Minutes Of Fire Research Articles

Overview of the Precipitates in a Ground-Coat Vitreous Enamel Using Analytical TEM

Precipitates in the ground-coat vitreous enamel, which form when the dried coating is fired and cooled on sheet steel, are essential for the function of the enamelling. They lead to an interlocked metal-glass interface and are triggered by redox-driven processes in a glass layer saturated with iron. Using analytical transmission electron microscopy, it is shown that alloys of the Fe-Co-Ni-Cu system not only precipitate near the interface, where they contribute to adhesion through an interlocking interface, but also form nanocrystallites that are finely distributed in the enamelled glass to a depth determined by the diffusivity of Fe2+ (30 μm after four minutes of firing) and probably contribute to the toughening of this glass layer. The saturation with iron also prevents the segregation of the glass flux and opacifier calcium fluoride, which only occurs far from the interface in the chemically unmodified base glass. At the metal-glass interface, however, phosphorus traces diffuse from the steel and precipitates in the form of calcium phosphate needles that grow into the enamelled glass.

DEVELOPMENT OF THE ASSESSMENT TECHNIQUE OF THERMAL IMAGING CAMERAS FOR FIREFIGHTERS

Issues of combating hazardous fire factors such as smoke and heat, which are being fought by the firefighters whit self-contained breathing apparatus (SCBA units) of State Emergency Service of Ukraine, remains one of the complicated tasks which should be solved by the operational units. The concentration of toxic substances in the first minutes of the fire are 12-100 times above the maximum. The average volume temperature in the first 5-10 minutes of fire can reach 140-900 оС. The rate of smoke spreading and toxic substances is very high. Every year, about 16 per 1 million people worldwide die from the cause of poisoning by combustion products during the fire, moreover, this trend is increasing every year.
 Therefore, the effectiveness of rescuing people, eliminating fires and carrying out rescue operations in the non-breathable environment depends, largely, on the speed of carrying out such operative actions, with the help of technical means one of which is a thermal imaging camera (TIC). As foreign practice shows, firefighters have widely used TICs during firefighting, searching victims and reconnaissance, however, in Ukraine, these devices have only just begun to appear in SES units. Thus, the study of the assessment of the parameters of TICs and their subsequent comparison is an urgent scientific task. The solving of which makes it possible to improve the efficiency of fire elimination during firefighting with zero visibility and a large number of combustion products by the SCBA units. Accordingly, there is a need for developing an assessment technique of the TIC parameters, which ensure the effectiveness of reconnaissance, searching the sources of fire and rescue operations by the SCBA units.
 The article describes the assessment methodology for estimating the parameters of TICs, according to which will be conducted experimental studies based on the fire module of Lviv State University of Life Safety. The aims of this study will identify the influence of fire environmental on the parameters of the TICs and on the efficiency of the reconnaissance process by the SCBA units in order to detect the fire cell and other issues. After conducting the research, comparative data will be presented that will allow to evaluate and select the most optimal variant of the TICs for the SES of Ukraine.

Development of a Microcontroller Based Emergency Lighting System with Smoke Detection and Mobile Communication Facilities

This paper describes a microcontroller based emergency lighting system, which can early detect fire and send the alarm message through a mobile network. This is achieved via smoke and gas detector technology added with integrated microcontroller, mobile communication and a LED emergency light. First five Minutes of fire is more important than last five hours [1]. Hence, it is important to have early detection of fire and start fire fighting in its inception. In many hazardous areas where flammable materials are handled, any leak or spillage may give rise to an explosive atmosphere. In this situation, early detection of leaking gas or smoke plays an important role in reducing fire deaths and injuries. In fact, immediately after detection of fire, fire fighting should be started by means of portable fire extinguishers or by informing the fire brigade. This developed system can initiate these functions by detecting the fire hazard, establishing the communication to dwellers and turning on the emergency light to show the exit route.

Concrete-Filled Double Skin Steel Tubular Columns Exposed to ASTM E-119 Fire Curve for 60 and 90 Minutes of Fire

Concrete-filled double skin steel tubular (CFDST) columns with outer steel tubes varying in diameter and thickness were exposed to ASTM E-119 fire curve for 60 and 90 minutes. All specimens (control and heated) failed by outward local buckling of outer steel tube, crushing of concrete and outward and inward buckling of inner steel tube. Residual Strength Index (RSI), secant stiffness and Ductility Index (DI) were calculated in order to compare the performance of control and fire-damaged CFDST columns. It was found that specimens with 90 minutes of fire exposure time possessed highest RSI. Meanwhile, secant stiffness seems to decrease with increased exposure time. And finally, CFDST columns became more ductile after being heated.

Comparison of Steel Trusses Analysed with Different Types of Fire Curves

The paper provides the analysis of steel truss under fire conditions according to the temperature method. The analysis was carried out for two variants of the fire curves (the standard one, used in traditional approach to fire design and a new one, proposed by the authors, called "exponential" curve). Both curves describe temperature of fire gases but they are obtained using different scenarios. In the case of the standard fire curve, increase in temperature is very rapid in the first minutes and then it decelerates. The exponential curve describes inverse situation: slow increase in temperature of fire gases followed by more rapid one. The fire history defined by the fire curve has great influence on temperature of an element in successive minutes of fire.