Wood scrap conversion plant for mfg. small fuel granules - esp. where sawdust is dried by gas obtd. from burning tree bark, and is then pressed into granules

摘要

Ligneous scrap, esp. wood scrap, is treated in a plant which includes a hopper for milled tree bark. The bark is fed by a doser into a boiler to provide combustion gas which flows through a static and mechanical dryer. The dryer is fed with damp sawdust from a second hopper; and the dry sawdust and gases are then fed into a cyclone. In the cyclone, the gases are fed to an exit chimney, whereas the sawdust is fed into a third hopper, which supplies a mill, mixer, and a granulating press. The sawdust granules obtd. from the press and cooled and sieved are fed by a bucket elevator to a row of storage hoppers. Used esp. for scrap obtd. in converting trees into machined planks etc. Cylindrical fuel granules are obtd. of small dia., contg. 12-18% moisture, and with density 500-900 kg/cu.m. The granules have a calorific value of 3800-4000 kcal/h.