Abstract:
A solid propellant gas generator comprising alkali chlorides, potassium fluorochlorinate, and aluminum which produces pure chlorinefluoride gas in the absence of other gaseous products.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to gas generators and is particularly directed to solid propellant gas generators for producing pure chlorinefluoride (ClF) gas in the absence of other gaseous products. 
     2. Description of the Prior Art 
     A multitude of solid propellant gas generators exist which are capable of producing mixtures of nitrogen trifluoride (NF 3 ) and fluorine (F 2 ) gases for the operation of continuous wavelength chemical DF or HF chemical lasers. These gas generators are all based upon a variety of NF 4   +  salts such as NF 4  BF 4 . 
     Recent developments in the pulsed operation of chemical lasers indicate that higher efficiencies can be achieved if chlorinefluoride (ClF) gas is employed. The presence of NF 3  degrades the performance which eliminates the systems based upon the NF 4   +  salts from consideration. 
     U.S. Pat. No. 4,003,771 describes a gas generator based upon potassium fluorochlorinate (KClF 4 ) for use in chemical lasers. However, the gases produced from the systems described would yield a mixture of ClF 3 , ClF, F 2 , and Cl 2  gases which would not lead to satisfactory pulsed laser performance. 
     SUMMARY OF THE INVENTION 
     Accordingly, there is provided by the present invention a solid propellant gas generator for producing pure chlorinefluoride gas in the absence of other gaseous products. 
     OBJECTS OF THE INVENTION 
     Therefore, it is an object of the present invention to provide solid propellant gas generators comprising a mixture of alkali chlorides, potassium fluorochlorinate, and aluminum. 
     Another object of the present invention is to provide a chlorinefluoride gas generator. 
     Yet another object of the present invention is to provide a solid propellant gas generator yielding chlorinefluoride gas in the absence of other gaseous products. 
     Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In accordance with the present invention, a solid propellant chlorinefluoride gas generator is provided comprising a stoichiometrically-balanced mixture of alkali chlorides, potassium fluorochlorinate, and aluminum. 
     Potassium fluorochlorinate (KClF 4 ) is the preferred oxidizing source and was chosen for its excellent thermal stability. Alkali chlorides or mixtures of various alkali chlorides must be present to supply the chlorine necessary to stoichiometrically balance the excess fluorine present in the KClF 4 . Small percentages of aluminum are added as the combustion fuel. The overall reaction can be represented by the equation: ##STR1## where M is preferably potassium, sodium, lithium, or mixtures thereof, and most preferably potassium; and X 1-3  are the molar reaction coefficients. The moles of alkali chloride (X 3 ) required to assure the production of pure ClF are determined from the equation: 
     
         X.sub.3 =X.sub.1 -1.5X.sub.2 
    
     The temperature of the ClF produced is controlled by moles of aluminum fuel (X 2 ) present in the composition. Care must be exercised to maintain the reaction temperature below the dissociation temperature of ClF, and in the case where M is lithium that the dissociation temperature of lithiumfluoroaluminate (Li 3  AlF 6 ) is not exceeded. 
     When mixtures of alkali chlorides are used in the gas generator propellants appropriate stoichiometric calculations will readily yield optimum molar percentages. 
     By way of illustration and not limitation, specific examples of typical compositions are given in Table 1. 
     
                       TABLE 1______________________________________Ingredient      Weight Percent______________________________________KClF.sub.4      69.50   72.33   75.40  74.19Al               1.25    2.60    4.06   1.33KCl             29.25   25.07   20.54  --NaCl            --      --      --     24.48ReactionTemperature (°K.)            654    1195    1640    795Weight Yield of ClF           46.3    43.9    38.5   49.4______________________________________ 
    
     The yield of ClF is improved at the same aluminum level as the molecular weight of the alkali chloride utilized is reduced. 
     Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.