Patent ID: 6880549

Claim:
A gas heater comprised of: a cylindrical housing having an air-intake end and an air-exhaust end; a cylindrical liner attached to the inner surface of said cylindrical housing at spaced-apart intervals and positioned generally concentrically within said cylindrical housing and also having an air-intake end and an air-exhaust end; means positioned proximate said air-intake end for drawing air in through said air-intake end, through said liner and out the air exhaust end; a combustion system positioned within said liner at the proximate midpoint of said housing, for burning gas, thereby heating the air as it travels through said liner, the combustion system comprising: a circularly-shaped burner tube positioned concentrically within said liner and having a plurality of gas exit holes on a side facing the air-exhaust end; a pair of truncated conical flanges attached to said burner tube adjacent to and on each side of the gas exit holes, said flanges extending radially outward from said burner tube, such that the distance between the flanges increases as the distance from the burner tube increases, and each flange having its own respective pattern of orifice ports; means for inletting gas into the burner tube; control means that communicates with said inletting means for variably controlling the amount of gas that enters said burner tube between the range of no gas entry to a pre-determined maximum value; and ignition means for igniting gas that initially exits said burner tube, said ignition means electrically connected to said control means and is activated when said control means allows gas to enter after being in the no gas entry range.