US Patent 8939759 Tubular burner

A tubular burner has: a mixing tube inclusive of an inlet port, a venturi section, and a tapered tube section; and a flame hole member having a plurality of flame holes and being adapted to be fitted into a front end region of the mixing tube. A flame hole member has a front plate and a rear plate, both of sheet metal make. The front plate has a first flame hole in the central portion of the front plate, and a plurality of second flame holes located around a periphery of the first flame hole. The rear plate has a first ventilation hole in the center thereof so as to lie opposite to the first flame hole, and a plurality of second ventilation holes of smaller diameter than the first ventilation hole.