EFFECT OF CATALYSTS ON THE DEFLAGRATION RATE OF AMMONIUM PERCHLORATE
Interim rept. 1 Jul 1968-30 Jun 1969
CALIFORNIA UNIV BERKELEY
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The burning rates of polycrystalline pellets of ammonium perchlorate from three sources and with different degrees of recrystallization Degree of recrystallization is used to mean the number of times ammonium perchlorate is successively recrystallized were measured and compared. The burning rate changed considerably in the first three successive recrystallizations and the data showed that the impurities affected the burning rate especially at high pressures. It was also found that occluded water in ammonium perchlorate pellets changed the deflagration rate considerably. These results indicate that one of the reasons for the disagreement among different investigators on the burning rate of ammonium perchlorate might well be the effect of traces of residual impurities which existed in the crystals and pellets used in the studies even after purification by recrystallization. The present study also indicates that the nature of impurities in the as received or recrystallized ammonium perchlorate depends on the source of supply. It was also found that pressing uniform pellets of reproducible quality is very difficult. Considerable experimental evidence exists which indicates that the distribution of catalyst has relatively little effect on its performance. To understand better the important parameters needed to explain the experimental data, a theoretical study was carried out. A mathematical model was developed to calculate the effectiveness factor for surface reactions coupled with surface diffusion on a solid-catalyst surface or bulk diffusion near the burning surface, with discrete adsorption centers. The solutions for integral-order reactions are presented.
- Physical Chemistry
- Ammunition and Explosives
- Combustion and Ignition