A burner for a rotary kiln comprising an elongated tubular body (6) having a longitudinal axis (L) and a discharge end (7) adjacent a combustion zone comprising a flame, at least one fuel supply pipe for transporting and ejecting fuel through a fuel pipe outlet (10) at the discharge end (7), the fuel being alternative fuel or a mixture of alternative fuel and fossil fuel, and at the discharge end (7), a number of high speed primary air jet outlets for ejecting primary air and being arranged, when seen towards the discharge end, along a closed line, such as a circle, outwardly of the fuel outlet (10) and surrounding the fuel outlet,
wherein at least one of the primary air outlets and preferably a number of the primary air outlets comprise a single orifice outlet or a multiple orifice outlet forming a flat jet air outlet (11) having a major axis and a minor axis and being configured to eject a flat jet air stream (13) having a flat fan pattern with a predetermined fan angle v.

A burner for a rotary kiln comprising an elongated tubular body (6) having a longitudinal axis (L) and a discharge end (7) adjacent a combustion zone comprising a flame, at least one fuel supply pipe for transporting and ejecting fuel through a fuel pipe outlet (10) at the discharge end (7), the fuel being alternative fuel or a mixture of alternative fuel and fossil fuel, and at the discharge end (7), a number of high speed primary air jet outlets for ejecting primary air and being arranged, when seen towards the discharge end, along a closed line, such as a circle, outwardly of the fuel outlet (10) and surrounding the fuel outlet,
wherein at least one of the primary air outlets and preferably a number of the primary air outlets comprise a single orifice outlet or a multiple orifice outlet forming a flat jet air outlet (11) having a major axis and a minor axis and being configured to eject a flat jet air stream (13) having a flat fan pattern with a predetermined fan angle v.

The present disclosure is directed to systems and methods for high flame temperature oxy-combustion that enables the capture of CO.sub.2 cost effectively. One part of the presently disclosed subject matter comprises an annular shroud burner which utilizes a supply of undiluted oxygen and minimal flue gas recycle to generate a high flame temperature to maximize efficiency. The annular shroud burner may deliver oxygen into a combustion zone where mixing of the oxygen and a stream of fuel occurs. Flue gas recycled from the exit of the combustion system serves the dual purpose of conveying the coal into the reaction zone, as well as providing local cooling and protection from high incident heat fluxes through the novel shroud cooling design. The annular shroud burner may be configured to produce an axial jet flame that controls the rate of mixing of oxygen and fuel, thereby extending the heat release. Oxygen and coal may be mixed in a ratio such that peak flame temperatures exceed 4,500 F. (2,482 C.) while the flow of recycled flue gas is regulated to control flame temperature and protect burner components and near-burner surfaces.

The disclosure relates to a burner for burning combustible material in the form of a comminuted wood product, especially fine material, with (a) a combustible material feed for supplying the combustible material, (b) a screw conveyor for conveying the combustible material, (c) a combustion zone, wherein the screw conveyor is arranged to convey the combustible material (18) from the combustible material feed (20) to the combustion zone, (d) an air feed for supplying air to the combustion zone, and (e) a burner mouth for leading combustion gases out of the combustion zone. According to the disclosure, a compacting zone is provided, which is configured behind the combustible material feed and in front of the combustion zone in the direction of material flow (M) of the combustible material, wherein an auger of the screw conveyor and the compacting zone are preferably designed to compress the combustible material in the compacting zone.

In this combustion burner and boiler, interference of ignition in a flame stabilizer is suppressed and flame stabilizing performance is improved by providing: a fuel nozzle which ejects a fuel gas that is a mixture of pulverized coal and air; a combustion air nozzle which ejects a fuel gas combustion air from outside of the fuel nozzle; a secondary air nozzle which ejects secondary air from the outside of the combustion air nozzle; and a flame stabilizer which comprises a first flame stabilizer main body which is arranged at the leading end of the fuel nozzle and separated by a prescribed space from the inner wall surface of the fuel nozzle and which forms a ring shape having as the center an axial line along the ejection direction of the fuel gas.

In this combustion burner and boiler, interference of ignition in a flame stabilizer is suppressed and flame stabilizing performance is improved by providing: a fuel nozzle which ejects a fuel gas that is a mixture of pulverized coal and air; a combustion air nozzle which ejects a fuel gas combustion air from outside of the fuel nozzle; a secondary air nozzle which ejects secondary air from the outside of the combustion air nozzle; and a flame stabilizer which comprises a first flame stabilizer main body which is arranged at the leading end of the fuel nozzle and separated by a prescribed space from the inner wall surface of the fuel nozzle and which forms a ring shape having as the center an axial line along the ejection direction of the fuel gas.

This solid fuel burner is provided with: a venturi tube in which a channel for mixed fluid in a fuel nozzle narrows toward the center in the channel cross section; a fuel concentrator that imparts, to the mixed fluid, a velocity component away from the center of the fuel nozzle; and a channel separation member that separates the channel of the fuel nozzle into an internal side and an external side; wherein the channel separation member is shaped in such a way that the cross sectional area of an external channel is larger at the downstream end than at the upstream end, and the upstream end of the fuel concentrator is located between the upstream end and the downstream end of an expanded portion of the venturi tube. This solid fuel burner prevents solid fuel particles, which is ground biomass fuel, from adhering and depositing inside the nozzle.

The present invention provides a solid fuel burner which ensures ignition performance and flame holding performance of a fuel nozzle. The present invention provides a solid fuel burner which achieves cost reduction by simplifying the structure of the fuel nozzle, for example, and which ensures the ignition performance and flame holding performance of the fuel nozzle. Further, the present invention provides a burner which enables stable combustion by both solid fuel and oil combustion with the suppression of soot and dust and mist generated during the oil start-up envisaged. The solid fuel burner of the present invention includes: a fuel nozzle straight tube portion allowing a mixing gas of a solid fuel and its carrier gas to flow therethrough; a fuel nozzle throttling portion narrowing a flow passage of the mixing gas passed through the fuel nozzle straight tube portion; a fuel nozzle diffusion portion horizontally expanding the flow passage of the mixing gas passed through the fuel nozzle throttling portion; a fuel nozzle outlet portion connected to the fuel nozzle diffusion portion and having an outlet flattened in shape; a ring-shaped outer peripheral flame stabilizer disposed on an outer periphery of the fuel nozzle outlet portion; and an inner flame stabilizer disposed in the fuel nozzle outlet portion and horizontally dividing the mixing gas passed through the fuel nozzle diffusion portion.

To provide: a fuel nozzle (51) that can inject fuel gas in which fuel and air are mixed; a flame stabilizer (54) provided on an axial center side near a tip end of the fuel nozzle (51); and a casing member (55) that partitions an inner flow channel in which the flame stabilizer (54) is provided and an outer flow channel on an outer side of the inner flow channel, inside the fuel nozzle (51), where the flow channel cross-sectional area of the inner flow channel partitioned by the casing member (55) expands in the flow direction of the fuel gas.

To provide: a fuel nozzle (51) that can inject fuel gas in which fuel and air are mixed; a flame stabilizer (54) provided on an axial center side near a tip end of the fuel nozzle (51); and a casing member (55) that partitions an inner flow channel in which the flame stabilizer (54) is provided and an outer flow channel on an outer side of the inner flow channel, inside the fuel nozzle (51), where the flow channel cross-sectional area of the inner flow channel partitioned by the casing member (55) expands in the flow direction of the fuel gas.