• 한국입자에어로졸학회지
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• 제6권4호
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• pp.173-183
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• 2010

The high temperature pleated filter bags which were used during this study were made of pleated nonwoven fabric of heat and acid resistant polysulfonate fibers which can withstand the heat up to $300^{\circ}C$ and have a filtration area which is 3 to 5 times larger than the conventional round filter bags. Cartridge module packed with 3 kind of the sulfur impregnated activated-carbon based sorbents were inserted in the inner of the pleated filter bag. This type of pleated filter bag was designed to remove not only the particulate matter but also the gaseous elemental mercury. The electrostatic precipitator part can enhance the particulate removal efficiency and reduce the pressure drop of the pleated filter bag by agglomerated particles to form a more porous dust layer on the surface of the pleated bag which is increased the filter bag cleaning efficiency. In addition, the most of particles are separated from the flue gas stream through the cyclone and the electrostatic precipitator part which were installed at the lower part and main body part of the convergence particulate collector, respectively. Thus reduce particulate loading of the high temperature pleated filter bags were applied in this study to analyze the removal characteristics of particulate matter and gaseous elemental mercury.

• 한국입자에어로졸학회지
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• 제5권4호
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• pp.159-170
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• 2009

A depth filter medium was newly designed in order to achieve high collection of dust and low pressure drop in this work. Multilayer depth filter media consist of an upstream layer of highly porous structure which allows particles to pass through and to follow by one or more downstream layers to hold the particles inside the media. For each filter media, flat sheet and pleated module were made of newly developed depth filter media and filter media of commercial products. Commercial depth filter cartridge for gas turbine air intake cleaning were used as reference for filtration area and pleat geometry of pleated modules. This work attempts to evaluate and compare the newly developed depth filter medium and two commercial filter media in terms of filtration parameters such as air permeability, initial pressure drop, particle retention and pressure drop variation with dust loading. According to the close examination the newly developed depth filter showed better performance compared to the commercial depth filter media.

• Korean Membrane Journal
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• 제3권1호
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• pp.32-38
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• 2001

Using the hollow fiber membrane module in a lab-scale membrane bioreactor, the anoxic- oxic (AO) process for nitrogen removal was operated for about one year. For the influent wastewater containing 1,200-1,400 mg $1^{-1}$ of CODcr and 200-310 mg $1^{-1}$ of nitrogen, this process achieved a high quality effluent of less than 30 mgCOD $liter^{-1}$ and 50 mgN $liter^{-1}$. The removal rate of organics was above 98% at a loading rate larger than 2.5 kgCOD $m^{-3}$$d^{-1}$. When the internal recycle from the oxic to the anoxic reactor changed room 2n to 600% rout the influent flow rate, the nitrogen removal rate increased from about 70 to 90% at a loading rate of 0.4 kgT-N m-s d-1. The initial increase of transmembrane pressure (TMP) was observed after a 4-month operation while maintaining the flux and MLSS concentration at 7-9 1 $m^2$ $h^{-1}$ and 6,000-14,000 mg $1^{-1}$, respectively. The TMP could be maintained below 15 cmHg for an 8-month operation. The chemical cleaning with an acid followed by an immersion in an alkali solution gave better cleaning result with the membrane operated for 10 month rather than that only by an alkali immersion.

• 전기학회논문지P
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• 제66권4호
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• pp.263-266
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• 2017

In this study, the characteristics of anti-pollution coatings on glass substrates through annealing treatment were investigated. To investigate the change of properties by coating method and number of annealing treatment, after the anti-pollution coating was performed on the surface of glass substrate in three ways, the annealing treatment was performed by setting three kinds of annealing treatment conditions. The annealing treatment method is a torch using gas, which is advantage in that it can be installed directly on the site in an easy way compared with a annealing treatment process which is generally difficult. The anti-pollution properties, contact angle, transmittance, hardness, and adhesion of films on glass substrate were measured under 9 conditions of combination of coating methods and annealing treatment conditions. It was confirmed that as the number of annealing treatment increases, the anti-pollution property of the film synthesized on glass substrate becomes better.

• Membrane and Water Treatment
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• 제3권3호
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• pp.141-149
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• 2012

The aeration provided in a Submerged Membrane Bioreactor (SMBR) improves membrane filtration by creating turbulence on the membrane surface and reducing membrane resistance. However, conventional hollow fiber membrane modules are generally packed in a vertical orientation which limits membrane scouring efficiency, especially when aeration is provided in the axial direction. In the present research, 3 innovative hollow-fiber membrane modules, each with a different membrane orientation, were developed to improve membrane scouring efficiency and enhance permeate flux. Pilot testing was performed to investigate the permeate flux versus time relationship over a 7-day period under different intermittent modes. The results indicated that the best module experienced an overall permeate flux decline of 3.3% after 7 days; the other two modules declined by 13.3% and 18.3%. The lower percentage of permeate flux decline indicated that permeate productivity could be sustained for a longer period of time. As a result, the operational costs associated with membrane cleaning and membrane replacement could be reduced over the lifespan of the module.

• 제어로봇시스템학회논문지
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• 제14권9호
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• pp.893-897
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• 2008

To achieve the challenges of low-cost MEMS gyros for the precise self-localization of mobile robots, this paper examines an effective method of minimizing the drift on the heading angle that relies solely on integration of rate signals from a gyro. The main idea of the proposed approach is to use wavelet de-noising filter in order to reduce random noise which affects short-term performances. The proposed method was applied to Epson XV3500 gyro and the performances are verified by the comparisons with an existing commercial gyro module of vacuum cleaning robots.

• 한국막학회:학술대회논문집
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• 한국막학회 1997년도 심포지움시리즈 Jan-97 수처리용 분리막 기술 및 응용
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• pp.87-109
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• 1997

Reverse osmosis(R/O), ultrafiltration(UF) and microfiltration (MF) processes are widely used for water treatment. In the seminar, characteristics of typical membrane modules including tubular, hollow fiber, plate and frame and spiral wound types will be discussed in detail. The design methods based on hydrodynamics for hollow fiber and spiral wound modules will be introduced analytically. Concentration polarization (CP) and membrane fouling mechnism as well as the techniques for CP reduction will be handled. The CP control techniques contain chemically modified membrane surface, pretreatment of feed water, operation of low trans-membrane pressure, chemical or physical cleaning methods and artificial production of various fluid turbulences near the membrane surface, etc. In especially, the recent commercial membrane modules for CP control including module rotation, vibration and Taylor or Dean vortex system will be introduced and discussed in detail.

• 멤브레인
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• 제27권1호
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• pp.104-107
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• 2017

역삼투막 운영에 있어서 유기물 오염에 대한 문제들을 해결하기 위해 많은 연구를 하고 있다. 현재 가성소다(NaOH)를 사용하여 유기물 오염 제거를 하고 있다. 본 연구는 지속적인 막오염 증가 문제를 해결하기 위한 물리/화학적 세정 기법으로서 기존에 사용하던 가성소다와 Micro-bubble를 이용하여 유기물 오염 제거 실험을 수행되었다. 멤브레인 강제 오염을 위해 Humic acid sodium, Bovine serum albumin, Sodium alginate 약품을 사용하여 유기물 오염을 시켰다. 유기물 오염에 따른 Flux를 관찰하였고, 가성소다와 Micro-bubble를 이용한 유기물 오염 제거 실험은 가성소다로만 사용했을 때보다 향상된 것을 관찰했다.

• 멤브레인
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• 제10권2호
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• pp.75-82
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• 2000

본 연구는 정수처리 공정에서 예상되는 오염물질에 대한 막의 투과성능과 오염현상을 알아보기 위하여 막의 깊이와 운전압력에 따른 압밀화 현상을 검토하였다. 막의 길이와 운전압력이 증가함에 따라 압밀화 현상도 증가하였다. MF막을 오염물질에서 고압(2.0 kg/$cm^2$)과 저압(0.5 kg/$cm^2$)으로 운전할 때, 고압 운전이 막힘현상(clogging)을 가속화 시켜 플럭스를 급격히 감소시키므로 저압 운전이 효과적이다. MF막을 Out-In방식으로 운전하였을 때, 막의 길이와 운전 압력에 관계없이 일정 시간 운전 후 비슷한 플럭스가 나타났다. 미생물 물질에 대한 막오염 현상을 파악하기 위해 중공사막을 강제 오염시킨 후 화학세정을 실시하였다. Biofouling된 막을 화학세정 하였을 때 산화능력이 우수한 $H_2O_2$와 NaOCl이 NaOH에 비해 살균능력과 탈착능력이 우수하다는 것을 알 수 있었다.

• 전기학회논문지P
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• 제64권3호
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• pp.182-186
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• 2015

We investigated that effects of annealing ambient on the characteristics of functional nano thin film synthesized on glass substrate. The functional nano thin films were annealed by using rapid thermal annealing (RTA) equipment in vacuum, oxygen and nitrogen ambient, respectively. The hardness of the functional nano thin films were measured by a standard hardness testing method (ASTM D3363) such as a H-9H, F, HB and B-6B pencil (Mitsubishi, Japan). Also, the adhesion of the functional nano thin films were measured by a standard adhesion testing method (ASTM D3359) using scotch tape (3M, Korea). The contact angle of the functional nano thin films was measured by a contact angle analyzer (Phoenix 300 Touch, S.E.O.). The optical property of functional nano thin films was measured via UV-visible spectroscopy (S-3100, Scinco).