Patent ID: 7726967

Claim:
A gas-fired burner unit for providing combustion and infrared radiation, the gas-fired burner unit comprising: a plenum for receiving a gas-air mixture; a plurality of downstream perforated metal plates mounted for receiving the gas-air mixture from the plenum and supplying the gas-air mixture to the combustion so that the combustion emanates outwardly from proximate downstream sides of the downstream perforated metal plates, wherein the downstream sides of the downstream perforated metal plates are exterior surfaces of the burner unit, the exterior surfaces of the burner unit are for emitting infrared radiation outwardly from the burner unit, and the downstream perforated metal plates are less than about 0.125 inches thick; a plurality of upstream perforated metal plates that are respectively mounted in series with, and are positioned upstream from, the downstream perforated metal plates; and a mounting plate positioned between the upstream perforated metal plates and the downstream perforated metal plates so that the mounting plate is upstream of the downstream perforated metal plates, wherein the mounting plate has a plurality of holes that extend through the mounting plate, the holes have circumferential walls that respectively extend at least partially around, and thereby at least partially define, a plurality of chambers that are substantially discrete with respect to one another and positioned between the downstream perforated metal plates and the upstream perforated metal plates, and the chambers are wider than perforations of the upstream and downstream perforated metal plates, and wherein perforations of the downstream perforated metal plates are respectively open to the chambers, and perforations of the upstream perforated metal plates are respectively open to the chambers, so that for each chamber of the plurality of chambers, a downstream end of the chamber is obstructed by and defined by one of the downstream perforated metal plates, an upstream end of the chamber is obstructed by and defined by one of the upstream perforated metal plates, the chamber is adjacent to and in fluid communication with both a plurality of the perforations of the one of the downstream perforated metal plates and a plurality of the perforations of the one of the upstream perforated metal plates, the plurality of perforations of the one of the downstream perforated metal plates are for receiving the gas-air mixture from the plenum by way of the chamber, and the chamber is for receiving the gas-air mixture from the plenum by way of the plurality of perforations of the one of the upstream perforated metal plates; and at least one venturi mounted for providing the gas and air to the plenum, wherein the burner unit is operative so that substantially all of the air required for completing the combustion is provided via the at least one venturi while the burner unit's firing rate exceeds about 350 BTUH/in 2 of the burner unit's emitting surface.