• 해양환경안전학회지
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• 제19권6호
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• pp.606-611
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• 2013

본 연구에서는 지역별 해상 기름회수능력을 설정할 목적으로 7개 항목에 대한 지역별 현황을 조사 분석하여 정규화한 결과와 계층분석과정을 이용하여 도출한 가중치를 바탕으로 권역내 각 지역별 위험도를 산출하였다. 산출된 위험도를 바탕으로 권역내 확보해야 하는 해상 기름회수능력인 $7,500k{\ell}$ 를 해당 지역의 위험도에 따라 해상 기름회수능력을 결정하여 지역별 적정 해상 기름회수능력을 제시하였다. 현행 해상 기름회수능력이 과하게 설정된 인천, 군산, 목포, 부산지역의 기름회수능력이 권역내 다른 지역으로 분산 배치되는 결과를 보였으며, 권역 중심지역의 경우 대산 $1,475k{\ell}$, 여수 $375k{\ell}$, 울산 $475k{\ell}$ 증가하는 것으로 나타났다. 해양사고의 원인적인 측면뿐만 아니라 환경 경제적인 측면까지 고려하여 제시된 지역별 해상기름회수능력 설정치는 현행 기준에 의한 설정치보다 균형적인 배치분포를 보이는 것으로 나타났다.

• 한국분무공학회지
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• 제26권2호
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• pp.96-103
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• 2021

In order to improve the overall efficiency and meet the emission regulations of boiler systems, the heat exchanging methods between inlet air and exhaust gas have been used in boiler systems, named as the waste-heat-recovery condensing boiler. Recently, to further improve the overall efficiency and to reduce the NOx emission simultaneously, the concept of the water injection into the inlet air is introduced. This study suggests the models for the optimized design parameters of water injection for waste-heat-recovery condensing boilers and performs the analysis regarding the water injection amount and droplet sizes for the optimized water injection. At first, the required amount of the water injection was estimated based on the 1^st law of thermodynamics under the assumption of complete evaporation of the injected water. The result showed that the higher the inlet air and exhaust gas temperature into the heat exchanger, the larger the amount of injected water is needed. Then two droplet evaporation models were proposed to analyze the required droplet size of water injection for full evaporation of injected water: one is the evaporation model of droplet in the inlet air and the other is that on the wall of heat exchanger. Based on the results of two models, the maximum allowable droplet sizes of water injection were estimated in various boiler operating conditions with respect to the residence time of the inlet air in the heat exchanger.

• 한국환경과학회지
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• 제13권9호
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• pp.747-757
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• 2004

The objectives of this study were to investigate the physical, chemical, and structural characteristics of the stream, especially Mugeo and Yeochon which are being changed to ecological stream by Ulsan city, and to acquire the considerations such as the planning element and plan criteria of the streams for making ecological stream system. Water quality, water quantity, vegetation, in stream structures and facilities, and land usage of the streams were investigated and the build up capabilities of ecological stream for the two streams were also analyzed. Planning elements for restoration to ecological stream included physical and biological purification methods in water quality, short term water acquire alternatives in water quantity, and vegetation recovery plan and improvement of habitation environment in ecological system, respectively. Planing elements in physical structures and facilities also included recovery of concrete levee and removal and recovery of covered channel.

• Environmental Engineering Research
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• 제25권2호
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• pp.222-229
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• 2020

Membrane assisted condenser is an innovative membrane operation that exploits the hydrophobic nature of microporous membranes to promote water vapor condensation and recovery. It can be used for water and chemicals recovery from waste gaseous streams. In this work, the testing of membrane condenser for water and ammonia recovery from synthetic streams (i.e., a saturated air stream with ammonia) simulating the plume of cooling tower is illustrated. The modeling of the process was carried out for predicting the membrane-based process performance and for identifying the minimum operating conditions for effectively recovering liquid water. The experimental data were compared with the results achieved through the simulations showing good agreement and confirming the validity of the model. It was found that the recovery of water can be increased growing the temperature difference between the plume and the membrane module (DT), the relative humidity of the plume (RH^plume) and the feed flow rate on membrane area ratio. Moreover, the concentration of NH₃ in the recovered liquid water increased with the growing DT, at increasing NH₃ concentration in the fed gaseous stream and at growing relative humidity of the feed.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2005년도 추계학술대회지
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• pp.165-170
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• 2005

본 연구는 탱크로리용 디스크식 유회수기 개발을 위한 기초 연구로 기존 유회수기 디스크와 기름의 흡착이 가능하다고 판단되는 몇 가지 재료의 디스크에 대한 유회수 차이를 실험을 통해 비교한 것이다. 실험 결과를 요약하면 다음과 같다. 모든 디스크에서 경유보다는 벙커 A유의 회수량이 높았으며, 경유에서는 디스크 소재별 유회수량이 모든 디스크에서 거의 차이가 없는 반면, 벙커 A유에서는 디스크 소재에 따라 회수 성능이 큰 차이를 보였다. 또한, 디스크 구동 시간대별 회수량은 경유의 경우, 모든 디스크 소재에서 초기 시간대부터 단위 구동 시간당 기름의 회수량 차이가 거의 없는 것으로 나타난 반면, 벙커 A유는 모든 소재에서 구동 초기시간에서 회수량이 직선적으로 증가하고 시간이 경과할수록 증가량이 완만한 경향을 보여 단위 구동 시간당 기름의 회수량이 시간에 따라 차이를 보이는 것으로 나타나 유류의 점도가 디스크 회수 성능에 영향을 미치는 것을 알 수 있었다. 또한, 벙커 A유를 대상으로 전체 회수량에서 순수 유회수량과 함수량을 비교했을 때 창문용 알미늄 소재의 디스크는 다른 재질의 디스크에 비해 기름의 회수량은 차이가 없으면서 상대적으로 물의 회수량은 매우 적게 나타나는 것으로 조사되어 함수량을 고려한 유회수 효율을 고려했을 때 가장 이상적인 결과를 보여주고 있어, 본 연구에서 목적하는 탱크로리 유회수기 디스크 소재로서 가장 유리하다는 것을 알 수 있었다.

• 해양환경안전학회지
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• 제11권2호
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• pp.103-108
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• 2005

본 연구는 탱크로리용 디스크식 유회수기 개발을 위한 기초 연구로 기존 유회수기 디스크와 기름의 흡착이 가능하다고 판단되는 몇가지 재료의 디스크에 대한 유회수 차이를 실험을 통해 비교한 것이다. 실험 결과를 요약하면 다음과 같다. 모든 디스크에서 경유보다는 벙커 A유의 회수량이 높았으며, 경유에서는 디스크 소재별 유회수량이 모든 디스크에서 거의 차이가 없는 반면, 벙커 A유에서는 디스크 소재에 따라 회수 성능이 큰 차이를 보였다. 또한, 디스크 구동 시간대별 회수량은 경유의 경우, 모든 디스크 소재에서 초기 시간대부터 단위 구동 시간당 기름의 회수량 차이가 거의 없는 것으로 나타난 반면, 벙커 A유는 모든 소재에서 구동 초기시간에서 회수량이 직선적으로 증가하고 시간이 경과할수록 증가량이 완만한 경향을 보여 단위 구동 시간당 기름의 회수량이 시간에 따라 차이를 보이는 것으로 나타나 유류의 점도가 디스크 회수성능에 영향을 미치는 것을 알 수 있었다. 또한, 벙커 A유를 대상으로 전체 회수량에서 순수 유회수량과 함수량을 비교했을 때 창문용 알미늄 소재의 디스크는 다른 재질의 디스크에 비해 기름의 회수량은 차이가 없으면서 상대적으로 물의 회수량은 매우 적게 나타나는 것으로 조사되어 함수량을 고려한 유회수 효율을 고려했을 때 가장 이상적인 결과를 보여주고 있어, 본 연구에서 목적하는 탱크로리 유회수기 디스크 소재로서 가장 유리하다는 것을 알 수 있었다.

• Environmental Engineering Research
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• 제22권3호
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• pp.277-280
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• 2017

Destablization and demulsification is a difficult task for the treatment of waste oil-in-water drilling fluid because of its "three-high" characteristics: emulsification, stabilization and oiliness. At present, China is short for effective treating technology, which restricts cleaner production in oilfield. This paper focused on technical difficulties of waste oil-in-water drilling fluid treatment in JiDong oilfield of China, adopting physical-chemical collaboration demulsification technology to deal with waste oil-in-water drilling fluid. After oil-water-solid three-phase separation, the oil recovery rate is up to 90% and the recycled oil can be reused for preparation of new drilling fluid. Meanwhile, harmless treatment of wastewater and sludge from waste oil-in-water drilling fluid after oil recycling was studied. The results showed that wastewater after treated was clean, contents of chemical oxygen demand and oil decreased from 993 mg/L and 21,800 mg/L to 89 mg/L and 3.6 mg/L respectively, which can meet the requirements of grade one of "The National Integrated Wastewater Discharge Standard" (GB8978); The pollutants in the sludge after harmless treatment are decreased below the national standard, which achieved the goal of resource recovery and harmless treatment on waste oil-in-water drilling fluid.

• Geosystem Engineering
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• 제21권6호
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• pp.335-343
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• 2018

Alkali-surfactant polymer flooding has become an important technique to improve oil recovery following the development of oil fields while the function of emulsification in enhanced oil recovery is rarely considered in the existing mathematical model for numerical simulation. In this paper, the mechanism of improving the recovery of the emulsification was analyzed in ASP flooding, and a relatively perfect mathematical model with deep filtration-theory was established, in which oil-water volume equation, saturation equation, viscosity equation, and permeability reduction equation are included. The new model is used to simulate the actual block of an oil field; the simulated results of the new model and an old model without considering the emulsification are compared with the actual well history. It is found that new model which is easy to be realized in numerical simulation has a high precision fitting, and the effect of adding oil and decreasing water is obvious. The sensitivity of emulsification was analyzed, and the results show that the water reducing funnel becomes wider and the rate of water cut decreases rapidly with the increase of emulsifying capacity, and then the rate of recovery slows down. The effect of increasing oil and decreasing water is better, and the degree of recovery increases. The emulsification of the ASP flooding is maintained at a moderate level, which corresponds to ${\Phi}=0.2$ in the new model, and the emulsification is applied to realize the general mathematical quantitative description, so as to better guide the oilfield development.

• 상하수도학회지
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• 제12권3호
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• pp.30-40
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• 1998

Increasing water consumption produced sludge problems of the water treatment plants. The objective of this study is to investigate aluminium coagulants recovery n acidic and alkaline conditions. Water treatment plant sludge produced in Pusan Metropolitan City were tested for the aluminium extraction process. Experiment samples were obtained in summer from water treatment plants of Deoksan and Myongjang. Aluminium coagulants used in these plants during the test period were polyaluminium chloride(PAC), polyaluminium sulfate organic(PSO), polyaluminium sulfate silicate(PASS). Aluminium contents of water treatment sludge were in the range of 7.2~10.9% of the total solids. The recovery percentages for aluminium and iron by acidic extraction method was evaluated to 88% and 42% respectively. Extracted mass variation for other materials such as iron, manganese, total organic carbon was observed during the extraction operation. Alkaline extraction produced more than two times amount of total organic carbon than that in the acidic extraction process.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.639-646
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• 2000

Hot air heater with light oil combustion is the most common heater for greenhouse heating in the winter season in Korea. However, since the heat efficiency of the heater is about 80%, considerable unused heat in the form of exhaust gas heat discharges to atmosphere. In order to capture this exhaust gas heat a heat recovery system for plant bed heating in the greenhouse was built and tested in the hot air heating system of greenhouse. The system consists of a heat exchanger made of copper pipes, ${\phi}\;12.7{\times}0.7t$ located inside the rectangular column of $330{\times}330{\times}900mm$, a water circulation pump, circulation plastic pipe and a water tame The total heat exchanger area is $1.5m^2$, calculated considering the heat exchange amount between flue gas and water circulated in the copper pipes. The system was attached to the exhaust gas path. The heat recovery system was designed as to even recapture the latent heat of flue gas when exposing to low temperature water in the heat exchanger. According to performance test it can recover 45,200 to 51,000kJ/hr depending on the water circulation rates of 330 to $690{\ell}$/hr from the waste heat discharged. The exhaust gas temperature left from the heat exchanger dropped to $100^{circ}C$ from $270^{circ}C$ by the heat exchange between the water and the flue gas, while water gained the difference and temperature increased to $38^{circ}C$ from $21^{circ}C$ at the water flow rate of $690{\ell}$/hr. And, the condensed water amount varies from 16 to $43m{\ell}$ at the same water circulation rates. This condensing heat recovery system can reduce boiler fuel consumption amount in a day by 34% according to the feasibility study of the actual mimitomato greenhouse. No combustion load was observed in the hot air heater.