Abstract: A burner fed with a hyper-stoichiometric mixture of air and gas-fuel comprises a diffuser on which rows of similarly shaped and evenly spaced parallel slots for the flow of said mixture are provided; said rows are separated from each other by an intermediate portion of diffuser having a substantially constant width and provided with further slots for the flow of said mixture, said further slots being non-parallel to said slots.

Abstract: A burner fed with a flow of an air-fuel mixture, has a venturi tube arranged at the inside of a tubular burner body provided with through apertures through which said flow passes. The venturi tube is supported and centered in the body at one of its ends. Additional support and centering means of said venturi tube are provided at the inside of said tubular body. The additional support and centering means are provided with control means controlling the distribution of said flow of said air-fuel mixture.

Abstract: A gas burner comprises an elongated tubular body with a sidewall which has outer end edges between which there are apertures which pass through the sidewall; a flange with a central through hole and an opposite base cap, the sidewall, flange and base cap being attached to one another in such a way that together they define a first mixing chamber, in which a flow of gas and air, received through the flange, exits the tubular body through the apertures in the sidewall; the flange and base cap having opposite guides; the sidewall being wound in a spiral and having juxtaposed longitudinal edges with fluid tight seals and outer end edges inserted in the guides with a play designed to allow the perimeter of the sidewall to expand or contract according to changes in the temperature of the body.

Abstract: The invention relates to an apparatus for heating fluids which includes a combustion chamber (20) in which the head (21c) of the burner with the burner openings (39) for the flames is juxtaposed with a wall (21a, 21b) of the chamber itself separating this latter from the lower portion of the apparatus; in the event of flammable substances being present in the environment surrounding the apparatus, these can enter the combustion chamber only through the openings (39) and the similar slots (50) formed in the wall (21a, 21b). This enables the ignition element (25) to ignite these substances as soon as they enter the chamber (20), thus preventing the formation of unwanted explosive or flammable mixtures in the chamber (20) and thereby contributing to the safety of the apparatus.

Abstract: In a method of combustion designed to achieve a further reduction in harmful emissions, especially of NOx and CO, which is viable at advantageously reduced noise levels and lower cost with any burner of a type comprising a slotted or pierced diffuser of thin sheet metal in receipt of fully or partly mixed gas and air supplies, typically in appliances comprising a heat exchanger such as the boilers of central heating systems, the essential steps are: a) supplying a uniform flow of fuel-air mixture to the slots; b) discharging the mixture from a pierced surface of substantially doughnut geometry comprising a slotted peripheral area (Ap) and an essentially solid central area (Ac) of prescribed proportions; c) bringing combustion to completion in a slender lamellar flame; d) regulating the rate of aeration to a value between 0.9 and 1.4, or e) to values less than 1.6; f) effecting a recycle of post-combustion gases.

Abstract: The process obtains a plurality of small flames which become violet when combusting natural gas. In particular the amount of primary air induced is at least 80% of the air stoichiometrically required for combustion; the secondary air laps all sides of each singly small flame arising from the small group of slots on the burner body, in the area where each flame leaves the surface of the burner body so as to swell it making its width at least as big as its height and/or alternatively the contact surface between each flame and the secondary air is increased right from the first steps in combustion, so that each small group creates a small flame with two divergent bladed wings, similar to "butterfly wings.