• Title/Summary/Keyword: Vapor phase

Search Result 1,125, Processing Time 0.034 seconds

Evaporative Modeling in n Thin Film Region of Micro-Channel (마이크로 채널내 박막영역에서의 증발 모델링)

  • Park, Kyoung-Woo;Noh, Kwan-Joong;Lee, Kwan-Soo
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.27 no.1
    • /
    • pp.17-24
    • /
    • 2003
  • A mathematical model of the hydrodynamic and heat transfer performances of two-phase flow (gas-liquid) in thin film region of micro channel is proposed. For the formulation of modeling, the flow of the vapor phase and the shear stress at the liquid-vapor interface are considered. In this work, disjoining pressure and capillary force which drive the liquid flow at the liquid-vapor interface in thin film region are adopted also. Using the model, the effects of the variations of channel height and heat flux on the flow and heat transfer characteristics are investigated. Results show that the influence of variation of vapor pressure on the liquid film flow is not negligible. The heat flux in thin-film region is the most important operation factor of micro cooler system.

Vapor Phase Mercury Removal by Sulfur Impregnated Activated Carbons and Sulfur Impregnation Protocol

  • Lee, Si-Hyun;Cha, Sun-Young;Park, Yeong-Seong
    • Carbon letters
    • /
    • v.2 no.1
    • /
    • pp.37-43
    • /
    • 2001
  • Mercury has been identified as a potential health and environmental hazardous material. Activated carbon adsorption offers promising potential for the control of mercury emissions, and sulfur impregnated (sulfurized) activated carbons has been shown to be an effective sorbent for the removal of vapor phase $Hg{\circ}$ from sources. In this work, vapor phase mercury adsorption by sulfur impregnated activated carbons were investigated. Sulfur impregnated activated carbons were made by variation of impregnation temperature, and the comparison of adsorption characteristics with commercial virgin and sulfurized carbons were made. Factors affecting the adsorption capacity of virgin and sulfurized activated carbons such as pore characteristics, functional groups and sulfur impregnation conditions were discussed. It was found that the sulfur allotropes plays a critical role in adsorption of mercury vapor by sulfurized activated carbons.

  • PDF

Metalorganic vapor-phase epitaxial growth of vertically well-aligned ZnO nanorods and their photoluminescent properties (수직배향된 산화아연 나노막대의 성장 및 발광특성에 관한 연구)

  • Jeon Yong-Ho;Park Won-Il;Lee Gyu-Cheol
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 2002.07a
    • /
    • pp.174-175
    • /
    • 2002
  • One-dimensional semiconductor nanowires and nanorods have attracted increasing interest due to their unique physical properties and diversity for potential electronic and photonic device applications., Unlike the conventional nanowires fabricated by metal catalyst-assisted vapor-liquid-solid (VLS) method, we developed metalorganic vapor-phase epitaxial (MOVPE) growth for which no catalyst is needed. The structural and photoluminecent properties will also be discussed. (omitted)

  • PDF

A Study on the Heat Transfer Characteristics and Performance of the High Temperature Range Heater Plate Using Liquid-Vapor Phase Change Heat Transfer (기-액 상변화 열전달식 고온 히터 플레이트의 작동 특성과 성능에 관한 연구)

  • Kang, Hwan-Kook;Yim, Kwang-Bin
    • Journal of the Korean institute of surface engineering
    • /
    • v.46 no.6
    • /
    • pp.283-289
    • /
    • 2013
  • The experimental study for the temperature uniformity on the wafer using liquid-vapor phase heat transfer mechanism is performed. For the experiment, the heater plate which is consist of stainless steel container, working fluid and electrical heater is designed, manufactured and tested at the range of 600 to $850^{\circ}C$. The results showed that the phase change type heater plate was much more uniform and stable temperature on the heater plate surface and wafer than the uniform heat flux type heater plate at the atmospheric condition. Also, the results of 300 mm outer diameter of heater plate showed that the same temperature uniformity compared with 230 mm.

Multiphase Flow Modeling of Molten Material-Vapor-Liquid Mixtures in Thermal Nonequilibrium

  • Park, Ik-Kyu;Park, Goon-Cherl;Bang, Kwang-Hyun
    • Journal of Mechanical Science and Technology
    • /
    • v.14 no.5
    • /
    • pp.553-561
    • /
    • 2000
  • This paper presents a numerical model of multi phase flow of the mixtures of molten material-liquid-vapor, particularly in thermal nonequilibrium. It is a two-dimensional, transient, three-fluid model in Eulerian coordinates. The equations are solved numerically using the finite difference method that implicitly couples the rates of phase changes, momentum, and energy exchange to determine the pressure, density, and velocity fields. To examine the model's ability to predict an experimental data, calculations have been performed for tests of pouring hot particles and molten material into a water pool. The predictions show good agreement with the experimental data. It appears, however, that the interfacial heat transfer and breakup of molten material need improved models that can be applied to such high temperature, high pressure, multi phase flow conditions.

  • PDF

Phase Equilibrium of Binary Mixture for the (propylene oxide + 1-pentanol) System at Several Temperatures

  • Kim, Jeong-lae;Kim, Hakmin;Park, Su In;An, Gyu Min;Kim, Min Gi;Shin, Moon Sam
    • Korean Chemical Engineering Research
    • /
    • v.57 no.1
    • /
    • pp.73-77
    • /
    • 2019
  • Isothermal (vapor + liquid) equilibrium data measurements were undertaken for the binary mixtures of (propylene oxide + 1-pentanol) system at three different temperatures (303.15, 318.15, and 333.15) K. The Peng-Robinson-Stryjek-Vera equation of state (PRSV EOS) was used to correlate the experimental data. The van der Waals one-fluid mixing rule was used for the vapor phase and the Wong-Sandler mixing rule, which incorporates the non-random two liquid (NRTL) model, the universal quasi-chemical (UNIQUAC) model and the Wilson model, was used for the liquid phase. The experimental data were in good agreement with the correlation results.

An Experimental Study of Vapor-Liquid Equilibrium for HFC12S+Propane Refrigerant Mixtures (HFC125+Propane 혼합냉매의 기-액 평형에 관한 실험적 연구)

  • 강준원;박영무;유재석;이종화
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.15 no.7
    • /
    • pp.563-571
    • /
    • 2003
  • The forty vapor-liquid equilibrium data of the binary system, HFC125+Propane, were measured between 273.15 and 313.15 K at 10 K interval and the composition range 0.2∼0.75, respectively. Experiments were performed in a circulation type apparatus in which the vapor phase was forced through the liquid phase. The composition at equilibrium were mea-sured by gas chromatography, and its response was calibrated using gravimetrically prepared mixtures. Vapor-liquid equilibrium data were calculated by using CSD equation of state and compared with the experimental data.

The Observation of Nucleation & Growth during Water Vapor Induced Phase Inversion of Chlorinated Poly(vinyl chloride) Solution using SALS

  • Jang, Jae Young;Lee, Young Moo;Kang, Jong Seok
    • Korean Membrane Journal
    • /
    • v.6 no.1
    • /
    • pp.61-69
    • /
    • 2004
  • Small angle light scattering (SALS) and field emission scanning electron microscope (FE-SEM) have been used to investigate the effects of alcohol on phase separation of chlorinated poly(vinyl chloride) (CPVC)/tetrahydrofuran (THF)/alcohol (9/61/30 wt%) solution during water vapor induced phase separation. A typical scattering pattern of nucleation & growth (NG) was observed for all casting solutions of CPVC/THF/alcohol. In the case of the phase separation of CPVC dope solution containing 30 wt% ethanol or n-propanol, the demixing with NG was observed to be heterogeneous. Meanwhile, the phase separation of CPVC dope solution with 30 wt% n-butanol was found to be predominantly homogeneous NG. Although the different phase separation behavior of NG was observed with types of alcohol additives, the resultant surface morphology had no remarkable differences. That is, even though the NG process by water vapor is either homogeneous or heterogeneous, this difference does not play a main role on the final surface morphology. However, it was estimated from the result of hydraulic flux that the phase separation by homogeneous NG provided the membrane geometry with lower resistance in comparison with that by heterogeneous one.

Synthesis and Their Properties of PP Graft Copolymers by E-beam Radiation and Vapor Phase Reaction (전자선 조사 기상 반응에 의한 PP 기재 공중합체의 합성과 특성)

  • 황택성;박진원;이재천
    • Polymer(Korea)
    • /
    • v.26 no.3
    • /
    • pp.287-292
    • /
    • 2002
  • Graft copolymerization of styrene and glycidyl methacrylate (GMA) to the peroxidized polypropylene (PP) fabric with E-beam in $O_2$ atmosphere was carried out in vapor phase with benzoyl peroxide (BPO) as an initiator. The degree of grafting of copolymers was increased with the increase of the reaction temperature and the highest degree of grafting was obtained at $70^{\circ}C$ with styrene, and at $80^{\circ}C$ with GMA. The highest degree of grafting of styrene grafted PP according to reaction time was higher than that of GMA grafted PP. In vapor phase graft polymerization, the degree of grafting of copolymers according to water composition in monomer mixture was effected by the boiling temperature of monomers.