Showing papers on "Burn rate (chemistry) published in 1994"

Azide-free gas generant compositions and processes

Abstract: Composition and process for inflating an automobile or aircraft occupant safety restraint bag which reduces the toxicity of the gases produced by gas generants. A relatively low energy nitrogen containing fuel is combined with a burn rate accelerator, such as an alkali metal salt, to form an azide-free gas generant composition which lowers the combustion temperature of the gas generants while also maintaining a rapid burn rate, thereby reducing toxicity of the resultant gases.

Apparatus for suppressing a fire

Abstract: An apparatus for suppressing a fire comprises a gas generator containing a propellant and a fire suppressant as a mixture of compacted powders. The average diameter of a fire suppressant particle is larger than the average diameter of a propellant particle and the larger fire suppressant particles form discrete cooling sites that do not dramatically reduce the propellant burn rate.

Propellant properties conducive to electrostatic discharge ignition

Abstract: A mechanism for electrostatic discharge (ESD) ignition of composite rocket propellants was developed based on review of recent literature on spark-induced ignition of gaseous fuel/air mixtures, dispersions of liquid fuel droplets in air, and solid energetic materials. Ignition implies substantial amounts of available propellant are consumed subsequently. The role of mechanical properties in facilitating ignition by maintaining subsurface hot spot pressure developed by the discharge and products of reaction was identified. Other analysis demonstrated additional thermophysical, thermochemical, chemical kinetics, and electrical propellant properties important to ESD sensitivity. Properties which facilitate ignition (e.g., low activation energy for ignition delay) and high propellant burn rate (e.g., small median diameter of oxidizer particle size distribution) favor combustion of the energetic material after a discharge, as do those which inhibit heat losses (small propellant thermal diffusivity) an...

High Pressure Windowed Chamber Burned Rate Determination of Liquid Propellant XM46

Abstract: : A high-pressure windowed strand burner has been used to obtain burning rates for XM46 over the pressure range from 10 to 300 MPa. Burn rates for the liquid XM46 were erratic due to surface irregularities. This burning surface variable was minimized by gelling; two different gelling agents were used. The burn rate (r) vs. pressure (p) can be adequately expressed by an exponential of the form r = Apn. A definite pressure break occurs around 70 MPa for gelled XM46. For pressures below about 70 MPa, n approx. 0.2 and for pressures between 70 and 300 MPa, the two different gelling agents gave n values of 1.0 and 1.2.

Castable double base propellants with compounds containing group IIA metal ions as ballistic modifers

Abstract: Propellant formulations are provided which include non-toxic burn rate modifiers. In order to produce a usable propellant formulation, it is necessary to control the burn rate of the propellant. Failure to adequately control the propellant burn rate often results in unacceptable performance of the propellant. It has been found that Group IIA metal salts, such as calcium carbonate and strontium carbonate, are capable of modifying the burn rate of propellants without resorting to lead as a burn rate additive. Accordingly, the use of from about 0.5% to about 5.0% Group IIA metal salt is taught as effective burn rate modifiers in propellants, in order provide non-toxic means for modifying the propellant burn rate.

Ultra-high burn rate gun propellants

Abstract: A family of ultra-high burn rate gun propellant systems based upon a nitrocellulose binder matrix, and containing a variety of azide components to provide formulations having reduced isochoric flame temperatures and ultra-high mass consumption rates.

Method and apparatus for making banded wrappers

Abstract: of EP0615702A method and apparatus for making banded smoking article wrappers is disclosed. The apparatus includes a cylindrical rotating applicator 60 that has alternating regions 64 of mesh material and regions 66 of solid material on its outside surface 51. The applicator allows repetitive patterns of additional slurry to be applied to a continuous web of paper so that the basis weight of the paper is repetitively increased. Such paper, when incorporated into a smoking article, modifies the burn rate characteristics of the article.