Ignition inhibiting gas water heater

Abstract

A gas water heater including a water container adapted to be heated by a gas burner; and an enclosure surrounding the burner, the enclosure having at least one entryway adapted to allow air and fumes to enter the enclosure without igniting flammable gases or vapors outside of the enclosure.

What is claimed is:  
     
         1 . A gas water heater comprising a water container adapted to be heated by a gas burner; and an enclosure surrounding said burner, said enclosure having at least one entry means adapted to allow air and extraneous fumes to enter said enclosure without igniting extraneous fumes outside of said enclosure.  
     
     
         2 . A water heater as claimed in    claim 1    wherein said entry means includes an aperture which is covered by a flame trap which prevents said burner from igniting extraneous fumes outside of said enclosure; and an air inlet through which air for combustion is drawn.  
     
     
         3 . A water heater as claimed in    claim 1    wherein said entry means is remote from said burner and includes a duct for passage of air to said burner.  
     
     
         4 . A water heater as claimed in    claim 2    wherein said entry means and said aperture are collocated or are a single item.  
     
     
         5 . A water heater as claimed in    claim 1    wherein said entry means is covered by a flame trap.  
     
     
         6 . A water heater as claimed in    claim 2    wherein said aperture is in the enclosure.  
     
     
         7 . A water heater as claimed in    claim 2    wherein the aperture is positioned proximate to a lower end of the enclosure.  
     
     
         8 . A water heater as claimed in    claim 2    wherein said aperture is positioned in a lower end of the enclosure.  
     
     
         9 . A water heater as claimed in    claim 2    wherein said aperture is positioned below said burner.  
     
     
         10 . A water heater as claimed in    claim 2    wherein said aperture is positioned to allow air and said extraneous fumes outside of said water heater to enter into an air passage leading to said burner.  
     
     
         11 . A water heater as claimed in    claim 2    wherein said aperture allows air and said extraneous fumes to enter the lowest point of said air passage.  
     
     
         12 . A water heater as claimed in    claim 2    wherein one or a combination of: a light detection or sensitive device; a flame detecting or sensitive device; a temperature sensitive or detecting device; a heat detecting or sensitive device; and an oxygen depletion sensitive or detection device, is located in said water heater to detect flame from said extraneous fumes if they have been ignited inside said enclosure.  
     
     
         13 . A water heater as claimed in    claim 1    wherein said entry means includes an air inlet which is not covered by a flame trap, said air inlet having its lowest opening at a height of not less than about 500 millimeters (20 inches) from a bottom portion of said enclosure.  
     
     
         14 . A water heater as claimed in    claim 1    wherein said entry means is located at or adjacent to the highest point of said enclosure, if said enclosure has a height of about 500 millimeters or greater, from a bottom portion of the enclosure.  
     
     
         15 . A water heater as claimed in    claim 1    wherein a snorkel device extends said entry means to a height above the highest point of said enclosure.  
     
     
         16 . A water heater as claimed in    claim 5    wherein said flame trap includes a heat conductive permeable material.  
     
     
         17 . A water heater as claimed in    claim 5    wherein said flame trap includes a screen made from woven or knitted mesh.  
     
     
         18 . A water heater as claimed in    claim 5    wherein said flame trap is made of either steel or stainless steel.  
     
     
         19 . A water heater as claimed in    claim 5    wherein a lint trap is included to wholly cover said aperture and said flame trap.  
     
     
         20 . A water heater as claimed in    claim 19    wherein said lint trap is formed by mesh placed in the path of lint or dust travelling to said flame trap.  
     
     
         21 . A water heater as claimed in    claim 1    further including a gas shut off means which shuts of gas supply to said burner and or a pilot burner if said air and extraneous fumes are ignited after entering said enclosure.  
     
     
         22 . A water heater as claimed in    claim 21    wherein said gas shut off means includes a heat sensitive means.  
     
     
         23 . A water heater as claimed in    claim 21    wherein said gas shut off means includes a flame sensitive switch.  
     
     
         24 . A water heater as claimed in    claim 21    wherein said gas shut off means includes an oxygen depletion sensitive means.  
     
     
         25 . A water heater as claimed in    claim 5    further comprising a jacket surrounding said water container and said enclosure and a base located beneath said enclosure.  
     
     
         26 . A water heater as claimed in    claim 25    wherein said flame trap is provided at or as part of the construction of joining areas of said base of said water heater to said jacket of said water heater, or said jacket to other components of said water heater or said base to other components of said water heater or at any location where said extraneous fumes could enter said enclosure.  
     
     
         27 . A water heater as claimed in    claim 5    wherein said flame trap is formed by a joining area of components of said water heater including either only gaps or apertures of a size small enough to act as a flame trap.  
     
     
         28 . A water heater as claimed in    claim 26    wherein said flame trap has been added to the joining area or is deliberately incorporated as part of said joining area.  
     
     
         29 . A water heater as claimed in    claim 28    wherein said flame trap is a layer of metallic mesh cooperating with said joining area to achieve a flame quenching or arresting function.  
     
     
         30 . A water heater as claimed in    claim 29    wherein said flame trap is inside of said water heater.  
     
     
         31 . A water heater as claimed in    claim 21    wherein said gas shut off means includes a light detection means.  
     
     
         32 . A water heater having a burner adapted to combust gas to heat a water container above the burner within an outer enclosure having an opening means to admit air required to combust the gas; and including air and fume flow means cooperative with said opening to reduce or eliminate a possibility of fumes adjacent the enclosure being ignited outside said enclosure by a gas flame associated with said burner.  
     
     
         33 . A water heater as claimed in claimed in    claim 5    wherein a fume detecting device is located in said water heater to detect said extraneous fumes after they have entered said enclosure.  
     
     
         34 . A water heater as claimed in    claim 1    wherein said entry means is positioned close to a lower end of the enclosure.  
     
     
         35 . A water heater as claimed in    claim 1    wherein said entry means is positioned in a lower end of the enclosure.  
     
     
         36 . A water heater as claimed in    claim 1    wherein said entry means is positioned below said burner.  
     
     
         37 . A water heater as claimed in    claim 1    wherein said entry means is positioned to allow air and said extraneous fumes outside of said water heater to enter into an air passage leading to said burner.  
     
     
         38 . A water heater as claimed in    claim 37   , wherein said entry means allows air and said extraneous fumes to enter the lowest point of said air passage.  
     
     
         39 . A water heater as claimed in    claim 37   , wherein one of or a combination of: a light sensitive device; a flame detecting device; a temperature detecting device; a heat detecting device; and an oxygen depletion measurement device, is located in said water heater to detect flame from said extraneous fumes after they have been ignited.  
     
     
         40 . A water heater as claimed in    claim 5    wherein said flame trap is a flame quenching or arresting means.  
     
     
         41 . A water heater as claimed in    claim 12   , wherein said device or said devices are included in a gas shut off device.  
     
     
         42 . A water heater as claimed in    claim 1   , wherein one of or a combination of: a light detection or sensitive device; a flame detecting or sensitive device; a temperature sensitive or detecting device; a heat detecting or sensitive device; and an oxygen depletion sensitive or detection device, is located in said water heater to detect flame from said extraneous fumes if they have been ignited inside said enclosure.  
     
     
         43 . A water heater as claimed in    claim 42   , wherein said device or said devices are included in a gas shut off device.  
     
     
         44 . A water heater comprising a burner adapted to combust gas to heat a water containment and flow means above the burner within an outer enclosure having an opening means to air required to combust the gas; and air and fume flow means cooperative with said opening means to reduce or eliminate a possibility of fumes adjacent the enclosure from being ignited outside the enclosure by a gas flame associated with said burner; said water heater including gas shut off means having a flame detecting or sensing device located in a path of flame external to a combustion chamber of said water heater and also located in any path of flame of said fumes ignited in the enclosure.  
     
     
         45 . A water heater as claimed in    claim 44    wherein said flame external to said combustion chamber is caused by flame spillage from said burner caused by a blockage of an exhaust flue connected to said combustion chamber.  
     
     
         46 . A water heater as claimed in    claim 44    wherein said flame external to said combustion chamber is caused by air starvation in said combustion chamber.  
     
     
         47 . A water heater comprising: 
 means for storing or containing water;    means forming a chamber adjacent said storing or containing means;    a burner located in said chamber; and    a flame trap associated with said chamber means permitting combustion air and extraneous gases, if present, into said chamber and capable of preventing ignition of extraneous gases outside said chamber.    
     
     
         48 . A water heater as claimed in    claim 47    further comprising a separate opening in said means forming a chamber for ingress of combustion air.  
     
     
         49 . A water heater as claimed in    claim 47    wherein said flame trap comprises a barrier selected from the group consisting of woven or knitted mesh, ported ceramic tile and heat resistant permeable materials of high thermal capacity.  
     
     
         50 . A water heater as claimed in    claim 47    further comprising a lint trap positioned to hinder contact of blocking materials with said flame trap.  
     
     
         51 . A water heater comprising: 
 a water tank;    a combustion chamber located below said tank;    a burner located inside said combustion chamber;    a flame trap positioned in a portion of structure associated with said combustion chamber, said flame trap permitting ingress of air and extraneous gases, if present, into said combustion chamber and prevent egress of flames from said structure.    
     
     
         52 . A water heater as claimed in    claim 49    further comprising a separate opening in said structure for ingress of combustion air into said combustion chamber.  
     
     
         53 . A water heater as claimed in    claim 51    wherein said flame trap comprises a barrier selected from the group consisting of woven or knitted mesh, ported ceramic tile and heat resistant permeable materials of high thermal capacity.  
     
     
         54 . A water heater as claimed in    claim 51    further comprising a lint trap positioned to hinder contact of blocking materials with said flame trap.  
     
     
         55 . A water heater as claimed in    claim 44    wherein said aperture is positioned above the height of said burner and in communication with a downward path of combustion air toward said burner.  
     
     
         56 . A water heater as claimed in    claim 55    wherein a flame sensitive sensor is positioned between said flame trap and an opening to said combustion chamber to detect flame external to said combustion chamber caused by one of: flame spillage from said burner caused by a blocked exhaust flue connected to said combustion chamber; air starvation in said combustion chamber; and extraneous fumes combusting between said flame trap and said combustion chamber.