스태틱 믹서 개발 및 응용

양희천,Yang, Hei-Cheon 한국마린엔지니어링학회 2007 한국마린엔지니어링학회지 Vol.31 No.5

One of the most widely used static mixers is Sulzer type mixer. However the structure of the element is so complicated that the mixing efficiency is better than others, whereas the pressure drop is larger than the others. Therefore new elements are necessary to reduce the pressure drop and to minimize the decrease of the mixing efficiency compared with the Sulzer ones. The objectives of this study are to develop new static mixer and to perform the experimental investigation in order to evaluate the performance of the new one, and to investigate the applicability of the one in an inline coagulant mixing system for water treatment, The pressure drops of the new static mixer elements were about 4-12% lower than that of the Sulzer SMX one, and the mixing efficiency of the Sulzer SMX one was about 2-5% higher than that of the new ones. The inline coagulant mixing system with a new static mixer element performed significantly better than the traditional mechanical mixing system for turbidity removal.

스태틱 믹서 개발을 위한 실험적 연구

양희천(Hei-Cheon Yang),박상규(Sang-kyoo Park),라병열(Byeong-Yeol Ra) 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.5

The objective of this study was to develop a new mixing element and to perform the experimental<br/> investigation of flow and mixing in a static mixer that could equipped the new element and the others.<br/> Glycerin, hydraulic oil and gear oil were used as mixing fluids. Pressure drops across the static mixer<br/> elements of different designs and different numbers were measured using a hydraulic manometer. The axial<br/> and cross-sectional views of tracer mixing were photographed using a digital camera. The pressure drops of<br/> SSM mixer were about 20% less than that of Sulzer mixer whereas the mixing performance of SSM mixer<br/> was not so good as that of Sulzer mixer.

수처리 공정의 유동특성에 미치는 이젝터의 구동노즐 면적비 및 거리비의 영향

양희천(Hei Cheon Yang) 대한기계학회 2018 大韓機械學會論文集B Vol.42 No.12

중앙구동 이젝터의 구동노즐 면적비 및 거리비가 유동특성에 미치는 영향에 대한 연구를 수행하였다. 측정 변수들을 이용하여 공기의 체적분율과 분류의 도달거리를 산출하였으며, 체적분율을 고려한 무차원 유효밀도를 이용하여 프라우드 수를 산출하였다. 구동노즐 면적비가 커지면 체적분율은 감소하였으며, 구동노즐 거리비나 프라우드 수가 커지면 체적분율은 증가 후 감소하였다. 구동노즐 면적비가 증가하면 운동량 분류영역이 커져서 준 수평분류의 거동이 나타나며, 운동량 분류의 도달거리와 분류선단의 총 도달거리는 증가하였다. Experiments were conducted to investigate the effects of the nozzle area and distance ratios of a central driven ejector on the flow characteristics. The air void fraction and jet penetration length were calculated using the measured data, and Froude number was calculated based on the dimensionless effective density when considering the air void fraction. Experimental results showed that the air void fraction decreased with the primary nozzle area ratio, and then increased and decreased with the primary nozzle distance ratio and Froude number. It was found that, as the primary nozzle area ratio increased, the discharged mixed jet behaved similar to a quasi-horizontal jet owing to the increase in momentum in the jet region, and the penetration lengths of the momentum and total jet increased.

이젝터의 유동특성이 산소전달율에 미치는 영향

양희천(Hei-Cheon Yang),김동준(Dong-Joon Kim),민영섭(Young-Seb Min) 한국유체기계학회 2011 유체기계 연구개발 발표회 논문집 Vol.2011 No.11

SMX 형 정적 믹서의 압력손실 특성

양희천(Hei-Cheon Yang),박정일(Jeong-Il Park) 대한기계학회 2008 大韓機械學會論文集B Vol.32 No.6

The objective of this study is to investigate experimentally the characteristics of pressure drop in SMX type motionless mixers. The motionless mixers used are SMX-O, SMX-H, SMXL-O and SMXL-H ones. The SMX-H and SMXL-H mixer elements have been designed to reduce the pressure drop as compared with the SMX-O and SMXL-O ones. The Reynolds number based on the bulk average properties of the water is in a range of 5000 to 13000. The pressure drops across the motionless mixers are measured and the friction factors are calculated using the pressure drop data. On the average, the friction factors of the SMX-H and SMXL-H mixers are about 8% and 15% lower than those of the SMX-O and SMXL-O ones. In addition, the proposed correlations from the experimental data for the friction factor are presented and compared with those obtained from the literature.

수중 수평 공기-물 이젝터의 분류 거동에 대한 실험적 연구

양희천(Hei Cheon Yang),박상규(Sang Kyoo Park) 대한기계학회 2020 大韓機械學會論文集B Vol.44 No.3

본 연구는 공기-물 이젝터를 이용하여 수중에서 수평으로 주입되는 2상 분류의 유입 및 분류 거동에 대한 실험적 연구를 목적으로 한다. 이젝터의 구동 노즐 면적비를 변수로 유입율 및 유출 계수를 산출하였으며, 수조 내의 주유동 방향 속도 분포를 측정하여 분류의 정량적 거동을 분석하였다. 면적비가 커지면 유입률은 감소하였으며, 유출 계수는 약간 증가하였다. 구동 노즐 면적비가 작고 출구 속도가 감소하면 디퓨저 출구 부근을 제외하고 부력 분류의 특성이 나타나며, 면적비가 커지고 출구 속도가 증가하면 수평 분류에서 부력 분류로 천이되는 거리가 길어지고, 분류 중심선 부근의 주유동 방향 속도가 증가하였다. This study aimed to experimentally investigate the entrainment and jet behavior in a submerged, horizontal, two-phase flow using a central driven air-water ejector. The entrainment ratio and discharge coefficient were calculated with the primary nozzle area ratio, and the quantitative behaviour of submerged horizontal jet was analyzed by measuring the stream-wise velocity in a two-phase jet tank. It was found that as the primary nozzle area ratio increased the entrainment ratio decreased and the discharge coefficient increased slightly. As the primary nozzle area ratio and the primary nozzle exit velocity decreased the mixed jet exhibited buoyancy jet behavior except in the vicinity of diffuser exit. Also, as the primary nozzle area ratio and primary nozzle exit velocity increased the transfer distance from a horizontal jet to a buoyancy jet and the stream-wise velocity near the jet centerline increased.

공기-물 혼합분류의 유량비에 따른 물질전달 특성

양희천(Hei Cheon Yang) 대한기계학회 2022 大韓機械學會論文集B Vol.46 No.5

본 연구는 중심노즐 이젝터를 이용한 공기-물 혼합분류의 물질전달 특성에 대한 실험적 연구를 목적으로 한다. 유량비에 따라 수조에 분출되는 혼합분류의 거동과 물질전달 계수 및 효율에 대해 정량적으로 분석하였다. 구동유량이 증가하면 유량비는 감소하고, 유량비가 증가하면 비 소요동력은 감소하였다. 유량비가 커지면 수평분류에서 부력분류로 천이되는 길이와 분류선단 도달길이가 감소하였다. 유량비가 커지면 총괄 물질전달 계수는 감소하며, 물질전달 효율은 약간 증가한 후에 감소하였다. The aim of this study was to experimentally investigate the mass transfer characteristics of air-water mixed jet with central nozzle ejector. Using the mass ratio, the mixed jet behavior discharged in a water tank, the mass transfer coefficient, and efficiency were analysed qualitatively. The mass ratio decreased with the primary flowrate, and the specific input power decreased with the mass ratio. Additionally, as the mass ratio increased, the transient length from horizontal jet to buoyancy jet, and the total penetration length of mixed jet decreased. Furthermore, with the increase in the mass ratio, the volumetric mass transfer coefficient decreased, while the mass transfer efficiency increased slightly and then decreased.

2 상 유동 및 물질전달 특성에 미치는 오리피스 노즐형상과 소요동력의 영향

양희천(Hei Cheon Yang) 대한기계학회 2016 大韓機械學會論文集B Vol.40 No.4

호기성 수처리 과정의 폭기에 소요되는 에너지의 이용효율을 높이기 위해서는 물질전달 특성뿐만 아니라 소요동력에 대한 연구가 필요하다. 본 논문은 수직 2 상 유동 및 물질전달 특성에 미치는 오리피스 노즐형상과 소요동력의 영향에 대한 실험적 연구를 목적으로 한다. 측정 변수들을 이용하여 유량비, 소요동력, 물질전달 계수 그리고 물질전달 효율을 산출하였다. 소요동력이 커지면 물질전달 계수는 증가하는 반면에 유량비와 물질전달 효율은 감소하였다. 무차원 면적비가 작은 오리피스 노즐의 유량비, 물질전달 계수 및 효율이 높게 나타났다. 물질전달 특성에 미치는 유량비, 소요동력 그리고 프라우드 수의영향을 평가하기 위한 실험식을 제시하였다. It is necessary to investigate the input power as well as the mass transfer characteristics of the aeration process in order to improve the energy efficiency of an aerobic water treatment. The objective of this study is to experimentally investigate the effect of orifice nozzle design and input power on the flow and mass transfer characteristics of a vertical two-phase flow. The mass ratio, input power, volumetric mass transfer coefficient, and mass transfer efficiency were calculated using the measured data. It was found that as the input power increases the volumetric mass transfer coefficient increases, while the mass ratio and mass transfer efficiency decrease. The mass ratio, volumetric mass transfer coefficient, and mass transfer efficiency were higher for the orifice configuration with a smaller orifice nozzle area ratio. An empirical correlation was proposed to estimate the effect of mass ratio, input power, and Froude number on the volumetric mass transfer coefficient.

유량비에 따른 에어레이션 공정의 산소전달 특성

양희천(Hei-Cheon Yang),박현성(Hyun-Sung Park),윤영현(Young-Hyun Yun),김동준(Dong-Jun Kim) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11

The aim of this study was to experimentally investigate the oxygen transfer characteristics in aeration process with central and annular nozzle ejectors. With the increase in the mass ratio, the oxygen transfer coefficient in the annular nozzle ejector increased and then decreased. The dissolved oxygen concentration in the central nozzle ejector decreased with the mass ratio. The mixed flow discharged in the aeration tank behaved like a buoyancy jet or a horizontal jet with the mass ratio.

관형 열반응기의 열전달 특성

양희천(Hei-Cheon Yang),박상규(Sang-Kyoo Park),라병열(Beong-Yeol Ra) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

Heat transfer augmentation based on the process intensification concept in heat exchangers and thermal reactors has received much attention in recent years, mainly due to energy efficiency and environmental considerations. The concept consists of the development of novel apparatuses and techniques that, compared to those commonly used today, are expected to bring dramatic improvements in manufacturing and processing, substantially decreasing equipment size, energy consumption, and ultimately resulting in cheaper, sustainable technologies. The objective of this paper was to investigate the heat transfer characteristics of tubular thermal reactor using static mixing technology. Glycerin and water were used as the test fluids and water was used as the heating source. The results for heat transfer rate were strongly influenced by tube geometry and flow conditions.