Patent ID: 7771663

Claim:
A system for keeping a medium ( 9 ) in a container ( 10 ) warm, comprising: a container ( 10 ) having a heatable surface ( 11 ) through which heat may be conducted into a medium ( 9 ) within the container; and a supply ( 28 ) of hydrogen; characterized by: a first valve operable to be closed unless the time period of a related timer has expired after said first valve has been armed to become open; a second valve ( 25 ) having a temperature responsive member ( 26 ) disposed in proximity with said container and responsive to either (i) the temperature of the container or (ii) the ambient temperature surrounding the container, said second valve operable to open in response to said temperature responsive member being below a first temperature and to close in response to said temperature responsive member being above a second temperature, said second temperature being not lower than said first temperature, said valves serially connected to said supply to provide, when said valves are both open, a source ( 24 ) of hydrogen for combustion to heat said heatable surface; and a hydrogen/oxygen catalytic combustor ( 13 ) selected from (a) an ejector combustor ( 13 a ) comprising— a heating surface ( 36 ), through which heat is to be conducted to a heat utilizing apparatus; an ejector ( 32 ) having an outlet, a primary inlet ( 31 ) in fluid communication with said source of hydrogen, and a secondary inlet ( 33 ) in fluid communication with air; and a hydrogen/oxygen combustion catalyst ( 34 ) disposed between said ejector outlet and said heating surface; and (b) a diffusion combustor ( 13 b ) comprising: a hydrogen/oxygen combustion catalyst ( 38 ) having first and second sides; a heating surface ( 12 ), through which heat is to be conducted to a heat utilizing apparatus, separated from said first side of said catalyst by a first space ( 39 ); a hydrogen conduit ( 43 ) for conducting hydrogen from said source to said first space; and a diffusion control device ( 40 ) disposed in air and separated from said second side of said catalyst by a second space ( 41 ); said heatable surface in contact with one of said heating surfaces, whereby hydrogen passing through said valves is catalytically combusted to heat the medium within said container.