• Title/Summary/Keyword: Vacuum characteristics

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An Experimental Study on the Dewatering from the Waste Lubrication Oil by Vacuum Evaporation (진공 증발에 의한 폐윤활유 속의 수분 제거에 관한 실험적 연구)

  • 정상현;박성제;홍원석;김용진;구경회
    • Journal of Energy Engineering
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    • v.12 no.3
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    • pp.216-222
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    • 2003
  • An experimental study on the characteristics of a dewatering due to vacuum evaporation in the waste lubrication oil were performed using a lab scale system. Evaporation characteristics were investigated for various performance factors. Results of evaporation characteristics as a function of vacuum pressure, oil temperature, initial water concentration, and nozzle type were obtained. Increasing the oil temperature and altering the nozzle type were found to increase the evaporation rate without increasing vacuum pressure requirement. The best performance is achieved for the nozzle which made porous material.

A Study on the Burning Characteristics of Composite Propellants at Low Pressure using Vacuum Strand Burner (Vacuum Strand Burner를 이용한 혼합형 추진제의 저압 연소특성 연구)

  • 김인철;유지창;박영규;이태호
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 1994.11a
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    • pp.39-45
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    • 1994
  • Combustion characteristics of the solid composite propellants were studied from burning rate, ignition and steady combustion processes, and structure of the extinguished surfaces. Optical Vacuum Strand Burner (OVSB) system was desisted and configured to study those. Burning rates of the propellants were measured by OVSB at low pressure range by developed ten method. video camera(30 frames/s) was used to take potographs of the phenomena of ignition and combustion of propellant within the test cell of the OVSB. Burning surfaces of the propellants that were extinguished by rapid depressurization method were analyzed with Scanning Electron Microscope. (SEM).

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Hardness and Distortion Characteristics of SCM415 Steel by Carburizing (진공침탄과 가스침탄에 의한 SCM415강의 경도 및 변형특성)

  • Park, S.J.;Rhee, K.S.;Kim, K.S.
    • Journal of the Korean Society for Heat Treatment
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    • v.15 no.6
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    • pp.269-271
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    • 2002
  • For the investigation of the hardness profiles and distortion characteristics of SCM415 steel, test pieces of SCM415 steel were gas and vacuum carburizing treated. The hardness profiles and distortion characteristics of vacuum and gas carburized SCM415 steel show different results. Vacuum carburizing can offer more improved hardness profiles than alternate methods of carburizing. Compared to alternate methods of carburizing, vacuum carburizing can offer improved mechanical properties and reduced cycle times of the process.

The Magnetic Field Characteristics of Multipolar Axial Magnetic Field type Electrodes for Vacuum Interrupter (진공인터럽터용 다극 종자계전극의 자계분포 특성)

  • Kim, Sung-Il;Park, Hong-Tae;Ahn, Hee-Il
    • Proceedings of the KIEE Conference
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    • 1999.11b
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    • pp.92-94
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    • 1999
  • This paper describes axial magnetic field characteristics of multipolar axial magnetic field type electrodes for vacuum interrupter used in vacuum circuit breaker. It was distinguished that axial magnetic field distribution in consideration of eddy current effect between electrodes by finite element method. Throughout experiment of magnetic field measurement, confirmed validity of numericla analysis.

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Development of a Plasma Training Lab kart: System Setup and Numerical Simulation

  • Joo, Junghoon
    • Applied Science and Convergence Technology
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    • v.26 no.6
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    • pp.195-200
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    • 2017
  • A mobile lab kart for plasma training is developed with a high vacuum pumping system, vacuum gauges and a glass discharge tube powered by a high voltage transformer connected to a household 60 Hz line. A numerical model is developed by using a commercial multiphysics software package, CFD-ACE+ to analyze the experimental data. Simulations for argon and nitrogen were carried out to provide fundamental discharge characteristics. Variations of the kart configuration were demonstrated: a glass tube with three electric probes, optical emission spectrometer attachment and infra red thermal imaging system to give more detailed analysis of the discharge characteristics.

SOME MECHANICAL FACTORS AFFECTING MACHINE MILKING CHARACTERISTICS UNDER SEMI-ARID CONDITION

  • Ali, A.K.A.;Farah, D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.5 no.3
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    • pp.475-480
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    • 1992
  • The effect of mechanical factors and season of the year on milking characteristics (milk yield, time of milking, rate of milk flow, stripping time and tripping milk) were studied on 26 Holstein Friesian cows, raised under Saudi Arabia environmental conditions. Cows were in the third and fourth lactation and reached the peak. Cows milked twice a day with equal intervals. Three vacuum levels (34, 38 and 42 cfm) and two pulsation ratios were used to form six vacuum-pulsation combinations. The study was carried during two seasons Autumn-Winter (S1) and Spring-Summer (S2). After absorbing the cow equations least square analysis was used to analyze the data. Vacuum level 38 cfm and pulsation ratio 70:30 was the best among all combinations of vacuum level-pulsation ratio. No significant effect (p < .01) for season, up to the seventh half minute, on the rate of milk flow. However, season of the year has a significant effect on total milk yield, stripping time and stripping milk.

Fabrication and Vacuum Performance Test of the NEG Pump for $10^{-9}$ Pa Chamber ($10^{-9}$ Pa대 용기를 위한 NEG 펌프 제작 및 진공성능 조사)

  • 박미영;인상렬
    • Journal of the Korean Vacuum Society
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    • v.10 no.3
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    • pp.312-320
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    • 2001
  • A Non-Evaporable Getter(NEG) pump was fabricated using Zr-V-Fe alloy modules to obtain $10^{-9}$ Pa range pressures. Pumping performances and activation characteristics were investigated and the pumping speeds for hydrogen, deuterium and carbon monoxide gases of the NEG pump were measured. And hydrogen desorption characteristics were examined during activation at $450^{\circ}C$. Futhermore the vacuum performance was compared with those of other high vacuum pumps as turbo-molecular pump, sputter-ion pump, and cryo pump by analyzing the residual gases of the system.

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Electrical and Optical Characterization of the Vacuum In-Line Sealed PDP Panel

  • Kwon, Sang-Jik;Kim, Jee-Hoon;Kim, Tae-Ho;Shon, Byeong-Kyoo;Yang, Hwi-Chan
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.832-835
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    • 2003
  • By using vacuum in-line driving and photoluminescence measuring method, we have observed the electrical and optical characteristics of the vacuum in-line sealing technology and analyzed the effect of the base vacuum level before filling the plasma gas. In the case of base vacuum level of $1{\times}10^{-3}$torr, the firing voltage of a 2-inch diagonal PDP panel was ranged from 310 to 345V depending on the plasma gas pressure of 200 to 300torr and luminous efficiency was ranged from 0.0227 to 0.0367 lm/W depending on the input voltage level of 330 to 225V. While, in the case of $1{\times}10^{-6}$, the characteristics were significantly improved. As a results, the firing voltage was ranged from 295 to 318V and luminous efficiency was from 0.0278 to 0.0451 lm/W.

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A Study on the Thermal Characteristics of the Low Temperature Vacuum Dryer by the Vacuum Chamber Temperature (진공실 온도에 의한 저온진공건조기의 열적 특성에 관한 연구)

  • Choe, S.Y.
    • Journal of Power System Engineering
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    • v.14 no.4
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    • pp.23-28
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    • 2010
  • Of the roughly four million known substances, about 60,000 are processed and sold ; many of these must be dried. Many materials are processed in the liquid state - ideal for mixing and reacting - but most products are needed or wanted as dry, or relatively dry, solids. Usually operation is just below atmospheric pressure, as with direct dryers, but some are built for vacuum operation with pressures as low as 26.66kPa abs.. In spite of the global-class aquiculture agriculture and fisheries technology of our country, the processing technologies are lags behind the other nations relatively. These problems are considered to be caused directly by the lack of drying technologies. This paper is concerned to the experimental results of drying heat transfer characteristics for the green energy type vacuum dryer for the high quality agriculture and fisheries production.

Changes in the Surface Characteristics of Gas-atomized Pure Aluminum Powder during Vacuum Degassing

  • Yamasaki, Michiaki;Kawamura, Yoshihito
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.1039-1040
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    • 2006
  • Vacuum degassing is essential in the preparation of RS P/M aluminum alloys to remove adsorbates and for the decomposition of hydrated-$Al_{2}O_3$ on the powder surface. Changes in the surface characteristics during vacuum degassing were investigated by X-ray photoelectron spectroscopy and temperature-programmed desorption measurement. Hydrated-$Al_{2}O_3$ decomposition to crystalline-$Al_{2}O_3$ and hydrogen desorption on the surface of argon gas-atomized aluminum powder occurred at 623 K and 725 K, respectively. This temperature difference suggests that the reaction converting hydrated-$Al_{2}O_3$ to crystalline-$Al_{2}O_3$ during vacuum degassing should be divided into the two reactions $"2Al+Al_{2}O_3{\cdot}3H_2O\;2Al_{2}O_3+6H_{surf}"and"6H_{surf}3H_2"$.

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