氣-液同時注入노즐을 使用한 氣泡塔의 特性 : Ⅰ. 流動 狀態 및 氣體滯留量 Ⅰ. Flow Pattern and Gas Hold-up

片茂實,金泰玉,李永淳 明知大學校 産業技術硏究所 1983 産業技術硏究所論文集 Vol.2 No.-

An experimental study was performed on the flow pattern and gas hold-up in a bubble column with a simultaneous gas-liquid injection nozzle as a gas distributor. The flow patterns in the bubble column were classified into three regions (bubble flow, bubble-jet flow and jet flow) by using Froude number based on the liquid velocity through the nozzle. In the bubble flow region under the condition of low liquid flow rate, Fr 〈 Frc, b, the gas hold up increases with increasing gas velocity and equals the gas hold-up in the bubble column at the same gas flow rate. In the bubble-jet flow and the jet flow regions, Fr〉 Frc, b, two different flow zones existed in the column : the lower zone and the upper zone. In the lower zone of the column, heavy liquid recirculation existed and gas hold-up was much larger than that in bubble column. By contrast, in the upper zone, small bubbles were uniformly dispersed in the column and gas hold-up was nearly 1.5 times that in the bubble flow region. As the liquid flow rate increased, gas hold-up in each zone greatly increased and influenced by superficial gas velocity and nozzle diameter. According to the mentioned above, empirical correlations of gas hold-up in each zone were obtained as a function of gas velocity, Froude number and ratio of nozzle to ejector diameter.

Srx La₁_x Fe₃_y계의 결정학적 구조와 비화학양론에 관한 연구

여철현,편무실,강삼룡 明知大學校 産業技術硏究所 1984 産業技術硏究所論文集 Vol.3 No.-

The solid solutions of the ?? systems with χ=1.00, 0.75 and 0.50 are prepared from stoichiometric mixtures of carbonate (SrCO₃), nitrate (Fe (NO₃)₃·9H₂O) and oxide (La₂O₃) by heating at 1300℃ for three days. Crystallographic structures of the solutions are all simple cubic systems and the lattice parameters of the cubic unit cells are enlarged with the introduction of lantanium according to their X-ray diffraction analysis. The mixed valence state of two kinds of Fe ion in the ferrite systems is analyzed by the Mohr salt titration method. It is possible to produce the nonstoichiometric compounds such as ?? by the appropriate heating treatment of the solutions under atmospheric air or oxygen pressure for a long time. The crystallographic structure and the nonstoichiometric compositions of the ?? systems are discussed with relation to their physical properties.

슬러리기포탑에서 고체입자들의 부유 및 혼합특성

김경조,김태옥,편무실 明知大學校 産業技術硏究所 1987 産業技術硏究所論文集 Vol.6 No.2

Suspension and mixing characteristics of solid particles were investigated in a slurry bubble column(SBC) with single nozzle by measuring critical gas velocity, settling velocity, longitudinal dispersion coefficient and logitudinal concentration distribution of solid particles. Experimental results showed that settling velocity of suspended solid particles in SBC was higher than that of single solid particle in liquid-solid system, and that settling velocity increased with increasing gas velocity and particle size and it was not influenced by slurry velocity and solid concentration. Also, longitudinal dispersion coefficient of solid particles increased with increasing gas velocity and it was higher than that of liquid phase for higher gas velocity. The effect of decreasing solid concentration. Furthermore, the effect of increasing gas velocity in continuous system had a large effect on axial distribution of solid particles than did in batch system. In this condition, the theoretical model proposed was applicable to predict suspension and mixing characteristics of solid particles.

기-액병류상향 고정층반응기에서 액체의 흐름과 축방향분산

함병호,조지훈,편무실,김태옥,손민일 明知大學校 産業技術硏究所 1996 産業技術硏究所論文集 Vol.15 No.-

For upward cocurrent gas-liquid flow in a fixed bed reactor, the flow and axial dispersion of liquid were investigated in an air-water-Zeolite particle system. Based on experimental residence time distributions, parameters of mixing models were evaluated with two proposed liquid mixing models: axial dispersion model with stagnant zone(DSM) and plug flow model with stagnant zone(PFM). Accordingly, the applicability and parameters of each mixing model were analyzed for various operating conditions. We found that the flow and axial mixing characteristics of liquid could be analyzed well by DSM and parameters were well estimated by curve fitting using trial and error method. Also, the fraction of stagnant zone was decreased with increasing liquid velocity, while the dimensionless mass transfer coefficient between dynamic and stagnant zones was increased, and these parameters estimated by DSM were lower than those by PFM. In dynamic zone, calculated Peclet number were increased with increasing liquid velocity and axial mixing characteristics of liquid tended to access to plug flow for the high liquid Reynolds number(about Re1>50). For the porous catalyst particle system the flow and axial mixing characteristics of liquid had nearly same tendency that for the nonporous particle(glass bead) system, while dimensionless mass transfer coefficient was lower value than that for it. In these conditions, correlations of these parameters were obtained for various operating conditions.

기-액분사반응기에서의 액체혼합특성

편무실,김태옥,이영순 명지대학교 1987 明大論文集 Vol.18 No.-

본 연구는 액체이젝터를 사용한 기-액분사반응기에서 비가역 2차액상반응계의 축방향분산계수와 축방향농도분포를 측정하여 액체혼합특성을 해석하였다. 실험결과. 낮은 액체속도에서는 반응기내의 액체혼합특성이 동일하였으나 액체속도가 증가할 수록 기포의 세분화가 이루어 지고 반응기 하부에서의 jet-mixing 으로 인하여 유동지역이 혼합지역과 분산지역으로 분리되었다. 이때 액체반응물의 축방향분산계수는 기체속도와 액체속도가 증가할 수록 감소하였으며 물-공기계에서 보다 상당히 감소되었다. 액체속도가 높은 범위에서 혼합지역은 완전혼합흐름으로 볼 수 있었고 분산지역은 소기포군이 균일한 분포를 유지하는 흐름을 나타 내었다. 또한 혼합지역의 존재로 인하여 비가역 2차반응의 전환율과 축방향농도분포는 상당히 변화하였다. 이때 제시된 액체혼합모델은 실험값과 잘 일치하였다. Liquid mixing characteristics was investigated in gas-liquid jet reactor with liquid ejector as gas distributor. Longitudinal dispersion coefficient and longitudinal concentration distribution of liquid phase were measured for irreversible second order system using saponification of ethyle acetate with sodium hydroxide. For lower liquid flow rate, experimental results showed that liquid mixing characteristics was identical in all section of reactor. As the liquid flow rate increased, however, two different flow zones(mixing zone and dispersed zone) existed with characteristics of bubble breakups and jet-mixing in lower section of reactor. Also longitudinal dispersion coefficient of liquid phase decreased with increasing gas and liquid velocity and it was fairly smaller than that for air-water system. For higher liquid flow rate, the mixing characteristics of mixing zone was regarded as almost completely mixed flow, and the dispersed zone constituted the uniform small bubble flow regime. Futhermore, it could be said that the existence of the mixing zone considerably affected to the overall conversion and longitudinal concentration distribution of liquid reactant. In this condition, the liquid mixing model proposed was well fitted to experimental datas.

방사선에 의한 결정의 결함구조에 관한 연구

呂鐵鉉,鄭元陽,片茂實,崔在時 연세대학교 자연과학연구소 1979 學術論文集 Vol.3 No.-

황산수소칼슘(KHSO_4) 포화용액으로부터 증발법으로 KHSO_4 단결정을 최적조건에서 생성시킨다. 11.25×10^6 렌트겐의 방사선(r-선)조사로 생긴 단결정의 방사선손상은 몇개의 상자성 중심을 형성한다. 그 결정들의 전자스핀공명 스펙트라를 상온에서 X-띠 전자스핀공명 분석기로 얻는다. 상자성종들의 전자스핀공명(ESR) 피-크들은 무등방성을 보이지만 g=2.003인 Gauss형 등방성 피-크가 생기는 것은 SO_3^-기 때문이다. 회전축 이외 제삼의 축과 자장간에 이루는 여러 각도에서 모든 상자성종들의 g-값들은 그종들의 무등방성 피-크들과 SO_3^-기의 등방성 피-크간의 거리로부터 구할 수 있다. 결정내에 성성된 기들의 주 g-값은 g^2을 Θ에 대하여 도시한 곡선으로부터 계산하였다. 모든 상자성종들은 대응되는 특성 주-값들로부터 확인되고 결정의 결함구조는 또한 이들 종으로 고찰된다. Single crystals of Potassium Hydrogen Sulfate(KHSO_4) have been grown from the saturated solution by the evaporation method at the optimum conditions. Radiation damages in the single crystal caused by r-irradiation of 11.25×10^6 Rentgen have given rise to several paramagnetic centers. Electron spin resonance(ESR) spectra of the crystals are obtained with the X-band EPR spectrometer at room temperature. The ESR peaks of the paramagnetic species are found to be anisotropic but an isotropic peak of Gaussian shape at g=2.0036 is assigned to SO_3 radical. The g-values of all the species at various angles between the other axis besides the rotating axes and the magnetic field are obtained from the distances between anisotropic peaks of the species and the isotropic peak of SO_3^- radical. The principal g-values of the trapped radicals are calculated from the plots of g^2 vs.Θ. All the species are identified with the corresponding principal g-values and the defect structure of the KHSO_4 crystal is also discussed in terms of the species.

氣一液噴射反應器에서의 氣體滯留量

李永淳,金泰玉,片茂實 明知大學校 産業技術硏究所 1985 産業技術硏究所論文集 Vol.4 No.-

An experimental study was performed on gas hold-up in a gas-liquid jet reactor with liquid ejector as a gas dirtributor. Gas hold-up was measured by manometric method for air-water system and irreversible order system using saponification of ethyl acetate with sodium hydroxide. The experimental results showed that the flow patterns bubble could be classified into bubble flow with characteristics of bubble coalescences and jet flow with characteristics of bubble breakups, and that gas hold-up for reaction system was larger than that for air-water system because of forming very small bubble in each flow region. In the bibble region under the condition of low liquid flow rate, one flow zone existed in the reactor and gas hold-up increased with increasing superficial gas velocity. In the jet flow region under the condition of high liquid flow rate, however, two different flow zones (mixing zone and dispersed zone) existed in the reactor and gas hold-up in the mixing zone was higher than that in the dispersed zone. In the mixing zone, which was the lower section in the reactor, heavy liquid recirculation existed and gas hold-up increased with superficial gas and liquid velocities. In the dispersed zone, which was the higher section in the reactor, small bubbles were uniformly dispersed and gas hold-up for air-water system was nearly 1.5 times that in the bubble flow region. By contrast, gas hold-up for reaction system increased with increasing liquid velocity.

산화유로퓸의 비화학양론적 조성과 전기전도성에 관한 연구

呂鐵鉉,高錫勤,元輝俊,片茂實 연세대학교 자연과학연구소 1982 學術論文集 Vol.9 No.-

EuOx로 표시되는 비화학양론적 조성식의 χ값은 대기압하에서 측정한 결과 100∼1200℃ 온도범위에서 1.0618∼1.6938이었다. 한편 EuO_1.5000+χ´의 생성엔탈피, ??H_f는 4.39㎉/mole이었다. EuOx의 전기전도도(σ)는 650∼1,100℃ 온도범위와 2×10^-1∼1-^-6atm 산소압력 범위에서 약 10^-1∼10^(-4)ohm^(-1)㎝^(-1)으로 반도성을 나타내었다. 그러나 650℃ 이하의 온도범위에서는 전기전도도 값은 불규칙성을 나타내었다. 전기전도도의 활성화에너지는 위의 실험조건에서 약 1.16∼1.22eV 범위에서 산소압력이 증가됨에 따라 커진다. 한편 전기전도도의 산소압력 의존성을 나타내는 1/n 값도 logσ를 logPo_2에 대하여 도시한 기울기에서 계산한 결과 1/5.4∼1/5.0로 700℃에서 1,100℃로 온도가 상승함에 따라 증가함을 알 수 있다. 이상의 χ값과 σ값 및 열역학적인 데이타를 사용하여 EuOx의 비화학양론적 전도성 메카니즘을 고찰하였다. The χ values of the nonstoichiometric chemical formula, EuOx, have been measured in a temperature range of 100 to 1200℃ under atmospheric pressure. The χ valuestvaried between 1.0618 and 1.6938. The enthalpy of formation of χ´ in EuO_1.5000+χ´ or ??H_f is 4.39㎉/mole under above conditions. The electical conductivities of EuO_χ(or σ) have been measured in a temperature range of 650 to 1,100℃ under oxygen pressures of 1^-6 to 2×10^-1 atm, and the σ values varied from about 10^-7 to 10^-4ohm^-1㎝^-1 within semiconductor range. However, the conductivities of the oxide below 600℃ show irregularity. The activation energies for the conduction increase with oxygen pressure from 1.16 to 1.22eV under the above conditions. The oxygen pressure dependence of the conductivity (1/n values calculated from the slopes of plots log σ vs log Po_2) increase from 1/5.4 at 700℃ to 1/5.0 at 1100℃. The nonstoichiometric conduction mechanism of the oxide is discussed with χ values, σ values and the thermodynamic data.

혼합원자가 $Sr_{1+x}Dy_{1-x}FeO_{4-y}$훼라이트계의 비화학양론과 물성 연구

여철현,이은석,편웅범,편무실,Chul Hyun Yo,Eun Seok Lee,Woong Bum Pyon,Moo Sil Pyon 대한화학회 1988 대한화학회지 Vol.32 No.1

Nonstoichiometric solid solutions of the $Sr_{1+x}Dy_{1-x}FeO_{4-y}$ system (x = 0. 00, 0. 25, 0. 50, 0. 75 and 1. 00) with layered $K-2NiF_4$ type structure were prepared at 1200$^{\circ}$C under atmospheric pressure. X-ray powder diffraction spectra show that the crystallographic phases of the samples are tetragonal within the x range. Nonstoichiometric chemical formulas have been determined by Mohr salt analysis and it shows that the amount of $Fe^{4+}$ ion or ${\tau}$ value increases with increasing x. Electrical conductivities of the samples which were measured in the temperature range of $-100{\sim}200^{\circ}$C under atmospheric air pressure are varied within the semiconductivity range of $l0^{-8}{\sim}10^{-2}(ohm^{-1}{\cdot}cm^{-1}$) and the activation energies are also varied from 0.02 to 0.08 eV. Mixed valency state of $Fe^{3+}$ and $Fe^{4+}$ in the sample of $Sr_{1.00}Dy_{1.00}FeO_{4.04}$ was identified again by Mossbauer spectrum at 200K. $K_2NiF_4$ 형 층상구조를 갖는 새로운 $Sr_{1+x}Dy_{1-x}FeO_{4-y}$ 계에서 x = 0. 00, 0. 25, 0. 50, 0. 75 및 1. 00 인 비화학양론적 화합물 고용체를 1200$^{\circ}$C 대기압하에서 제조하였다. X-선 회절분석에 의하여 결정구조학적 상들은 모든 시료의 경우 정방정계임을 알 수 있었다. Mohr 염 분석으로 비화학양론적 화학식을 결정하였고 x가 증가함에 따라 $Fe^{4+}$의 몰수(${\tau}$값)가 증가하였다. $-100{\sim}200^{\circ}$C의 온도범위에서 측정한 각 시료의 전기전도도는 $l0^{-8}{\sim}10^{-2}(ohm^{-1}{\cdot}cm^{-1}$)범위의 반도성을 보이며 활성화 에너지는 0.02∼0.08(eV)의 범위에서 변하였다. $Sr_{1.00}Dy_{1.00}FeO_{4.04}$에 대한 $Fe^{3+}$와 $Fe^{4+}$의 혼합원자가 상태를 200K에서 측정한 Mossbauer spectrum으로 재확인하였다.

산화툴륨의 비화학양론

여철현,이은석,편웅범,최재시,편무실,Chul Hyun Yo,Eun Seok Lee,Woong Bum Pyon,Jae Shi Choi,Moo Sil Pyon 대한화학회 1989 대한화학회지 Vol.33 No.1

Tm$_2O_2$의 비화학양론적 조성과 전기전도도률 $2\;{\times}\;10^{-1}\;-1\;{\tiems}\;10^{-4}$ atm의 산소압력과 700 에서 1100$^{\circ}$C의 온도에서 연구하였다. $TmO_{1.5+X}$ 에서 x값은 0.1004∼0.0110의 범위에서 변하였다. 비화학양론적 조성의 생성엔탈피는 5.40∼4.71 kcal/mole 이었으며, 전기전도도를 온도의 함수로 도시한 결과 활성화 에너지의 평균치는 1.65 eV이었다. 전기전도도의 산소분압의존성은 직선성을 보였으며, 700∼1100$^{\circ}$C의 온도범위에서 ${\sigma}{\alpha} PO{\frac{1}{2}^{/5.3}$임이 밝혀졌다. 비화학양론적 조성의 생성과 전기전도도는 3+로 이온화된 금속공위에 기인한다. The nonstoichiometry and electrical conductivities of Tm$_2O_3$ were studied in the oxygen pressure $2\;{\times}\;10^{-1}\;-1\;{\tiems}\;10^{-4}$ atm under the temperature ranges from 700 to 1100$^{\circ}$C. The x values of $TmO_{1.5+X}$ were varied in the ranges of 0.1004∼0.0110. The enthalpies of formation of the nonstoichiometric compounds were found to be 5.40-4.71 kcal/mole, and the average activation energy obtained from the plots of log conductivity vs. 1000/T was 1.65 eV. The Po$_2$ dependencies of the electrical conductivity were found to be linear and closely approaximated to ${\sigma}{\alpha} PO{\frac{1}{2}^{/5.3}$ in the temperature range 700∼1100$^{\circ}$C. The nonstoichiometry and the electrical conductivity are due to trivalent metal vacancies.