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  Hydrogen burner with a shut-off valve near the gas jetsUSPTO Application #: 20070254252Title: Hydrogen burner with a shut-off valve near the gas jets Abstract: A gas burner includes a distribution chamber formed between walls within the burner, with the walls extending parallel to one another. A shut-off valve, adjacent to an inlet hole through which a gas, preferably hydrogen, used as a fuel, enters the distribution chamber, closes when the pressure of the gas being supplied drops below a predetermined level, so that air is not allowed to flow backward into the apparatus supplying the gas, thus preventing potentially explosive conditions. (end of abstract) Agent: Ronald V. Davidge - Coral Springs, FL, US Inventor: Guenter Schaefer USPTO Applicaton #: 20070254252 - Class: 431080000 (USPTO) Related Patent Categories: Combustion, Timer, Programmer, Retarder Or Condition Responsive Control, By Combustion Or Combustion Zone Sensor, Of Shutdown By Response To Sensed Combustion Failure Or Overheat, By Electrical Control Circuit, Thermoelectric Generator Sensor The Patent Description & Claims data below is from USPTO Patent Application 20070254252. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The invention relates to apparatus providing for the combustion of hydrogen in air, and, more particularly to provisions within such apparatus for preventing the formation of an explosive mixture of hydrogen and air. SUMMARY OF THE BACKGROUND ART [0003] A conventional gas burner includes a mixing chamber in which the gas used as fuel is mixed with air and a distribution chamber in which the mixture is fed to a number of individual channels to form gas jets, with combustion occurring outside these individual channels. A valve for controlling the rate at which gas flows into the gas burner is located before the mixing chamber, often in a location remote from the gas jets. A problem with using this type of burner for hydrogen gas results from a potential for air to mix with the fuel within the distribution chamber, the mixing chamber, and associated tubing back to the point at which a shut-off valve is provided in the event of a failure in the gas supply pressure. The accumulation of a mixture of hydrogen and oxygen in such a large and extended enclosed space may result in an explosion, particularly when an attempt is made to restart the combustion process. [0004] The patent literature includes a number of descriptions of apparatus configured particularly for hydrogen combustion. A number of patent documents describe hydrogen burning apparatus in which the hydrogen is mixed with air or oxygen before combustion is applied. In general, a catalyst is used so that combustion can occur at a relatively low temperature. For example, European Patent EP 1179709 B1 describes a hydrogen combustion heater operated by bringing a mixture of hydrogen gas and air into contact with a catalyst to achieve a catalytic oxidation of hydrogen gas. The ratio of air to hydrogen flowing into the mixing area is controlled to limit the combustion to a mild oxidation that avoids firing the hydrogen gas. [0005] U.S. Pat. No. 6,019,172 describes a flameless process in which air and a fuel gas are heated in separate streams so that, when the streams are combined, the temperature of the mixture exceeds the autoignition temperature, with the temperature being less than that which would result in the oxidation upon mixing being limited by the rate of mixing. [0006] U.S. Pat. No. 5,190,453 describes a staged combustor including a first combustion stage for burning a fuel rich mixture of a fuel, preferably hydrogen, and an oxidizer, preferably oxygen. A plurality of serially positioned secondary combustion stages, downstream of the first stage, are provided for receiving secondary flows of oxidizer to the increasing mass of combustion efflux. The gradual increase of oxidizer/fule ratios provides a resultant substantially stoichiometric combustion. A cooling system is provided for cooling these combustion stages. [0007] International Patent Publication No. WO 2005/024301 A1 describes a burner in which hydrogen is mixed with air and burned in a burning chamber on a catalyzer at a low temperature in a flame-free manner. [0008] U.S. Pat. No. 4,614,176 describes apparatus for heating air by burning hydrogen, with the combustion occurring in direct proximity to a metal hydride fuel storage means in order that the combustion heat effects the release of hydrogen from the metal hydride. The hydrogen mixes with air in a mixing and distributing area before flowing through catalytic combustion reactors. (See abstract, col. 2, lines 44-50). [0009] U.S. Pat. App. Pub. No. 2001/0018915 A1 describes a catalytic heater burning a mixture of hydrogen and oxygen to heat water that is circulated to warm a diver's suit. [0010] While the prior art describes apparatus for providing certain desirable features of hydrogen combustion, what is needed to gas burner preventing the accumulation of a substantial mixture of hydrogen and air or oxygen in the event of a failure of the combustion process or an interruption in an adequate flow of hydrogen through the gas burner. SUMMARY OF THE INVENTION [0011] In accordance with a first aspect of the invention, apparatus is provided including a pair of walls extending parallel to one another to form a distribution chamber, an input hole, a plurality of channels, and a shut-off valve. The distribution chamber extends between the walls, one of which includes the input hole. The channels extend outward within the walls from the distribution chamber and along a periphery of the distribution chamber. The shut-off valve, which is outwardly adjacent the input hole extending into the distribution chamber, allows a gas used as fuel to flow into the distribution chamber when the shut-off valve is open. The shut-off valve closes in response to a drop in the pressure at which the gas used as a fuel is supplied through the shut-off valve. [0012] In one version of the invention, the shut-off valve is a check valve responding directly to a decrease in gas pressure. In another version of the invention, a thermal sensor is provided adjacent a combustion area formed by gas jets, with the shut-off valve being closed in response to a signal from the thermal sensor indicating that a temperature has fallen below a predetermined level due to a failure of the combustion process. Such a failure would naturally occur if the pressure at which the gas used for fuel were to drop below a level supporting combustion in the device. In yet another version of the invention, the shut-off valve is a check valve receiving the gas used as a fuel through a valve that is closed in response to detecting a combustion failure. In each case, the closing of the shut-off valve prevents a backward flow of air into the apparatus supplying the gas used as a fuel, which is preferably hydrogen, so potentially explosive conditions within this apparatus supplying the gas are avoided. [0013] Potentially explosive conditions may also be avoided by mixing the gas used as a fuel with air only after it has passed through the channels leading from the distribution chamber to form gas jets, or the gas used as a fuel may be mixed with air within the distribution chamber. Preferably, the volume of the distribution chamber is minimized. BRIEF DESCRIPTION OF THE FIGURES [0014] FIG. 1 is a transverse cross-sectional elevation of apparatus for hydrogen combustion built in accordance with a first embodiment of the invention; [0015] FIG. 2 is a bottom plan view of the apparatus of FIG. 1; [0016] FIG. 3 is a bottom plan view of a distribution plate within the apparatus of FIG. 1; [0017] FIG. 4 is a fragmentary bottom plan view of a version of the apparatus of FIG. 1 having an alternative cap plate; [0018] FIG. 5 is a fragmentary transverse cross-sectional elevation of the apparatus of FIG. 4, taken as indicated by section lines 5-5 therein; [0019] FIG. 6 is a plan view of an alternate version of the apparatus of FIG. 1 having a valve stopping a flow of fuel in response to a combustion failure; [0020] FIG. 7 is a bottom plan view of apparatus for hydrogen combustion built in accordance with a second embodiment of the invention; Continue reading... Full patent description for Hydrogen burner with a shut-off valve near the gas jets Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Hydrogen burner with a shut-off valve near the gas jets patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Hydrogen burner with a shut-off valve near the gas jets or other areas of interest. ### Previous Patent Application: Ultra-low nox burner assembly Next Patent Application: Double-flame lighter Industry Class: Combustion ### FreshPatents.com Support Thank you for viewing the Hydrogen burner with a shut-off valve near the gas jets patent info. 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