• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.264-268
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• 2007

The filtration performance of micron-sized metal fibrous filter was improved by synthesizing carbon nanotubes grown on the surface of metal fibers. The carbon nanotubes are grown with bush-like nanostructures covered around the micron-fibers or web-like nanostructures crossing between the fibers at different synthetic conditions. Filtration efficiency of CNT-metal-filter was measured and compared with the efficiency of the raw metal filter without CNTs. The developed CNT-metal-filter has higher filtration efficiency without significant difference in pressure drop compared with the conventional metal filter, which is because the carbon nanotubes function as the trap of pollutant nanoparticles.

• Proceedings of the Korean Fiber Society Conference
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• 2007.11a
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• pp.217-218
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• 2007

• Composites Research
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• v.35 no.1
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• pp.47-51
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• 2022

In order to efficiently control the heat generation of electronic devices, many research has been conducted on thermally conductive composite materials. In this study, milled carbon fiber was dispersed in four solvent to investigate the relationship of carbon fiber alignment according to dispersion by solvents, and carbon fiberreinforced composite material(CFRP) was manufactured using vacuum filtration. To evaluate the arrangement of CFRP the arrangement of the prepared specimen was observed under an optical microscope, and thermal conductivity was measured by Laser Flash Analysis. The Through-plane thermal conductivity of CFRP using NMP and Ethanol was 10.79 W/mK and 10.57 W/mK respectively, which were improved by 218% and 209% compared to the In-plane thermal conductivity. The high viscosity of the solvent greatly affects the shear of the fluid, and it seemed to determine the alignment of the filler.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.4
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• pp.10-17
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• 2000

The change of fiber length, freeness, initial forming drainage velocity, specific filtration resistance, final drainage time and wet web dryness were measured to investigate the effect of the refining load on the drainage characteristics of pulp. The arithmetic average fiber length after refining with higher refining load was shorter than that obtained with lower refining load. Higher refining load decreased initial forming drainage velocity, final drainage time and wet web dryness. The refining load also affected the relationship between freeness and specific filtration resistance, initial forming drainage velocity, final drainage time. It was found that the specific filtration resistance is better than freeness to predict the drainage characteristics of pulp and the wet dryness.

• Journal of the Korean Applied Science and Technology
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• v.31 no.1
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• pp.59-65
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• 2014

Indoor air quality including metro subway is of recent interests in large cities. Inflow air to the inside of the train and circulating air flow through MVAC of stations contain large amount of iron based fine particles. This paper evaluated the collection of such a dust by magnetic filters as comparing to conventional particle capturing mechanisms such as inertia, direct impaction and diffusion. It was found that filtration velocity, magnetic field intensity, and fiber size were the most important parameters for magnetic filtration. Application of magnetic force obviously enhances the collection efficiency particularly in fine modes smaller than 10 mm. However, its effect was found greater in 2.5 mm than submicron particles.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.144-148
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• 2005

The industrial development of large scale deep bed filters has been a very important step in the process of drinking water production and more recently in the tertiary treatment of wastewater. The target of deep bed filtration is the retention is the retention of small particles generally smaller than 30 microns at relatively small concentration, generally less than 30 mg/l from natural water (surface water or aquifers) or secondary treated wastewater. The relation between the retention efficiency and the characteristics of the particles has been extensively studied experimentally and through different models of retention. During the last years the development of new technologies (fiber filter, membrane modules) lead to more intensive processes compared to conventional sand filtration. Fiber filters can combine intensification with a decrease in specific energy needed however they cannot be operated under gravity like sand filters. Membrane filters (UF or MF) are much more intensive and efficient than sand filters. The specific energy needed is not so high (about $0.1Kwh/M^3$) but is higher than sand or fiber filter. A Life Cycle Analysis (LCA) has to be made for a complete comparison between these technologies taking in account that the efficiency of particle retention obtained by membrane filters is unique.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.3
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• pp.87-91
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• 2010

Wood and non-wood material is widely used as a medium for filtration. It is a relatively low cost material and because of its construction, can be used to filter small particles(${\sim}5{\mu}m$). This fiber filter is concerned with characterizing some of the physical properties of wood & non-wood materials particularly relating to filtration of particles from dilute suspensions. In addition, they are nonuniform and tortuous as a result of the formation and variations in individual fibers.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.3
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• pp.371-380
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• 2004

In the dust separation by using porous filter media, the structure of dust layer deposited on the filter surface of filter medium directly affects the effective filtration. The present study has investigated the specific resistance (K$_2$') of the dust layer and its porosity ($\varepsilon$$_{c}$) for three different filters; FA composite filter, metal fiber filter and stainless filter. The specific resistance (K$_2$') increased and at the same time the cake porosity ($\varepsilon$$_{c}$) decreased with the increase of filtration velocity, possibly due to the compressible effect of dust layer. However, under the low dust concentration, subsequent dust particles would block the open channels through the layer resulting in high specific resistance of the layer. The FA composite filter among three filters was shown to be the most effective filter for dust cake filtration at low filtration velocities less than 0.1 m/s for an approximate dust concentration of 5 g/㎥.

• Environmental Engineering Research
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• v.23 no.2
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• pp.210-215
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• 2018

Coal seam gas (CSG) water, to be discharged, has been usually treated in reverse osmosis (RO) plants which require extensive and expensive pre-treatment. However, current low gas prices have been a great driver for relevant industries to seek for alternative cost-effective technologies in the aspect of its beneficial use and fit-for-purpose usable water production. In this paper, a combined system with a two-stage pore control fiber (PCF) filtration and a RO system was designed and tested for CSG water treatment. Also, a coagulation reactor was placed in front of the PCF to further enhance suspended solid removal. More than 99% of SS were removed through the PCF filtration while organic, total nitrogen and total phosphorous were mostly removed by the RO system. Especially along with a decrease in conductivity, the total dissolved solid derived from salts was mainly removed in the RO system. Having $OH^-$ undetected, $HCO_3{^-}$ was found to be a dominant compound and its removal efficiency was 97-98% after the RO treatment. And a Fe(III) type of Polytetsu, which was the first to be tested in this paper, was found to be a better option than a Al(III) type of Poly Aluminium Chloride due to its greater coagulation efficiency and applicability at a broader range of pH than the Al(III) type. In addition, there was no noticeable change in oxidation reduction potential, suggesting that an additional process is required to oxidize non-ionic organic carbons (detected as total organic carbon).

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.135-143
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• 2005

It was evaluated that the effect of turbidity removal by Pore Controllable Fiber Filter(PCF) installed in NS(Naksang) small water treatmant plant(system) using under flow water as raw water in the study. The results of the study are as the followings. Firstly, the removal efficiency of turbidity by PCF without coagulation(in operation mode not using coagulants) was mostly below 20 percent. On the other hand, when operation using proper coagulants, that of turbidity was mostly over 80 percent. Secondly, slow sand filtration after PCF, total turbidity removal efficiency of final treated water was 84.3 percent, and the contribution by PCF was 57.1 percent and that of slow sand filtration was 27.7 percent. Therefore the introduction of PCF as pre-treatment process would be helpful to reduce the loading of high turbidity of slow sand filtration. Thirdly, the results of particle counter measurements showed that when operated PCF with coagulants, fine flocs captured or adsorbed at the pore of PCF were flow out into the effluents from 120 minutes after backwashing because of the increase of headloss of PCF. Therefore the decision of backwashing time should made consideration into the outflow of fine flocs from PCF. Fourth, coagulant dosages on PCF at the same turbidity was largely variable because of the effect of the raw water characteristics and the turbidity increase velocity at rainy days, therefore flexible coagulant dosages should be considered rather than fixed coagulant dosage by the influent jar-test result.