| 摘要 |
<p>The recovery of heat values from biomass materials such as wood waste or peat. Wood waste or ''hog fuel'' from the forest industries is of particular interest. It has been discovered that this material can be burned with no fossil fuel support in an air suspension-type burner, located in a boiler (34), without the need to finely pulverized the full fuel stream. One portion of the biomass fuel stream is ground (16) so that it is less than 100 νm in diameter and fed (30) to the burner. This fine portion serves as an ignition component and should comprise about 20% of the total heating value of the fuel, using a conventional air suspension burner, or 10% of the total heating value using a staged burner, when the burners are operated at full load. The balance of the fuel fed (32) to the burner can be of much larger particle size. This can be up to 10 mm or even greater in maximum dimension if used with a grate equipped boiler. If the boiler lacks a grate, the principal fuel component should not exceed about 1 mm in thickness and 4 mm in any other dimension if carryover is to be avoided. A key aspect of the invention is the discovery that the total amount of ignition fuel component should be maintained constant regardless of burner load.</p> |
