음의 유전영동에 의한 가상 기둥 어레이를 이용한 연속적 입자 크기 분류기

장성환(Sunghwan Chang),조영호(Young-Ho Cho) 대한기계학회 2008 大韓機械學會論文集B Vol.32 No.11

We present a continuous size-dependent particle separator using a negative dielectrophoretic (DEP) virtual pillar array. Two major problems in the previous size-dependent particle separators include the particle clogging in the mechanical sieving structures and the fixed range of separable particle sizes. The present particle separator uses the virtual pillar array generated by negative DEP force instead of the mechanical pillar array, thus eliminating the clogging problems. It is also possible to adjust the size of separable particles since the size of virtual pillars is a function of a particle diameter and applied voltage. At an applied voltage of 500 ㎑ 10 Vrms (root mean sqaure voltage) sinusidal wave and a flow rate of 0.40 ㎕ min?¹, we separate 5.7 ㎛-, 8.0 ㎛-, 10.5 ㎛-, and 11.9 μm-diameter polystyrene (PS) beads with separation purity of 95%, 92%, 50%, and 63%, respectively. The 10.5 μm- and 11.9 μm-diameter PS beads have relatively low separation purity of 50% and 63%. However, at an applied voltage of 8 Vrms, we separate 11.9 ㎛-diameter PS beads with separation purity over 99%. Therefore, the present particle separator achieves clog-free sizedependent particle separation, which is capable of size tuning of separable particles.

HRT 변화에 따른 미세입자 분리 특성

안광호(Kwangho Ahn),안재환(Jaehwan Ahn),김이태(I Tae Kim),김석구(Seog Ku Kim),강성원(Sungwon Kang),박은주(Eunzoo Park),이영섭(Youngsup Lee) 大韓環境工學會 2013 대한환경공학회지 Vol.35 No.12

유체 내에서 발생된 음파 또는 초음파가 반사벽에 의해 반대방향으로 진행하면서 일정한 파동을 형성하는 음파를 음 향정재파(acoustic standing wave)라고 한다. 본 연구에서는 주파수 1.0 MHz와 2.0 MHz의 음향정재파 발생모듈을 설치한 연 속식의 입자분리장치에서, 유입수의 층류(laminar flow)를 고려하여, 수리학적체류시간(HRT) 변화에 따른 입자분리 특성을 살펴보았다. 정재파 가동에 다른 입자분리장치 내의 수온은 1.3~2.8℃ 정도 증가하였으나 정재파 형성에 큰 영향을 주지 않 았다. 주파수 1.0 MHz 가동 시 HRT 1시간에서 2시간, 4시간으로 길어짐에 따라 입자분리 효율(탁도)은 각각 64.1%, 70.0%, 74.3%로, 2.0 MHz에는 HRT에 따라 각각 58.0%, 61.8%, 70.7%로 증가된 것으로 나타났다. 즉, 동일한 주파수일 경우 HRT에 따라 처리효율이 10% 이상 차이가 발생하고 있으며, 1.0 MHz 주파수에서는 2시간, 2.0 MHz에서는 4시간 정도에서 70% 이 상의 처리효율을 유지할 수 있다. 주파수 1.0 MHz와 2.0 MHz를 동시에 가동한 결과, HRT 1시간, 2시간, 4시간에서의 입자 분리 효율은 각각 63.8%, 70.6%, 77.6% 나타나 연속된 정재파의 발생 보다는 HRT가 입자분리에 많은 영향을 주는 것을 알 수 있었다. Fluid generated within the sonic or ultrasonic waves are reflected by the wall, while the opposite direction forming a predetermined sound wave to the acoustic standing wave is referred to. In this study, the frequency of 1.0 MHz and 2.0 MHz acoustic standing wave generation module is installed in a continuous particle separation device, the laminar flow of influent, taking into account the hydraulic retention time (HRT) in accordance with changes in particle separation characteristics investigated. Operation of a standing wave in the particle separation device about 1.3~2.8℃ temperature is increased, but did not significantly affect the formation of standing waves. During operation, the HRT 1 hr frequency 1.0 MHz 2 hr, 4 hr longer as the particle separation efficiency (turbidity) were 64.1%, 70.0%, 74.3% and, 2.0 MHz has 58.0%, respectively, depending on HRT, 61.8%, 70.7% in the respectively. That is, the same frequency, the HRT treatment efficiency is 10% or more, depending on differences in generation and, 1.0 MHz frequency, 2 hr, 2.0 MHz 4 hr at about 70% or more of the processing efficiency can be maintained. Frequency of 1.0 MHz and 2.0 MHz operation at the same time, as a result, HRT 1 hr, 2 hr, 4 hr particle separation efficiency of 63.8%, respectively, 70.6%, 77.6%, rather than the generation of standing waves appear continuous HRT is affecting a lot of particles to separate could know.

우리나라 현존 토양정화 기술의 해양오염퇴적물 정화사업 적용 가능성 검토

김경련(Kyoung Rean Kim),최기영(Ki Young Choi),김석현(Suk Hyun Kim),홍기훈(Gi Hoon Hong) 大韓環境工學會 2010 대한환경공학회지 Vol.32 No.12

해양오염퇴적물 정화기술의 조속한 국내 정착을 위하여, 육상 토양오염 정화공법들이 해양퇴적물에도 적용될 수 있는지를 해양오염퇴적물 정화사업이 고려되는 울산 방어진과 진해 행암만의 퇴적물을 대상으로 해양오염퇴적물에 활용 가능한 설비를 갖춘 입자분리 및 세척의 세 공법을 사용하여 중금속 제거 가능성을 위주로 평가하였다. 모래에 비하여 중금속 농도가 높은 울산 방어진의 니질 및 점토질에서 각 공법별 중금속 제거 정도는 입자분리의 경우, 비소(As) 81.5%, 수은(Hg) 93.8%이고, 세척의 경우, 카드뮴(Cd) 72.2%, 수은(Hg) 87.1%이며, 같은 분야의 다른 세척의 경우, 카드뮴(Cd) 70.8%, 납(Pb) 65.6%로 나타났다. 실증실험 결과로부터 사용한 입자분리 및 세척 공법은 모래뿐만 아니라 니질과 점토질 크기의 미세입자에 함유된 중금속까지 효과적으로 처리할 수 있다는 것을 확인하였다. 또한 입자분리보다 입경별 분리, 공정수에 의한 세척, 산 또는 유기용매 등 첨가제에 의한 물리적, 화학적 반응 등 처리공정으로 구성된 세척공법에 의한 중금속 제거가 보다 효과적인 것으로 나타났다. 한편 모든 조건에서 처리한 산물의 중금속 농도는 토양오염우려기준 중 3지역 기준에 적합하므로, 중금속 처리뿐만 아니라 처리한 산물을 육상에서 매립지용 복토재, 토목, 건설용 재생토사 등으로 재이용하기위한 처리기술로서 적합한 것으로 판단된다. Soil remediation technologies were experimented to evaluate whether the technologies could be used to apply remediation of contaminated marine sediment. In this research, marine sediments were sampled at "Ulsan" and "Jinhae" where remediation projects are considered, and then the possibility of heavy metal removal was evaluated throughout the technologies. Heavy metal concentration of silt and clay fraction was higher than that of sand fraction at "Ulsan". Heavy metal removal of the silt and clay fraction was arsenic (As) 81.5%, mercury (Hg) 93.8% by particle separation, cadmium (Cd) 72.2%, mercury (Hg) 93.8% by soil washing technology, cadmium (Cd) 70.8%, lead (Pb) 65.6% by another soil washing technology. Based on experimental results, tested particle separation and soil washing technologies could be used to remove heavy metals of sand fraction and silt and clay fraction. Heavy metal removal by soil washing technology which was composed of separation, washing and physical or chemical reaction by additives such as acid, organic solvents was more effective comparing to that of particle separation. Since heavy metal concentration of all treated samples was suitable for national soil standards, all the tested technologies were could be used not only to remove heavy metals of marine contaminated sediment but also to reuse treated samples in land.

용존이산화탄소부상(DCF) 공정의 입자분리 특성과 부상효율

곽동희,이영동,정흥조,김성진,유영훈,박양균 대한상하수도학회 2011 상하수도학회지 Vol.25 No.4

A series of laboratory experiments carried out to investigate the particle separation efficiency and flotation characteristics using CO2 bubbles. The primary objective of this study was to find out the feasibility of CO2 bubbles as an applicable unit of flotation process in tap-water and wastewater treatment plant. The fundamental measurements were conducted to characterize the CO2 bubble from the physical viewpoint in water including bubble size distribution and rising velocity under various operational conditions. In addition, the removal efficiency of solid was experimented using the lab scale plant applied CO2 bubbles, namely the dissolved carbon dioxide flotation (DCF) process. The DCF process using carbon dioxide bubble, which is an advantage as the decrease and the reuse of Green-House gas, can be a promising technology as an water treatment process. On the other hand, the further research to decrease the bubble size distribution of CO2 is required to enhance the particle separation efficiency. A series of laboratory experiments carried out to investigate the particle separation efficiency and flotation characteristics using CO2 bubbles. The primary objective of this study was to find out the feasibility of CO2 bubbles as an applicable unit of flotation process in tap-water and wastewater treatment plant. The fundamental measurements were conducted to characterize the CO2 bubble from the physical viewpoint in water including bubble size distribution and rising velocity under various operational conditions. In addition, the removal efficiency of solid was experimented using the lab scale plant applied CO2 bubbles, namely the dissolved carbon dioxide flotation (DCF) process. The DCF process using carbon dioxide bubble, which is an advantage as the decrease and the reuse of Green-House gas, can be a promising technology as an water treatment process. On the other hand, the further research to decrease the bubble size distribution of CO2 is required to enhance the particle separation efficiency.

실험실 규모의 음향정재파를 이용한 수중의 입자분리 특성

안재환(Jae Hwan Ahn),강성원(Sung Won Kang),안광호(Kwang Ho Ahn),김이태(I Tae Kim),김석구(Seog Gu Kim),안호상(Ho Sang Ahn),이영섭(Young Sup Lee) 大韓環境工學會 2012 대한환경공학회지 Vol.34 No.12

실험실 규모의 음향정재파 장치를 이용하여 수체에 포함된 입자의 분리특성을 알아보았다. 음향정재파는 음파 또는 초음파와 유사한 파장으로 반사벽에 의해 발생된 파가 돌아오면서 일정한 파장을 형성한다. 이때 수중에 분산되어 있던 미세한 입자들은 음압이 0인 파장의 절점(node) 부분에 모이게 된다. 주파수 28.0kHz와 1.0MHz의 음향정재파 트랜스듀서를 이용 하였고, 수체에 포함된 입자는 평균 입경 6.8μm의 카올린과 100.5μm의 레드머드를 사용하였다. 수체 내에 음향정재파가 형성되면 발생된 파장에 의한 음압으로 수온이 0.15∼0.20℃/min 정도 상승된다. 카올린과 레드머드의 초기 농도는 0.1, 0.2, 0.3, 0.4, 0.5g/L로 동일하게 제조하였다. 1.0MHz의 주파수에서 5분경과 후 음향정재파가 가장 뚜렷하게 형성되었을 때의 반응조내의 탁도 제거율은 카올린은 18.2%∼56.2%로, 입경이 큰 레드머드는 23.0%∼53.6%의 분리효율을 나타내었다. 28.0kHz 주파수에서는 입자분리가 이루어지지 않았다. Characteristics of particle separation in water using labscale acoustic standing wave were studied. Acoustic standing wave is similar to either sound wave or ultrasonic, which makes a constant wave while returning to the origin by reflector. During that time, particulates dispersed in water are collected on the node of wave, where a sound pressure is zero. Acoustic standing wave transducer as of 28.0kHz and 1.0MHz were utilized and 6.8μm kaolin and 100.5μm redmud in average diameter were used as experimental materials in water. Once acoustic standing wave are generated in water, water temperature rises by 0.15∼0.20℃/min due to a sound pressure. Initial concentration of kaolin and redmud were controlled to have same as of 0.1, 0.2, 0.3, 0.4, 0.5g/L, respectively. Removal efficiency of the turbidity in a reacting chamber after 5 minutes, when acoustic sound wave was formed in most distinct, was measured to have 18.2∼56.2% for kaolin and 23.0∼53.6% for redmud at 1.0MHz. Particle separation was not observed at 28.0 kHz.

T-GDI 엔진의 속도 및 하중이 블로우바이 가스의 오일입자 크기와 오일분리기 성능에 미치는 영향에 대한 실험 및 수치적 연구

정수진 ( Soo-jin Jeong ),오광호 ( Kwangho Oh ) 한국분무공학회 2020 한국액체미립화학회지 Vol.25 No.4

The worldwide focus on reducing the emissions, fuel and lubricant consumption in T-GDI engines is leading engineers to consider the crankcase ventilation and oil mist separation system as an important means of control. In today’s passenger cars, the oil mist separation systems mainly use the inertia effect (e.g. labyrinth, cyclone etc.). Therefore, this study has investigated high efficiency cylinder head-integrated oil-mist separator by using a compact multi-impactor type oil mist separator system to ensure adequate oil mist separation performance. For this purpose, engine dynamometer testing with oil particle efficiency measurement equipment and 3D two-phase flow simulation have been performed for various engine operating conditions. Tests with an actual engine on a dynamometer showed oil aerosol particle size distributions varied depending on operating conditions. For instance, high rpm and load increases bot only blow-by gases but the amount of small size oil droplets. Submicron-sized particles (less than 0.5 μm) were also observed. It is also found that the impactor type separator is able to separate nearly no droplets of diameter lower than 3 μm. CFD results showed that the complex aerodynamics processes that lead to strong impingement and break-up can strip out large droplets and generate more small size droplets.

입자분리효율을 높이기 위한 새로운 기술

Ebie, Kunio,Jang, Il-Hun 대한상하수도학회 2004 상하수도학회지 Vol.18 No.2

Polysilicato-iron coagulant (PSI) is receiving attention in Japan as a substitute for aluminum-based coagulants. In the first part of this article, coagulation, sedimentation and filtration experiments were carried out using kaolin clay particles as the turbidizing material and four types of PSI with various molar ratios of polysilicic acid to ferric chloride (Si/Fe ratio). Results demonstrate that use of a PSI with a high Si/Fe ratio can cause a more dramatic decrease in treated water turbidity but a higher suction time ratio (STR) than when PACl is used. However, optimization by increasing the rapid agitation strength GR is found to greatly improve the STR. In addition, the series of filtration experiments verified that optimization of GR is greatly effective in controlling rapid increases in filter head loss, and also formation of a thin aging layer in the upper part of the filter bed by slow-start filtration is effective in improving filtered water turbidity over the entire filtration process. The second part of this article describes two innovative filtration techniques to increase the particle separation efficiency; (1) coagulant-coated filter medium by enhancing the electrical potential of the surface of the filter medium, and (2) coagulant dosing in influent by controlling the electrical potential of particles entering the filter layer. From the results of the various filtration experiments using a pilot plant, these two techniques were found to be very effective to reduce the effluent water turbidity from the start to the end of a filter run. Moreover, in the filtration experiments using these two methods simultaneously, higher removal efficiency of approximately 3-log (99.7%) was realized, resulting that the finished water turbidity was accordingly reduced to 0.004㎎/L.

회전하는 나선형 마이크로 채널을 이용한 입자 분리 및 정렬

김수빈(Subin Kim),비빈프라사드(Bibin Prasad),김중경(Jung Kyung Kim) 한국가시화정보학회 2015 한국가시화정보학회 학술발표대회 논문집 Vol.2015 No.12

Separation of particles based on different sizes, detection of pathogenic bacteria and isolation of leukocytes from whole blood are typical applications of spiral or helical microchannels. Several microfluidic point-of-care (POC) devices have been developed for monitoring HIV/AIDS by counting CD4 cells but researches are still pursuing to develop a more efficient low-cost device that can be used in developing and underdeveloped countries. The present study focuses on developing a CD4+ T-cell counting device for HIV/AIDS monitoring with the aid of a helical microchannel. For the experiment 10 μm sized particles were used for visualization with a fluorescence microscope system. A sample with the viscosity as that of blood and other samples with different viscosities were also prepared to determine the effect of density and viscosity on alignment of the particles. The channels were spun using a DC motor controlled by an Arduino board with a Bluetooth shield. It was found that for low viscosity samples the particles were not aligned when the channel was kept stationary and an alignment was achieved when the channel was spun due to the combination of centrifugal and gravitational forces. For a sample with viscosity as that of blood, alignment of particles were obtained even without spinning. Since an alignment of particles was achieved for a sample with viscosity as that of blood, the same approach can be applied for aligning and counting CD4+ T cells in blood samples collected from patients.

등속전기영동을 이용한 입자의 운동성 특성 연구

안진효(J. H. An),주윤하(Y. H. Joo),박현우(H. W. Park),이춘영(C. Y. Lee),박철우(C. W. Park) 한국가시화정보학회 2010 한국가시화정보학회 학술발표대회 논문집 Vol.2010 No.11

Recently, the precise cell separation method has great attentions in the bio-engineering research field with advancement of bio technology. In the present study, we separated the isotacho marker particles from the suspending particle mixture solution using isotachophoresis technique in the micro-channel. As a result, the particle migration velocity was increased proportional to the applied electric field strength.

접촉각과 가열이 증발 액적 내 입자 분리에 미치는 효과

송현수(Hyunsoo Song),유정열(Jung Yul Yoo) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

Micro-particle separation has been applied to various fields such as microfluidics, microbiology, pharmacy, and chemistry for a long time. In this study, we propose a novel technique which can separate di-disperse particles of different densities in a sessile drop, by using “Coffee Stain Effect” and “Cheerios Effect”. The temperature and contact angle are the major factors which determine the evaporation mode of a drop, so that the experiments are conducted for various wettability conditions with and without heating. As a result, by analyzing the distribution of particles in a dried drop quantitatively, it is revealed that the particles can be separated efficiently at room temperature and small contact angles.