• Title/Summary/Keyword: Dry Process

Search Result 1,764, Processing Time 0.025 seconds

Modeling for a Coke Dry Quenching Process Using a Theory of a Porous Material (다공질 물질의 냉각현상 연구를 통한 코크스냉각공정의 모델링)

  • Kim, Joo-Han;Lee, Yong-Ju;Kim, Ki-Seok
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.21 no.5
    • /
    • pp.697-701
    • /
    • 2012
  • Numerical modeling for a coke dry quenching process was developed and evaluated. The cokes had similar characteristics to a porous material, therefore, its quenching analysis was simplified as a cooling process of porous blocks. A uniform inlet temperature and constant properties of materials in the oven were also assumed. With given operating conditions, temperature profiles in the cokes were calculated and compared to the actual values. The calculated temperature gradient was high at the upper part of the coke flow and the cooling rate decreased as cokes came down to the exit port. The exit port temperature of cokes was similar to the measured value, however, temperature-dependent material properties and operating conditions must be considered to predict the temperature precisely. The calculated results could be applied to design a coke oven to produce high quality cokes.

Correlation analysis between cutting conditions and cylindricity in MQL turning (MQL 선삭가공에서 절삭조건과 원통도의 상관관계 분석)

  • Shin, Sung-Woo;Hwang, Young-Kug;Lee, Choon-Man
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.8 no.3
    • /
    • pp.74-81
    • /
    • 2009
  • At present, industries and researchers are looking for ways to reduce the use of lubricants because of ecological and economical reasons. Therefore, metal cutting is to move toward dry cutting or semi-dry cutting. One of the technologies is known as MQL machining. This paper presents an investigation into MQL machining with the objective of evaluating cylindricity and cooling effect for the turning process of SM45C. To reach this goal, cylindrical-outer-diameter turning experiments are carried out according to cutting conditions with fluid, MQL and dry machining methods. A cutting force, tool-shank temperature and cylindricity of workpiece are measured and analyzed. The correlation between cutting conditions and cylindricity are evaluated according to cooling lubricant environments.

  • PDF

Implementation of a Dry Process Fuel Cycle Model into the DYMOND Code

  • Park Joo Hwan;Jeong Chang Joon;Choi Hangbok
    • Nuclear Engineering and Technology
    • /
    • v.36 no.2
    • /
    • pp.175-183
    • /
    • 2004
  • For the analysis of a dry process fuel cycle, new modules were implemented into the fuel cycle analysis code DYMOND, which was developed by the Argonne National Laboratory. The modifications were made to the energy demand prediction model, a Canada deuterium uranium (CANDU) reactor, direct use of spent pressurized water reactor (PWR) fuel in CANDU reactors (DUPIC) fuel cycle model, the fuel cycle calculation module, and the input/output modules. The performance of the modified DYMOND code was assessed for the postulated once-through fuel cycle models including both the PWR and CANDU reactor. This paper presents modifications of the DYMOND code and the results of sample calculations for the PWR once-though and DUPIC fuel cycles.

Development of Dry Forming Mold for the Feasibility Study of Dry Forming of Paper (건식초지기술의 가능성 평가를 위한 건식초지기 개발)

  • Kim, Jong-Min;Youn, Hye-Jung;Lee, Hak-Lae
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.39 no.2 s.120
    • /
    • pp.1-8
    • /
    • 2007
  • To examine the feasibility of dry forming technology for papermaking, a dry forming mold (DFM) was developed and evaluated. Main fanning section of DFM was a cylindrical tube, and at the top of the mold a stirring equipment was placed to disperse dry fibers. These fibers were screened using a hole type screen plate placed just under the stirring equipment and dropped freely on the fanning wire located 0.9 m below of the screen plate to form a dry fiber pad. The vertical and horizontal velocity of air flow in the forming cylinder were evaluated and analyzed to find the most effective method of air flow control in the cylinder. Humidification and pressing conditions to obtain a decent dry fanned papers were examined. Results showed dry fanned papers can be prepared with this dry forming mold. And this mold can be used to examine the effect of the papermaking process factors including pressing pressure, drying temperature, humidification on sheet quality of dry formed papers.

Partially Dry-Transferred Graphene Electrode with Zinc Oxide Nanopowder and Its Application on Organic Solar Cells (ZnO 나노 분말 코팅 기반 건식전사 그래핀 전극 제작 및 유기태양전지 응용)

  • Jo, Yeongsu;Woo, Chae Young;Hong, Soon Kyu;Lee, Hyung Woo
    • Journal of Powder Materials
    • /
    • v.27 no.4
    • /
    • pp.305-310
    • /
    • 2020
  • In this study, partially dry transfer is investigated to solve the problem of fully dry transfer. Partially dry transfer is a method in which multiple layers of graphene are dry-transferred over a wet-transferred graphene layer. At a wavelength of 550 nm, the transmittance of the partially dry-transferred graphene is seen to be about 3% higher for each layer than that of the fully dry-transferred graphene. Furthermore, the sheet resistance of the partially dry-transferred graphene is relatively lower than that of the fully dry-transferred graphene, with the minimum sheet resistance being 179 Ω/sq. In addition, the fully dry-transferred graphene is easily damaged during the solution process, so that the performance of the organic photovoltaics (OPV) does not occur. In contrast, the best efficiency achievable for OPV using the partially dry-transferred graphene is 2.37% for 4 layers.

A Comparative Study of a Dielectric-Defined Process on AlGaAs/InGaAs/GaAs PHEMTs

  • Lim, Jong-Won;Ahn, Ho-Kyun;Ji, Hong-Gu;Chang, Woo-Jin;Mun, Jae-Kyoung;Kim, Hae-Cheon;Cho, Kyoung-Ik
    • ETRI Journal
    • /
    • v.27 no.3
    • /
    • pp.304-311
    • /
    • 2005
  • We report on the fabrication of an AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor (PHEMT) using a dielectric-defined process. This process was utilized to fabricate $0.12\;{\mu}m\;{\times}\;100 {\mu}m$ T-gate PHEMTs. A two-step etch process was performed to define the gate footprint in the $SiN_x$. The $SiN_x$ was etched either by dry etching alone or using a combination of wet and dry etching. The gate recessing was done in three steps: a wet etching for removal of the damaged surface layer, a dry etching for the narrow recess, and wet etching. A structure for the top of the T-gate consisting of a wide head part and a narrow lower layer part has been employed, taking advantage of the large cross-sectional area of the gate and its mechanically stable structure. From s-parameter data of up to 50 GHz, an extrapolated cut-off frequency of as high as 104 GHz was obtained. When comparing sample C (combination of wet and dry etching for the $SiN_x$) with sample A (dry etching for the $SiN_x$), we observed an 62.5% increase of the cut-off frequency. This is believed to be due to considerable decreases of the gate-source and gate-drain capacitances. This improvement in RF performance can be understood in terms of the decrease in parasitic capacitances, which is due to the use of the dielectric and the gate recess etching method.

  • PDF

Compressive Strength Correlation of Very-Early-Strength Dry-Mix Shotcrete on Test Method (측정방법에 따른 속경성 건식 숏크리트 압축강도의 상관관계)

  • Yun, Kyong-Ku;Choi, Sung-Yong;Kim, Jin-Woung;Kil, Yong-Su
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.11 no.10
    • /
    • pp.3988-3997
    • /
    • 2010
  • Shotcrete was a mortar or concrete that is pneumatically projected at high velocity onto a subject. It has been applied for tunneling, underground big-spaces, slope stabilization. Shotcrete is increasing use in structure repair. The dry-mix shotcrete require a smaller equipment, easy maintenance, possible of very-earlystrength materials than wet-mix shotcrete, which make this process attractive and economic for structural repairs. It is common practice core compressive strength to the dry-mix shotcrete quality control. This test is very difficult estimating eraly-strength of Very-Early-Strength Dry-Mix Shotcrete. The purpose of this research was to analyze the correlation of test results among cube test, core test, pullout test and maturity. The correlationship analysis of test results among cube test, core test, pullout test and maturity showed more than 90%.

A Study on the Chlorobenzene and Chlorophenol Behavior in Plasma Type Pyrolysis/Gasfication/Melting Process (플라즈마 방식 열분해 가스화용융시설의 공정별 클로로벤젠 및 클로로페놀 배출거동에 관한 연구)

  • Shin, Chan-Ki;Shin, Dae-Yun;Kim, Ki-Heon;Son, Ji-Whan
    • Journal of environmental and Sanitary engineering
    • /
    • v.22 no.2
    • /
    • pp.9-20
    • /
    • 2007
  • The incineration process has commonly used for wastes amount reduction and thermal treatments of pollutants as the technologies accumulated. However, the process is getting negative public images owing to matter of hazardous pollutants emission. Specially dioxins became a main issue and were mostly emitted from municipal solid wastes incineration. In this reason, pyrolysis/gasification/melting process is presented as an alternative of incineration process. The pyrolysis/gasification/melting process, a novel technology, is middle of verification of commercial plant and development of technologies in Korea. But the survey about the pollutant emission from the process, and background data in these facilities is necessary. So in this survey, t is investigated that the behavior of chlorobenzenes and chlorophenols in plasma type pyrolysis/gasification/melting plant of pilot scale. We investigated discharging behavior of each phase of chlorobenzene through each process in the plsasma type pyrolysis/gasification/melting process. From this result, it was found that about 99 percent of particle-phase chlorobenzene was removed, but on the other hand gas-phase chlorobenzene was increased by about 600 percent through heat exchanger, flue gas cooling, system and semi dry absorption bag filter(SDA/BF). Also, this investigation presented that di-chlorobenzene(DCB) tri-chlorobenzene(TCB), tetra-chlorobenzene(TeCB), penta-chlorobenzene (PCB), except mono-chlorobenzene(MCB) and hexa-chlorobenzene(HCB) were increased through the flue gas cooling system and the semi dry absorption bag filter(SDA/BF). It was investigated that concentration of particle-phase chlorophenol was decreased by about 66 percent, but on the other hand, concentration of gas-phase chlorophenol was increased by about 170 percent through heat exchanger, flue gas cooling system, and semi dry absorption bag filter(SDA/BF). Also, it was found that di-chlorophenol(DCP), tri-chlorophenol(TCP), and penta-chlorophenol(PCP) were increased through the flue gas cooling system, and the semi dry absorption bag filter(SDA/BF). It can be considered that small-scale pilot facility and short investigation period might cause the concentration increase through the flue gas cooling system and the semi dry absorption bag filter(SDA/BF). A further study on real-scale pilot facility and accurate investigation may be required.

A Dry-patterned Cu(Mg) Alloy Film as a Gate Electrode in a Thin Film Transistor Liquid Crystal Displays (TFT- LCDs) (TFT-LCDs 게이트 전극에 적용한 Cu(Mg) 합금 박막의 건식식각)

  • Yang Heejung;Lee Jaegab
    • Korean Journal of Materials Research
    • /
    • v.14 no.1
    • /
    • pp.46-51
    • /
    • 2004
  • The annealing of a Cu(4.5at.% Mg)/$SiO_2$/Si structure in ambient $O_2$, at 10 mTorr, and $300-500^{\circ}C$, allows for the outdiffusion of the Mg to the Cu surface, forming a thin MgO (15 nm) layer on the surface. The surface MgO layer was patterned, and successfully served as a hard mask, for the subsequent dry etching of the underlying Mg-depleted Cu films using an $O_2$ plasma and hexafluoroacetylacetone [H(hfac)] chemistry. The resultant MgO/Cu structure, with a taper slope of about $30^{\circ}C$ shows the feasibility of the dry etching of Cu(Mg) alloy films using a surface MgO mask scheme. A dry-etched Cu(4.5at.% Mg) gate a-Si:H TFT has a field effect mobility of 0.86 $\textrm{cm}^2$/Vs, a subthreshold swing of 1.08 V/dec, and a threshold voltage of 5.7 V. A novel process for the dry etching of Cu(Mg) alloy films, which eliminates the use of a hard mask, such as Ti, and results in a reduction in the process steps is reported for the first time in this work.