슬러지 건조로 설계를 위한 3차원 CFD 모델 개발

전영남,송형운,백원석 조선대학교 환경공해연구소 2006 環境公害硏究 Vol.19 No.1

The purpose of this study lies primarily on the development of the sludge dryer for the dehydrated sludge of moisture content with 70~80 wt.%. The sludge dryer was modified from the rotary kiln type dryer. A numerical simulation on the thermal flow performance in the sludge dryer was carried out to investigate the design factor and operating conditions, Parametric screening studies were carried out for variations of the following variables: dryer shape, injection length of combustion air, velocity of combustion air, temperature of combustion air. By predictive results, the sludge dryer has a good drying characteristics so that input sludge increased with retention time by recirculation zone of high temperature combustion gas in the bed of sludge dryer. Parametric screening studies have been conducted to study optimal dryer shape and operating condition.

저 발열량 페유 소각기 개발에 관한 실험적 연구

전영남,백원석,송형운,유경석,김성천 조선대학교 환경공해연구소 2004 環境公害硏究 Vol.18 No.-

The advanced waste oil incinerator is suggested that has heat recirculation region in the combustor to burn out the waste oil completely in high temperature zone and heat recuperator in the left side of combustion cavity which plays a role of the flame stabilization of main burner flame by heat recovery of exhaust gas to incinerate waste oil contained water. In order to investigate a simultaneously incineration efficiency of the vessel waste oil contained the hazardous waste which occurs from the vessel and the sea outflow waste oil experiments have been carried out using the emulsion fuel mixed the water and bunker fuel oil C and the blend mixed the light oil and the waste surrogate material (acetonitrile:CH_(3)CN). The results of experiments showed that the waste oil incinerator developed in this study was excellent for the incineration efficiency of waste oil at an air ratio of 1.46 and DRE (destruction and removal efficiencies) of CH_(3)CN was 99.9996% ("5 nines"). And optimum operating conditions for the secondary air flow rate of internal mix burner, preheating temperature and injection point of shipboard waste oil contained acetonitrile were suggested.

보일러내의 Nox 저감 3차원 수치모델

전영남,송형운,김정열,유경석 조선대학교 환경공해연구소 2004 環境公害硏究 Vol.18 No.-

This paper presents numerical simulation of the flow and combustion process in a pulverized coal fired utility boiler of 350MWe with 24 swirl burners installed at the boiler front wall. The numerical model is applied to an Eulerian-Eulerian model of coal combusiton and NOx formation, It uses Eulerian, time averaged, conservation equations for all the dependent variables. Especial attention is paid to the accuracy of the representation of the several physical submodels of the coal particle, such as particle drying, volatilization or heterogenous combustion. In this systematic investigation, burning characteristics of pulverized coal were calcuated temperature, NOx, unburned carbon content of char and exhaust gas composition in utility boiler. Parametric screening studies have been achieved for the suggestion of improvement operating conditions for reducing NOx and unburned carbon content.

덤프 소각기에서 CCI₄/C₃H_(8)분해 특성에 관한 연구

전영남,채종성,송형운,김미환 조선대학교 환경공해연구소 2001 環境公害硏究 Vol.17 No.1

A major source of the hazardous waste generated is from chemical industries producing plastics, herbicides, pesticides and chlorinated solvents. All of these processes produce a class of hazardous waste termed the chlorinated hydrocarbons(CHCs), either directly or from undesirable side reactions. Generally, hazardous waste is physical characteristics of difficult destruction at high temperature. We investigated the destruction characteristics of hazardous waste through incineration. A nonequilibrium combustion model was used to describe the effect of the chemical kinetics due to the flame inhibition characteristics of CCU which was used as the surrogate of hazardous waste. In this study, the numerical simulation data for 3-dimensional dump combustor shows a quantitative good agreement with experimental data. Also dump incinerator shows high destruction efficience of CCl_(4). And parametric screening studies was carried out through numerical simulation with changed CCl_(4)/C_(3)H_(8) ratio, waste injection velocity and waste equilibrium ratio.

3차원 수치모델링을 통한 스토커식 도시페기물 소각로의 연소특성 및 운전성능 최적화

전영남,송형운,김미환,채종성 조선대학교 환경공해연구소 2001 環境公害硏究 Vol.17 No.2

3차원 수치모델링을 통한 스토커식 도시폐기물 소각로의 연소특성 및 운전성능 최적화

전영남,송형운,김미환,채종성 조선대학교 환경연구소 2001 環境硏究 Vol.17 No.2

This study has developed the 3-dimensional numerical model, and applied for the investigation of combustion characteristics and optimized operating conditions in MSW incinerator, in Gwangju. The model developed in this study has verified through the correspondence between the predicted and the measured temperature in combustion chamber which is operating as reference condition. By predictive results. The Sangmoo incinerator has a good characteristics of combustion and low emission, even though after burning zone produces incomplete products by which primary air is introduced not enough. Parametric screening studies have been achieved for the suggestion of optimal operating conditions. For the optimum of combustion characteristics, operating conditions should be changed with varying the property of wastes.

덤프 소각기에서 CCI_4/C_3H_8 분해 특성에 관한 연구

전영남,채종성,송형운,김미환 조선대학교 환경연구소 2001 環境硏究 Vol.17 No.1

A major source of the hazardous waste generated is from chemical industries producing plastics, herbicides, pesticides and chlorinated solvents. All of these process produce a class of hazardous waste termed the chlorinated hydrocarbons(CHCs), either directly or from undesirable side reactions. Generally, hazardous waste is physical characteristics of difficult destruction at high temperature. We investigated the destruction characteristics of hazardous waste through incineration. A nonequilibrium combustion model was used to describe the effect of the chemical kinetics due to the flame inhibition characteristics of CCl_4 which was used as the surrogate of hazardous waste. In this study, the numerical simulation data for 3-dimensional dump combustor shows a quantitative good agreement with experimental data. Also dump incinerator shows high destruction efficience of CCl_4. And parametric screening studies was carried out through numerical simulation with changed CCl_4/C_3H_8 ratio, waste injection velocity and waste equilibrium ratio.

뇌동맥류성 지주막하 출혈 후 지연허혈신경결함에 대한 평가에 있어서의 Acetazolamide단일광자방출전산화 단층촬영술의 역할

김형중,김은영,하윤,윤승환,박형천,박현선 The Korean Neurosurgical Society 2004 Journal of Korean neurosurgical society Vol.35 No.2

인천지역 TDI 노출 작업자에서 직업성천식 유병율

김형렬,김철우,홍윤철,전형준,김치년,김현수,이지나,신주연,고동희,노재훈 大韓産業醫學會 2004 대한직업환경의학회지 Vol.16 No.2

목적 : TDI는 직업성천식을 일으키는 대표적인 물질로 알려져 있다. 과거 TDI에 노출된 작업자들의 천식 발생률을 5~6%가량 보고하였고, 국내에서도 2-20%에 이르는 유병율을 보고한바 있다. 작업환경이 많이 개선되고, 노출량이 감소된 최근에도 TDI에 의한 직업성천식에 대한 보고가 많이 이루어지고 있어, 이에 대한 적극적인 조사와 진단과정을 통해 유병율을 구하고 질병발생의 변화양상을 파악해 보고자 하였다. 방법 : 인천지역에서 특수건강진단을 수행하는 2개 기관의 TDI 노출 근로자 400여명 중, 사업장의 규모가 50인 이상이며 사업주가 연구진행을 허락한 사업장에서 근무하는 근로자 중 직접적으로 TDI에 노출되는 작업에 종사하는 근로자 170명을 연구대상으로 하였다. 이들에 대해 설문지와 산업의학의사의 면담을 통한 작업관련성 평가를 근거로 정밀대상자를 선정하고 이들에 대해 메타콜린 유발시험, TDI 유발시험 등을 수행하여 직업성천식을 확인하였다. 결과 : 설문조사 결과 11명이 직업과 관련하여 천식증상을 보이는 것으로 나타났고(6.9%), 이중 7명에서 메타콜린 유발검사 양성소견을 보였다. TDI에 의한 특이유발시험 결과 1명에서 양성반응이 나타나, 이 집단에서 TDI에 의한 직업성천식의 유병율은 0.58%였다. 결론 : 과거 국내연구에서 TDI에 의한 직업성천식의 유병율이 2~20%에 이르렀던 데 비해, 본 연구에서는 0.58%로 나타났다. 이는 국외 논문에서도 나타나는 경향으로 작업장 노출량 감소로 점차 발생률이 감소하는 양상을 보이고 있다. 그러나 이미 증상이 나타난 근로자들이 부서를 옮기거나, 직장을 그만둠으로 인해 그 유병율이 과소평가되었을 가능성도 있다고 판단된다. Objecdives: This study was carried out to estimate the prevalence of isocyanate-induced occupational asthma in toluene diisocyanate (TDI) exposed workers. Methods: We examined 170 workers who had been directly exposed to TDI through a medical questionnaire, physical examination, and pulmonary function test. Based on screening examination, workers with suspected occupational asthma were selected for further evaluation such as methacholine and TDI challenge tests. Results: Eleven (6.9%) among 170 workers complained of symptoms of occupational asthma. and 7 among these 11 symptomatic workers showed positive responses to the methacholine challenge test (4.1 %). One spray painter was confirmed as having the TDI induced occupational asthma following a positive response to TDI challenge test. Conclusions: The prevalence of TDI-induced asthma was at 0.58% was lower than that for former studies (2-20%). Improved workplace environment, lower level of TDI exposure compared to the past, and the healthy workers effect may have contributed to this low rate of asthma prevalence in workers with TDI exposure.

Nicotine이 배양된 정상 인체 멜라닌세포의 멜라닌화에 미치는 영향

최천필,김영일,이진우,이무형 경희대학교 동서의학연구소 2006 東西醫學硏究所 論文集 Vol.2006 No.-

Nicotine, the active ingredient of tobacco, causes increased platelet aggregation, endothelial cell damage and alterations in prostacyclin and thromboxane metabolism. Skin changes with nicotine include brown pigmentary staining of hands and nails, leg ulcers, cyanosis, decreased skin temperature and other signs of arterial insufficiency. However, the effect of nicotine on melanization is not well established. The purpose of this study is to evaluate the effect of nicotine on melanization in cultured normal human melanocytes. In order to evaluate non-cytotoxic dose of nicotine, we exposed various concentrations (0.01, 0.1, 1, 10, 100, and 1000 μg/ml) of nicotine to melanocytes and examined cell cytotoxicity using MTT assay. There was no cytotoxicity below 0.1 μg/ml of nicotine. After exposure to 0.1μg/ml nicotine on cultured normal human melanocytes, we investigated the effects of nicotine on the expression of tyrosinase (TYR), tyrosinase-related protein 1 (TYRP1), DOPAchrome tautomerase (DCT) at the protein levels in human skin melanocytes. There was no significant difference in the expression of TYR, TYRP1, and DCT protein after treatment with nicotine compared to the untreated control. These results suggest that short-term nicotine exposure had no direct melanogenic effect, in vitro.