Ignition system for monopropellant combustion device

Chilenski, J. J.

English

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NATIONAL AERONAUTICS AND SPACE ADMINISTRATION 
WASIIINGTON. D.C. 20546 
REPLY TO 
ATTN OF: 
FROM : 
July 27, 1970 
~~I/~cientific & Technical Information Division 
Attention: Miss Winnie M. Morgan 
~~/0ffice of Assistant General 
Counsel for Patent Matters 
SUBJECT: Announcement of NASA-Owned 
U.S. Patents in STAR 
In accordance with the procedures contained in the Code GP 
to Code US1 memorandum on this subject, dated June 8, 1970, 
the attached NASA-owned U.S. patent is being forwarded for 
abstracting and announcement in NASA STAR. 
The following information is provided: 
U.S. Patent No. 
Corporate Source : California Institute of Technology 
Supplementary 
Corporate Source : Jet Propulsion Laboratory 
NASA Patent Case No.: XNP-00249 
Please note that this patent covers an invention made by an 
employee of a NASA contractor. Pursuant to Section 305(a) of 
the National Aeronautics and Space Act, the name of the 
Administrator of NASA appears on the first page of the patent; 
however, the name of the actual inventor (author) appears at 
the heading of Column No. 1 of the Specification, following the 
words ". . . with respect to an invention of. . . ." 
Gayle Parker 
Enclosure: 
Copy of Patent 
I q (NASA CR OR TMX OR AD NUMBER) 
Y 
(THRU) 
A (CATEGORY) 
https://ntrs.nasa.gov/search.jsp?R=19700028933 2020-03-17T02:15:01+00:00Z
FIG. D 
PREsSURE OAS (N2) 
PRESSURE 
WpplY TANK (N2 H4) 
FIG. 2 
FIG. 3 
INVEWTOR. 
JOHN J. CHlLENSKl 
ATTORNEY 
3,120,138 United States Patent O6ce , ,,
James E. Webb. administrator of the 
2 
oxidizer tube is dimensioned to receive a 
tics and space Admidstration, with respect to am inven- 
tion of John J. Chilensld 
Filed Mar. 3, 1962, Ser. No. 180,391 
4 Clainnsc (el. 60-35.6) 
Monopropellant devices, such as rocket motors, utilize 
a porous catalyst bed suitably supported in the rocket 
motor chamber. A monovro~llant is forced into the 
charge of an oxidizer, such as nitrogen &&oxide, chlo- 
rine trifluoride or nitric acid. The amount of o x i b r  
contained in the tube 12 is calculated to afford pasitive 
ignition of the catalyst bed when discharged into the 
rocket motor chamber 2. The extended end of the t u b  
12 is joined to a flange plate 14 which caps an end wall 15 
of a pressure vessel 16. The confronting sides of the 
plate 14 and the end wall 15 have confronting deal 
cavities 17 and 18. Interposed between the cavities 
and clamped between the flange plate 14 and end wall 
15 is a rupture diaphragm 19. The cavity 17 comuni-  
catalyst bed, and when i&ted, continues to decompose cates with the tube 12; whereas, the cavity 18 c o m e -  
and generate a pressure until the supply is terminated. cates with the interior of the pressm vessel 16 through 
This invention is directed to ignition systems for effecting 16 an orifice 19. 
ignition and decomposition of the monopropellant and A small tube 20 communicates initially beheen the 
included in the object of this invention are: interior of the pressure vessel 16 and a radial passagp: 
First, to provide an ignition system for monopropellant 21 communicating with the cavity 17 and oxidizer tubs, 
devices wherein a predetermined charge of an oxidizer 12. The tube 20 is adapted to be sealed by Wing pinched 
is introduced into the combustion chamber of the device 20 or flattened as indicated by 22 in FIG. 3. 
simultaneously with initial introduction of the monopro- Operation of the jgnition device is as follows: 
pellant to produce a hypergolic action which instantly With the control valve 13 closed, a charge of oxidizer 
ignites the catalyst bed so as to ignite and sustain decom- is introduced into the tube 12, for example a supply port, 
position of the monopropellant. not shown, similar to the passage 21 in the plate 14. 
Second, to provide an ignition system of this class 25 While the valve 13 remains closed, but with the connect- 
which is lightweight and free of moving parts, except for ing tube 20 open, the pressure vessel 16 is charged with 
valves, thereby providing an ignition system which is par- an inert gas such as nitrogen. The gas pressurizes the 
ticularly adapted for use in rocket vehicles. tube 12 also so that the pressure on opposite sides of the 
Third, to provide an ignition system of this class which rupture diaphragm 19 is equalized. After the pressure 
is capable of operation irrespective of gravity conditions 30 vessel is charged, the connecting tube is sealed by being 
or atmospheric pressure, including conditions of zero flattened as indicated by 22. 
gravity and zero pressure. The supply tank 8 and supply line 7 are filled with a 
With the above and other objects in view as may a p  monopropellant, and are pressurized to a pressure deter- 
pear hereinafter, reference is directed to the accompany- mined by the regulator 10. On w m a n d ,  the control 
ing drawings, in which: 35 valves 6 and 13, which may be solenoid operate$ are 
FIGURE 1 is a diagrammatical view showing a con- opened. The monopropellant flows from the supply tank 
ventional monopropellant rocket motor, and monopro- under a constant pressure determined by the regulator 
pellant supply and indicating diagrammatically the igni- 10. The opening of the valve 13 first bleeds the s d l  
tion means in association therewith. quantity of inert pressure gas sufficiefitly to cause the di- 
FIGURE 2 is an enlarged, substantially diagrammati- aphragm to rupture whereupon the inert gas in the pres- 
cal, partially sectional, partially elevation view of the ig- sure vessel functions to drive the oxidizer forcibly into 
nition means taken through -2 of FIG. 1. the motor chamber. The oxidizer, on entering the motor 
FIGURE 3 is a further enlarged fragmentary sectional chamber, ignites the catalyst and causes the monopro- 
view of the pinch tube taken through 3-3 of FIG. 2. pellant to decompose. Once started, the monopropellant 
Illustrative of a monopropellant device is a rocket 45 continues to decompose as long as the supply lasts. 
motor 1, having a cylindrical motor chamber 2, a nozzle It will be observed that flow of the oxidizer is not de- 
3 at the aft end thereof, and a closed head 4 at its for- pendent upon gravitational forces, nor is it &ecta:d by 
ward end. Suitably supported in the chamber 2 is a external pressures. Consequently, the oxidizer m y  be 
porous catalyst bed. A conventional catalyst bed is pre- depended upon to be discharged instantaneously on com- 
pared from small porous cylinders of alumina (Ala03) " mand into the rocket motor chamber irrespectively of 
and equirnolal solutions of the these conditions. 
nitrates of iron (Fe(N03)3.9HaO) Although I have shown and described a p d d s  em- 
nickel (Ni(N03)2-6HzO), and bodiment of my invention by way of illustration, the in- 
cobalt (Co(N03) 2. 6H20) vention is not limited thereto, but includes the 55 tions. combinations. and arranmments set forfh in the m- 
impregnating and coating the cylinders. The solution pend'ed claims. ' 
- 
is evaporated to dryness and heated until evolution of I claim: 
nitrogen dioxide (NO2) is terminated leaving oxides of 1. An ignition means for monopropellant devices, hav- 
the iron, nickel and cobalt. ing a catalyst bed, and means for introducing on wm- 
The head 4 is provided with one or more nozzles 5 mand, a monopropellant therein, said ignition means 
connected through a control valve 6 to a supply line 7. comprising: a pressure container for a charge of an oxi- 
The supply line is connected with a monopropellant sup- dizer; a pressure vessel for a charge of inert propeIling 
ply tank 8, Wed with a monopropellant such as hydro- gas; a rupture diaphragm for separating said vessel and 
zene (N2&). The monopropellant is pressurized by an container; means for initially equalizing pressures in said 
inert pressure gas such as nitrogen (Na) supplied from 65 vessel and container to provide an initial condition of 
a pressure tank, not shown, through a supply line 9 and zero pressure differential across said diaphragm; means 
pressure regulator 10. The structure thus far described for introducing said oxidizer into said catalyst 'bed, and a 
may be considered as conventional. valve interposed between said introducing means and 
The hydrazine reacts with the oxides of iron, nickel pressure container, operable on opening to reduce the 
and cobalt so that they are reduced to free metals. 70 pressure in said oxidizer container thereby to cause rup- 
Fitted in the head 4 is an oxidizer nozzle 11 connected ture of said diaphragm and propulsion of said oSdizer 
with an oxidizer tube 12 through a control valve 13. The into said catalyst bed. 
x -.,, A 
& m sr dC *+ 
S,lS0,7SS 
3 4 
2. An ignition means for monopropellant devices hav- compartment is likewise pressurized to e q u W  the pres- 
ing a chamber containing a catalyst bed, and valve means sure across said diaphragm; said diaphragm adapted on 
for introducing a monopropellant therein, said ignition opening'of said valve means 'to rupture, thereby to cause 
means comprising: .valve means for controlling intro- said inert gas to propel said oxidizer into said catalyst bed 
duction of an oxidizer into said catalyst bed chamber;' 6 chamber. 
means defining a compartment initially closed by said 4. A monopropellant rocket motor, comprising: a ' 
valve for receiving a pressurized charge of oxidi i ;  rocket motor having a motor chamber and nozzle; a cata- 1 
means defining a chamber for an inert pressure gas, said . lyst bed in said motor chamber; a first means contain- 
oxidizer and inert gas being pressurized to essentially the ing a pressurized supply of monopropellant; a first valve 
same pressure; means initially isolating said oxidizer com- 10 means responsive to remote command for connecting said 
partment and inert gas chamber, said means being oper- first means with said motor chamber to introduce said 
able on opening of said valve means to release said inert monopropellant therein; a second means containing a 
gas into said oxidizer compartment thereby to drive said pressurized charge of oxidizer; an inert gas pressure ves- 
oxidizer from said compartment into said catalyst bed sel; a rupture diaphragm initially isolating said second 
chamber. ' 15 means and pressure vessel; and a second valve respon- 
3. An ignition means for monopropellant devices hav- sive to remote command for opening said second means 
ing a chamber containing a catalyst bed, and valve means to said motor chamber thereby to reduce the pressure 
for introducing a monopropellant therein, said ignition therein and cause said diaphragm to rupture, whereby said 
means comprising: valve means for controlling introduc- inert gas propels skid oxidizer into said motor chamber. 
tion of an oxidizer into said catalyst bed chamber; means 20 
defining a compartment intially closed by said valve for References Cited in the file of this patent 
receiving a charge of oxidizer; means defining a chamber 
for an inert pressure gas; a rupture diaphragm initially UNITED STATES PATENTS 
isolating said oxidizer compartment and inert gas cham- 2,743,577 Malick --------------, May 1, 1956 
her; an W u w r  tube i n i w y  b Y P d g  said diaphragm 26 2,972,227 Men ,,---,---------, Feb. 21, 1961 
whereby on pressurizing said chamber with inert gas, sad 


Ignition system for monopropellant combustion devices Patent

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