• 한국화재소방학회논문지
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• 제25권1호
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• pp.57-62
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• 2011

인화점은 공정안전을 평가할 때 산업공정에서 가연성 액체의 중요한 연소 특성 가운데 하나이다. 본 연구에서는 클리브랜드 개방식 장치를 사용하여 n-propanol + formic acid계와 acetic acid + propionic acid계의 인화점을 측정하였다. 실험값은 Raoult의 법칙과 최적화 기법에 의해 추산된 값과 비교하였다. 그 결과, 최적화 기법에 의한 추산값이 Raoult의 법칙에 의한 추산값 보다 실험값에 더욱 근접하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.410-412
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• 2011

Magnetic cables that can deliver high frequency AC electric power safely for flammable or sensitive workplaces preventing from arcs and electric shocks are firstly proposed in this paper. To deliver the power for a long distance, several new magnetic cable structures which drastically reduce the parallel leakage flux by appropriate magnetic shield between the magnetic cables are suggested; hence, the output power can be improved more than ten times. The proposed magnetic cables are fully analyzed and verified by simulations and experiments with good agreement. The output power and efficiency for a prototype magnetic cable of 1.5m long and 1 cm gap between parallel cores were measured as 154W and 67 %, where the source current and frequency were 10 A and 20 kHz, respectively.

• 한국연소학회지
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• 제3권1호
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• pp.1-10
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• 1998

Lots of techniques are adopted for a flame stabilization and a high-load combustion. But the techniques being used were passive control method which have to change combustor shape like pilot flame, flame stabilizer, pressure profile, etc. Active control method which is not necessary to transform its shape is employed. Acoustical excitation is broadly used for its convenience in changing frequency and intensity. Both acoustical excitation and flame stabilizers were adopted to study their relationship. So, we investigated flammability limits. Flame visualization. And mean temperature in the condition of various frequencies, intensities, and flame stabilizers. As a consequence, flammability limit were advanced in acoustically excited flame at some frequencies. Coherent structure was extended to the downstream region through acoustical excitation and a size of vortice was curtailed. Also width of recirculation zone was magnified. In addition, Effects of acoustical excitation was stood out at 25mm flame stabilizer rather than another ones.

• 한국분말재료학회지
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• 제10권5호
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• pp.310-317
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• 2003

Two-component ceramic (alumina-zirconia) composites were fabricated by a soft-solution process in which polyethylene glycol (PEG) was used as a polymeric carrier. Metal salts and PEG were dissolved in ethyl alcohol without any precipitation in 1:1 volume ratio of alumina and zirconia. In the non-aqueous system, the flammable solvent made explosive, exothermic reaction during drying process. The reaction resulted in formation of volume expanded, porous precursor powders by a vigorous decomposition of organic components in the precursor sol. The PEG content affected the grain size of sintered composites as well as the morphology of precursor powders. The difference of microstructure in sintered composite was attribute to the solubility and homogeneity of metal cations in precursor sol. At the optimum amount of the PEG polymer, the metal ions were dispersed effectively in solution and a homogeneous polymeric network was formed. It made less agglomerated particles in the precursor sol and affected on uniform grain size in sintered composite.

• 한국안전학회지
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• 제17권2호
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• pp.69-75
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• 2002

Current fire safety in the construction sites has developed piecemeal over a considerable period of time. However, the law and regulation of fire safety is insufficient to protect fro in the construction sites. The frequency of fire in the construction sites is very rare but it brings longterm deterioration durability of building structure and large scale industrial calamity. There are many process of works and each work deals with many kind of flammable material, so it is very difficult to find a proper safety fire prevention. This study executed the questionnaire and fire experiment of the welding work to provide effective fire prevention counterplan.

• 조명전기설비학회논문지
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• 제28권10호
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• pp.49-55
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• 2014

This paper is basic study for development of an advanced photoelectric type smoke detector that has high reliability by reducing the occurrence of nuisance alarms. This paper was attempted to distinguish optical characteristics of the typical fire smoke particle and non-fire smoke particle. According to UL 268 standards, three types of test fires (the paper, the wood and the flammable liquid) were used in this paper for measurement of the fire smoke particles, and the water vapor and the cigarette smoke that were known as the main cause of the nuisance alarms were also used for the non-fire smoke particles. A smoke detection chamber was created, which was equipped with one light source and several light sensors for enabling simultaneous detection of light extinction and scattering, respectively. This paper analyzes the optical characteristics of each smoke particle using this chamber.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2007년도 제34회 KOSCO SYMPOSIUM 논문집
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• pp.133-138
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• 2007

Influence of changing combustor pressure on flame stabilization and emission index in the swirl-stabilized flame was investigated The combustor pressure was controlled by suction fan at combustor exit. Pressure index ($P^{\ast}=P_{abs}/P_{atm}$), where $P_{abs}$ and $P_{atm}$ indicated the absolute pressure and atmosphere pressure, respectively, was controlled in the range of $0.7{\sim}1.3$ for each equivalence ratio conditions. The flammable limits of swirl flames were largely influenced by changing combustor pressure and they showed similar tendency with laminar flames. $NO_x$ emission index decreased with decreasing pressure index for overall equivalence ratio conditions. R.m.s. of pressure fluctuations is increased with decreasing combustor pressure. This flame fluctuation caused incomplete combustion , hence CO emission index increased. These oscillating flames were measured by simultaneous $CH{\ast}$ chemiluminescence time-series visualization and pressure fluctuation measurement.

• 한국안전학회지
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• 제2권1호
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• pp.11-16
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• 1987

A study was performed on combustion rates of three kinds of combustible substances under a few different combustion conditions. To measure the combustion rates by weight method, I contrived an apparatus using a sensitive load cell. The experimental results by the combustion tests of various combustible substances shows that the combustion circumstances, eg., air supply condition and the existence of flammable oil. And it is found that the time constant T in case of oil absence is smaller than that in case of oil existence, and the time constant T in case of enforced air-entrained condition is greater that in case of natural air-entrained condition.

• 한국안전학회지
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• 제24권5호
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• pp.28-33
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• 2009

The thermochemical parameters for safe handling, storage, transport, operation and process design of flammable substances are explosion limit, flash point, autoignition temperatures(AITs), minimum oxygen concentration(MOC), heat of combustion etc.. Also it is necessary to know explosion limit at high temperature and pressure. For the safe handling of benzene, lower explosion limit(LEL) at $25^{\circ}C$, the temperature dependence of the explosion limits and flash point were investigated. And the AITs for benzene were experimented. By using the literatures data, the lower and upper explosion limits of benzene recommended 1.3 vol% and 8.0 vol%, respectively. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for benzene, and the experimental AIT of benzene was $583^{\circ}C$. The new equations for predicting the temperature dependence of the explosion limits of benzene is proposed. The values calculated by the proposed equations were a good agreement with the literature data.

• Korean Chemical Engineering Research
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• 제58권4호
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• pp.610-617
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• 2020

In process installations, chemicals operate at high temperature and high pressure. Propylene is used as a basic raw material for manufacturing synthetic materials in the petrochemical industry; However, it is a flammable substance and explosive in the gaseous state. Thus, caution is needed when handling propylene. To prevent explosions, an inert gas, carbon dioxide, was used and the changes in the extent of explosion due to changes in pressure and oxygen concentration at 25 ℃, 100 ℃, and 200 ℃ were measured. At constant temperature, the increase in explosive pressure and the rates of the explosive pressure were observed to rise as the pressure was augmented. Moreover, as the oxygen concentration decreased, the maximum explosive pressure decreased. At 25 ℃ and oxygen concentration of 21%, as the pressure increased from 1.0 barg to 2.5 bar, the gas deflagration index (K_g) increased significantly from 4.71 barg·m/s to 18.83 barg·m/s.