secondary cells with lithium anodes and immobilized fused_salt

I
65.
GAS GEHEPAT'OR PROPELTANTS
E. S. Sutton, C. F:. Vriesen, and E. J. Pacano~?slrj
I Thiokol Chenical Corporation
Elkton Division
Elkton, Xaryland
I
The properties of ammonium perchlorate have made it the oxidizer of choice
for composite sclid propellants for the past 20 years. Its ability to produce
propellant comFositions with high flane tenperatures and densities has made it
extremely useal to the missile propulsion industry.
Recently, it has become
possible to convert this versatile oxidizer to another nissilc S;JS~UJ application,
that of wdm gcs Generator propellats.
I Werm gas Cenerztor propellants are required for driviw turbine-alternator
I systems for electrical power generation, for actuating jet-controlled attitude
control system, and for propellin(; torpedo propulsion units. Despite the
advantages or' m.ioniun perchlorate, it has been difficult to utilize it in these
applications, because of the inherently high flame temperature (b500° to 55OOOF)
of propellants 'Jased on it. Because of the materials of construction used in
warn gas cenerator systems, the flame temperatures of these propellants are
limited to values in the region of 2200' to 2300OF.
In propellant technology, rechction of flame temperature is most conveniently
obtained by rcducix the oxidizer to el (G//F) ratio to a verj 1011 value, so that
the conposition is extremely fie1 rich. In Figure 1 a plot is shown of flame
temperature versus the weight percent of llH4Cl04 for a mixture of ammonium
perchlorate ani 2 Q-pical low oxygen content, high fuel content polymeric hydrocarbon
binder. Although aluminum powder is normally used as a fuel component in
solid propellants, it has been omitted for two reasons: it increases flame
temperature to still hi&er (and undesirzble) values, while producing solid
A1203 particles as ul eyhaust component. For most gas generator systems, the
presence of solid perticles in the coalrustion products is extremely undesirable
because of the resultvlt clogging and erosion of the metallic portions of the
system.
I
Emuination of Figure 1 shows that the gradual reduction of the IIHqClOq
1, content from 9q: to 7% reduces the flame temperature from 5000'F down to the ,
desired level of 22009, simply by greatly reducing the oxidation ratio of the
!
system. Tne oxidation ratio decreases from 4.33 down to 1.15 for these two
9 compositions, vhere oxidation ratio is defined as:
A)
Oxidation Ratio =
co Atoms
CC Atoms + 3 Df Atoms
Unfortunately, this reduction .results in undesirably hi& levels of solid
carbon in the coxxistion products vhen. these are exhausted to the ztmosphere.
%is can be seen in Table 1, where the level for the hi& fuel content binder is
6.455 solid crr2cn by weight. iJo carbon is found in the combustion chamber at
1000 psia, but eqmion of the gases to 14.7 psia results in copious quantities
of >lack snolre .
wo methods are'applicable to the solution of this problem. The first of these
involves substitution o$ much higher-oir.gen content binders for the polymeric fuel.
In Figure 1 and Table I the results of substituting highly oxygenated polyester .