Earticle

The reasons of fire which take place in the mountain of trash are surveyed. Ascending induction, outdoor air shutoff, surface upper blocking, inhibit internal air circulation, internal spray water, internal spray water and inhibit internal spray water are the experimental conditions. For the selected trash dump, the heater is operated artificially until the temperature goes up to 50℃ and experiments are repeated for the above six conditions. Also, thermal imaging camera, infrared thermometer and gas meter are applied to collect the data for the assigned time intervals, which is very useful to contribute to the establishment of a scientific fire investigation system and fire fighting activities.

The need for safety standards of lithium battery is gradually required, but systematic analysis is still insufficient. There is still an objective and empirical accident analyzing method for batteries after ignition. The explosion pattern is analyzed, through non-destructive analysis (X-ray SEM) and destruction (disassembly) analysis of the battery. The possibility of accident after the ignition is suggested through the experiment of the internal shot and the overcharge representation. If the battery penetrates a part of the battery can with an external impact (nail), battery swells and an internal short circuit between the impact object and the jelly roll (electrode plate) happens. Ignition and explosion patterns by swelling, short-cut and overcharge are analysed and evaluated systematically by experiments. These results can be shared not only by the objective and reasonable analysis method of lithium secondary batteries but also by the fire investigation technique.

Ignition mechanism of dry bit which is applied to the exterior insulation finishing system in building is analysed and constructive methods to prevent the fire are suggested. For the experiment, surface finishing conditions, separation distances and kinds of ignition sources are selected as experiment variables, and danger of fire is confirmed through replication experiment. And through the re-ignition test, the fire ignition mechanism of the dry bit applied to the building is identified, and the fire prevention and casualty reduction measures are classified into institutional and technical aspects. Establishing practical preventive measures and technical alternatives that can be applied to the fire investigation are suggested.

Arson uses the combustion promoter and leaves a special fire pattern, but accidental fire also gives the similar fire pattern of arson and it’s easy to misunderstand the reason. Experiments are conducted to determine whether a small amount of combustion promoter is used or not. Components remaining on the floor material are detected by a tester or GC/MS at a fire. Changes in the detection results of combustion promoters occur depending on the degree of carbonization and time of flooring. Effective ways to collect evidence at fire prevention sites using combustion stimulants are conducted, which gives useful dada to determine the fire reason.

Vehicle fire which took placed in Tongyeong-si is analysed. For the theta engine of Hyundai Motors, there exists ignition trace in the lower part of engine room. In the backside of third piston, small hole is found, and engine oil is dripped on the hot surface, in which leaked oil is spreaded on the exhaust system. At the beginning of operating period, oil density is low, but it is increased and finally causes ignition, as the vehicle stops. The tensile stress of connecting rod causes the vehicle fire. Although car manufacturer does not agree, design of connecting rod must be reinforced. Also, product liability must be strengthened.

Gas explosions in cutting nozzle happen frequently. For the case of gas explosion, LPG container valve is opened, but torch valve is closed. Slow gas leakage during night is the reason of gas explosion. Backfire measurements and gas valve durability experiments are performed by KS B 4601. Internal defects in the torch result in explosions. Depending on the kinds of gases, gas leakages of torch is measured by a gas detection camera. The most dangerous explosion is occurred by leaking the mixture of LPG and oxygen. For the gas torch and the oxygen cutting system, equipments for the prevention of backfire and durability test and related regulatory laws must be reinforced, to prevent the gas explosion accidents.

Thermal efficiency of diesel engine is higher than that of gasoline engine. But diesel engine requires more strict environmental regulations, due to the pollution. Vehicle manufacturers continue to develope the more efficient devices, reducing detrimental emission gas. EGR system reduces diesel engine NOx and widely used. However, while technological development and improvement of the technology of the exhaust gas abatement device has been made, the side effect increases the vehicle fire. Recent outbreak of fire in a manufacturer's diesel vehicles has surged, and many experts have pointed out that the cause of the fire is a defect in the EGR system and the ignition of carbon sludge attached to the intake system. The structure and the operating principle of EGR system, which is pointed out as the cause of the fire, are investigated and also, the possibility of the fire by the fire recurrence experiment of the carbon sludge is analysed.