The Guardian AND EVENING STAR, With which is incorporated "The West Coast Times.” WEDNESDAY APRIL 13th, 1921. USE OF PULERIZED COAL.

Hokitika Guardian, 13 April 1921, Page 2

The Guardian AND EVENING STAR, With which is incorporated "The West Coast Times.” WEDNESDAY APRIL 13th, 1921. USE OF PULERIZED COAL.

j.N view of tile present-day necessity lor the conservation ot coal resources, the following resume of an article in the Commerce Monthly, published by the National Bank of Commerce in New York, may prove of interest. It is - pointed out that the fundamental economic advantage in burning pulverised coal lies in the complete stage to which I combustion is carried in the furnace. The contact surface between eoal and I air is greatly increased by splitting the coal into numerous particles of small isize. The second advantage in the pulverization of solid fuel is the fact I that it floats in the air, spreads and is carried off by even small air currents. ITliis makes the intimate mixture of coal and air very easy. It simplifies Ithe construction of burners and guarantees economical combustion. T lie fini or the coal powder the more nearly ideal conditions for complete combustion are j approached. Where proper apparatus and 'methods are- in use, however, other I more tangible economies are effected by j the use of powdered fuel. The labour I cost of firing is materially lowered and losses during short periods when steam pressure is not required are reduced to 11 a minimum. No air is allowed to pass through the furnace when firing operations stop, so that the radiant heat of the furnace is absorbed by tho boiler, avoiding the losses which occur with grates or stokers through the constant burning up of fuel and incomplete combustion of the gases generated from hanked fires. The time necessary to get up steam is reduced by half when pulverized coal is substituted for tbc same fuel in lump form. Recent experiments also show an economy in fuel consumption which is said to he as high as 30 per cent. Until very recently the impression has prevailed that only certain grades of bituminous eoal were suitable for powdering. All the most recent developments in the use of powdered coal as a fuel for steam generating plants have been made with anthracite culm, at one time definitely abandoned as a fuel suitable for powdering. High volatile soft eoal gives best results, hut mixtures of such a ejrwde of coal with anthracite culm have proved entirely satisfactory, and pulverization may he applied to any solid fuel, peat, lignite or bituminous coals of any grade, as well as anthracite and coke. It is estimated that, although the practice of using pulverized coal in the cement industry dates back only to the last fifteen years, a saving of 100,i OIK) tons of coal per 1,000,OIK) tons of charge smelter is made annually in the United States. “The economic importance, therefore, of conserving the present workable supplies of high-grade coal and of making available the vast and almost untouched reserves of lowgrade fuel which are known to exist near the surface in many parts of the globe, makes every progress in the use of powdered or pulverised coal during the last decade of special significance.” During 1919 it is estimated that be- ' tween 10,900,000 and 12,000,000 tons of coal were pulverized for industrial consumption in the United States. Oi 1 this amount 6,000,000 tons were con- 1 sumed in the making of Portland com- s ent, 2,000,000 tons in tho iron and steel * industries. 1,500,000 tons in copper re- ‘ fining, while at least 250,000 tons wore I ' used in power plants. The remaining ' resumption of pulverized fuel was div- j vidod among a large variety of indnstrial uses. j 01