• Fire Science and Engineering
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• v.17 no.4
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• pp.86-91
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• 2003

Since the air stream in the room controlled by HVAC system affects on he expected response of conventional detectors which are designed in accordance with normal characteristics of air stream in the fire incident, unexpected operation time delay may occur in fire. In order to solve this problem and to improve sensitivity so that to initiate fire in its early stages for minimizing damage and protecting people, we studied and developed Air Sampling Smoke Detector. The Air Sampling Smoke Detector is a kind of active-type fire detection system. it draws air continuously from the protected area through an air sampling pipe network to the smoke density analyzer. This study presents smoke density analysing technique and air intake balancing technique through an air sampling pipe network. As a result of evaluating, Air Sampling Smoke Detector was much more sensitive than conventional smoke detectors that passively wait for smoke to reach them and was not affected by ambient airflow in the room by means of balanced air intake through the sampling holes.

• Fire Science and Engineering
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• v.31 no.3
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• pp.11-18
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• 2017

In this study, a non-halogen type organic-inorganic hybrid flame retardant sol, which can impart flame resistance to synthesize silicate of inorganic material and silane coupling agent of organic material by a sol-gel method, were newly manufactured. The addition of flame retardant will prevent loss of life in a fire because smoke from the flammability of interior finishing materials used as the construction materials poses a major danger. The smoke density measurement standard based on flame retardant performance standards, experiments were conducted according to the test equipment and procedures of ASTM E 662. The non-flaming mode experiment and the flaming mode experiment were conducted to confirm the performance of the manufactured flame retardant sol. As a result, the manufactured flame retardant sol improved the physical properties and heat resistance of existing flame retardants, and decreased the smoke production of the fire. Therefore, it may be possible to reduce the damage caused by smoke and expand the applications to various interior finishing materials.

• Membrane and Water Treatment
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• v.8 no.4
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• pp.381-393
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• 2017

The inorganic components in tobacco sheet extract have significant influence on the sensory taste of the cigars and the harmful component delivery in cigarette smoke. To identify the contributions of the divalent inorganic components on harmful components delivery in cigarette smoke, a self-made selective electrodialysis was assembled with monovalent ion-selective ion exchange membranes. The influences of current density and extract content on the desalination performance were investigated. Result indicates that the majorities chloride, nitrate, and sulfate ions were removed, comparing with 50-60% of potassium and only less than 10% of magnesium and calcium ions removed in the investigated current density. The permselectivity of the tested cations across the Selemion CSO cation exchange membranes follows the order: $K^+>Ca^{2+}>Mg^{2+}$. A current density of $15mA/cm^2$ is an optional choice by considering both the energy consumption and separation efficiency. When the extract contents are in the range of 7%-20%, the removal ratios the potassium ions are kept around 60%, while the removal ratios of the calcium and magnesium ions fluctuate in the range of 16-27% and 8-14%, respectively. The tobacco smoke experiments indicated that the divalent metal ions have dual roles for the harmful component delivery in cigarette smoke. The divalent potassium and calcium ions were unfavorable for the total particulate matter emission but beneficial to decrease the HCN delivery in the mainstream cigarette smoke. The selective electrodialysis is a robust technology to decrease the harmful component delivery in cigarette smoke.

• Fire Science and Engineering
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• v.25 no.4
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• pp.94-102
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• 2011

Hot smoke test is done in a subway tunnel. Alcohol trays of 1.0 MW and smoke generators are used for generating hot smoke. The fans equipped with the tunnel are successively run 9 min after smoke generation. It is verified how hot smoke is controlled by fans. Velocity and direction of flow, temperature and smoke density are measured and analyzed for smoke control performance of the tunnel with fans and analyzed from the fire-safety-point of view. Velocity of smoke flow is obtained by using measured velocity and temperature at the ceiling of the tunnel. The time when smoke-control flow is builded up is different for the different positions. Velocity distributions at various positions will be used for the boundaries and the comparison data in numerical simulations for evaluation on smoke-control facilities of subway tunnel.

• Journal of Korean Tunnelling and Underground Space Association
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• v.5 no.4
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• pp.389-400
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• 2003

In order to recommend the mechanical smoke exhaust operation mode, Subway Environmental Simulation (SES) is used to predict the airflow of the inlet and outlet tunnel for the subway station. Fire Dynamic Simulation (FDS) is used the SES's velocity boundary conditions to clarity the smoke exhaust effectiveness by the variations with mechnical ventilation system. We compared each 6 types of smoke exhaust systems for the result of smoke density and temperature distributions for 1.5m height from the subway station base in order to clarify the safety evaluation for the heat and smoke exhaust on subway fire.

• Fire Science and Engineering
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• v.24 no.4
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• pp.27-32
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• 2010

Recently, increases of population density due to the industrialization in the metropolitan cities has caused the high-density and integration of life environment. Then various high-rise buildings are constructed for accommodation. However, high-rise building fires can cause high casualties due to increases of smoke spread velocity through the vertical shaft. In this study, the new program based on the enthalpy conservation for analysis of energy transfer for smoke control system, CAU_ESCAP, was developed. CAU_ESCAP was validated by comparing with the result of ASCOS. The characteristic of smoke control was analysed by using CAU_ESCAP for high-rise building fires.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.5
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• pp.905-912
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• 2022

Virtual reality, one of the core technologies of the 4th industrial revolution, is entering a new phase with the spread of low-cost wearable devices represented by Oculus. In the case of disaster evacuation drills, where practical training is almost impossible due to the risk of accidents, virtual reality is becoming a new alternative that enables effective training. In this paper, we propose a smoke modeling method that can be applied to fire evacuation drills implemented with virtual reality technology. In the event of a fire, smoke spreads along the aisle, and the density of the smoke changes over time. The proposed method models the smoke by applying a procedural function that can reflect the density of smoke calculated through simulation to the model in real-time. Implementation results in the background of the factory show that the proposed method produces models that can express the smoke according to the user's movement.

• Journal of the Korean Society of Safety
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• v.26 no.4
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• pp.111-119
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• 2011

This study was designed to provide basic data applicable to fire investigation through consideration of combustion products and propose vulnerability of combustibles through analysis of $CO_2$ emission. In order to achieve these research objectives, characteristics of combustion products such as smoke release rate of each part(raw leaves, branches and barks), $CO_2$ emission and ash production were considered targeting on 6 oak species(Quercus variabilis Blume, Quercus aliena Blume, Quercus serrata, Quercus mongolica Fisch, Quercus dentata Sapling and Quercus acutissima) using cone calorimeter and smoke density tester. As a result, it was found that raw leaves release smoke more relatively than branches and barks, when they burn, and that Quercus variabilis Blume has the highest smoke density. Also, Quercus acutissima released CO and $CO_2$ which are respectively, 6.67 times and 1.43 times more than Quercus variabilis Blume with low $CO_2$ emission. In addition, branches released CO and $CO_2$ more relatively. There was a big difference in ash production among raw leaves(3.1 g), branches(10.5 g) and barks(16.43 g). It was identified that Quercus serrata produces ashes which are nearly 9.95 times more than Quercus variabilis Blume. It demonstrates that Quercus serrata contains relatively higher minerals and that Quercus variabilis Blume can leave lots of traces like stain and carbonization, as it releases smoke a lot and it's difficult to predict visibility, when a forest fire breaks out in its community area. It is also considered that smoke particles containing oil in the air leave strain on the surface of a tree, and that CO and $CO_2$ emission increases, when crown fire to burn branches breaks out.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.11
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• pp.1474-1480
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• 2018

When fires occur in high-rise buildings, it is difficult to determine whether each escape route is safe because of complex structure. Therefore, it is necessary to provide residents with escape routes quickly after determining their safety. We propose a method to measure the visibility of the escape route due to the smoke generated in the fire by analyzing the images. The visibility can be easily measured if the density of smoke detected in the input image is known. However, this approach is difficult to use because there are no suitable methods for measuring smoke density. In this paper, we use principal component analysis by extracting a background image from input images and making it training data. Background images and smoke images are extracted from images given as inputs, and then the learned principal component analysis is applied to map of as a new feature space, and the change is calculated and the visibility due to the smoke is measured.

• Fire Science and Engineering
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• v.17 no.4
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• pp.36-41
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• 2003

This experimental study shows the combustion characteristics for each coating thickness of water and oil paint which are used as fire retardant paints that prevent fire propagation through cables in underground culverts and trays. To evaluate combustion characteristics, smoke density(ASTM E 662) and Limited Oxygen Index(ASTM D 2863) experiment method was used. As the results of this study, the combustion characteristics of fire retardant paints produced the following : (a) The molt suitable coating thickness of fire retardant paint was 1.5∼2.0 mm in water paint and 0.2 mm in oil paint. (b) Flaming method in experiments of smoke density were found to be higher than Non-flaming method. (c) Water paint has the fire retardant effect and characteristics better than oil paint in measurement results of smoke density and oxygen index. (d) The oxygen index of water and oil fire retardant was able to know that it was satisfied a standard (30 or above).