GB1120889A - Rocket motor construction - Google Patents

Abstract

1,120,889. Rocket motors. THIOKOL CHEMICAL CORP. 11 Oct., 1966, No. 45483/66. Heading F3A. [Also in Division F1] In a rocket motor comprising a combustion chamber and a tank for storing at least one propellant liquid which tends to decompose and so produce a high pressure in the tank, a connection is provided between a point in the tank where gas collects and the exterior of the tank, the connection extending through the wall of the tank and being sealed thereto, there being a gas permeable, liquid impermeable filter in the connection whereby gas may be vented from the tank. The rocket motor shown comprises inner and outer walls 5, 4 which define an annular space 8 which is divided by a partition 10 into two compartments 8A and 8B which are utilized for liquid propellant storage, the compartment 8A being for storage of liquid oxidizer such as inhibited red fuming nitric acid, and compartment 8B for storage of liquid fuel such as unsymmetrical dimethyl hydrazine, the compartments being filled through openings 12, 13 which are then sealed. The inner wall 5 defines a combustion chamber 9 to the rearward end of which is mounted a propulsion nozzle 14. A solid propellant charge 38 is inserted into the forward portion of the combustion chamber and an igniter 15 is provided to fire the charge 38. When the charge 38 is fired, the resulting pressure increase bursts the bands 23 and 24 and the pressure gases pass through ports 20 and 22 to pressurize the oxidizer and fuel storage compartments 8A, 8B respectively. At the same time the pressure gases pass through the perforated end wall 40 and act on the slide valve 31 which moves to the left shearing the seal cups 35, 36 and placing the ports 33, 34 in communication with the orifices 25, 26. The pressurized fuel and oxidizer propellants now pass into the combustion chamber where the mixture is ignited by the hot gases from the solid fuel charge 38. The pressure produced in the chamber bursts the closure disc 51 and the gases discharge through the nozzle 14. The fuel flowing to the aligned orifices 26, 34 passes adjacent the wall of the combustion chamber through a space defined by a tubular baffle 11 so as to effect cooling. A device 42 is provided to prevent excessive pressure building up in the fuel storage compartment 8B during storage either in the horizontal position shown or in the vertical position preparatory to firing, the device comprising a collecting head 44 having perforations 47 and containing a suitable gaspermeable, liquid-impermeable material such as a porous fluoro-carbon resin. A tube 45 passes from the head 44 through the wall of the fuel storage compartment and into combustion chamber 9 where it is connected to an expansible container 46 which is disposed within a retainer 50. Any gas collecting in the ullage space 43 will thus pass into the container 46 and so prevent excess pressure being created within the fuel storage compartment. The container 46 and the retainer 50 are discharged through the nozzle 14 as the rocket is fired, the slide valve 30 severing the tube 45 as it moves to the left and then sealing the open end. - Reference has been directed by the Comptroller to Specifccation 942,047.