流動層內 總括傳熱係數에 關한 硏究

蔡萬秉 서울산업대학교 1977 논문집 Vol.10 No.1

溫度測定에 依한 反應速度의 解析 : The hydrolysis of acetic anhydride in dilute aqueous solution

蔡萬秉 서울産業大學校 1976 논문집 Vol.9 No.1

Generally, the determination of liquid phase reaction rate been carried out by measuring the concentration in discrete time intervals. This method, however, requires a rapid concentration measurement not to disturb the continuation of the reaction. In some instances, continuous measurement of concentration are possible such as the measurement of PH, electrical conductivity, colorimetry, etc, though these continuous methods are not generally applicable. In this investigation the continuous measurement of temperature is applied for the determination of the reaction rate of the hydrolysis of acetic anhydride in dilute aqueous solution. The temperature-method may be widely used when the reaction heat can give a resonable temperature change to the reaction system since system since the method is simple and give a considerable degree of accuracy. In the present experiment the reaction has been started by pouring acetic anhydride into the reaction vessel containing water after the temperature of the vessel immersed in a constant temperature bath reached that the bath. The temperature difference between the vessel and the bath is continuously recorded until the difference becomes negligible. The initial anhydride concentration is about 0.04 mole ?? at 20°∼50℃. By analyzing the experimental results, it can be concluded that the reaction is apparently the first order irreversible one with the activation energy of 11.62Kcal. ?? until the degree of the anhydride conversion becomes 90 percent. The result is also found to have a sufficient degree of accuracy by comparing the previous works of this subject.

수용액에 있어서 염화암모니움 유도체에 대한 겉보기 및 분몰랄 부피에 관한 연구

蔡萬秉 釜山工業學校 1970 論文集 Vol.10 No.-

염화암모니움 유도체, A-NH₃?Cl(A=NH₂, -OH, -NH₃Cl)의 겉보기몰랄부피(Apparent molal lume; Φ?) 및 부분 몰랄부피(Partial molal volume; V?)를 30℃와 50℃에서 측정하였다. 0.01M에서 0.2M에 이르는 여러 농도의 용액에 대하여 부력법을 적용하고 용매와 용액의 밀?차를 소수점 이하 5위까지 구하였다. 실험결과 cation의 charge effect가 hydrophobic effect보? 우세하고 limiting slope, S?,는 실험온도에 관계없이 이론치와 거의 일치하였다. A=H,R,Φ일때에 대한 다른 연구자들의 data와 비교하여 볼 때 cation의 charge effect는 ?kali 금속이온과 alkyl cation의 중간이었다. cation의 표면전하는 질소 또는 산소원자의 lone ?air 때문에 약화되었다고 생각된다. The apparent molal volumes(Φ?) and partial molal volumes(V。) of the derivatives of ammonium chloride A-NH?Cl, where A is -NH₂, -OH, -NH?Cl, C?H?-respectively, were determined by means of float method down to fifth decimal places in concentration range 0.2M>C>0.01 M at 30°and 50℃. The data for Φ? and V。obtained in this work have been compared with those of other electolytes particulary with A=H, R and R?N. The experimental result was interpreted in terms of charge effect of cations and limiting slope Sv, and also specific partial molal volumes b?. It has been observed that the charge effect of cations is stronger than corresponding hydrophobic effect, and showed as the borderline case betweon alkali metal ion and alkyl cations. Slightly weak surface charge of cations uch as NH₂-NH³?, HO-NH₃? observed in this experiment is presumbly due to the unshared electron pair of nitrogen and oxygn atoms.

銅粒子에 對한 充塡層電極의 實驗的 硏究

蔡萬秉 서울産業大學校 1982 논문집 Vol.17 No.1

Most studies of the packed bed electrodes have so far emphasized the theoretical analysis of the electrodes which were assumed to operated in the state of either activation polarization or limiting current alone. A practical packed bed which is partly activation controlled and partly mass-transfer controlled has not been fully in investigated. The purpose of this paper is to observe, via experimental means, the effects of the flow rate of electrolyte and the effects of current on the potential and current distribution of the electrode. Hopefully, the data would help enhance our understanding of a real reactor of engineering interest.

排水液中 金屬 Ion의 除去를 위한 充塡床電極의 機械論的 Model

蔡萬秉 서울産業大學校 1980 논문집 Vol.13 No.1

A mathematical model of a porous cathode cell is derived in terms of fundamental kinetic parameters for the deposition of metals from dilute solutions. The model is used to design a pilot plant to treat electroplating waste effluents. Experimental results show that the plant can reduce the concentration of copper, nickel, chromium and zinc by at least 90% at acceptable current efficiencies.

단일노즐을 사용한 슬러리 기포탑에서의 상 체류량

蔡萬秉,李永淳 서울産業大學校 1988 논문집 Vol.27 No.1

Phase hold-up was investigated in a slurry bubble column with a single nozzle as a gas diatributor. Experimental results showed that mean gas hold-up was larger than that for air-water system and it was not influenced by solid concentratiion, slurry velocity and solid particle size. By contrast, liquid hold-up decreased with increasing gas velocity and solid concentration,and it was not influenced by slurry velocity and solid particle size. Futhermore, variations of phase of phase hold-up for slurry system with a single nozzle was different from that for general three phase system.

電氣化學 流動反應器內에서 單一層 充塡床 電極의 硏究

蔡萬秉 서울産業大學校 1983 논문집 Vol.18 No.1

Experimental measurements are reported for a packed bed electrode consisting of a single planar layer of uniform copper plated spheres located between platinum anodes and restrained by two plane porous PVC diaphragms. Two mass transfer copper sulphate, were investigated and the electrochemical mass transfer data in the range 39<NRe<520 correlated by the equation NShNSc?=0.83NRe??? the Reynolds and Sherwood numbers being defined in terms of particle diameter. Variations of electrode potential throughout the bed were found to be small enough to ensure reaction selectivity in the system.

솔-젤공정에 의한 한외알루미나 여과막의 기공보정에 관한 연구

채만병,조원준,정은정,이진휘,서동호 서울産業大學校 1996 논문집 Vol.44 No.1

서로 다른 입자 크기의 3층 구조를 갖는 튜브 형태의 한외 알루미나 분리막은, 일반적으로 제조공정중 분리층에 결손부분이 발생하기 때문에 낮은 선택도 및 제거율을 보인다. 이와같은 결손부분을 보정하기위하여 습도조절에 의한 선택적 적심(alternative wetting by controlled humidity)을 한 수 colloidal silical 솔을 적용하여 처리하고 특성을 평가 하였다. Sealing처리한 분리막에 대한 누수여부를 평가하기 위하여 3가지의 염료로 조사하였고, 보정전분리막과 보정후분리막에 대한 SEM, 액체으 투고도, 선택도 및 P.E.G./물 혼합물의 제거율을 측정하였다. P.E.G 2000, 12000 및 35000에 대한 제거율은 각각 약 0.6, 18 및 17% 향상된 결과를 보였으나 colloidal silica 솔의 deposition에 기인하여 투과율의 감소는 77%였다. 이상의 결과에서 보면 습도조절에 의한 선택적 적심법은 비록 deposition에 의한 문제점을 내포하고 있으나 액체분리를 위한 알루미나 한외여과막의 보정에 효과적인 방법이다. The 3-layer type alumina membrane consisting of different pore size shows the decreased selectivity and rejection because of cracks in the separation layer generally occurred during the manufacturing process. To modify these cracks, the colloidal sol is applied by sol-gel process after treating by alternative wetting method using controlled humidity(Alternative Wetting Method by controlled humidity) and evaluated the characteristics. For the evaluation of the leakage for the sealed membrane, the sealed membranes were tested by 3 kinds of dyes. For the comparing of native and modified membranes, the modified membranes for the cracks treated by Alternative Wetting Method by controlled humidity were also tested by SEM, permeability by liquid equipment, selectivity and rejection of the P.E.G./water mixtures. The results showed that the rejections were increased ca. 0.6, 18 and 17 % for the P.E.G. polyethyleneglycol 2000, 12000 and 35000 individually. The permeabilities are decreased, however, 77% for the pure water caused by deposition of colloidal silica sol after caulking. In conclusion, the Alternative Wetting Method by humidity control had the effect for the modification of ultrafiltration alumina membrane for separation of liquids and gases, though having problem of deposition.

수용액에 있어서 염화암모니움 유도체에 대한 겉보기 및 분몰랄 부피에 관한 연구

채만병 釜山工業大學校 1970 論文集 Vol.10 No.-

원형에서부터 전주각의 분리에 관한 연구

채만병 釜山工業大學校 1975 論文集 Vol.16 No.-