This article presents an experimental investigation of the flame characteristics of the gasoline pool fire. A series of experiments with different pool sizes and mixture contents were conducted to study the combustion behavior of pool fires in atmospheric conditions. The initial pool area of 0.25 m2, 0.66 m2, and 2.8 m2, the initial volume of fuel and time of burning process, and the initial gasoline thickness of 20 mm were determined in each experiment. The fire models are defined by the European standard EN 3 and were used to model fire of the class MB (model liquid fire for the fire area 0.25 m2), of the class 21B (model liquid fire for the fire area 0.66 m2), and 89B (model liquid fire for the fire area 2.8 m2). The fire models were used to class 21B and 89B for fuel by Standard EN 3. The flame geometrical characteristics were recorded by a CCD (charge-coupled device) digital camera. The results show turbulent flame with constant loss burning rate per area, different flame height, and different heat release rate. Regression rate increases linearly with increasing pans diameter. The results show a linear dependence of the HRR (heat release rate) depending on the fire area (average 2.6 times).
The article considers the granulometric analysis of selected samples of tropical wood dust from cumaru (Dipteryx odorata), padauk (Pterocarpus soyauxii), ebony (Diospyros crassiflora), and marblewood (Marmaroxylon racemosum) using a Makita 9556CR 1400 W grinder and K36 sandpaper, for the purpose of selecting the percentages of the various fractions (<63; 63; 71; 200; 315; 500 μm) of wood dust samples. Tropical wood dust samples were made using a hand orbital sander Makita 9556CR 1400 W, and sized using the automatic mesh vibratory sieve machine Retsch AS 200 control. Most dust particles (between 50–79%) from all wood samples were under 100 μm in size. This higher percentage is associated with the risk of inhaling the dust, causing damage to the respiratory system, and the risk of a dust-air explosive mixture. Results of granulometric fractions contribution of tropical woods sanding dust were similar. Ignition temperature was changed by particle sizes, and decreased with a decrease in particle sizes. We found that marblewood has the highest minimum ignition temperature (400–420 °C), and padauk has the lowest (370–390 °C).
This paper presents the results of monitoring the behaviour of selected wood species exposed to a small ignition initiator. We specifically aimed to investigate the effect of retardant coating on the combustion process of the wood species spruce (Picea abies), red spruce (Larix decidua), Scots pine (Pinus sylvestris), ash (Fraxinus excelsior L.), beech (Fagus sylvatica), and oak (Quercus robur) when exposed to a small initiator of ignition. At the same time, we studied the effect of different types of fungicidal agents (based on N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine; alkyl (C12–16) dimethylbenzyl ammonium chloride or 3-iodo-prop-2-inylbutylcarbamate) on the effectiveness of a flame retardant (containing ferric phosphate) applied to the selected fungicide-treated wood samples. The experimentally obtained mass-loss and flame-spread results were statistically evaluated using the QtiPlot software program. A significant dependence of mass loss and surface flame spread on wood species was the primary focus. It was only confirmed for the surface-flame-spread variable. The dependence of the effect of fungicide treatment on the effectiveness of the selected retardant was confirmed. Fungicidal coatings with the active ingredient alkyl/benzyl (C12–16) dimethylbenzyl ammonium chloride indicated the lowest mass loss rate and flame spread for all wood samples.
Due to the increasing number of battery electric vehicles (BEV) on the roads and the number of BEV accidents with the occurrence of a fire, full-scale fire tests of BEVs were carried out. For initiation, the BEVs were mechanically damaged, forming a gap with a size of 15 cm × 15 cm. The external heat source was a 300 kW propane burner with a maximum power of 54.0 kW and a length of 54 cm. The flame of the propane–butane fuel mixed in air at a temperature of 1970 °C was inserted directly into the battery pack. The increase in the temperature was monitored as a function of time through thermocouples at selected locations of the BEV until the point of initiation. Thermocouples were placed 10, 30, and 50 cm from the place of BEV surface. Accordingly, to obtain the temperature–time curves from the experiment measurement, critical temperatures were subsequently evaluated. The fire tests on BEVs can be described according to the individual phases of the fire. The external heat source started the initiation process at the 25 min time mark. Consequently, the phase of a developed fire with a dynamic course started. A sharp rise in temperature occurred. Within two minutes, the temperature rose to 1056.9 °C. After the initiation source was removed, there was decline in temperature and re-ignition to the stage of a fully developed fire. Thermocouples recorded temperatures in the range of 900 °C. The resulting dynamic process of a BEV fire with a sharp increase in temperature is a problem for the implementation of firefighting works and the liquidation of traffic accidents. Furthermore, foam extinguishing was part of the experiments. In both cases after the foam application, the temperature on the thermocouple T1 (distance was 10 cm from the surface of the BEV) dropped from 486.1 °C to 76 °C after 10 s of application.
Firefighting units in the Slovak Republic are well prepared for extinguishing fires of vehicles with internal combustion engines. However, the expansion of electromobility is also coming to Slovakia. It is essential to pay attention to this topic from the point of view of repression. This article deals with car fire blankets. The main objective is to verify and compare the effectiveness of extinguishing internal combustion engine vehicle (ICEV) fires and high-voltage traction battery (HTB) fires using car fire blankets. The effectiveness of a car fire blanket was determined based on the analysis of temperature drops during large-scale fire tests of ICEVs and HTBs. The temperature was recorded by four thermocouples. Two thermocouples were placed at 0.7 m from the ICEV and HTB; one thermocouple was placed in the interior of the ICEV and inside the HTB; one thermocouple was placed on the roof of the ICEV and the surface of the HTB. Subsequently, the results were compared based on temperature–time curves obtained from experimental measurements. Applying the car fire blanket to the ICEV fire caused a drop in temperature on all thermocouples. The most significant temperature drop was recorded in the interior of the vehicle. Specifically, the temperature dropped from 724 °C to 140 °C. However, the application of the car fire blanket had a different effect on the HTB fire. There was a minimal temperature change in the thermocouple on the right side at a 0.7 distance. The other thermocouples identified a slight increase in temperature.