Hot air heater and method of operating same

Abstract

A hot air heater having a burner tube surrounding a combustion area. The combustion gases travel from the burner tube through first and second circumferential and concentric annuluses surrounding the burner tube. Cool ambient air used for heating is blown over the outside surfaces of the annuluses and heat from the combustion gases is transferred to the ambient air used for heating by way of the surfaces of the jackets defining the annuluses.

I claim:  
     
         1 . Method of heating cool air, said method comprising inletting combustion air used for combustion within a burner, combusting said air with a fuel to produce hot combustion gases within a combustion area, passing said combustion gas from said combustion area into a first and second jacket surrounding said combustion area, each of said first and second jackets being defined by surfaces and heating cool ambient air passing over said surfaces of said first and second jackets.  
     
     
         2 . Method as in  claim 1  wherein said combustion gases are passed through an exhaust communication port between said first and second jackets.  
     
     
         3 . Method as in  claim 2  and further comprising passing said cool ambient air over the outsides of said first and second jackets by a fan.  
     
     
         4 . Method as in  claim 3  and further comprising exhausting said combustion gases following passage through said second jacket.  
     
     
         5 . Method as in  claim 4  wherein said cool ambient air is heated as said ambient air moves over said surfaces within a heater annulus surrounding said jackets.  
     
     
         6 . Method as in  claim 5  wherein said first and second jackets are formed to be concentric with said combustion area.  
     
     
         7 . A hot air heater comprising a combustion area for combustion of air and fuel, a first jacket surrounding said combustion area for allowing combustion gases to circulate therethrough, a second jacket outside said first jacket to allow said combustion gases to circulate therethrough and a combustion gas outlet to allow said combustion gases to exhaust from said hot air heater following passage through said first and second jackets.  
     
     
         8 . A hot air heater as in  claim 7  wherein said combustion area is within a burner tube.  
     
     
         9 . A hot air heater as in  claim 8  wherein said first and second jackets are concentric with said burner tube.  
     
     
         10 . A hot air heater as in  claim 9  and further comprising an exhaust communication port between said first and second jackets.  
     
     
         11 . A hot air heater as in  claim 10  and further comprising an exhaust port to exhaust said combustion gases from said second jacket.  
     
     
         12 . A hot air heater as in  claim 11  and further comprising a source of cool air for heating said cool air by said combustion gases.  
     
     
         13 . A hot air heater as in  claim 12  wherein said first and second jackets are defined by surfaces and further comprising a fan to blow said cool air over said surfaces of said first and second jackets.  
     
     
         14 . A hot air heater as in  claim 13  wherein said cool air is heated within a heater annulus and further comprising an outlet for said heated ambient air from said heater annulus.