GB347914A - Process of and means for the mechanical preparation of pulverised solid materials - Google Patents

Abstract

347,914. Helical blade conveyer drying - apparatus. MADORE, N., 26, Rue Bourgelat, Alfort, Seine, France. May 23, 1930, No. 15868. [Class 34 (ii).] In a process for preparing pulverized fuel &c. a pulverizer e, Fig. 2, is fed with coal &c. by a band or screwconveyer h which receives coarse material from the separator g together with finely ground material from the storage receptacle if such receptacle is filled beyond the point l. If the screw h is not completely filled by this material then material from a dryer a is deposited into the screw h by a screw b through an orifice d, the fresh material necessary to replace that taken from the dryer being supplied by a hopper c, Fig. 3, to the discharge end of the screw b where it enters the dryer. The ground material from the pulverizer e is discharged up the pipe f, Fig. 4, by the draught created by a fan 6, Fig. 2, the air escaping through an orifice 11 back to the pulverizer; an opening 12 is provided in the dryer a through which fine material is drawn. The dryer a is provided with inclined, rotating paddles 2 mounted on a shaft 1 and the screw b conveys the coal from the outlet 4 to the inlet 3 in a closed circuit. A dust extractor 19 fitted with perforated plates 20 deposits the dust on to the screw b. Hot air enters the dryer at 17, Fig. 4, leaves at 18 and after passing through the dust-box escapes at 21 either to the intake side of the primary air faces which carry the pulverized coal to the burners or to the intake side of a fan which expels it to the atmosphere. In a modification the paddles 2 effect a preliminary disintegration of the coal which is delivered to a grating 25, Fig. 5 (not shown), unbreakable material being collected in a receptacle under the dryer.