| 摘要 |
A method of injection and combustion control and related injection nozzles and lances are described which facilitate the merging of the combustion of fossil fuels and separately added solid biomass waste product fuels in the form of pelletized chars and fine particulates. The teachings of this inventor's earlier patent, "Variable Gas Atomization," U.S. Pat. No. 4,314,670, (referred to herein as VGA) are employed. They are applied in a distinctly different manner so as to enable air conveyed and injected solids to be accelerated, propelled and distributed in the combustion zone of fossil or biomass fuel boilers. While the use of an annular nozzle configuration with conically flared exit tips is generally similar, the functions to be performed, and the related conical exit configuration, differ. An assembly of five concentric, annular tubes and conically shaped exit tips is used to deliver air conveyed biomass fuel as an annular stream between two higher velocity air streams, both of which converge so as to accelerate and propel the biomass fuel, and distribute it into the flame zone produced in a conventional fossil fueled boiler. The additional air required for combustion of the biomass fuel is fed to the expanding plume produced by the fuel delivery stream and adjoining air streams. A portion of the combustion air is delivered through the inside of the inner tube in sufficient volume to provide the entrainment flow produced by the expanding air streams. In so doing, it prevents undesirable recirculation of combustion gases and unburned fuel. The remainder of the combustion air is delivered through an additional annular nozzle located on the opposite side of the expanding streams to similarly mix with the fuel.
|
