• Fire Science and Engineering
• /
• v.33 no.3
• /
• pp.51-55
• /
• 2019

To prevent ozone depletion caused by CFCs, the replacement of Halon with clean agents has been developed in the fire protection field along with refrigerants, detergents, and foaming agents. The alternatives for Halon 1211 have been developed in the portable fire extinguisher area and HCFC-123 is used widely as a clean fire extinguishing agent. The type of expellant gas is important because their own vapor pressure is low. In this study, HCFC-123, HCFC-124, HFC-125, and Novec-1230 were selected as fire extinguishing agents and CO₂, which is expected to improve the fire extinguishing ability, was chosen as the expellant gas. For each agent, experiments changing the agent and CO₂ amount were carried out and HCFC-123 showed a good result, as expected. The extinguisher, HCFC-123 of 1.5 kg, showed the same ability to suppress a class A and B fire as the extinguisher, HCFC-123 of 2.5 kg, which is currently sold on the market. According to this result, the expellant gas has a subsidiary fire extinguish effect. This can reduce the amount of HCFC fire extinguishing agent, which is categorized in the phase-out alternatives, and is a more eco-friendly and economical fire extinguisher than the previous one. This study can also help solve the problems of CO₂ fire extinguishers for class B and C fires, and can be used to extinguish electric and electron facilities fire, which contains large amounts of class A fire combustibles.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.18 no.5
• /
• pp.413-418
• /
• 2016

Recently, a mega project such as Korea-China or Korea-Japan undersea tunnel project has been emerged for detail discussion and the interest in undersea tunnel is on the rise. More severe damage by train fire is expected in undersea tunnel comparing to ground tunnel and thus the study on more efficient fire extinguishing system, besides existing disaster prevention design is underway. To that end, a full-scale fire tests using CAF fire extinguishing system which has been developed by modifying traditional foam fire extinguishing system for fire suppression at rescue station in timely manner were conducted over 7 times. The test was conducted after setting the rescue station in virtual tunnel with a car of KTX. As a result of using compressed air foam directly to the fire source, 30 liter of Heptane combustibles was extinguished within 1 minutes. Applicability of compressed air foam to train fire at rescue station in undersea tunnel was has been proven and further study is considered required while changing the nozzle angle and location so as to achieve quick and easy extinguishing goal, making use of the advantage of CAF, as well as to reduce the fire water and chemicals required.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.20 no.1
• /
• pp.31-40
• /
• 2012

In order to making resources for the organic wastes, it is very important to understand for the life cycle of wastes before the physicochemical analysis and engineering technology. Therefore we try to fine the solution through the interdisciplinary consilience between natural science and social science for the management of refuge in summer resort. Summer visitors of beach answered that fly tipping of refuse was 65.56% and insufficient separation was 17.78% about the survey. But insufficient separation was 42.5% and fly tipping was 37.5% in valley. The survey for the effective methods at reducing refuse was represented that campaign and teaching was 47.78%, fine was 23.33% and using the standard bags was 18.89% in beach. Campaign and teaching was 37.5%, using the standard bags was 37.5% and fine was 15% in valley. Bulk density of refuse in gyeongpo beach was measured in $74kg/m^{3}$. This value was three times as much low than municipal solid wastes. Moreover, the composition of refuses in beach showed that combustible materials was 81.1% and incombustible materials was 18.9%. Moisture, ash and combustibles were analyzed 19.0%, 9.2% and 91.8% respectively.

• Fire Science and Engineering
• /
• v.29 no.2
• /
• pp.79-83
• /
• 2015

The fire accident is a representative type of disaster that can largely impact on business. Therefore, precautionary measures and rapid initial response is very important when a disaster occurs. The storage of porous combustibles is inevitable in coal yard, plywood processing industry, and others that are currently operating. Initial fire fighting of fire and identifying the ignition point in such a porous combustible storage space are so difficult that if the initial response is failed, being led to deep-seated fire, surface fire is likely to result in secondary damage. In addition, deep-seated fire can cause personal injuries and property damage due to a large amount of toxic gases and reignition. Therefore damage reduction measures is required around the storage space to handle a porous flammable. Improving the penetration performance of the concentration of the surfactant is carried out as underlying study, which is about an deep-seated fire extinguishing efficiency augmentation when using wetting agents. The porous materials used in the experiments is radiata pine wood flour, which occupies more than 75% of the domestic wood market. Fire fighting water is selected as Butyl Di Glycol (BDG), which is being used for infiltration extinguishing agent, and the experiment was carried out by producing a standard solution. The experiment was carried out on the basis of the Deep-Seated Fire Test of NFPA 18. The amount of watering, porous material to the internal amount of penetration, and runoff measurement out of the porous material was conducted. According to experimental results, as the surface tension is reduced, the surfactant concentration macroscopic penetration rate decreases, but infiltration to a porous material is shown to have growth characteristics.

• Fire Science and Engineering
• /
• v.33 no.4
• /
• pp.28-34
• /
• 2019

Regardless of the ignition source, the main factors affecting the spread of flames to the human body are combustibles. The sound absorption material, which is the finishing material used in music institutes and karaoke rooms, consists of polyurethane that generates a large amount of toxic gas with a high amount of combustion gases during a fire. Still, the current law does not require the use of impregnated finishing materials for tutoring services with less than 100 users. In this study, the rate of flame diffusion was measured using the MultiRaelite composite gas measuring instrument (target substance VOC, HCHO, SO₂, CO₂, CO, HCN, and NO₂) for the collection of sound-absorbing materials installed in the actual music academy. The results showed that the toxic gas found in this experiment exceeded the allowable concentration of TWA (Time Weighted Average) and STEL (Short Term Exposure Limit). In addition, a comparative combustion test of the general sound absorber and non-combustion sound absorbing materials on the market showed wide differences in ignition and diffusion. Therefore, based on the results of the experiment, private institutes with less than 100 users should be mandated to use non-combustion sound absorbing materials.

• Journal of Environmental Health Sciences
• /
• v.19 no.4
• /
• pp.51-58
• /
• 1993

The integrated solid waste management for Seoul Metropolitan city can be established on the basis of the following hierarchy of priorities: 1. Efforts for source reduction should be propelled by both government and citizens to achieve the effects of resource conservation. The adequate production and consumption which are environmentally amenable and sustainable can be induced by the reasonable imposition of deposit money for waste treatment to one-time use products. To accomplish source reduction effectively, the induction of legal and institutional regulation of producer and consumer participation is requisite. 2. For resource recovery, wastes generated should be recycled as far as practicable. Community residents are responsible to separate discharge, the authorities concerned have responsibility of separate collection, and recycling industry should be assissted through tax reduction and financing. Resource separation facilities can be constructed at Kimpo Metropolitan landfill site for wastes not separately collected due to some unavoidable circumstances. 3. Garbage should be composted. Garbage is uneconomical for incineration, because it has high moisture content and low calorie, thus there is no reason for the incineration of garbage even though garbage is classified into combustibles. Composting facilities can be located at sites which are not densely populated and easily accessible to transportation, for example, Kimpo Metropolitan landfill site. Compost produced can be managed by the authorities for the use of fertilizer to a green tract of suburban land and farms. 4. Nonhazardous combustible wastes not recyclable can be utilized for thermal recovery at the incinerators which are completely equipped with pollution control devices. According to the trend of local autonomy and the equity principle of local autonomous entities, incineration facilities of minimal capacity required can be constructed at each districts of Seoul Metropolitan city which have organized local assembly. In case of Yangcheon district, the economically combustible waste quantity is about 260 tons/day which exceeds 150 tons/day, the incineration capacity of existing facility. But, from now on, waste quantity can be reduced substantially by the intensive efforts of citizens for source reduction and recycling and the institutional support of administrative organizations. Especially, it is indispensable for the government to constitute institutional and technological bases that can recycle paper and plastics form 43% of waste generated. A good time for constructing of incineration facilities for municipal solid waste can be postponed to the time that pollution control technologies of domestic enterprises are fully developed to satisfy the standards of air pollution prevention, because the life expectancy of Kimpo Metropolitan landfill site is about 25 years. Within this period, institutional improvements and technological advancements can be attained, while the air qual. ity of Seoul Metropolitan city can be ameliorated to the level to afford incineration facilities. 5. For final disposal, incombustibles and ash are landfilled sanitarily at Kimpo Metropolitan landfill site.

• The Journal of Traditional Korean Medicine
• /
• v.15 no.1
• /
• pp.113-127
• /
• 2006

Objectives: This study was produced to examine the effects of moxibustion that had been played important role to traditional oriental medical treatment on disease. Recently, it was reported that moxi-tar which is generated in the process of moxibustion as burning combustibles decreased nitric oxide(NO) and inducible NO synthase (iNOS) generation in cellular experiments. Methods: Carrageenan-induced arthritis rat model was used to test the effect of moxi-tar as a chronic pain model. Diluted moxi-tar was single injected in several acupoints or combined with electroacupuncture (l ms, 2 Hz, and 2 mA) into contralateral ST36 acupoint for 30 min to assess the synergic effects. After the treatment, behavioral tests measuring stepping force were periodically conducted during the next 12 hours. Endogenous NO and iNOS, cyclooxygenase-2 (COX-2), and c-Fos protein expression in the spinal cord were examined on a rat model of carrageenan-induced arthritis. Results : After the induction of arthritis, rats subsequently showed a reduced stepping force of the affected limb for at least the next 4 days. The reduced stepping force of the limb was presumably due to a painful knee, since oral injection of indomethacin produced temporary improvement of weight bearing. Maxi-tar produced significant improvement of stepping force of the hindlimb affected by the arthritis lasting at least 9 hours. The magnitude of this improvement was equivalent to that obtained after an oral injection of 3 mg/kg of indomethacin and this improvement of stepping force was interpreted as an analgesic effect. Maxi-tar produced the improvement of stepping force of the affected hindlimb in a dose-dependent manner. Both NO production and iNOS, COX-2 protein expression increased by arthritis were suppressed by maxi-tar. Moxi-tar on combination with electroacupuncture (EA) produced more powerful and longer lasting improvement of stepping force of the hindlimb affected by the arthritis than either moxi-tar or EA did. Conclusion : The present study suggest that maxi-tar produces a potent analgesic effect on the chronic knee arthritis pain model in the rat and that moxi-tar-induced analgesia modulate endogenous NO through the suppression of iNOS/COX-2 protein expression.

• Journal of the Society of Disaster Information
• /
• v.17 no.3
• /
• pp.617-626
• /
• 2021

Purpose: The purpose of this study is to evaluate the fire srpead risk of building exterior and roofing materials due to the firebrand of forest fire occurring in the urban areas. Method: In order to achieve this research purpose, by selecting building materials used for exterior and roofing materials of buildings, the time to ignition, total heat release, and heat release rate were investigated, and a forest fire firebrand system was established to the possibility of fire spread was confirmed. Result: As a result of the cone calorimeter test, the roofing material had a similar or faster ignition time due to radiant heat compared to the exterior material with the steel plate exposed to the outside, and showed a higher heat release rate and total heat release than the exterior material. Although it was affected by the flammable material, it was confirmed that it did not spread easily due to the limited amount of combustible material, and carbonization marks appeared inside. Conclusion: The cone calorimeter test method has been shown to be useful in understanding the combustion characteristics of building materials by radiant heat, but the fire spread due to a firebrand in a forest fire is directly affected by the flame due to the ignition of surrounding combustibles, so finding a direct correlation with the cone calorimeter method is difficult. It is judged that the roof material may be more vulnerable to the spread of fire due to the fire than the exterior material.

• Journal of the Society of Disaster Information
• /
• v.19 no.3
• /
• pp.608-623
• /
• 2023

Purpose: Recently, the number of logistics warehouses has been on the rise. In addition, as the number of such logistics warehouses increases, number of fire accidents also increases every year, increasing the importance of preventing fires in large logistics warehouses. Method: investigated aspirating smoke detectors that are emerging as adaptive fire detectors in logistics warehouses. Then, through fire simulation (FDS), logistics warehouse modeling was conducted to compare and analyze the detection speed of general smoke detectors and aspirating smoke detectors according to four stages of fire growth and three locations of fire in the logistics warehouse. Result: Growth speed in Slow-class fires and Mediumclass fires, the detection speed of aspirating smoke detectors was faster regardless of the location of the fire. However, in Fast-class fires and Ultra-Fast-class fires, it was confirmed that the detection speed of general smoke detectors was faster depending on the location of the fire. Conclusion: It was confirmed that the detection performance of the aspirating smoke detector decreased as the fire growth speed increased and the location of the fire occurred further than the receiver of the aspirating smoke detector. Therefore, even if an aspirating smoke detector is installed in a warehouse that stores combustibles with high fire growth rates, it is judged that an additional smoke detector is attached far away from the receiver of the general smoke detector to increase fire safety.

• Journal of the Society of Disaster Information
• /
• v.10 no.4
• /
• pp.583-597
• /
• 2014

Fire caused by heater has various causes as many as the types of heater. also, lots of damage of human life and property loss are caused, since annually continuous fire accident by heater in traditional market is frequently occurring. There are not many cases of fire due to heater in most of residential facilities such as general house, apartments, etc., because they are supplied with heating boiler, however the restaurant, store and office of the market, sports center, factory, workplace, etc. still use heater, e.g. oilstove, electric heater, etc., so that they are exposed to fire hazard. Also, when investigating the number of fire due to heater, it was analyzed to occur in order of home boiler, charcoal stove, oilstove, gas heater/stove, electric stove/heater, the number of fire per human life damage was analyzed in order of gas heater/stove, oil heater/stove, electric heater/stove, briquette/coal heater. Also, gas and oil related heater were analyzed to have low frequency, however, with high fire intensity. Therefore, this research aimed at considering more scientific fire inspection and identification approach by reenacting and reviewing fire outbreak possibility caused by combustibles' contact and conductivity under the normal condition and abnormal condition in respect of ignition hazard, i.e. minimum ignition temperature, carbonization degree and heat flux along with it, due to oilstove and electric stove, which are still frequently used in public use facility, traditional market, and, of which actual fire occurrence is the most frequent. As the result of reenact test, ignition hazard appeared very small, as long as enough heat storage condition is not made in both test objects(oilstove/electric stove), however carbonization condition was analyzed to be proceeded per each part respectively. Eventually, transition to fire is the ignition due to heat storage, so that it was analyzed to ignite when minimum heat storage temperature condition of fire place is over $500^{\circ}C$. Particularly, in case of quartz pipe, the heating element of electric stove, it is rapidly heated over the temperature of $600^{\circ}C$ within the shortest time(10sec), so that the heat flux of this appears 6.26kW/m2, which was analyzed to result in damage of thermal PVC cable and second-degree burn in human body. Also, the researcher recognized that the temperature change along with Geometric View Factor and Fire Load, which display decrease of heat, are also important variables to be considered, along with distance change besides temperature condition. Therefore, the researcher considers that a manual of careful fire inspection and identification on this is necessary, also, expects that scientific and rational efforts of this research can contribute to establish manual composition and theoretical basis on henceforth fire inspection and identification.