Gas-Fired Portable Heater

Abstract

A portable gas fired heater includes a combustion chamber having an air inlet and an air outlet. A low DC voltage (optionally AC voltage) fan or blower directs air through the combustion chamber so that the air is heated. Preferably, a vortex generator is located between the fan or blower and the combustion chamber such that air entering the combustion chamber swirls. The heater is designed to have a low center of gravity and thus difficult to tip-over. Nevertheless, several safety features are provided including a tip-over switch, thermal coupler, temperature limit switch, and a manual shutoff.

1 . A portable gas fired heater, comprising:
 a combustion chamber having an air inlet and an air outlet;   a burner tube located in the combustion chamber;   a gas flow tube coupled to the burner tube and adapted to be coupled to a source of burnable gas;   means for propelling a stream of air into the air inlet; and   a vortex generator located between the air inlet and the means for propelling a stream of air, said vortex generator including a substantially conical part and a plurality of stationary vanes extending outward from said substantially conical part which cause the stream of air to be turbulent as it enters the air inlet.   
   
   
       2 . A heater according to  claim 1 , further comprising:
 an adjustable air flow director adjacent to said air outlet.   
   
   
       3 . A heater according to  claim 1 , wherein:
 said means for propelling a stream of air is an electric fan.   
   
   
       4 . A heater according to  claim 3 , wherein:
 said fan is a low voltage DC fan.   
   
   
       5 . A heater according to  claim 3 , wherein:
 said fan is an AC fan.   
   
   
       6 . A heater according to  claim 1 , wherein:
 said means for propelling a stream of air is a squirrel cage blower.   
   
   
       7 . A heater according to  claim 6 , further comprising:
 a relatively wide foot, said relatively wide foot and said squirrel cage blower together forming a support for said heater.   
   
   
       8 . A heater according to  claim 6 , wherein:
 said blower is a low voltage DC blower.   
   
   
       9 . A heater according to  claim 6 , wherein:
 said blower is an AC blower.   
   
   
       10 . A heater according to  claim 1 , wherein:
 said heater has a low center of gravity.   
   
   
       11 . A heater according to  claim 1 , further comprising:
 sound dampening means adjacent said air outlet.   
   
   
       12 . A heater according to  claim 11 , wherein:
 said sound dampening means includes a perforated plate.   
   
   
       13 . A heater according to  claim 1 , further comprising:
 a safety device selected from the group consisting of a tip-over switch, a thermal coupler, and a temperature limit switch.   
   
   
       14 . A portable gas fired heater, comprising:
 a gas combustion chamber having an air inlet and an air outlet;   a burner tube located in said combustion chamber;   a gas supply tube coupled to said burner tube and adapted to be coupled to a source of burnable gas;   means for propelling a stream of air into the air inlet; and   a plurality of safety devices including a tip-over switch, a thermal coupler, and a temperature limit switch each of which is automatically operable to turn off said gas fired heater.   
   
   
       15 . A heater according to  claim 14 , wherein:
 said tip-over switch is centrally located underneath said heater, and said thermal coupler and temperature limit switch are located inside said combustion chamber.   
   
   
       16 . A heater according to  claim 14 , further comprising:
 a gas valve operatively coupled to said safety devices.   
   
   
       17 . A heater according to  claim 14 , wherein:
 said temperature limit switch prevents said heater from operating at a temperature of at least 87° F.   
   
   
       18 . A heater according to  claim 14 , wherein:
 said tip-over switch prevents said heater from operating if the heater tips at least 15 degrees.   
   
   
       19 . A portable gas fired heater, comprising:
 a gas combustion chamber having an air inlet and an air outlet;   a burner tube located in the combustion chamber;   a gas flow tube coupled to the burner tube and adapted to be coupled to a source of burnable gas;   means for propelling a stream of air into the air inlet;   a vortex generator located between the air inlet and the means for propelling a stream of air, said vortex generator including a substantially conical part and a plurality of stationary vanes extending outward from said substantially conical part which cause the stream of air to be turbulent as it enters the air inlet; and   a plurality of safety devices including a tip-over switch, a thermal coupler, and a temperature limit switch each of which is automatically operable to turn off said gas fired heater.   
   
   
       20 . A heater according to  claim 19 , further comprising:
 a supporting foot wider than said combustion chamber.   
   
   
       21 . A heater according to  claim 20 , wherein:
 said heater has a low center of gravity.