Ignition system for rocket engine combustion chambers operated by non-hypergolic propellant components

• US 3,943,706 A
• Filed: 12/27/1973
• Issued: 03/16/1976
• Est. Priority Date: 01/10/1973
• Status: Expired due to Term

• Current Assignee: Messerschmitt-Bolkow-Blohm GmbH
• Original Assignee: Messerschmitt-Bolkow-Blohm GmbH
• Inventors: Grafwallner, Franz, Schutz, Manfred
• Primary Examiner(s): Croyle, Carlton R.
• Assistant Examiner(s): Ross, Thomas I.
• Application Number:
  US05/428,840
• Time in Patent Office: 810 Days
• Field of Search: 60/259, 60/212, 60/213, 60/250, 60/39.46, 60/39.48, 60/261, 60/39.82 H, 60/39.14, 60/204
• US Class Current: 60/204
• CPC Class Codes: F02K 9/48 driven by a gas turbine fed by propellant combustion gases or fed by vaporized propellants or other gases

Abstract

An ignition system for rocket engine combustion chambers which are operated by non-hypergolic propellant components and particularly for the pre-combustion chambers of main stream engines of this type, comprises a main combustion chamber having injector means for injecting a propellant component into the combustion chamber for combustion therein. Since the propellant components employed are non-hypergolically reactive, they are ignited by an ignition agent which is produced by the pressure of a first propellant component which is non-hypergolically reactive with the ignition agent into the combustion chamber. The second propellant component which reacts with the ignition agent hypergolically is also introduced into the combustion chamber so that ignition takes place immediately. The arrangement includes a storage tank for the ignition agent having a piston movable therein by admission of the propellant component which is non-hypergolically reactive with the ignition agent to one side of the storage space which contains the ignition agent which in turn is moved by the piston from the other side of the storage space out through a connecting passage into the combustion chamber. After the piston has travelled an amount sufficient to direct a predetermined quantity of the ignition agent into the combustion chamber, the piston passes a port which communicates the propellant component with the combustion chamber so that it can flow after the ignition agent into the combustion chamber for reaction with the other propellant component which is also introduced into the combustion chamber.

Claims

1. An ignition system for rocket engine combustion chambers operated by non-hypergolic propellant components, and particularly for precombustion chambers of main stream engines, comprising wall means defining a main combustion chamber having a thrust nozzle discharge and a precombustion chamber connected to said main combustion chamber, said precombustion chamber generating gases having one propellant component in excess of the other, a gas turbine in the connection between said main and said precombustion chambers operable by the gases perfused by said precombustion chamber and discharging these gases after use into said main combustion chamber, first and second propellant component pumps connected to and driven by said turbine, storage means for an igniting agent for storing said igniting agent in a gaseous state under a pressure which is lower relative to a pressure required to transport the igniting agent to said precombustion chamber, a first propellant component supply tank for storing a first propellant component which is non-hypergolically reactive with said igniting agent and which is connected to said first propellant component pump, a second propellant component supply tank for storing a second propellant component which is hypergolically reactive with said igniting agent but not with said first propellant component and which is connected to said second propellant component pump, respective first and second delivery conduits connected between said first and second propellant component pumps and said precombustion chamber for the flow of said components to said precombustion chamber, piston means movable in said storage means and dividing said storage means into an ignition agent space on one side of said piston means and a pressurizing gas-receiving space on the other side of said piston means, first and second storage tanks for separately storing second and first gaseous non-hypergolic propellant components under high pressure connected respectively to said precombustion chamber and to said pressurizing gas-receiving space for forcing said piston to move in a direction to compress the igniting agent and to subsequently direct it through said first delivery conduit to said precombustion chamber, said storage space means having a port uncoverable by substantially complete movement of said piston to evacuate said ignition agent and to communicate the space containing said first gaseous propellant component with said first delivery conduit for its flow through said first delivery conduit after the flow of the ignition agent, said first storage tank connection to said pressurizing gas-receiving space having valve means operable only upon starting of said engine to pressurize said pressurizing gas-receiving space.

2. An ignition system for rocket engine combustion chambers, according to claim 1, wherein said storage means comprises a cylinder having an outlet in said first conduit and having a collapsible bellows in said cylinder with an interior space containing said igniting agent communicating with the outlet of said storage space means and to said precombustion chamber, said bellows being spaced inwardly from said cylinder walls and defining an annular space around said bellows which is sealed off from the interior of said bellows which communicates with said outlet.

3. An ignition system for rocket engine combustion chambers, according to claim 2, including a bypass line connected from said storage means port to said first conduit having a check valve therein permitting flow only from said storage space means to said outlet.

4. A method of igniting a rocket engine of the main stream type which includes a main combustion chamber and a precombustion chamber which generates one propellant component-rich gaseous products which drive a turbine in the connection between the precombustion chamber and the main combustion chamber and in which the turbine, in turn, dirves first and second propellant component pumps which are connected respectively to propellant components which are separately pumped to the precombustion chamber and to the main combustion chamber and using an igniting agent which is stored in a separate storage vessel having a sealed piston member which is movable in the vessel to discharge the igniting agent and also using first and second storage tanks of high pressure, gaseous non-hypergolic propellant components and wherein the igniting agent is hypergolically reactive with only one of said first and second components and the high pressure gaseous components in the storage tanks are non-hypergolic, comprising upon starting of the engine connecting the second storage tank through the storage vessel for the igniting agent at a location behind the piston to move the piston to pressurize the igniting agent and to force it to said precombustion chamber while the piston maintains a separation of the second storage tank high pressure gas from the igniting agent during its flow into said precombustion chamber and after the igniting agent has flown out of its storage vessel directing the high pressure gaseous propellant component from said first storage tank into said precombustion chamber to effect ignition thereof hypergolically with said igniting agent and subsequently adding said first and second propellant components to said precombustion chambers by delivery thereof by the pumps driven by said turbines to complete the combustion operation.

5. A method of igniting a rocket engine combustion chamber, according to claim 4, wherein the space in the storage space containing the igniting means is divided by a collapsible bellows and the igniting agent is maintained in the collapsible bellows which is compressed by movement of the piston so that it does not come into contact with the walls of the storage space.