Radiant Heating Assembly with Liner Tube and Temperature Limiting Device

Abstract

A radiant heating assembly includes a fuel valve, a blower, a controller configured to control the fuel valve and the blower, and a heat exchanger or burner tube configured to limit external surface temperature through the use of a liner tube and a temperature limiting device. The liner tube can be installed internally into the walls of a heat exchanger or burner tube to decrease the surface temperature of the heat exchanger.

What is claimed: 
     
         1 . A radiant heating assembly comprising:
 a burner for receiving air and fuel, and for combustion and emitting heated exhaust; and   an elongated heat exchanger in fluid communication with said burner defining a first end, a second end and a length extending between said first and second ends, said elongated heat exchanger comprising:
 an outer tube disposed along at least a portion of said length and defining an interior; 
 a liner tube disposed within said interior along at least a portion of said length and defining an inner chamber for receiving the heated exhaust from the burner; and 
 at least one spacing element coupled to one of said liner tube and said outer tube and engaged with the other of said liner tube and said outer tube for spacing said liner tube from said outer tube along at least a portion of said length. 
   
     
     
         2 . A radiant heating assembly in accordance with  claim 1 , wherein said at least one spacing element is fixed to said liner tube. 
     
     
         3 . A radiant heating assembly in accordance with  claim 2 , wherein said outer tube defines an indent for receiving said at least one spacing element for locating said liner tube to said outer tube. 
     
     
         4 . A radiant heating assembly in accordance with  claim 1 , wherein said spacing element is a depression integrally formed with said liner tube. 
     
     
         5 . A radiant heating assembly in accordance with  claim 1 , wherein said outer tube is disposed along an axis and said at least one spacing element concentrically aligns said liner tube along said axis. 
     
     
         6 . A radiant heating assembly in accordance with  claim 1 , wherein said liner tube and said outer tube are comprised of a single metallic material. 
     
     
         7 . A radiant heating assembly in accordance with  claim 6 , wherein said material is alloy steel. 
     
     
         8 . A radiant heating assembly in accordance with  claim 1 , wherein said liner tube defines a first surface facing said outer tube and said outer tube defines a second surface facing away from said liner tube, said first surface having a first surface temperature and said second surface having a second surface temperature lower than said first surface temperature. 
     
     
         9 . A radiant heating assembly in accordance with  claim 1 , further including a plurality of spacing elements. 
     
     
         10 . A radiant heating assembly in accordance with  claim 9 , wherein said plurality of spacing elements are radially disposed about and coupled to said liner tube. 
     
     
         11 . A radiant heating assembly in accordance with  claim 10 , wherein said plurality of spacing elements define angles between adjacent spacing elements, with said axis being a vertex for each angle, said plurality of spacing elements are radially disposed about said liner tube such that angles between said plurality of spacing elements are equal. 
     
     
         12 . A radiant heating assembly in accordance with  claim 10 , wherein said plurality of spacing elements define angles between adjacent spacing elements, with said axis being a vertex for each angle, said plurality of spacing elements are radially disposed about said liner tube such that angles between said plurality of spacing elements are unequal. 
     
     
         13 . A radiant heating assembly in accordance with  claim 10 , wherein said plurality of spacing elements are disposed about said liner tube such that said spacing elements form a spiral about said liner tube along at least a portion of said length. 
     
     
         14 . A radiant heating assembly in accordance with  claim 1 , further including a fuel valve for providing the fuel to said burner. 
     
     
         15 . A radiant heating assembly in accordance with  claim 14 , further including a blower for providing the air to said burner. 
     
     
         16 . A radiant heating assembly in accordance with  claim 15 , further including a controller configured to control an amount of the air and the fuel provided to said burner. 
     
     
         17 . A radiant heating assembly in accordance with  claim 1 , wherein said liner tube and said outer tube comprise a U-shape. 
     
     
         18 . An inner tube assembly for a radiant heating assembly, with the radiant heating assembly comprising a burner for receiving air and fuel, and for combustion and emitting heated exhaust, and comprising an elongated heat exchanger in fluid communication with the burner for receiving the heated exhaust from the burner, with the elongated heat exchanger comprising an outer tube defining an interior comprising:
 a liner tube disposed within the interior, and said liner tube defining an inner chamber in fluid communication with the interior for receiving the heated exhaust from the burner; and   at least one spacing element coupled to said liner tube for spacing said liner tube from the outer tube, directing the heated exhaust within the interior, and reducing surface temperature of the elongated heat exchanger.   
     
     
         19 . A radiant heating assembly comprising:
 a burner for receiving air and fuel, and for combustion and emitting heated exhaust;   an elongated heat exchanger in fluid communication with said burner defining a first end and a second end and a length between said first and second ends;   a controller configured to control the amount of the air and the fuel provided to said burner; and   a temperature limiting device coupled to said elongated heat exchanger comprising:
 a tube having an exterior surface and an interior surface, with said interior surface defining a tube interior in fluid communication with said elongated heat exchanger, and with said tube coupled to said elongated heat exchanger along said length; and 
 a temperature limit switch coupled to said exterior surface of said tube, with said temperature limit switch being operable between a first state when temperature of said exterior surface is at or below a predetermined temperature and a second state, different from said first state, when said temperature of said exterior surface is above said predetermined temperature. 
   
     
     
         20 . A radiant heating assembly in accordance with  claim 19 , wherein said temperature limit switch is in electrical communication with a power source and said controller, with said controller receiving power from said power source when said temperature limit switch is in said first state for allowing said burner to receive air and fuel, and with said temperature limit switch prohibiting said controller from receiving power when said temperature limit switch is in said second state for restricting said burner from receiving the air and fuel. 
     
     
         21 . A radiant heating assembly in accordance with  claim 20 , wherein said elongated heat exchanger defines a temperature profile along said length of said elongated heat exchanger, with said temperature limiting device coupled to said elongated heat exchanger at a predetermined location, and wherein said predetermined location is located along said length at a distance from said burner where said exterior surface temperature is highest with respect to said temperature profile. 
     
     
         22 . A temperature limiting device for a radiant heating assembly, the radiant heating assembly comprising a burner for receiving and combusting air and fuel and for emitting heated exhaust, the radiant heating assembly comprising an elongated heat exchanger in fluid communication with the burner for receiving the heated exhaust from the burner, and a controller configured to control the amount of the air and the fuel provided to the burner, the temperature limiting device comprising:
 a tube defining an exterior surface and an interior surface, with said interior surface defining a tube interior in fluid communication with and coupled to the elongated heat exchanger;   a temperature limit switch coupled to said exterior surface of said tube, with said temperature limit switch being operable between a first state when temperature of said exterior surface is at or below a predetermined temperature and a second state, different from said first state, when said temperature of said exterior surface is above said predetermined temperature.   
     
     
         23 . A temperature limiting device in accordance with  claim 22 , wherein said temperature limit switch is in electrical communication with a power source and the controller, with the controller receiving power from said power source when said temperature limit switch is in said first state for allowing the burner to receive air and fuel, and with said temperature limit switch prohibiting the controller from receiving power when said temperature limit switch is in said second state for restricting the burner to receive the air and fuel.