# US 8,230,672 B2 · Spark-integrated propellant injector head with flashback barrier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,230,672 B2 - Document ID: US8230672B2 - Status: Granted - Kind: B2 - Application number: 11/950,174 - Filed: 2007-12-04 - Published: 2008-07-24 - Granted: 2012-07-31 - Earliest claimed: 2006-12-04 - Assignees: Firestar Engineering, LLC - Inventors: Gregory Stuart Mungas; David James Fisher; Christopher Mungas - Web page: https://patentgrep.com/patent/US8230672B2 ## CPC - F02K 9/52: Injectors - F02K 9/94: Re-ignitable or restartable rocket- engine plants; Intermittently operated rocket-engine plants - F02K 9/95: characterised by starting or ignition means or arrangements (safety devices F02K9/38) - F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00) ## Abstract High performance propellants flow through specialized mechanical hardware that allows for effective and safe thermal decomposition and/or combustion of the propellants. By integrating a sintered metal component between a propellant feed source and the combustion chamber, an effective and reliable fuel injector head may be implemented. Additionally the fuel injector head design integrates a spark ignition mechanism that withstands extremely hot running conditions without noticeable spark mechanism degradation. ## Claims ### Claim 1 A combustion system comprising: a housing defining a cooling chamber and a combustion chamber separated by a flame barrier, wherein the cooling chamber is disposed around an electrode assembly, and the flame barrier comprises fluid paths with a diameter of less than about 10 microns that are configured to prevent combustion from propagating through the flame barrier, the electrode assembly comprises an interface sheath encompassing an insulating tube which encompasses an electrode; and a fuel inlet tube is disposed through the housing into the cooling chamber. ### Claim 2 (depends on 1) The combustion system of claim 1, wherein the electrode assembly is part of a spark ignition assembly that further comprises an electrical connector and a power supply. ### Claim 3 (depends on 1) The combustion system of claim 1, wherein the combustion chamber comprises an ablative liner adjacent the housing. ### Claim 4 (depends on 1) The combustion system of claim 1, wherein the combustion chamber defines proximal and distal ends, wherein the flame barrier is at the proximal and a throat constriction is at the distal end. ### Claim 5 (depends on 1) The combustion system of claim 1, wherein the fluid paths have a diameter of less than about 0.5 micron. ### Claim 6 (depends on 1) The combustion system of claim 1, wherein the electrode comprises a tip, single point, double point, triple point, quadruple point, star or split configuration. ### Claim 7 (depends on 1) The combustion system of claim 1, further comprising a seal between the flash barrier, the cooling chamber and the housing. ### Claim 8 (depends on 1) The combustion system of claim 1, wherein the cooling chamber receives fuel via the inlet tube. ### Claim 9 (depends on 1) The combustion system of claim 1, wherein the cooling chamber is adapted to cool the electrode assembly. ### Claim 10 A combustion system comprising: a housing defining a chamber having distal and proximal ends; the housing defining a cooling chamber at the proximal end, a combustion chamber at the distal end and a flame barrier between the cooling chamber and the combustion chamber, wherein the flame barrier is fluid-permeable and comprises fluid paths configure to prevent combustion from propagating through the flame barrier; an electrode assembly disposed through the proximal end of the housing through the cooling chamber and through the flame barrier terminating at a surface of the flame barrier adjacent the combustion chamber, wherein the electrode assembly comprises an electrode disposed within an insulating tube, and wherein the insulating tube is disposed within an interface sheath; and a fuel inlet tube disposed through a side of the housing into the cooling chamber, wherein the fluid paths have a diameter of less than about 1 micron. ### Claim 11 (depends on 10) The combustion system of claim 10, wherein the fluid paths have a diameter of less than about 0.5 microns. ### Claim 12 (depends on 10) The combustion system of claim 10, wherein the fluid paths have a diameter of less than about 0.2 microns. ### Claim 13 (depends on 10) The combustion system of claim 10, wherein the fluid paths have a diameter of less than about 1 cm. ### Claim 14 (depends on 10) The combustion system of claim 10, wherein the interface sheath and the flame barrier comprise materials having similar coefficients of thermal expansion. ### Claim 15 (depends on 10) The combustion system of claim 10, wherein the interface sheath and the flame barrier each comprise one or more of stainless steel alloy, pure nickel, nickel alloys, niobium, rhenium, molybdenum, tungsten, tantalum, tantalum alloys, sintered ceramic or laminate structures. ### Claim 16 (depends on 10) The combustion system of claim 10, wherein the combustion chamber comprises an ablative or high temperature liner adjacent the housing. ### Claim 17 (depends on 10) The combustion system of claim 10, wherein the combustion chamber defines a throat constriction at the distal end of the housing. ### Claim 18 (depends on 10) The combustion system of claim 10, wherein the electrode comprises a tip, single point, double point, triple point, quadruple point, star or split configuration. ### Claim 19 (depends on 10) The combustion system of claim 10, further comprising a seal between the flash barrier, the cooling chamber and the housing. ### Claim 20 (depends on 10) The combustion system of claim 10, wherein the cooling chamber receives fuel via the inlet tube. ### Claim 21 (depends on 10) The combustion system of claim 10, wherein the cooling chamber is adapted to cool the electrode assembly. ### Claim 22 A method of preventing flashback between a combustion chamber and a feed propellant and for providing regenerative cooling of an electrode assembly comprising: providing a propellant inlet into the cooling chamber, wherein a cooling Chamber circumscribes the electrode assembly; providing a micro-fluidic flame barrier configured to prevent combustion from propagating through the flame barrier to separate the cooling chamber and a combustion chamber, wherein the micro-fluidic flame barrier comprises paths having a diameter of about 5 microns or less, and running feed propellant through the fuel inlet, into the cooling chamber and through the flame barrier. ### Claim 23 (depends on 22) The method of claim 22, wherein the flame barrier comprises fluid paths having a diameter of about 2 microns or less. ### Claim 24 (depends on 22) The method of claim 22, wherein the fluid paths have a diameter of about 1 microns or less. ### Claim 25 (depends on 22) The method of claim 22, wherein the fluid paths have a diameter of about 0.5 microns or less. ### Claim 26 (depends on 22) The method of claim 22, wherein the fluid paths have a diameter of about 0.2 microns or less.