An air swirler has a radially outer wall bounding an annular passage. The radially outer wall has an axially extending portion and a radially convergent portion which converges towards an outlet of the passage. Downstream of the outlet, the passage facing surface of the radially outer wall becomes divergent. The region in which the passage facing surface of the radially outer wall is convergent then divergent defines the flare. A circumferential and axially extending recess is provided in the radially outer wall opposite the flare. A reinforcement of material with superior wear properties to the material of the main body is built in the recess to a radius which coincides with that of the outer surface of the axially extending portion of the radially outer wall. The reinforcement can conveniently be added to the main body by means of a laser consolidation ALM process.

A burner suitable for the over stoichiometric combustion of a hydrocarbon source, comprising a nozzle (2) for the formation of a diffusion flame outside the burner, and said nozzle (2) comprising one (20) or more (21, 22) tubular bodies which define a channel (25) or a plurality of coaxial channels (23, 24) for respective reactant streams, wherein the or each of the tubular bodies forming said nozzle (2) are made of a technical ceramic material.

The invention relates to a burner, particularly for the gasification of solid carbonaceous materials by partial combustion. The burner comprises a central channel (2) and at least one coaxial channel (6). The channels (2, 6) are defined by concentric walls (3, 5) having free downstream outer ends profiled to define an annular slit (10) forming a discharge end of the coaxial channel (6) and converging towards an adjacent discharge end of the central channel (2). The burner (1) is encased by a cooling jacket (14) and comprises a front face (21) with double walls spaced by one or more baffles (28) defining a coolant flow path operatively connected to the cooling jacket (14). The cooling jacket (14) has an upstream section (14A) and a transitional section (25) narrowing down to the front face (21) having a smaller outer diameter than the upstream cooling jacket section.