• Fire Science and Engineering
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• v.31 no.1
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• pp.50-57
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• 2017

The present article discusses the response characteristics of smoke detector chamber due to dust and wind velocity. Although situations have improved in terms of early sensing of fires as the smoke detectors are applied indoors, studies tend to place insufficient focus on the side effects and malfunction that can be caused by diversified life dust produced indoors and environmental requirements, etc. Therefore, in the present study, 4 types of photoelectric smoke detectors with different forms and structures of smoke chamber were selected as the experimental objects, and dust test was conducted with fly ash, talcum powder and fiber dust as experiment samples to study indoor applicability of the smoke detectors in terms of their response to diversified dust and wind velocity. Also, to observe response characteristics due to pollution level inside the smoke chamber, wind velocity for dust test were set additionally at 0.25 m/s, 0.5 m/s, and 1.0 m/s. Based to the experimental results, fly ash, talcum powder, and fiber dust (black hair powder) were found to be suitable at the dust test reference wind velocity conditions of 0.25 m/s for both operation test and non-operation test after dust application. On the other hand, under the harsh wind velocity conditions of 0.5 m/s and 1.0 m/s, malfunction of unwanted alarm was observed in non-operation tests in the case of fly ash and talcum powder, and non-operation was confirmed to occur in the case of fiber dust as the alarm failed to operate normally in operation tests.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.471-474
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• 2009

Formaldehyde (FA) is a carcinogenic compound present in cigarette smoke. In this study, the amount of formaldehyde was analyzed in 5 kinds of cigarettes and the inhibitory effect of plant volatile extracts on the formation of FA was investigated. After extraction of the cigarette sample, FA was converted into its thiazolidine derivatives by reaction with cysteamine, and then measured using a gas chromatography-nitrogen phosphorus detector (GC-NPD). The concentrations of FA in cigarette smoke were found between 138.24 and $217.82{\mu}mol/g$ cigarette smoke. Extracts isolated from Welsh onion (Allium cepa L.), garlic (Allium sativum L.), crown daisy (Chrylsanthemum coronarium L.), green pepper (Capsicum annuum L.), and sesame dropwort (Oenanthe javanica DC) were used for analyzing their inhibitory effects on the formation of FA. The inhibitory effects of extracts of Welsh onion, garlic, crown daisy, green pepper, and sesame dropwort on the formation of FA were 64, 47, 38, 47, and 19%, respectively.

• Fire Science and Engineering
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• v.25 no.6
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• pp.73-82
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• 2011

This study was performed to analysis the influence of smoke alarm detector on evacuation safety in housing fire. The analysis was conducted by CFAST fire simulation program and building EXODUS evacuation program. The effects of the earlier response time on evacuation safety were investigated by using evacuation simulation program with several steps of different response time and smoke alarm activation time for 4 occupants. The smoke detecter was activated 37.1 second after fire. The first two mortuary were occurred for 170 seconds of response time at the end of living room near exit. But for the 37.1 seconds of response time 4 occupants evacuated safely. From this study, the fire alarm detector is more important for safety evacuation in housing fire.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1734-1737
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• 1997

The conventional fire detection devices are operated after a processed fire phase, which are sensing only a high density of somke level or high temperature heat. They are not so precision to detect a fire in the early phase to protect the facility form the fire. We need to develope a new high precision smoke detection system to keep expensive industrial facilities most reliably form fire. A new optical precision smoke detection system was developed. It monitors very low level density of smoke particles in the air. It is operated continously through many years without a stop or any malfunction. The developed precision smoke detection system will be installed in important industrial facilities, such as power plants, underground common tunnel, main control rooms, computer rooms etc.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.155-158
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• 2008

In this study we compared corrosion resistance tests which were carried out according to the national technique standard and the UL standard to ensure the reliability of smoke detectors in foul weather. The sensitivity of smoke detectors became so blunt that the least operational smoke concentration was a maximum change of 13% in the national technique standard, while it was a maximum change of 145% in the UL standard. As a result of this study the test method of corrosion resistance was made an objective evaluation in the national technique standard. Therefore it could be said that a basis of developing the test method of corrosion resistance was prepared for our country.

• Fire Protection Technology
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• s.56
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• pp.14-19
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• 2014

• Fire Protection Technology
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• s.28
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• pp.48-54
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• 2000

The technique detects radiant energy form a flaming fire of fuels contained carbonaceous material can be applied to fast growing fires. This technique applied detectors are ultimately effective when early detecting fire alarm system is required or the smoke and heat detectors can not applied. In Korea Fire regulation, a flame detector should be install in case that the installation height is higher than 20[m], chemical plant, hangar refinery. Therefore it is really necessary that a flame detector has to be developed as soon as possible. With foundation technique of flame detector, ideal sensing element and stable circuit design, a trial UV flame detector is manufactured. The stable and reliable technique of flame detector is established through the repeateed perfomance test and modification. An early detecting fire alarm device is developed through the modification, supplement of the structure and circuit. Results of the R & D for the manufacture of an excellent flame detecting device is carried out with the establishment of technique for the mass production and the qualified manufacturing process.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2759-2764
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• 2014

Smoke detector is commonly used to reduce fire detection time. However, technical problems regarding its inaccuracy of laser beam-receiving point on the surface of the sensor associated with incoming interference are identified when the laser transmitter and receiver are installed at a distance of about 100m. In this paper, we propose the auto focus alignment algorithm with high precision to adjust tilting angle of lasers caused by environmental interference so that solve existing issues using multi-level worm gear set.

• Fire Science and Engineering
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• v.28 no.5
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• pp.64-70
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• 2014

The neural networks were able to be used by analyze fire source with the optical characteristics of smoke particles. The neural networks were learned the optical characteristics for three types test fire (paper, wood, flammable liquid). These test fires which were adopted in this study were also used to performance test of smoke detector according to UL268. A smoke chamber which was able to detect light extinction and scattering simultaneously was created. The optical characteristics of smoke particles were measured by the smoke chamber. And the results were used to input data for the neural networks. The neural networks distinguished the fire source accurately for paper fire, wood fire or flammable liquid fire. The neural networks distinguished accurately the combined fire source such as paper-wood fire, paper-flammable liquid fire or wood-flammable liquid fire.

• International Journal of Safety
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• v.11 no.1
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• pp.6-10
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• 2012

This paper presents a study on the analysis for reducing the number of false alarms in fire detection system. In order to intelligent algorithm fuzzy logic is adopted in developing fire detection system to reduce false alarm. The intelligent fire detection algorithm compared and analyzed the fire and non-fire signatures measured in circuits simulating flame fire and smoldering fire. The algorithm has input variables obtained by fire experiment with K-type thermocouple and optical smoke sensor. Also triangular membership function is used for inference rules. And the antecedent part of inference rules consists of temperature and smoke density, and the consequent part consists of fire probability. A fire-experiment is conducted with paper, plastic, and n-heptane to simulate actual fire situation. The results show that the intelligent fire detection algorithm suggested in this study can more effectively discriminate signatures between fire and similar fire.