• Title/Summary/Keyword: 압력주입

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A Study on Air Permeability and Radius of Influence During SVE/Bioventing (SVE/Bioventing시 토양의 투기계수 및 영향반경에 관한 연구)

  • 이철효;장원용;전연호;이진용;이강근
    • Journal of the Korean Society of Groundwater Environment
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    • v.7 no.1
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    • pp.24-31
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    • 2000
  • Soil air permeability and influence of radius in air injection/extraction tests were estimated. These are important factors in the determination of optimal design for SVE or bioventing system. For evaluation of the effects of air leakage from the ground surface on those factors, Theis (1935) and Hantush (1960) methods were used in the data analysis. The air permeability of the studied area was in the range of 1.64$\times$$10^{-7}$~5.66$\times$$10^{-6}$ $\textrm{cm}^2$, and this result would be used for the design of SVE or bioventing system.

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Measurement of Liquid Entry Pressure of PE and PVDF Hollow Fiber Membranes in Membrane Distillation Process (막증류 공정에서 PE 및 PVDF 중공사막의 액체투과압력 측정에 관한 연구)

  • Min, Ji Hee;Park, Min Soo;Kim, Jinho
    • Membrane Journal
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    • v.25 no.3
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    • pp.216-222
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    • 2015
  • The method measuring LEP (liquid entry pressure) was optimized to evaluate the wettabilities of hydrophobic membranes which might affect long-term durability of membrane in MD (membrane distillation) process. Conductivity of the permeate was monitored to measure the LEPs of PE (polyethylene) and PVDF (polyvinylidene di-fluoride) hollow fiber membranes from highly concentrated synthetic feed water of 20 wt% NaCl. Holding time over 5 min and the ratio of membrane area to the tank volume more than $10m^2/m^3$ were required to ensure LEP value.

Steady-state Thrust Characteristics of Hydrazine Thruster for Attitude Control of Space Launch Vehicles (우주발사체 자세제어용 하이드라진 추력기의 정상상태 추력 특성)

  • Kim, Jong Hyun;Jung, Hun;Kim, Jeong Soo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.16 no.6
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    • pp.48-55
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    • 2012
  • An ambient hot-firing test was carried out for the hydrazine thruster which may be employed in the space launch vehicles. The thruster is designed to produce 67 N (15 $lb_f$) of nominal steady-state thrust at an inlet pressure of 2.41 MPa (350 psia). A scrutiny into the performance characteristics of thruster is made in terms of thrust, propellant supply pressure, mass flow rate, chamber pressure, and temperature at the steady-state firing mode. As a result, it is ensured that the practical performance efficiencies are above 89.1% compared to its ideal requirements.

A Numerical Study on Hydraulic Behavior in a Fractured Rock Medium with Hydromechanical Interaction (수리역학적 상호작용을 고려한 균열암반매질에서의 수리학적 거동에 대한 수치적 연구)

  • Jeong, Woochang;Park, Youngjin
    • Journal of the Korean GEO-environmental Society
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    • v.10 no.2
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    • pp.61-68
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    • 2009
  • This paper presents the numerical investigation for the hydraulic behavior of a fractured rock mass with a hydromechanical interaction which may be considered during the in-situ hydraulic injection test. These experiments consist in a series of flow meter injection tests for fractures existing along an open hole section installed in a borehole, and experimental results are applied for testing a numerical model developed to the analysis and prediction of such hydromechanical interactions. Field experimental results show that conductive fractures form a dynamic and interdependent network, that individual fractures cannot be adequately modeled as independent systems, that new fluid intaking zones generate when pore pressure exceeds the minimum principal stress magnitude in that borehole, and that pore pressures much larger than this minimum stress can be further supported by the circulated fractures. In this study, these characteristics are investigated numerically how to influence the morphology of the natural fracture network in a rock mass by using a discrete fracture ntework model.

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A Study on the Heating of Lipiodol during Lymphangiography (림프관 조영술 시 리피오돌의 가온에 관한 고찰)

  • Kang, Rae-Wook;Kim, Jae-Seok
    • Journal of the Korean Society of Radiology
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    • v.14 no.5
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    • pp.597-602
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    • 2020
  • The study was conducted to improve the efficiency of the test and to reduce the exposure dose of patients and operators by analyzing the difference in the moving speed of Lipiodol according to the temperature during lymphography. The device for injecting Lipiodol at a constant pressure was self-made, and after inserting Lipiodol into the Connecting Tube, the moving speed of the contrast agent was photographed at temperatures of 26℃, 36℃, and 46℃ using a heat transfer device. Lipiodol movement time from the Support Catheter to 20cm was measured and analyzed, and statistical significance was confirmed. In the 46℃ environment, the average moving time was 11 seconds, at 36℃ the average was 13 seconds, and at 26℃ the average was 17 seconds. Lipiodol showed a significant difference in moving time with increasing temperature (p<.001), and it was confirmed that the higher the temperature, the faster the moving speed. In the case of lymphangiography, when heated to a certain temperature (46 degrees) rather than injecting Lipiodol at room temperature, the injection speed can be increased and the speed of movement in the lymphatic vessel can be improved.

Optimization Study for Pressure Swing Distillation Process for the Mixture of Isobutyl-Acetate and Isobutyl-Alcohol System (Isobutyl-Acetate와 Isobutyl-Alcohol 이성분계의 압력변환증류 공정 최적화 연구)

  • Cho, Sung Jin;Shin, Jae Sun;Choi, Suk Hoon;Lee, Euy Soo;Park, Sang Jin
    • Korean Chemical Engineering Research
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    • v.52 no.3
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    • pp.307-313
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    • 2014
  • In this study, an optimization process design has been performed to separate 99.9 mol% of Isobutyl Acetate from binary azeotropic mixture of Isobutyl Acetate and Isobutyl Alcohol system using a Pressure Swing Distillation (PSD). PSD is used to separate binary azeotropic mixtures using the difference between the relative volatilities and azeotropic compositions by changing the system pressure. Non-Random Two Liquid (NRTL) model for liquid phase and the Peng-Robinson equation for vapor phase are used. An optimization study for the reflux ratio and feed stage locations which minimize the total reboiler heat duties are studied. Since PSD process consists of two columns, i.e. high pressure and low pressure, the effect of column sequence on the optimum conditions is reported.

Effect of Orifice Type and Number on the Mixing and Flow Characteristics in In-line Mixer (관내 혼화장치의 오리피스 형상과 개수에 따른 혼화 및 유동특성)

  • Jeong, Seon Yong;Chung, Won Sik;Rhi, Seok Ho;Lee, Kye Bock;Lee, Dae Gyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.2
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    • pp.6-13
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    • 2017
  • This study examines the effect of the type and number of orifices in an in-line mixer to improve the mixing performance and pressure loss. Recently, in-line non-power-consuming mixers have been increasingly used to complement mechanical mixers, which have a long dwell time, noise, excessive energy consumption, and high maintenance costs. An in-line mixer with an orifice for efficient mixing in water treatment was examined by numerical analysis using the commercial code FLUENT. The flow characteristics of pressure loss and velocity distribution within the mixer and the mixing efficiency were compared with and without the orifices. The CFD results show that the mixing efficiency was improved, but the pressure loss was increased by the in-line mixer with an orifice. A sensitivity study was also done on the principal parameters.

Effect of Suction Pressures with Respect to the Operational Modes Using the Quorum Quenching in the Membrane Bioreactor (생물막 반응기내 quorum quenching을 이용한 운전방식에 따른 흡입 압력의 영향)

  • Min Hyeong, Kim;Eeung Mo, Koo;Hyeok, Kim;Hyun-Suk, Oh;Kun Yong, Chung
    • Membrane Journal
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    • v.32 no.6
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    • pp.465-474
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    • 2022
  • The suction pressure was measured with respect to operational time by the backwashable flat sheet membrane module in membrane bioreactor (MBR). The membrane module having the nominal pore size of 0.2 ㎛ and the effective membrane area of 128cm2 was submerged in MLSS 8,000 mg/L active sludge aqueous solution. The suction pressure was observed with respect to permeation flux and the quorum quenching (QQ) treatment. The effects of FR and SFCO operation methods were compared and analyzed in the experimental groups: vacant bead (VB), BH4 and DKY-1 beads. The suction pressure reduction was the most effective for the permeation flux 40 L/m2 ⋅h with the injection of DKY-1 QQ beads. Also, the suction pressure reduction by the backwashing method was more than twice for using DKY-1 QQ beads.

An Optimal Design of Gas Lift in Offshore Oil Reservoirs Considering Oil and Injected Gas Composition (해저 오일 저류층 내 오일 및 주입가스 조성에 따른 가스리프트 공법의 최적 설계)

  • Kim, Young-Min;Shin, Chang-Hoon;Lee, Jeong-Hwan
    • Journal of the Korean Institute of Gas
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    • v.22 no.4
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    • pp.39-48
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    • 2018
  • This study presents optimal design of gas lift considering composition of reservoir oil and injected gas which can affect gas lift performance in offshore oil reservoir. Reservoir simulation was conducted by using reservoir models which were built in accordance with API gravity of oil. The results of simulation reveal that oil production rate is considerably increased by gas lift when the reservoir productivity decrease. As a results of response curve analysis for gas lift using well models, gas injection rate to improve the production rate increases as the API gravity of oil decreases and the specific gravity of injected gas increases. The optimal design of gas lift was carried out using multiple lift valves. Consequently, gas lift can be operated at relatively low injection pressure because of decrease in injection depth in comparison to the single lift valve design. The improved oil production rates were analyzed by coupling between reservoir model and well model. As a results of the coupling, it is expected that natural gas injection in the heavy oil reservoir is the most efficient method for improving oil production by gas lift.

Study on the Separation of CO2 from Flue Gas Using Polysulfone Hollow Fiber Membrane (폴리설폰 중공사막을 이용한 연소 배기가스 중 이산화탄소 분리에 관한 연구)

  • Kim, Seongcheon;Chun, Jeonghyeon;Chun, Youngnam
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.2
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    • pp.147-152
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    • 2014
  • In this research, polysulfone hollow fiber membrane was used to recover $CO_2$ which is one of greenhouse gases from flue gas stream being emitted after the combustion of fossil fuels. The prerequisite requirement is to design the membrane process producing high-purity $CO_2$ from flue gas. For separation of $CO_2$, a membrane module and flue gas containing 10% carbon dioxide was used. The effects of operating conditions such as pressure, temperature, feed gas composition and multi-stage membrane on separation performance were examined at various stage cuts. Higher operating pressure and temperature increased carbon dioxide concentration and recovery ratio in permeate. Recovery ratio and separation efficiency increased if a higher content of $CO_2$ injection gas composition. Three-stage membrane system was producing a 95% $CO_2$ with 90% recovery from flue gas. The separation efficiency of three-stage membrane system was higher than one-stage system.