• 한국가스학회:학술대회논문집
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• no.5
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• pp.183-188
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• 2002

• Food Science and Industry
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• v.43 no.3
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• pp.22-31
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• 2010

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.192.2-193
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• 2003

기존 저온저장고의 가습방법을 개선하고 아울러 음이온을 농산물의 선도 유지에 이용하고자 아쿠아이온발생시스템의 설계, 제작이 레너드효과를 응용하여 이루어졌다. 시스템의 아쿠아음이온의 발생량은 42,965음이온/cc, 입자크기는 $10^3$$\mu\textrm{m}$ 이하, 가습속도는 0.13$\ell$/h이었으며 85% 이상의 고습도 조건에서도 결로가 발생하지 않는 상태로 가습이 가능하였다. 아쿠아이온 클러스터에 의해 저장고는 90% 이상의 균일한 고습도와 정온을 유지할 수가 있었다. 아쿠아이온시스템의 경우 유해가스와 분진등을 흡착, 제거하여 저장고 내를 청정하게 유지시키는 기능이 있는데, 에틸렌가스 제거 효과는 초기 농도 50ppm에서 5분후에 50% 이상이 제거되고 2시간 후에는 3ppm 이하로 제거되었다. 아쿠아이온발생시스템이 브로콜리, 잎상추, 애호박 등의 보관에 적용되었다. 아쿠아이온발생시스템이 부착된 저장고($0^{\circ}C$)에서 20일동안 보관한 경우 기존 저장고에 보관한 경우에 비하여 감모율, 부패율 및 관능적 품질에 있어서 유의적으로 우수한 차이를 나타내었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.1013-1019
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• 2011

In this paper, simulation works for a multi-stage cascade refrigeration cycle using propane, ethylene and methane as refrigerants have been performed for the liquefaction of natural gas using Peng-Robinson equation of state built-in PRO/II with PROVISION release 8.3. The natural gas feed compositions were supplied from Korea Gas Corporation and the flow rate was assumed to be 5.0 million tons per annual. Supply temperature for propane refrigerant was fixed as $-40^{\circ}C$, that for ethylene refrigerant as $-95^{\circ}C$, and that for methane refrigerant as $-155^{\circ}C$. For the multi-stage refrigeration cycle, three-stage refrigeration was assumed for propane refrigeration cycle, two-stage refrigeration for ethylene refrigeration cycle and three-stage refrigeration for methane refrigeration cycle. Natural gas was finally cooled and liquefied to $-162^{\circ}C$ by Joule-Thomson expansion. Conclusively, 91.71% by mole of the natural gas liquefaction ratio was obtained through a cascade refrigeration cycle and Joule-Thomson expansion and 0.433 kW of compression power was consumed for the liquefaction of 1.0 kg/hr of natural gas.

• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.768-775
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• 2010

Adsorption dynamics of ethane/ethylene mixture gas and desorption dynamics during the displacement desorption with propane as a desorbent in the column filled with faujasite adsorbent were investigated experimentally and theoretically. The simulation that adopted heat and mass balance and an ideal adsorbed solution theory (IAST) for the multicomponent adsorption equilibrium well predicted the experimental breakthrough curves of the adsorption and desorption. At the adsorption breakthrough experiments, roll-ups of ethane increased as the adsorption pressure increased and the adsorption temperature decreased. During the displacement desorption with propane in the column saturated with ethane/ethylene mixture gas, almost 100% of ethylene was obtained for a certain time interval. The adsorption strength of the desorbent greatly affected the adsorption and re-adsorption dynamics of ethylene. The re-adsorption capacity for ethylene has been greatly reduced when iso-propane, which is stronger desorbent than propane, was used as desorbent. It was found from the simulation that the performance of the displacement desorption process would be superior when the ratio of ${(q_s{\times}b)}_{C_2H_4}/{(q_s{\times}b)}_{C_3H_s}$ was 0.83, that is, the adsorption strengths of ethylene and the desorbent were similar.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2005.11a
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• pp.325-330
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• 2005

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.552-558
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• 2011

In this paper, simulation works for a cascade refrigeration cycle using propane, ethylene and methane as a refrigerant have been performed for the liquefaction of natural gas using Peng-Robinson equation of state built-in PRO/II with PROVISION release 8.3. The natural gas feed compositions were supplied from Korea Gas Corporation and the flow rate was assumed to be 5.0 million tons per annual. Supply temperature for propane refrigerant was fixed as $-40^{\circ}C$, that for ethylene refrigerant as $-95^{\circ}C$, and that for methane refrigerant as $-155^{\circ}C$. Natural gas was finally cooled and liquefied to $-162^{\circ}C$ by Joule-Thomson expansion. Conclusively, 91.64% by mole of the natural gas liquefaction ratio was obtained through a cascade refrigeration cycle and Joule-Thomson expansion.

• Horticultural Science & Technology
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• v.19 no.2
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• pp.174-178
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• 2001

Absorption potential of oak charcoal was estimated using simulated static and dynamic systems to establish a model for practical application of the charcoal in modified atmosphere (MA) packaging and during the storage of 'Fuji' apples. Practical MA packaging was performed using $60{\mu}m$ PE film zipper bags in which five apples were placed. Absorption potential of oak charcoal was $58.4{\mu}L/100g$ charcoal for ethylene and 583 mg/100 g charcoal for carbon dioxide. Effects of enclosing a 100 g-charcoal packet inside a MA package seemed not to last long enough for quality maintenance of 'Fuji' apples stored at $0^{\circ}C$ for three months. During extended storage, ethylene and $CO_2$ levels were not significantly reduced by charcoal treatment. Nevertheless, absorption of carbon dioxide appeared to alleviate the incidence of $CO_2$-related internal browning disorder. Modelling study of practical storage and marketing procedure indicates that 0.19 kg charcoal/day is required to offset $CO_2$ production from 15 kg of apples at $0^{\circ}C$. The amount of charcoal should be increased to 3.10 kg/day if ethylene is a target gas. From the practical point of view, the results suggest that charcoal could be used only for small unit packages for a short period.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.3
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• pp.257-262
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• 2011

A low capacity generator converted to high capacity of 40m3 is designed and developed in order to use the hydroxy gas in the steel manufacturing process. For efficient design, it is increased from 8 electrode tubes to 10 electrode tubes as well as expanding the diameter of cell integument up to two times bigger, which can increase the amount of hydrogen occurrence per a cell significantly. In addition, circulating pump and pipe, heat exchanger of affiliated SUS material have been used in the circulation of electrolysis catalyst, and circulating cooling section and piping design are also developed. The flame trap is designed into all-in-one suitable check valve in the flow rate of 28-35m3/h and its application is possibly applied in work operation. It is found that the efficiency of generator developed is enhanced substantially up to 84%. It is expected that the application in this field can be expanded significantly by this study.

• Analytical Science and Technology
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• v.25 no.6
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• pp.382-387
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• 2012

Ethylene oxide ($C_2H_4O$, EtO) is used as a raw material for the production of ethylene glycol and other industrially important material such as ethanolamines and also used as a disinfecting agent. It is applied for gas-phase sterilization of thermally sensitive medical equipment, and for processing of storage facilities as a mixture with fluorinated hydrocarbon. In this perspective, accurate determination of the mole fractions of components in the liquefied gas mixture is required for the quality control and safety of production and use. Each component of the liquefied gas mixture has different chemical and physical properties such as vapor pressure and boiling point. Therefore, we can suppose that analytical results can be different according to the introduction method for the gas phase of upper layer, or for the liquid phase of lower layer in gas cylinder. In this study, we designed a new on-line sample injection device for the liquefied gas mixture in liquid or gas state, and applied to the analysis of liquefied gas mixture of ethylene oxide and fluorinated hydrocarbons by GC/AED (gas chromatograph-atomic emission detector). We studied performance of AED, and effect of sample introduction and selected wavelength to the accuracy and repeatability of analytical results.