Ignition pressure

Ignition, pressure, burning rate, and thmst characteristics over temperature range... 

Fig. 13.17 shows the structure and principle of a T-bumer, as used to measure the response function of propellants. Two propellant samples are placed at the respective ends of the T-burner. The burner is pressurized with nitrogen gas to the test pressure level. The acoustic mode of the burning established in the burner is uniquely determined by the speed of sound therein and the distance between the burning surfaces of the two samples. When the propellant samples are ignited, pressure waves travel from one end to the other between the burning surfaces of the samples. When a resonance pressure exists for a certain length of the T-bumer, the propellant is sensitive to the frequency. The response function is determined by the degree of amplification of the pressure level. 

Figure 8.10. Threshold ignition pressure pi versus Hs/O rutin for ignition of propellants A, B, C, M

It predicts ignition delay times for space rocket engines and ignition pressure spikes (Ref 40)... 

Ignition pressures, determined at one temperature for a series of fuels, increase as the knock ratings of the fuels increase (125, 159). 

Fig. 14 Four-way valve for switching between ignition and operation pressure. The setting for the ignition pressure (left side) bypasses the capillary loop...

Fig. 23 Plasma chamber (a) before ignition (b) at ignition pressure after arc discharge (c) at operation pressure...

Outlets provided in the generator case for hot gas flow, igniter, pressure measurement, and safety diaphragm. 

The early work on phosphine oxidation, which was mostly concerned with the upper explosion limit, was reviewed by Trautz and Gabler. They also found that mixtures of PH3 and O2 ignited under diminished pressure and that this upper pressure limit was not dependent on surface effects. The ignition pressure depended on the [02]/[PH]3 ratio, the temperature, and the presence of foreign gases it increased with [PH3], fell with increasing [H2O], but was nearly independent of the presence of N2, N2O, H2, CO, CO2, and NH3. It rose sharply with increasing temperature. 

The reader should also note that the width of the flammability limits (the range between the lower and upper flammability limits) is a function of ignition energy, ignition pressure, ignition temperature, inert gas concentration, and relative humidity of the mixture. 

Figure 11-22. Ignition in H2-O2 mixture stimulated by the fast ionization wave. Solid curve is for H2-O2 without diluents recorded ignition pressures have been adjusted by removing partial pressure of He. Temperatures and pressures are those after passage of the refleeted shoek, but before the fast-ionization-wave energy deposition.

When chain termination at the wall occurs in the diffusion region, we obtain bg/p instead of the constant b. Thus, the cubic equation obtained for the upper and lower ignition pressures is... 

An explosion range is reduced by a decreasing temperature at a constant pressure. The minimum ignition pressure increases and vice versa. 

Figures 6.3 and 6.4 [8] show the dependence of the explosion range, including the minimum ignition pressure and the maximum explosion pressure, particularly at pressure less than or equal to the atmospheric pressure, on the mentioned influencing factors.

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