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.

벽에 충돌하는 디젤분무의 특성에 대한 수치적 연구

양희천,정동화,유홍선,Yang, Hui-Cheon,Jeong, Dong-Hwa,Yu, Hong-Seon 대한기계학회 1998 大韓機械學會論文集B Vol.22 No.5

It is unavoidable that the fuel spray impinges on the wall of piston cavity in a compact high-pressure D.I. diesel engine. Therefore the characteristics of impinging spray are the very significant information on the consideration and the simulation of its combustion processes including the formation mechanism of exhaust emission and the design of the combustion chamber. In this paper, the numerical simulation was performed to study the characteristics of impinging spray. The spray-wall impingement model used is Watkins and Park's model. Calculation parameters are the inclination angles and the ambient pressures. As the inclination angle increases, the impinging spray develops mainly to the direction of the downstream and scarcely flows to that of the upstream. The shape on the wall of the impinging spray is the circle in the case of the normal impingement, while it is the ellipse in that of the oblique impingement. As the ambient pressure increases, the growth of impinging spray on the wall in the radial direction decreases owing to the increase in the resistance of the ambient.

부수게 製造에 관한 연구

梁熙天(Hee-Cheon Yang),洪載植(Jai-Sic Hong),金中晩(Joong-Man Kim) 한국식품과학회 1982 한국식품과학회지 Vol.14 No.2

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.

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.

수평 폭기공정의 2상 분류거동

양희천(Hei Cheon Yang),박용신(Yong Sin Park),안정민(Jeong Min Ahn),조홍근(Hong Gyun Cho) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.11

The aim of this study was to experimentally investigate the characteristics of entrainment and flow in a submerged horizontal two-phase jet using central driven air-water ejector. The streamwise velocity was measured by a propeller velocity meter, and the pressures of ejector were measured with a 5-channel digital pressure indicator. The air volume fraction was calculated by dividing the suction air flow rate by the air-water mixture flow rate. As the primary flow rate increases the entrainment ratio increases slightly. The discharge coefficient for characterizing the frictional losses in the ejector nozzle was about 0.62. It was found that the horizontal mixed jet behaved like a horizontal momentum jet or a buoyancy jet with the downstream distance or the primary flow rate.

2000 년도 공동추계 학술발표회 / 상수처리 (2) : 인 주입에 의한 생물활성탄의 처리특성

양희천(Hee Cheon Yang),강용태(Yong Tae Kang) 대한상하수도학회 2000 공동추계 학술발표회 논문집 Vol.2000 No.-

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.

아그배 Peroxidase의 정제 및 특성

양희천(Hee-Cheon Yang),손희숙(Hee-Suk Son),심규광(Kyu-Kwang Shim),오찬호(Chan-Ho Oh),최동성(Dong-Seong Choi) 한국식품영양과학회 1992 한국식품영양과학회지 Vol.21 No.1

아그배로 부터 아세톤 침전, DEAE-cellulose 칼럼 크로마토그라피, Ultro-AcA 54겔여과의 과정을 거쳐 peroxidase를 분리 정제하고, 그의 특성을 조사하였다. 아그배peroxidase의 반응 최적 pH는 4.5, 반응 최적 온도는 80℃이었고, 30℃ 이하의 온도와 pH 5.0에서 안정하였으며, 80℃에서 15분간 보존했을 때 거의 불활성화되었다. OPDA에 높은 활성을 나타내었으나, phenol류 기질에 대해서는 약간의 활성을 나타내었으며, OPDA와 H₂O₂에 대한 Km치는 각각 1. 65mM, 7.97mM이었다. 아그배 peroxidase에 대한 저해작용은 L-ascorbic acid와 sodium L-ascorbate가 가장 컸고, 금속이온 중 Mn^(2+)만이 5mM 농도에서 효소의 활성을 증가시켰다. Peroxidase in the fruit of Malus sieboldii (Regel) Rehder was partially purified by DEAE-cellulose column chromatography and Ultro-AcA 54 gel filtration. The optimum pH of peroxidase was 4.5 and optimum temperature was 80℃. The enzyme was stable at pH 5.0 and below 30℃, and inactivated by heat treatment at 80℃ for 15min. In the presence of 30mM H₂O₂ Km value on o-phenylenediamine as substrate was 1.65mM, and in the presence of 10mM o-phenylenediamine Km value on H₂O₂ was 7.97mM. L-Ascorbic acid and sodium L-ascorbate greatly inhibited the enzyme activity and among several metal ions Mn^(2+) only increased the activity at 5mM.

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.