GB172067A - Apparatus for pulverising ore and the like - Google Patents

Abstract

172,067. Johnston, G. July 30, 1920. Roller mills.-Apparatus for pulverizing ores &c. comprises one or more pairs of rolls fitted with adjusting-mechanism and relief means, the material to be comminuted being delivered in a stream of air at substantially the peripheral speed of the rolls. As shown, two pairs of rolls A, B and C, D are mounted one above the other in bearing-blocks E sliding in headstocks F, the rolls of each pair being forced towards each other by heavy springs G. The width of pass between each pair of rolls is regulated by means of cams H carried by spindles J connected by spur gearing K, L to shafts M provided with discs N by rotation of which the cams H are adjusted. The discs N bear indications of the adjustment and are locked by fingers I serving as pointers to the indications. The rolls &c. are enclosed within airtight casings Q, and the material to be treated is drawn in at the inlet aperture R by suction applied to the outlet apertures S. A diaphragm T in the aperture R divides the ingoing stream of air and material into two portions directed upon the peripheries of the rolls A, B which are driven by pulleys U at a surface speed equal to that of the stream. A guiding-device V having upon its top a series of narrow triangular teeth W, alternate ones of which are oppositely inclined, is arranged beneath the nip of the rolls A, B and directs the material into ducts X leading to the lower rolls C, D, the nip of which is narrower and the surface speed of which is proportionately greater than those of the rolls A, B. A device Z similar to the guide V directs the comminuted material from the rolls C, D into the outlets S whence it is delivered to a settling-chamber.