|
|
Determination ignition temperature of flammable liquids in different conditions
SABELA, Marek
This master thesis named Determination of ignition temperature at flammable liquids under various conditions deals with atmospheric as well as specific technological, non-atmospheric, conditions. The measurements proved that the ignition temperature at luquids decreases with increasing preassure in a vessel. Based on comparison with foreign sources, it was possible to prove that even size of a vessel influences the ignition temperature. The bigger the vessel the lower the ignition temperature. The measurements are carried out in a closed vessel under isochronic conditions. This method guarantees there is no air exchange between vessel and the surroundings. To equip such measurements the Technical Institute of Fire Protection built specific facility capable of providing necessary conditions. The main goal of the experiments is to determine ignition temperature at selected flammable liquids under variable initial pressures and under various oxygen concentration and to compare the results with available sources in literature. Heptan and Pentan were chosen for this comparison and the experiments were carried out at various initial pressures of 100 kPa, 200 kPa, 500 kPa in a vessel. Apart from comparison of measured values by Technical Institute of Fire Protection along with cooperating institute PTB Braunschweig, this thesis focuses on determination of the lowest oxygen concentration at various initial pressures under which no ignition of tested flammable chemicals happens. Our experiments proved that when the atmospheric pressure in a closed vessel reaches 10%, the tested flammable liquid is not ignitable. When the measures are carried out under higher initial preassures in the vessel the oxygen percentage in the vessel is significantly lower.
|
|
|
Stanovení požárně technických charakteristik vybraných látek vybranými metodami
SABELA, Marek
This bachelor paper deals with determination of technical and fire characteristics of selected substances by particular methods. This paper proved that age of material influences ignition of both construction and decorative car materials that were compared. Their point of ignition decreased, their qualities such as toughness and elasticity got worse too. In order to get the aforementioned results, Setchkin's method was applied. Furthermore, using this method, samples of inflammable materials from 5 various car brands produced in the same year were compared. The comparison focused on materials from compartments, engine covers and seats in order to measure their ignition. Measuring showed that positioning of these materials in the cars has crucial influence on inflammability of material. Another key factor tempering the measured figures proved to be fire-retardants which increase heat resistance of material. Another method applied was conic calorimetry. It enabled to determine the figures representing heat release rate, total heat release and efficient calorific value as these figures serve as input parameters for modelling fires. The measurements were carried out in vertical and horizontal situations. The same materials from two different car brands were compared. The comparative method was applied on all parts made of plastic sincr the positioning of components used is the same for both producers. The position of researched samples proved to be crucial. The qualities measured and researched by the aforementioned methods are also described in detail. Additionally, it is also mapped how the measuring devices are set, under which conditions the tests are carried out and finally, which parameters the samples possess
|
guest ::
