Determination ignition temperature of flammable liquids in different conditions

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