Feb., 1914
T H E J O U R N A L OF I N D U S T RI A L A N D E SGI,VE E RI N G C H E M I S T R Y
CURRENT INDUSTRIAL NEWS EVALUATION OF PULPWOOD I n a n address delivered by Martin L. Griffin, Chief Chemist of the Oxford Paper Co., before the Maine Section of the American Chemical Society in Bangor, Oct. 17th, Mr. Griffin shows how unsatisfactory the prevailing units of measurement in the lumber trade have come to be, when applied to the valuation of wood for pulp and he says: Dimension measure units are only properly applicable t o dimension products, as lumber. When wood is t o be valued for its yield in pulp, it should be measured in terms of its useful products like other commodities: as coal in heat units; ores in terms of their metallic content; fertilizers in terms of potash, phosphoric acid and ammonia. Up to the present time manufacturers of pulp, buying wood upon the cord dimension unit, not only suffer by the variation in yield of pulp in the same, and different species, as spruce and balsam, but also by the uncertainty as to the solid contents of the cord. VALUATION BY VOLUME-A cord of wood is defined to be a stack 4 ft. high and wide and 8 f t . long containing 128 cu. ft. Thesolid contents of such a cord are affected by various conditions, such as: I. LENGTH OF STICKS-sticks are never entirely straight and smooth, and in piling them one above another there always remain cracks, which become larger, the longer the sticks are and vice versa. With four feet sticks as standard, changes in the stick length, from one foot to six feet, vary the difference in the solid volume of the same stack measure from 14 per cent t o 35 per cent. 2. DIAMETER OF sTIcKs-The smaller the sticks, the greater the number, and number of cracks to the cord and consequently less wood. The difference in solid volume of two stacks, whose sticks are twice as large in one case as in the other, may amount to 13 per cent; and if the sticks of the one are four times as large as those of the other, this difference may amount t o 25 per cent. 3. SPLIT wooD-Large sticks are often split to facilitate handling and drying. After splitting they cannot be stacked as closely as before. This swelling amounts t o 5-6 per cent. As a rule, the longer and thinner the sticks split, the greater is the swelling of the stack. 4. FORM OP sTrcK-The straighter and smoother the sticks, the smaller the air spaces between them and consequently the greater the solid contents. 5. SPECIES-soft woods contain on the average about 3 per cent more solid wood t o the cord than hard woods, due t o straighter habits of growth and smoother bark. 6. GREEN AND DRY WOODS-with the drying of wood there is a consequent shfinkage in volume. Green hard wood will shrink by completely air-drying from 9-15 per cent and dry soft, 9-10 per cent. 7. PILING AND FIXING THE STACK-The higher the stack the less closely can i t be piled. The heavier the stick and the weaker the piler, the less close is the piling. It has been observed t h a t there is more solid wood in a stack when only one end supporting stake is used than when two are used. There always remains some space between the stakes holding the stacks together and the wood, therefore, the fewer the stakes supporting ends or the longer the piles, the more solid wood. Just here arise many controversies over wood measurements where the method of scaling in cars is employed. An ordinary freight car will hold three crosswise stacks in each end and one short lengthwise stack between, making the equivalent of seven short staked piles having fourteen ends, about a cord to a stack. There are also many minor
I
details which affect the amount of solid wood in the unit measure Since i t is obvious that each stick of wood involved cannot be scaled and the sum total in solid feet obtained, a method of drawing representative sample cords may be employed and these measured. A sample may not only truly represent a grade of quality, but when drawn a t a proportional rate, it may as truly represent a quantity. Thus if every fifth stick is drawn as wood is running on a conveyor or in a sluice until one cord is gathered, we know that four other equal portions, alike in all particulars, have passed. Such a sample can be measured by any standard of value, including quality and substance. If such a mode of sampling is applied according to the theory of averages, the sample will represent the quality, and there remains only the counting of the whole number of sticks to determine with precision the total quantity in terms of any unit by which the sample is valued. If all pulp wood were equally dry, of the same specific gravity, and would yield the same amount of fiber per unit volume, this method would be adequate. Such is not the case. VALUATIONBY WEIGHT-Bulk commodities are now very generally bought and sold by weight. Wood can be so valued and in many instances this method is easily applicable and has its advantages. According to the plan of valuing wood by solid volume as outlined, if we take the weight of the sample volume we approach much nearer the measurement of the substance. Such a sample weighing would be accurate and applicable alike t o wood driven in the rivers or freighted by rail. \&h'ere wood is shipped by rail, its weight adds another important factor, namely-the freight, and this must be paid by the mill. Here the weight and moisture test reveal the substance and the water upon which freight must be paid. A cord of spruce wood will weigh from 3300 lbs. to 4400 lbs. according as it has 35 per cent to 50 per cent moisture, and this difference in moisture may add j o cts. per cord to the cost of the wood a t the mill. The author concludes his address by suggesting t h a t buyers and sellers of wood get together and study their joint interests and a t least save a large sum of money now paid to the railroads for hauling wet and green wood. PROGRESS IN T H E FIXATION O F NITROGEN IN SCANDINAVIA The London Times Engineering Supplement for Oct. I j , 1913, refers to the successful commercial development of the process for oxidizing ammonia to nitric acid by means of the catalytic action of platinum (see Eng. Pats. 698 and 8300 of 1902, and Addition to Fr. Pat. 317,544 of 1902; J . S. C. I . , 1902, j48; 1903, 93, 420). The carbide works a t Odda, Xorway, when operations were started, comprised I O furnaces, each with a capacity of 7-8 tons of carbide per 24 hours. Ten more furnaces, of 16-18 tons capacity each, have recently been added. The temperature is maintained a t 5720' F. (3160' C.), the electrodes of the older furnaces taking 1400 kilowatts and those of the newer ones, 3joo kilowatts. It is stated that the rndiation of heat from the new furnaces is less than from a steam boiler. The hot gases from the furnaces are used in the limekilns instead of producer-gas. The annual output, 32,000 tons up till recently, is now 80,000 tons of carbide. Most of this carbide passes direct t o the calcium cyanide works of a n associated company, which, a t the present time, has a n annual output of 80,ooo tons, the number of furnaces having been increased nearly sevenfold since the opening of the works four years ago. The nitrogen used is prepared by the Linde process, IOO tons of air being liquefied daily. The furnaces have a capacity of I ton
