Abstract: A combustion head for a burner is provided with an outer sleeve, which houses, on the inside, a first feeding device to feed a gaseous fuel into an oxidizing air flow fed along the outer sleeve by means of a pneumatic ventilation device, at least one swirl device, which is configured to cause a primary flow F1 of gaseous fuel and oxidizing air flowing out of the outer sleeve to make a helical movement, and at least one feeding channel with an annular shape, which is obtained between the outer sleeve and the swirl device in order to feed a secondary flow F2 of oxidizing air around the primary flow F1; a second feeding device being mounted on the outside of the outer sleeve and being connected to a gaseous fuel source.

Abstract: A combustion head for a burner is provided with an outer sleeve, which houses, on the inside, a first feeding device to feed a gaseous fuel into an oxidizing air flow fed along the outer sleeve by means of a pneumatic ventilation device, at least one swirl device, which is configured to cause a primary flow F1 of gaseous fuel and oxidizing air flowing out of the outer sleeve to make a helical movement, and at least one feeding channel with an annular shape, which is obtained between the outer sleeve and the swirl device in order to feed a secondary flow F2 of oxidizing air around the primary flow F1; a second feeding device being mounted on the outside of the outer sleeve and being connected to a gaseous fuel source.

Abstract: An air-gas premixing device to be inserted into a low-NOx gas burner. The device comprises a ring nut adapted to rotate about a symmetry axis passing through its geometric center. The rotation of the ring nut causes: the rotation of a shutter for closing/opening an air-passage section for a fraction of the air from a ventilation group; and the rotation of a premixing pipe provided with an eyelet for the passage of a combustible gas; so that the air and the combustible gas are mixed in said premixing pipe to obtain a decrease of NOx emissions.