Method and apparatus for the combustion of solid fuel

Claim 2

A process for the gasification of a solid particulate fuel by partial combustion, which comprises the steps of: injecting into a pre-mix zone along a central flow axis a stream of transfer fluid having the particulate fuel disposed therein to form a central flow stream; impinging a plurality of primary oxygen containing streams upon the central stream of transfer fluid having the particulate fuel disposed therein at an angle in the range of 30° to 60° relative to the central flow axis and having a velocity exceeding the velocity of the central stream; and injecting a plurality of secondary oxygen containing gas streams into the pre-mix zone at a velocity in excess of the fuel stream for forming a shroud around the central stream as the mixture of fuel and gas streams flow from the pre-mix zone through a converging-diverging nozzle having a throat section into a combustion zone.

Claim 3

The process of claim 1, wherein: the primary oxygen containing stream is injected into the pre-mix zone at a relative mean velocity of about ten to about seventy meters per second greater than the mean velocity of the central fuel stream.

Claim 4

The process of claims 1 or 2, wherein: the mean velocity of the gas and fuel streams through the nozzle section is about 35 to about 100 meters/second.

Claim 5

The process of claims 1 or 2 wherein: the gas and fuel streams are directed through the nozzle section to achieve a swirl number of about 0 to about 1.1.

Claim 6

The process of claims 1 or 2 wherein: the primary oxygen containing gas streams are impinged of the central flow stream to achieve a mean axial velocity at the exit of the nozzle of about 1.5 to about 10 times the mean axial velocity of the central flow stream.

Claim 7

The process of claims 1 or 2 wherein: the secondary oxygen containing gas streams are injected to achieve a mean axial velocity at the exit of the nozzle of about 1.5 to about 10 times the mean axial velocity of the central flow stream.

Claim 8

A burner apparatus for the gasification of a solid particulate fuel by partial combustion, including: a burner having a pre-mix chamber forming a central longitudinal axis; a central inlet port formed on said central longitudinal axis for enabling injection of a stream of transfer fluid having the particulate fuel disposed therein into said pre-mix chamber; a converging-diverging nozzle having a throat section disposed on said central longitudinal axis to provide an outlet for said pre-mix chamber for enabling central flow in said pre-mix chamber along said central axis, the axial length of the diverging part of said nozzle being about 0.5D to about 2D, where D is the diameter of the narrowest section of the throat section; a plurality of primary gas inlets disposed about said central inlet port, said plurality of primary gas inlets directed radially inwardly at an angle of between 30° to 60° relative to the central longitudinal axis; and a plurality of secondary gas inlets about said central inlet port, said plurality of secondary gas inlets directed radially inwardly to form a uniform shroud of gas around the central stream.

Claim 9

A burner apparatus for the gasification of a solid particulate fuel by partial combustion, including: a burner having a pre-mix chamber forming a central longitudinal axis; a central inlet port formed on said central longitudinal axis for enabling injection of a stream of transfer fluid having the particulate fuel disposed therein into said pre-mix chamber; a converging-diverging nozzle having a throat section disposed on said central longitudinal axis to provide an outlet for said pre-mix chamber for enabling central flow in said pre-mix chamber along said central axis, the axial length of the diverging part of said nozzle being about 0.5D to about 2D, where D is the diameter of the narrowest section of the throat section; a plurality of primary gas inlets disposed about said central inlet port, said plurality of primary gas inlets directed radially inwardly at an angle of between 30° to 60° relative to the central longitudinal axis; and a plurality of secondary gas inlets about said central inlet port, said plurality of secondary gas inlets directed radially inwardly to form a uniform shroud of gas around the central stream.

Claim 10

The burner of claim 7, wherein: the axial length of the pre-mix chamber between the fuel inlet and the diverging part of the nozzle is about D to about 3D, where D is the diameter of the narrowest section of the nozzle.

Claim 11

The burner of claim 7, wherein: the surface of the diverging portion of the nozzle forms an initial angle with the throat section relative to the central axis of 95° to form a tulip shape.