US2935846A - Reaction motor feed system - Google Patents

Description

May 10, 1960 J. NEALE ET AL REACTION MOTOR FEED SYSTEM Filed July 13. 1956 E?" 1 1446A 4mm (l/W455 ,rmzcouza INVENTORS United, States Patent,

REACTION MOTOR SYSTEM Jack Neale, Sparta, and Charles F. Malcolm, Jr., B oouton, NJ., assignors, by mesne assignments, to Throkol Chemical Corporation, a corporation of Delaware Application July 13, 1956, Serial No. 597,696 1 Claim. (Cl. 60- 3948) .Whilethis methgd isiuseful, it penalizes the overall system since bulkyegas tankage is required and therefore alarge overall weight is incurred, this being undesirable for use in aircraft and ,many other applications.

In another method which has beenused heretofore, the propellant supply tanks are directly pressurized with the hot gases from the combustion of a solid or liquid propellant charge'in a gas generatorl- .Whilethi's' method has the advantage of low system weight and relative simplicity, the extremely hot gases create problems in flow control ofthe gases and which contains the gases. .In the present invention, however, the best featuresof these systems are combined into a single system wherein the propellant supply tanks are pressurized by means of in the materials of the structure a gas such as helium and nitrogen which is heated prior 1 to its entering the supply tanks, gas has the. advantage of maintaining the pressure in the supply tankswh'ile decreasing the density of the gas and thereby decreasing its mass flow, hence a smaller supply of pressurizing gas required for a given amou nt ofjprop'ellants to bepre'ssurized. Moreover pressure regulation of the pressurizing gas is easily accomplished before heating so that the simplicity of the system is unimpaired.

It is, therefore, an object of this invention to provide an improved means of pressurizing the propellants in a liquid propellant reaction motor feed system.

Another object of the present invention is to provide an improved means for pressurizing the propellants in a liquid propellant reaction motor feed system wherein a substantial reduction in weight of the overall system is obtained while at the sametime the system remains substantially free of moving parts.

Still another object of the present invention is to provide an improved means for pressurizing the propellants in a liquid propellant reaction motor feed system wherein the primary pressurizing gas is heated, thereby decreasing the mass of primary gas required to maintain its pressure while at the same time the advantages of low system weight, general system simplicity and relatively low temperature of the pressurizing gas are retained.

Another object of the present invention is to provide an improved means for pressurizing the propellants in a liquid propellant reaction motor feed system wherein the primary pressurizing gas is heated by direct admixture of the gas with the hot gases obtained from a gas generator, thereby decreasing the mass of primary gas required to Heating the pressurizing maintain the necessary pressure, while at the same time the advantages of low system weight and general system simplicity are retained. I

Still another object of the present invention is to provide an improved means for pressurizing the propellants in a liquid propellant reaction motor feed system wherein the primary pressurizing gas is heated by passing it within close proximity to the hot gases emanating from a gas generator, thereby decreasing the mass of primary gas required to maintain the necessary pressure, while at the same time the advantages of low system weight and general system simplicity are retained.

Other objects and advantages of the present invention willbecome apparent from the following description.

The invention is illustrated in the accompanying drawings in which Figure 1 shows the invention as applied to a reaction motor feed system, and

Figure 2 shows an alternate arrangement for adding heat tothe primary pressurizing 'g'as.

While the drawings show the invention in a preferred embodiment as applied to a rocket propulsion system, it is to be understood that the invention has great usefulness wherever there is a need for a light weight liquid pressurizing system. i

The preferred embodiment of the invention, as shown in Figure 1, includes a reaction motoror combustion chamber 10, a reservoir 11 containing liquid fuel propellant such as gasoline or other hydrocarbons, and a reservoir 12 containing liquid oxidizer'such as nitric acid.

- Remotely-controlled valves 13 and 14 are provided in the fuel and-oxidizer propellant supply lines 34" and 35, and check valves 15 and 1-6 are provided in the pressurizing gas supply'lines32 and 33. The pressurizing gaseous mixture 17 is composed of the primary pressurizing gas 19 and the hot gases 21. -Gases 21 are the gaseous products of combustion of a solid propellant 23 in the gas generator 22. While the figure shows the solid propellant as a powder charge 23, other means for obtaining heated or hot gases 21 such as the combusting of two liquid propellants or. the decomposition gases from a mono-propellant suchas concentrated hydrogen peroxide could be utilized. v

The hot gases 21 from gas generator 22 pass into a heat adder 18 through conduit 25, a remotely-controlled valve 26. and injection orifices 27. The primary pressurizing gas 19, WhiCh' iS an inert gas such as helium, nitrogen or the like, flows into heat adder 18 from a pressure container 20, through a conduit 28, through pressure-reducing regulating valve 30, and then through remotely-controlled valve 29, while the gaseous mixture 17, flows into propellant reservoirs or tanks 11 and 12 by means of passage through conduits 31, 32 and 33 and check valves 15 and 16. The propellants pressurized by gases 17 are then forced into the interior of the combustion chamber of motor 10 through conduits 34 and 35 and valves 13 and 14 upon the opening of valves 13 and 14.

Figure 2 illustrates an alternate type of heat adder or heat exchanging device 36. In the figure the hot gases 21 communicate with heat adder 36 by means of conduit 25, and the pressurizing gas 19 communicates with heat adder 36 by means of conduit 28 as before. 'However, direct admixture of gases 19 and 21 is prevented by the heat-exchanging walls 40 which divide the heat adder 36 into compartments 38 and 39. Also an exhaust conduit 37 is provided so that the hot gases 21 can flow continuously into and out of the heat adder or exchanger 36.

The gases 21 entering conduit 37 can be conducted to other heating devices or to the atmosphere.

In operation, reservoirs 11 and 12 are filled with their respective liquid propellants through pressure-tight inlet ace-me ts filler caps 11:: and 12c, and the caps are then replaced. Helium or nitrogen reservoir 20 is filled with gas under pressure which flows through conduit 28a and regulator 30 to valve 29. Valves 26 and 29 are then opened and propellant charge 23 in gas generator 22 is ignited by electrical igniter 24. As the charge burns, high temperature gases are produced which flow through conduit 25, valve 26 and ports or orifices 27 into heat adder 18. At the same time, nitrogen, or helium as the case may be, flows from reservoir 20 through conduit 28a, regulator 30, valve 29 and conduit 28b directly into heat adder 18, where the relatively cold nitrogen and the hotter gases are admixed and the nitrogen is heated. The resultant heated mixed gas then passes out of heat adder 18 through conduits 31, 32 and 33 and check valves 15 and 16 into reservoirs 11 and 12 through inlets 11a and 12a, respectively, there exerting its pressure upon the liquid propellants therein. Upon the opening ofyalves 15 and 16, the liquid propellants will be forced from their reservoirs by the pressure within the reservoirs, through valves 13 and 14 and their respective conduits 34 and 35 into rocket motor where the fuel is ignited in the presence of the oxidizer.

The extent of the pressure in the system is controlled by the setting of regulator 30, the amount of the hot gases added being so small in quantity as not to materially afiect the final pressure in the reservoirs due to theirvery high temperature and consequent very eflective heating of the relatively cold gas.

Valves 26; and 29 are of a three-way type sothat flow throughthem can be permitted, shut 011 or vented to the atmosphere through vents 26a and 29a for both control and safety purposes. Check valves and 16 are provided for safety purposes to prevent flow back through the system in the event of large downstream combustion pressure surges sometimes experienced in the rocket em gine art. v

In those systems where the heat adder or heat ex-. changer 36 shown in Figure 2 is used, the operation is identical except that the hot and cold gas are notadmixed. Also, it may be desirable to time the entrance of the hot gases 21 into the exchanger 36. ahead of the primary gases 19 so that a preheating of the exchanger may occur,

With either method described herein, a heatingof the primary pressurizing gas is obtained with resultant savings in weight due. to the decrease in primary gas density with increased temperature. The weight of the hot gas generator and its combustible charge is negligible, since the volume of hot gas required to. effect a sizable decrease in prirnary. gas weight can be obtained from a very small amount of solid propellant charge 23.

While there have been shown and described and pointed out the fundamental novel features of the invention as 7 applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in V the form and details of the device illustrated and in its operation may be made by those skilled in the art, without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claim.

What is claimed is:

A pressurized liquid propellant feed system for a reaction motor comprising a high pressure source of inert pressurizing gas, a heat adder, at least one chamber in said heat adder, conduit means communicably connecting said chamber in said heat adder to said pressurizing gas source, a regulating valve in said conduit means between said pressurizing gas source and said heat adder chamber, a gas generator which produces gases of higher temperature than the gas from said pressurizing gas source, means for causing operation of said gas generator, conduit means communicably connecting said gas generator to said heat adder chamber, said chamber common to said gases from. the pressurizing gas source and said higher temperature gases from said gas generator so that heating of said gas from the pressurizing gas source is efiected by the. admixture therewith ofthe gases from said gas generator, at least one reservoir with at least one inlet and at least one outlet, propellant contained in said reservoir, conduit means communicably connecting the said heat adder chamber outlet with said reservoir inlet so as to. conductsaid admixed gases-in saidheat adder chamber to the interior of said reservoir, and conduit means communicably connecting saidreservoir to the combustion chamber of a. reaction motor.

References Cited in the tile of this patent UNITEDv STATES, PATENTS

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