• Title/Summary/Keyword: Dilute Flow

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Development of Polymeric Adsorbents for the Treatment of Colored Waste Waters and Re-use of the Treated Water (II) - Quaternary Aminized Cellulosic Adsorbent - (유색폐수처리를 위한 고분자 흡착제의 개발과 처리수의 사용(II) - 4급 아민화 셀룰로오스 흡착제 -)

  • Soo-Min Park;Woo-Kyung Sung
    • Textile Coloration and Finishing
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    • v.4 no.3
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    • pp.131-135
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    • 1992
  • Quaternary aminized cellulosic adsorbents (C $A_{QA}$ ) which exhibit adsorption capacities for anionic dyestuffs for the treatment of colored waste water and re-use of the treated water were studied. The isotherms and thermodynamic parameters of C.I. Acid Orange 7, solution considered as a model of negatively charged coloring matters for C $A_{QA}$ , were determined. Batch method and flow method were employed to determine decoloring capacity of cellulosic adsorbents for Orange 7. The cellulosic adsorbents exhibited much better adsorption capacity than activated carbon. Furthermore the exhausted cellulosic adsorbents could be readily regenerated by washing with dilute sodium hydroxide.

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Mechanical Degradation of Polymers in Dilute Solution. The Influence of the Mixed Solvents II. (稀搏溶液에서의 Polymer의 機械的 切斷. 混合溶媒의 영향 Ⅱ)

  • Yeong Moo Won
    • Journal of the Korean Chemical Society
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    • v.16 no.1
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    • pp.50-55
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    • 1972
  • The mechanical degradation of $poly(\alpha-methyl$ styrene) in several mixed solvents (chlorobenzene-n-butyl alcohol, chlorobenzene-sec-butyl alcohol, chlorobenzene-Kerosene, chlorobenzene-methylketone) was studied using the capillary flow method. The velocity constant of scission reaction (K) and the limited degree of polymerization (g) were compared at the same value of [${\eta}$], which is considered as the parameter of molecular dimension of polymers in solution. As results, (K) did not change much, even if the species and the volume fraction of poor(non-) solvents changed, while the value of (g) changed according to the species of poor (non-) solvents and the value of [${\eta}$] these results were discussed.

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Numerical Analysis of Silicon Deposition in CVD Reactor (화학기상 성장법에 의한 실리콘 부착에 관한 수치해석)

  • Kim, In;Baek, Byung-Joon;Yoon, Jeong-Mo;Lee, Cheul-Ro
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.359-364
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    • 2000
  • The fluid flow, heat transfer and the local mass fi-action of chemical species in the chemical vapor deposition(CVD) manufacturing process are numerically studied. The deposition of silicon from dilute silane is hydrogen carrier gas in a horizontal CVD reactor is investigated. The effect of inlet carrier gas velocity, mass fraction of silane, susceptor angle on the deposition thickness and uniformity was represented.

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Flow of Dilute Polymer Solutions in the Confined geometry (한정된 공간에서의 희석 고분자 용액의 흐름)

  • 박오옥
    • The Korean Journal of Rheology
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    • v.4 no.1
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    • pp.62-69
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    • 1992
  • 한정된 공간 속을 희석 고분자 용액이 흐를 때 그공간의 특성 길이가 고분자의 그 것과 비슷한 경우에는 실험적으로 무한 공간에비하여 점도가 작게 됨을 보였다, 잔탄 검 용 액과 폴리아크릴 아미드 용액이 원통형 다공을 가진 고분자 막을 통해 흐를때의 점도를 뉴 톤 영역뿐 아니라 비뉴톤 영역에서도 한꺼번에 측정할 수 있는 흐름장치를 만들어 실험하였 다, 뉴톤 점도는 다공의 크기가 줄어들수록 줄어드는 경향을 보였는데 이는 두 특성 길이의 비로서 설명할수 있었다, 비뉴톤 점도 영역에서의 지표(power law index)는 폴리아크릴 아 미드 용액에서는 차이가 발견되지 않았으나 잔탄 검용액에서는 다공의 크기가 감소할수록 점점 작은 값을 보였다, 이것은 두 고분자 사슬의 경직성 차이에 기인된다 하겠다. 결론적으 로 벽 근처에 분차 크기 정도의 고분자 희박 영역이 존재하고 그 영역내에서는 고분자 사슬 의 배향 구조가 제한적이다고 하는 이론적 설명과 부합되는 결과를 얻었다.

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Hydrodynamic Characteristics of the Rectangular Type Circulating Fluidized Bed (4각 순환유동층의 수력학적 특성)

  • Hyun, Sang Yeol;Rhee, Kwan Seok
    • Journal of the Korean Society for Heat Treatment
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    • v.10 no.4
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    • pp.232-236
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    • 1997
  • A rectangular type circulating fluidized bed (CFB) with an internal nozzle and two partition walls was proposed. In this modified CFB, an internal nozzle and two slanted partition walls were additionally set in the riser. This cold mode apparatus was made of acrylic resin; the riser was 1500mm high and $1000{\times}1000mm^2$ in the cross sectional area, the internal nozzle was 200mm high and 10mm in the inner diameter, and the partition wall was 7mm thick. Glass beads of $91{\mu}m$ in the mean diameter were employed as bed materials. In the cold mode by using the proposed CFB with an internal nozzle, it was possible to change the particle hold up by changing the gas flow ratio of the nozzle to the total(Qn/Qt). It was found that the inflection point which devided the bed structure between the dense and the dilute phase in the riser varied with Qn/Qt.

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Alcohol Production to reduce Energy Consumption by Membrane Separation and Heat Medium -Basic Studies on Alcohol Recovery with Fermentation Process Using the Membrane- (분리막과 열매체를 이용한 저에너지 소비형 알코올 제조 -분리막을 이용한 발효공정에서 알코올 회수의 기초적 연구-)

  • 김재형;박돈희
    • KSBB Journal
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    • v.6 no.4
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    • pp.379-383
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    • 1991
  • Pervaporation can be successfully utilized to recover alcohol from fermentation broths and dilute process streams. Polydimethylsiloxane (thickness: $60\mu$m), such as hydrophobic membrane have been employed in this application to produce an enriched product. The fermented alcohol was continuously extracted, and simultaneously concentrated by pervaporation, from the membrane bioreactor, and the extracted alcohol concentration was 6 to 10 times higher than in the broth. This experimental conditions were 6-10 Torr vacuum line, pH=5, $32^{\circ}C$, 3.5 liters of working volume, 200rpm of agitator speed, and 0.14 wm aeration flow rate.

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Application of Lumley's Drag Reduction Model to Two-Phase Gas-Particl Flow in a Pipe(II) - Mechanism of Heat Transfer- (고체 분말이 부상하는 2상 난류 수직관 유동에 대한 Lumley의 저항감소 모델의 적용 (II) - 열전달 기구 -)

  • 한기수;정명균;성형진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.1
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    • pp.214-224
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    • 1990
  • A "two-fluid" model using thermal eddy diffusivity concept and Lumley's drag reduction theory, is proposed to analyze heat transfer of the turbulent dilute gas-particle flow in a vertical pipe with constant wall heat flux. The thermal eddy diffusivity is derived to be a function of the ratio of the heat capacity-density products .rho. over bar $C_{p}$ of the gaseous phase and the particulate phase and also of the ratio of thermal relaxation time scale to that of turbulence. The Lumley's theory dictates the variation of the viscous sublayer thickness depending on the particle loading ratio Z and the relative particle size $d_{p}$/D. At low loading ratio, the size of viscous sublayer thickness is important for suspension heat transfer, while at higher loading, the effect of the ratio .rho. $_{p}$ over bar $C_{p}$$_{p}$/ .rho. $_{f}$ over bar $C_{p}$$_{f}$ is dominant. The major cause of decrease in the suspension Nusselt number at lower loading ratio is found to be due to the increase of the viscous sublayer thickness caused by the suppression of turbulence near the wall by the presence of solid particles. Predicted Nusselt numbers using the present model are in satisfactory agreements with available experimental data both in pipe entrance and the fully developed regions.

Effects of Micro-fin Structure on Spray Cooling Heat Transfer in Forced Convection and Nucleate Boiling Region (강제대류 및 핵비등영역에 있어서 마이크로 휜 형상이 분무냉각 열전달에 미치는 영향)

  • Kim, Yeung-Chan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.11
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    • pp.983-990
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    • 2010
  • In the present study, spray cooling heat transfer was experimentally investigated for the case in which water is sprayed onto the surfaces of micro-fins in forced convection and nucleate boiling regions. The experimental results show that an increase in the droplet flow rate improves heat transfer due to forced convection and nucleate boiling in the both case of smooth surface and surfaces of micro-fins. However, the effect of subcooling for fixed droplet flow rate is very weak. Micro-fins surfaces enhance the spray cooling heat transfer significantly. In the dilute spray region, the micro-fin structure has a significant effect on the spray cooling heat transfer. However, this effect is weak in the dense spray region. A previously determined correlation between the Nusselt number and Reynolds number shows good agreement with the present experimental data for a smooth surface.

Study on the Ethanol Recovery Process using Dircet Contact Heat Exchange (고온의 기포접촉에 의한 에탄올 회수공정에 관한 연구)

  • Lee, Won-Young;Yeo, Sang-Do;Choi, Yong-Hee
    • Korean Journal of Food Science and Technology
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    • v.27 no.2
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    • pp.176-180
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    • 1995
  • Direct contact heat exchange (DCHE) method has been employed to investigate the separation of ethanol from dilute aqueous solutions. Bubbles at high temperature were dispersed into a continuous liquid phase, generating temperature gradient in air-liquid interface, which causes heat and mass transfer accordingly. The experiments were performed in the ranges of jet regime air flow. The air-water stripping coefficient increased $5{\sim}10,\;and\;1{\sim}1.5$ times as temperature and air flow rate increased, respectively. The recovery ratio based on the initial ethanol concentration reached into 80% at the air flow rate of 84.88 m/min. The initial ethanol concentration showed little effect on the stripping coefficient and the recovery ratio.

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Sensitivity Analysis to the Design Factor of Ocean Outfall System (방류관 설계인자에 대한 민감도 분석)

  • 김지연;이중우
    • Journal of Korean Port Research
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    • v.14 no.3
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    • pp.361-371
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    • 2000
  • A demand of marine outfall system has been much increased for the effective disposal of the wastewater due to population and industrial development at the coastal areas. The outfall system discharges primary or secondary treated effluent into the coastline, or at the deep water, or between these two. The discharge is carried out by constructing a pipeline on the sea bed with a diffuser or with a tunnel, risers and appropriate. The effluent, which has a density similar to that of fresh water, rises to the sea surface forming plume or jet, together with entraining the surrounding salt water and becomes very dilute. Thus there have been growing interests about plume behaviour around the outfall system. Plume or jet discharged from single-port or multi-port diffuser might cause certain impacts on coastal environment. Near field mixing characteristics of discharged water field using CORMIX model have been studied for effective outfall design various conditions on ambient current, depth, flow rate, effluent concentration, diffuser specification, port specification etc.. This kind of analysis is necessary to deal with water quality problems caused by the ocean discharge. The analyzed result was applied to the Pusan Jungang effluent outfall system plan.

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