摘要:
The present invention relates to the preparation and burning of biomass-derived fuels such as wood waste or peat. Wood waste or "hog fuel" from the forest industries is of particular interest. Normally the entire stream of this material must be finely ground if it is to be successfully burned in an air suspension burner without any fossil fuel support. It has now been discovered that a bimodally sized fuel can be used. Only about 10-20% of the total heat energy is provided from a portion ground to a size less than about 100 .mu.m. This serves as an ignition component for a principal fuel which may be of much larger size. The usual hog fuel pile contains both bark and wood. Of these two materials, bark is much more friable and easily ground to fine particle size than wood. A major reduction in grinding energy is achieved by selecting the more friable material to be ground to fine size as the ignition fuel. The more resistant material is used as the principal fuel. When using a bimodal system, best results are obtained when the amount of ignition fuel sent to the burner is maintained constant. Load swings are accommodated by varying only the principal fuel component.
摘要:
The present invention relates to 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 without the need to finely pulverize the full fuel stream. One portion of the biomass fuel stream is ground so that it is less than 100 .mu.m in diameter. 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 can be of much larger particle size. This can be up to about 10 mm or even greater in maximum dimension if used with a grate equipped boiler. If the boiler lacks a grate, the principle 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. The principal fuel component is modulated to accommodate load swings. Thus, at lower loads a higher percentage of the total heat energy is derived from the ignition fuel component.
摘要:
A laminated product has an organic polymer layer on at least one surface of a substrate of cellulosic material impregnated with polyisocyanate. The substrate is preferably made from substantially delignified cellulosic material and an isocyanate resin. The isocyanate resin comprises a polyisocyanate, preferably PMDI, and may include a miscible organic solvent, preferably one such as propylene carbonate having a high boiling point and low flammability and toxicity. The substrate may be cured with an uncured overlay sheet positioned on the cured substrate and then cured to bond the substrate and overlay. Alternatively, a cured overlay may be adhesively or otherwise secured to a previously cured substrate. As yet another alternative, an uncured overlay sheet and uncured substrate may be placed in position and simultaneously cured. An overlay may be positioned on one or both major surfaces of a substrate sheet.
摘要:
A method is disclosed for producing a polyureacellulose composite material from substantially delignified cellulosic material and an isocyanate resin. The isocyanate resin comprises a polyisocyanate, preferably PMDI, and a miscible organic solvent, preferably one such as propylene carbonate having a high boiling point and low flammability and toxicity. The composite surprisingly exhibits values of physical parameters that are at least as good as, and sometimes far superior to, corresponding parameters of similar composites made using neat (undiluted) polyisocyanate. Single- and multiple-ply composites can be made, employing only a single curing step.
摘要:
Discontinuous fibers are entrained in a gaseous medium and coated while entrained with a substantially continuous coating of a binder material. Plural coatings of various binder materials may be applied to the entrained fibers. Also, one or more solid particulate materials may be adhered to the fibers by the binder material as the binder material dries. The binder material may be heat bondable and mixed with other fibers for use in producing a wide variety of products.
摘要:
Discontinuous fibers are entrained in a gaseous medium and coated while entrained with a substantially continuous coating of a binder material. Plural coatings of various binder materials may be applied to the entrained fibers. Also, one or more solid particulate materials may be adhered to the fibers by the binder material as the binder material dries. The binder material may be heat bondable and mixed with other fibers for use in producing a wide variety of products.