Improvements in or relating to a method and apparatus for coating pulverulent materials, especially coal fines, with pitch in the manufacture of compressed fuel or briquettes

摘要

709,231. Mixing appliances. RIEUX. C. G. H. Nov. 15, 1951 [March 29, 1951], No. 26815/51. Class 86 [Also in Groups XII and XXIX] In a process for coating pulverulent materials. especially coal fines, with pitch in the manufacture of fuel briquettes, heated pitch is sprayed on to the material by means of a gaseous fluid, for example air, which is at a temperature of about 300-400‹C. and a pressure of 50-90 grams per sq. cm., the gaseous fluid only contacting the pitch after its discharge from an orifice. In the apparatus shown in Fig. 1 a blower 1 forces air through a tube rest 2 disposed in a heating chamber 3 and delivers hot air to the outer envelope 4 of a spraying device which has a number of nozzles 5. Pitch is heated in a vessel 6 and delivered by a pump 7 to an inner tube 8 of the spraying device which has a number of projecting tubes 9 corresponding to the number of spraying nozzles 5. The arrangement is such that the pitch leaving the tubes 9 is surrounded by an annular and vertical jet of heated air which atomizes the pitch (see Group XXIX). The spraying device may be associated with any suitable mixing apparatus such as an inclined revolving tube into which the coal fines are discharged from a drying furnace. The mixing apparatus described in Specification 684,377, [Group XIII], may be used.