Spontaneous Ignition Delay of Fuel Spray Injected into a Gas Stream

抄録

Spontaneous ignition delay of fuel spray injected into a hot gas stream produced by burning of propane has been measured, using a test rig consisting of 200φ×3 m parallel duct. Results obtained were compared with those by Mullins, who had carried out the same experiment in the range of higher stream temperature and velocity, and with the delay obtained by other methods at atmospheric pressure. Conclusions can be summarized as follows : Controlling factor of ignition delay in a gas stream is considered to be of chemical nature judging from activation energy, 35 to 45 kcal/mol. It depends predominantly on the temperature and less on the physical factors such as velocity or spray condition. This is explained as follows : In spite of rapid formation of uniform mixture, velocity and concentration prevailing is outside the stability range of fuel spray and cannot lead to flame propagation against other ignition processes.