to a certain value, which for materials with a nanofiber layer is much shorter, which minimizes engine component wear. For materials with nanofibers, flow resistance increase intensity is greater, which results from surface filtration. Filtration efficiency of each filter material sample A, B, C, D and E was assessed with the filtration quality coefficient including the efficiency and flow resistance. In the available literature, the problem of increasing filtration efficiency in the initial period is known, but there are no results for specific filter materials. Research shows that filter material characteristics are closely related. Each increase in efficiency and accuracy of intake air filtration reduces engine components wear, but it is related to flow resistance increase in the engine intake system, which reduces its power, and increases need for more frequent filter servicing.

scholarly journals Influence of fiber diameter on filtration performance of polyester fibers

2019 ◽  
Vol 23 (4) ◽  
pp. 2291-2296 ◽  
Author(s):  
Xin Zhang ◽  
Yue-Sheng Fan ◽  
Guo-Ji Tian ◽  
Huan Wang ◽  
Hong-Li Zhang ◽  
...  
Keyword(s):  
Influencing Factors ◽  
Fiber Diameter ◽  
Counting Efficiency ◽  
Filtration Efficiency ◽  
Filtration Velocity ◽  
Filtration Performance ◽  
Filter Materials ◽  
Significant Difference ◽  
Polyester Fibers

The filtration performance of four kinds of coarse polyester filters commonly used in the market was studied experimentally. The results showed that these filter materials had better filtration efficiency for particles larger than 5 ?m. There was a significant difference among the same grade filters on filtration efficiency and resistance. The maximum counting efficiency of all four Samples can be achieved when the filtration velocity was 1.1 m/s. Fiber diameter was one of the main influencing factors that affect the efficiency and resistance of polyester filters. The comprehensive effect was relatively good when the Sample fiber diameter was small.

scholarly journals Unravelling the process of petroleum hydrocarbon biodegradation in different filter materials of constructed wetlands by stable isotope fractionation and labelling studies

2021 ◽  
Author(s):  
Andrea Watzinger ◽  
Melanie Hager ◽  
Thomas Reichenauer ◽  
Gerhard Soja ◽  
Paul Kinner
Keyword(s):  
Stable Isotope ◽  
Constructed Wetlands ◽  
Hydrogen Isotope ◽  
Petroleum Hydrocarbon ◽  
Isotope Fractionation ◽  
Isotope Effects ◽  
Filter Material ◽  
Hydrocarbon Biodegradation ◽  
Stable Isotope Fractionation ◽  
Filter Materials

AbstractMaintaining and supporting complete biodegradation during remediation of petroleum hydrocarbon contaminated groundwater in constructed wetlands is vital for the final destruction and removal of contaminants. We aimed to compare and gain insight into biodegradation and explore possible limitations in different filter materials (sand, sand amended with biochar, expanded clay). These filters were collected from constructed wetlands after two years of operation and batch experiments were conducted using two stable isotope techniques; (i) carbon isotope labelling of hexadecane and (ii) hydrogen isotope fractionation of decane. Both hydrocarbon compounds hexadecane and decane were biodegraded. The mineralization rate of hexadecane was higher in the sandy filter material (3.6 µg CO2 g−1 day−1) than in the expanded clay (1.0 µg CO2 g−1 day−1). The microbial community of the constructed wetland microcosms was dominated by Gram negative bacteria and fungi and was specific for the different filter materials while hexadecane was primarily anabolized by bacteria. Adsorption / desorption of petroleum hydrocarbons in expanded clay was observed, which might not hinder but delay biodegradation. Very few cases of hydrogen isotope fractionation were recorded in expanded clay and sand & biochar filters during decane biodegradation. In sand filters, decane was biodegraded more slowly and hydrogen isotope fractionation was visible. Still, the range of observed apparent kinetic hydrogen isotope effects (AKIEH = 1.072–1.500) and apparent decane biodegradation rates (k = − 0.017 to − 0.067 day−1) of the sand filter were low. To conclude, low biodegradation rates, small hydrogen isotope fractionation, zero order mineralization kinetics and lack of microbial biomass growth indicated that mass transfer controlled biodegradation.

Some Relationship between Safety Factor of Earthquake Slope and Related Parameters

2011 ◽  
Vol 422 ◽  
pp. 688-692
Author(s):  
Xiao Hei He ◽  
Geng You Han ◽  
Rui Hua Xiao
Keyword(s):  
Numerical Simulation ◽  
Rock Mechanics ◽  
Safety Factor ◽  
Limit Equilibrium ◽  
Static Method ◽  
Acceleration Coefficient ◽  
The Wenchuan Earthquake ◽  
Stability Of Slope ◽  
The Stability ◽  
The Relationship

Abstract:Since the Wenchuan earthquake happened, the slope stability had been paid much more attention. The safety factor is an important parameter that can be used to evaluate the stability of slope. The pseudo-static method that based on limit equilibrium and the method of numerical simulation can calculate the safety factor accurately, but the velocity that gets the result is slow. If we can establish the relationship between safety factor and some other parameters, then we can calculate the safety factor by using the relationship more quickly. This paper establishes much relationship, such as the relationship between the rock mechanics parameters and the average danymic safety factor, the relationship between the rock mechanics parameters and the ratio of average danymic safety factor to static safety factor, the relationship between the rock mechanics parameters and the average earthquake acceleration coefficient, the relationship between the average earthquake acceleration coefficient and the ratio of average danymic safety factor to static safety factor, and the relationship between the earthquake acceleration coefficient and the ratio of danymic safety factor to static safety factor on the condition of different rock mass.

Innovation in SMEs: the role of employee training in German SMEs

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Irem Demirkan ◽  
Ravi Srinivasan ◽  
Alka Nand
Keyword(s):  
Research And Development ◽  
Boundary Conditions ◽  
Product Innovation ◽  
Employee Training ◽  
Lower Proportion ◽  
Economic Research ◽  
Content Type ◽  
The Relationship ◽  
Practical Implications

PurposeThis paper explores the role of effective resource and knowledge management capabilities on product innovation capabilities of the small and medium-sized enterprises (SMEs). Specifically, the authors research the role of the human resource investments in the form of employee training in developing firm's innovation capabilities and how SMEs manage these investments when we account for the boundary conditions such as the level of employee education, SME size and the frequency of investments in research and development (R&D).Design/methodology/approachThe authors use survey data conducted by The Centre for European Economic Research (Zentrum für Europäische Wirtschaftsforschung – ZEW). The final sample for analysis includes 983 SMEs from Germany that belong to 13 different industries. The authors use hierarchical OLS regression to test the hypotheses presented in this paper.FindingsThe authors find a positive association between increased investments in employee training and product innovation capabilities in the context of SMEs. More specifically, the authors’ findings support that (1) the relationship between employee training and innovation capabilities is weaker in industries with greater proportion of employees with university degrees, (2) the effectiveness of investments in employee training is lower among larger SMEs than smaller SMEs, and (3) continuous R&D weakens the relationship between training expenditure and innovation capabilities. While on the one hand the authors’ findings contribute to the debate of whether employee training is necessary for SMEs by affirming this notion, on the other hand the authors show that investments in employee training have differing implications for small and large SMEs within boundary conditions. Moreover, these findings have practical implications for the managers of all SMEs in terms of management of their knowledge resources.Research limitations/implicationsThe authors’ research makes important contributions to the study of innovation in SMEs. First, the authors contribute evidence to the debate whether employee training is necessary for SMEs by showing that employee training is particularly important for SMEs that are smaller in size, have lower proportion of employees with university degrees and when they invest in research and development in a targeted manner. The authors also demonstrate that investments in employee training is not a waste, rather such investments can increase the likelihood of survival for many of these firms through its positive impact on product innovation.Practical implicationsFor managers of SMEs, the authors’ findings suggest that while investments in employee training are important, the managers of particular SMEs with above-mentioned qualities should be persistent in such investments and must make deliberate efforts to reap the benefits in terms of innovative capabilities. Unlike large firms, who have the financial means to carry out investments in an abundant manner, SMEs appear to be more enterprising with their scarce resources when we also consider the role of investments in human resources.Originality/valueThe authors’ research makes important contributions to the study of innovation in SMEs. First, the authors contribute evidence to the debate whether employee training is necessary for SMEs by finding that employee training is particularly important for SMEs that are smaller in size, have lower proportion of employees with university degrees and when they do not invest in R&D continuously. The authors also demonstrate that investments in employee training is not a waste, but such investments can increase the likelihood of survival for many of these firms.

On the Friction Coefficient in the Numerical Simulation of Tidal Wave Propagation

2010 ◽  
Author(s):  
Z. Y. Song ◽  
C. Cheng ◽  
F. M. Xu ◽  
J. Kong
Keyword(s):  
Numerical Simulation ◽  
Wave Propagation ◽  
Friction Factor ◽  
Tidal Wave ◽  
Computational Time ◽  
Numerical Dissipation ◽  
Courant Number ◽  
Time Step ◽  
Large Time Step ◽  
The Relationship

Based on the analytical solution of one-dimensional simplified equation of damping tidal wave and Heuristic stability analysis, the precision of numerical solution, computational time and the relationship between the numerical dissipation and the friction dissipation are discussed with different numerical schemes in this paper. The results show that (1) when Courant number is less than unity, the explicit solution of tidal wave propagation has higher precision and requires less computational time than the implicit one; (2) large time step is allowed in the implicit scheme in order to reduce the computational time, but the precision of the solution also reduce and the calculation precision should be guaranteed by reducing the friction factor: (3) the friction factor in the implicit solution is related to Courant number, presented as the determined friction factor is smaller than the natural value when Courant number is larger than unity, and their relationship formula is given from the theoretical analysis and the numerical experiments. These results have important application value for the numerical simulation of the tidal wave.

scholarly journals AN INVESTIGATION ON THE EFFECTS OF MICRO-PARAMETERS ON THE STRENGTH PROPERTIES OF ROCK

2021 ◽  
Vol 36 (1) ◽  
pp. 111-119
Author(s):  
Behzad Jafari Mohammadabadi ◽  
Kourosh Shahriar ◽  
Hossein Jalalifar ◽  
Kaveh Ahangari
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Friction Coefficient ◽  
Critical Stress ◽  
Friction Angle ◽  
Strength Properties ◽  
Brazilian Tensile Strength ◽  
The Relationship

Rocks are formed from particles and the interaction between those particles controls the behaviour of a rock’s mechanical properties. Since it is very important to conduct extensive studies about the relationship between the micro-parameters and macro-parameters of rock, this paper investigates the effects of some micro-parameters on strength properties and the behaviour of cracks in rock. This is carried out by using numerical simulation of an extensive series of Uniaxial Compressive Strength (UCS) and Brazilian Tensile Strength (BTS) tests. The micro-parameters included the particles’ contact modulus, the contact stiff ness ratio, bond cohesion, bond tensile strength, the friction coefficient and the friction angle, and the mechanical properties of chromite rock have been considered as base values of the investigation. Based on the obtained results, it was found that the most important micro-parameters on the behaviour of rock in the compressive state are bond cohesion, bond tensile strength, and the friction coefficient. Also, the bond tensile strength showed the largest effect under tensile conditions. The micro-parameter of bond tensile strength increased the rock tensile strength (up to 5 times), minimized destructive cracks and increased the corresponding strain (almost 2.5 times) during critical stress.

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