Wood specific gravity

Physical Properties. Physical properties of waste as fuels are defined in accordance with the specific materials under consideration. The greatest degree of definition exists for wood and related biofuels. The least degree of definition exists for MSW, related RDF products, and the broad array of ha2ardous wastes. Table 3 compares the physical property data of some representative combustible wastes with the traditional fossil fuel bituminous coal. The soHd organic wastes typically have specific gravities or bulk densities much lower than those associated with coal and lignite. 

Specific gravity is direcdy related to the bulk density of waste fuels prepared ia a variety of ways. Solid oven-dry (OD) wood, for example, has a typical bulk density of 48.1 kg/m (301b/ft ). In coarse hogged form, eg, <1.9-cm minor dimension, this bulk density declines to about24kg/m (151b/ft ). In pulverized form, at a particle size <0.16 cm, this bulk density declines to 16—19 kg/m (10—12 Ib/ft ). Similar relationships hold for municipal waste, agricultural wastes, and related fuels. 

Table 2. Specific Gravity of Some Common Woods Growing in the United States...

Because of the plasticizing action of the resin-forming materials, the wood can be compressed under considerably lower pressures than dry, untreated wood. For example, treated spmce, cottonwood, and aspen veneer, dried to a moisture content of 65 but not cured, are compressed, when subjected to a pressure of only 1.72 MPa (- 17 atm) at 149°C, to about half the original thickness and a specific gravity of - 1.0. 

Gotinfo cedrela wood yields an oil of specific gravity and optical... 

A sesquiterpene has been isolated from the essential oil of Cannabis Indica. This may fairly be considered a definite body, as it has been isolated by many different observers and described by them at different times. Valenta first mentions it. Vignolo describes it as a mobile liquid boiling at 256°, of specific gravity -897 at 15°, and slightly laevo-rotatory. Wood, Spivey, and Easterfield give the boiling-point as 258° to 259°, the specific gravity as -898 at 18°, and the rotation as - 8-6°. 

In the Woods Hole Oceanographic Institute s three-man 1,800 m (6,000 ft.) depth vehicles, approximately 5,000 lb. of syntactic foam were used to provide buoyancy. With a specific gravity of 0.68, it required three pounds of material to gain one pound of... 

The penetration and cooling action of water is required with Class A fires, e.g. those involving paper, wood, textiles, refuse. Extinguishment of a Class B fire can be achieved by the smothering action of dry chemical, carbon dioxide or foam. Most flammable liquids will float on water (refer to Table 5.1 under Specific gravity ), so that water as a... 

Wood is a composite material that is made, up basically of a mixture of three main constituents, cellulose, hemicellulose, and lignin (see Textbox 54), all of them biopolymers synthesized by the plants, which differ from one another in composition and structure (see Textbox 58). The physical properties of any type of wood are determined by the nature of the tree in which the wood grows, as well as on the environmental conditions in which the tree grows. Some of the properties, such as the density of wood from different types of trees, are extremely variable, as can be appreciated from the values listed in Table 71. No distinctions as to the nature of a wood, whether it is a hardwood or a softwood, for example, can be drawn from the value of its specific gravity. 

Fuel Oils Refined petroleum products having specific gravities in the range of 0.85 to 0.98 and flash point temperatures above 55 °C. This includes auto diesel, industrial heating fuels, various bunker fuels, furnace fuels. Refer to Chapter 4 for specific examples and discussion of properties. Fuel Value Refers to the amount of potential energy that can be released by a fuel during combustion. Expressed in units of BTUs per pond of fuel. Examples are asphalt (17,158 BTU/lb typical value), LPG (18,000 BTU/lb), wood shavings (8,250 BTU/lb). 

The Hanoverian pound, which, is that given in the preceding table, is equivalent to 1 031114 English. It may be seen from this table, that most of the results show the specific gravity of the samples examined to be about half that of water. A fair average of the value of wood, subjected to desiccation in open sheds, can only be arrived at by ascertaining the weight. 

Marcos Boll has shown that, for every fifty-six ports of actual wood contained in an ordinary stack, there are forty-four of unoccupied space. In prosecuting his inquiries into this snbjcct, he determined the real amount of matter in a given bulk of wood, the tabulated specific gravity having been previously ascertained by coating the wood with varnish as already stated... 

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