• Proceedings of the Korean Radioactive Waste Society Conference
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• 2009.11a
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• pp.345-345
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• 2009

전기화학적 환원 기술을 이용한 고온 용융염 전해환원의 결과 생산되는 금속전환체는 다공성 특성에 의해 전해환원의 매질인 용융염을 함유하게 된다. 전해환원과 후속 전기화학 공정인 전해정련의 전해질은 각각 LiCl과 LiCl-KCl 공융염으로 상이하기 때문에 이렇게 금속전환체에 포함된 LiCl 염이 동반되어 전해정련 공정에 도입될 경우 전해정련 공정의 공융염 조성을 어긋나게 한다. 이에 따라 금속전환체의 잔류염은 효과적으로 제거되어야 하며 공정으로 감압 증류에 의한 잔류염 제거 공정이 고려되고 있다. LiCl은 증기압이 비교적 낮기 때문에 감압의 고온 조건이 공정에 필요하다. 그러나 상평형도 분석 결과 전해환원 공정에서 산화물을 담아 음극으로 사용되어 환원된 금속전환체와 함께 도입되는 SUS 재질의 바스켓과 사용후핵연료 금속전환체의 주된 원소인 우라늄과는 공융할 수 있기 때문에 LiCl 증발 온도는 $720^{\circ}C$ 이하로 유지되어야 한다. 이와 같은 조건에서 LiCl 증발 속도를 높이기 위해서는 감압 조건이 필수적이다. 본 연구에서는 감압조건에서 LiCl 휘발 실험을 위해 폐쇄형 및 개방형 반응기를 제작하여 압력 조건 및 Ar 유량 등에 따른 LiCl 휘발율을 측정하였다. 증발된 LiCl은 일정 감압 조건에서 분말형으로 냉각부위에 회수 될 수 있었으나 완전 진공 조건에서는 결정형으로 냉각 부위에 응축되는 것으로 확인 되었으며 일정 진공 조건에서는 Ar 유량에 따라 증발량이 의존하지 않는 것으로 나타났다. 연구 결과 증발염의 취급 빛 이송을 위해 분말형 회수를 목표로 설정할 수 있었으며 공정조건으로 일정 수준의 감압 조건을 제시하였다. 이 후 후속 연구로 장치의 대형화 및 증발 속도 향상을 위한 추가적인 연구가 계획되어 있으며 연구 결과에 기초하여 공학규모 파이로 공정 시설인 PRIDE에 도입될 장치의 기초 설계 자료를 생산할 예정이다.

• Journal of Energy Engineering
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• v.2 no.1
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• pp.123-132
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• 1993

This work is focussed on the reduction of ethanol separation energy from alcohol fermented broth and categorized into the development of a computer program for the design of the pressurized/depressurized distillation process which has been regarded as one of the energy-reducing models for the conventional distillation process, the optimization of operating conditions of distillation towers by means of the developed program, and the evaluation of the total annual energy cost of pressurized/depressurized distillation columns compared with that of the conventional single distillation columns. The operating pressures are, in case of pressurized/depressurized distillation, 3103/760 mmHg, 3103/450 mmHg, 3103/160 mmHg, and in case of conventional distillation, 760 mmHg. The optimum reflex rations which the sum of the annual energy cost and the annual fixed cost for each process becomes minimum are 3.7475/2.9111 for the operating pressures of 3103/760 mmHg, 3.814/2.9712 for 3103/450 mmHg, 3.0783/2.2400 for 3103/150 mmHg, and 3.8544 for the atmospheric operating pressure. And the annual energy cost of pressurized/depressurized distillation process for the above-mentioned operating pressures is distributed between 42% and 47% of that of conventional distillation process.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.83-89
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• 2003

A temperature- and pressure-reducing process is utilized to handle the spent fuel assembly in the post-irradiation examination facility. This process includes three separated unit processes. First one is the decontamination process to clean the spent fuel assembly casks. The second process is the temperature-reducing process to reduce the temperature elevated by decay process in the spent fuel assembly. The third process is the filtration process to remove insoluble particles existed in the casks using filters. Up-to-date technologies as well as practical theories related to the temperature- and pressure-reducing process is reviewed in this report. The test-operation process for various tests and the test results of the temperature- and pressure-reducing process for J-44 and K-23 spent fuel assemblies are also described in detail. This report must be effectively used for the normal operation of the facility with the awareness of unprecedented problems which could occur by continuing operation of the PIE facility.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.11a
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• pp.115-115
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• 2000

제지 공정의 효율적인 운영을 위해 공정변수를 확인하는 작업은 매우 중요하다. 탈수 특성 평가를 위하여 SR(Shopper- RegIer)과 CSF(Canadian Standard Freeness tester) 그리고 원형 수초지기 동의 비난류 상태의 자연탈수 특성 평가 장치와 동적 조건의 감압식 탈수성 분석기 퉁이 도입되어 있으나 제지 공정에 보다 더 근접한 탈수, 보류 특성을 평가 하기 위하여 특히 wet-end 첨가제들의 효능을 보다 정확히 분석할 수 있도록 난휴 발생과 감압 탈수 둥을 유도한 탈수 특성 평가 장치 개발의 필요성이 커지고 있다Il, 2) 이미 소개된 RDA-HSF

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.1
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• pp.52-61
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• 2016

To inject huge amount of $CO_2$ for CCS application, high pressure pipeline transport is accompanied. Rapid depressurization of $CO_2$ pipeline is required in case of transient processes such as accident and maintenance. In this study, numerical analysis on the depressurization of high pressure $CO_2$ pipeline was carried out. The prediction capability of the numerical model was evaluated by comparing the benchmark experiments. The numerical models well predicted the liquid-vapor two-phase depressurization. On the other hands, there were some limitations in predicting the temperature behavior during the supercritical, liquid phase and gaseous phase expansions.

• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.1
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• pp.34-40
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• 1985

An investigation has been made on the growth phenomena of epitaxial layer and polysilicon from SiH2 Cl2 in H2 and the etch phenomena of them from HCI in H2, at the system pressures of 1.0 atm (atmospheric process) and 0.1 attn (reduced pressure process). From the experimental equations for the growth rates and etch rates. the relevant process conditions for the selective epitaxy are predicted for the case of using mixtures of SiH2Cl2 and HCI in H2. As a result, it is found that selective epitaxial growth region exists in the concentration range investigated for the reduced pressure process but it does not for the atmospheric Process. This is due to the differences in the growth rates and etch rates at atmospheric and reduced pressure.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.5
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• pp.41-45
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• 1984

The production of high-quality epitaxial layers almost always involves an etching step of silicon substrates with HCl gas prior to epitaxy, In this work, an investigation has been made on the etch rate and the etch-pit formation as a function of HCl gas concentration and etch temperature at atmospheric pressure (1 atm.) and reduced pressure (0.1 atom.). As a result, it is found that the etch rate is proportional to the square of the HCI gas concentration (XHC12) and the apparent ativation energy is between 0 and 111 Kcal/mole for both ammospheric and reduced pressure operation. From these results, it is expected that the HCI etching of silicon in reduced pressure operation proceeds, as in atmospheric operation, via the reaction ; Si + 2HCl ↔ SiCl2 + H2.

• Food Science and Preservation
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• v.16 no.6
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• pp.869-874
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• 2009

We aimed to develop a new salting method to improve the quality of Dombaegi. The changes in quality characteristics of Dombaegi during salting using different salting methods (dry and brine salting) and salting pressures (vacuum and atmospheric pressure) were investigated. Moisture content was highest in Dombaegi prepared by brine salting under atmospheric pressure. Salt content was greater when salting was conducted under vacuum compared with atmospheric pressure. Water-holding capacity and water activity were higher under vacuum pressure than at atmospheric pressure and after dry salting compared with brine salting. Color change varied greatly when Dombaegi samples salted at atmospheric pressure and under vacuum were compared, and was affected more by dry salting than brine salting. Springiness was higher after salting under vacuum, and in dry conditions. The results showed that dry salting under vacuum provided better quality characteristics compared with other methods. Therefore, salting under vacuum was the optimal salting process.

• Culinary science and hospitality research
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• v.20 no.3
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• pp.13-21
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• 2014

We developed a method for improving the antioxidant activities of Citrus extracts through cyclic low pressure drying(CLPD) and a high hydrostatic pressure extraction (HPE) process. Citrus fruits were prepared for water extraction at $60^{\circ}C$ and 300 MPa for 5 min (high hydrostatic pressure extraction, HPE5) and 15 min (high hydrostatic pressure extraction, HPE15) after cyclic low pressure drying method. Extraction yields obtained by cyclic low pressure drying and high hydrostatic pressure extraction process were 20.41, 23.47, and 28.19%, respectively. Total polyphenol contents were increased by combined process. Generally, CLPD and HPE resulted in higher yields than the conventional extraction process. Further, HPE15 showed 48.21% DPPH radical scavenging activity (EDA, %) at $1,000{\mu}g/mL$. In general, antioxidant activities of Citrus increased by CLPD and HPE. Therfore, CLPD and HPE of Citrus resulted in higher antioxidant activity than conventional water extraction.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1997.11a
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• pp.7-14
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• 1997

화학공장은 열 없이는 돌아갈 수 없으며 가열로는 공장운전에 있어서 열의 중요한 원천이 된다. 대부분의 공정에 설치되어 있으며, 원유정제공정, 감압증류공정, 탈황공정, 그리고 접촉개질공정 등에서 가열로는 열을 공급하는 주요한 장치이다. 본 연구는 멀티미디어 기술 및 화학 공정 지식을 이용하여 가열로 운전 기술 교육을 위한 새로운 훈련 시스템을 개발한 것이다 이 시스템을 실제 공정에 사용한 결과, 조업자를 교육시키는데 유용하며 특히 운전시 발생할 수 있는 사고를 예방함에 있어 큰 효과가 있음이 증명되었다. (중략)