Weyerhaeuser Company Limited

United Technologies Corporation

Robert M Spurrell

James F Lincoln

Gregory P Golike

Terry N Adams

Terry B Jordan

Manfred K Buder

Grant G Karsner

Edward A Huenniger

Warren R Hensey

Craig A Brown

The purpose of the present invention is to prevent or minimize the damage to a carton caused by sudden impact. This damage results most often from the cartons being dropped from some height. The type of carton damage is usually corner fracture. The tensile forces applied to the corner as the carton hits causes a tear to form at the base of the vertical score line where the carton folds to make the bottom corner. A single score line is formed in and at the side of the side panels of a carton. Each score line extends outwardly from each side of the side vertical score lines which define the side panels of the carton. The purpose of these score lines is to induce a fold to form preferentially at the intersection of the score line and the vertical score line and away from the carton bottom corner when the carton is dropped or suddenly shocked. Each of the score lines should be long enough and placed a distance from the bottom wall to induce the fold line to form preferentially away from the bottom corner.

Container

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.

Energy recovery from biomass using fuel having a bimodal size

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.

Method for reducing comminution energy of a biomass fuel

Overall heat recovery from wet wood waste, particularly sawmill-generated hog fuel, is improved by a process for predrying the fuel. A wet oversize fraction of the fuel is combusted in a fluid bed reactor providing heat for drying the remaining smaller sized fraction of the waste pile to about 10-30% moisture by weight. The gaseous products of the fluid bed burning are contacted with the fuel fraction in, preferably, a rotary dryer. The dried fuel is then screened into coarse and fine fractions. The coarse fraction is fed onto a grate of a wood waste boiler. The fines fraction is injected into the boiler combustion in an air suspension. The amount of fuel fed to the fluid bed reactor is 10-25% of the total fuel flow, depending upon the moisture content of the fuel. The gases fed to the rotary dryer are less than about 1,200.degree. F., to minimize 'blue haze,' by combining with minimum outside air.

Heat recovery from wet wood waste

A two dimensional expansion nozzle having a rotating plug serves to block flow, meter flow and afford thrust vectoring. Adjustable walls cooperate to obtain these features and may be adjusted independently to vary nozzle throat area. Cooling means are disclosed. This invention has particular application for VTOL aircraft.

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Auburn, WA, United States of America

Robert M Spurrell