Abstract: No exit-flame burner includes nested elongate mixing and ignition tubes. The mixing chamber tube is of shorter length than the ignition chamber tube and is nested coaxially. The first ends of the ignition and mixing chamber tubes are sealed by a sealing member. A gas port for delivery of oxygen-bearing gas is formed in the sealing member. A gas diffuser is nested coaxially within the mixing chamber tube. A fuel-feeding bore within the gas diffuser is aligned coaxially within the mixing chamber tube. The gas diffuser is shaped as a rhombus in cross-section along the longitudinal axis to thereby define a rim around an apex thereof. The rim extends substantially around, closely adjacent to, a corresponding inside surface of the mixing chamber tube to thereby define an upstream gas plenum upstream of the rim between the rim and the sealing member.

Abstract: No exit-flame burner includes nested elongate mixing and ignition tubes. The mixing chamber tube is of shorter length than the ignition chamber tube and is nested coaxially. The first ends of the ignition and mixing chamber tubes are sealed by a sealing member. A gas port for delivery of oxygen-bearing gas is formed in the sealing member. A gas diffuser is nested coaxially within the mixing chamber tube. A fuel-feeding bore within the gas diffuser is aligned coaxially within the mixing chamber tube. The gas diffuser is shaped as a rhombus in cross-section along the longitudinal axis to thereby define a rim around an apex thereof. The rim extends substantially around, closely adjacent to, a corresponding inside surface of the mixing chamber tube to thereby define an upstream gas plenum upstream of the rim between the rim and the sealing member.

Abstract: A nozzle assembly for use in a hot air torch wherein the hot air torch utilizes a source of compressed air and a source of gaseous fuel. The hot air torch has a handle portion which holds a first pipe carrying pressurized air and a second pipe carrying propane under pressure. The first pipe containing pressurized air splits into two passageways, each passageway having a valve with which flow can be regulated. As propane travels through the second pipe to an exhaust outlet nozzle, pressurized air travels into a burner tube and an annular plenum surrounding the burner tube. The burner tube has circumferentially spaced openings. The compressed air from the plenum goes through the openings and travels radially inwardly toward the exhaust nozzle. The exhaust nozzle has a generally frusto-conical shaped exterior side surface to present a frusto-conical surface against which air jets from the circumferentially spaced openings in the burner tube impinge.