GB196203A - An improved crushing and grinding mill - Google Patents

Abstract

196,203. Wriedt, F., and Milo Machinery Co. Proprietary, Ltd. May 29, 1922. Stationary drum and internal centrifugal crushing- blocks; roller - and - ring mills; disc and like mills.- A grinding or crushing mill for granular materials comprises a stationary cylindrical surface, one or more series of grinding- elements movable over the surface, means for facilitating the entry of material between the grinding-elements and the cylindrical surface, and means on the surface of the grinding-elements for displacing the material transversely to the direction of motion of the grinding-elements and from one end of the cylindrical surface to the other. As shown in Figs. 1 and 2, the grinding pads or shoes 22 are pivoted upon pins 21 fixed in spiders 20 carried by the shaft 15, and are pressed against the inside of the casing 10 by springs 23 secured to pins 24 on the spiders. The leading portions of the pads 22 are chamfered or bevelled to form spaces 25 into which the material can readily enter, and grooves or channels 26 may be formed in the chamfered portions of the pads. The grooves are preferably set obliquely to the leading edges of the pads so as to move the material transversely to the direction of motion of the pads. Fig. 5 shows a pad 22 formed with tapered grooves 27 instead of having its leading edge chamfered. The pads are arranged in series in parallel planes, and the pads of each series are positioned opposite to the spaces between adjacent pads of each adjoining series, and preferably the ends of each pad of a series project into the spaces between the pads in the adjoining scries. The grooves 26, 27 can be varied in form and extent in the different series. The material passes from a hopper 30 carried by the end-cover 11 into a supply chamber 31, whence it is fed into the pulverizing-chamber by oblique or helical vanes 32 on the shaft 15. The material may undergo a preliminary crushing between discs 33, 34 which are dished on their sides and provided with radial bars or ribs, the disc 33 being secured to the cover 11 and the disc 34 to the shaft 15. Thrust bearings 19 are provided for the shaft 15, and the distance between the discs 33, 34 is regulated by means of nuts 35 on the ends of the shaft 15. The crushed material is delivered through an outlet 28 in the cover 12 into a delivery shoot 29. Tapered or conical rollers 38, Fig. 7, may be used instead of, or in addition to, the pads 22. The rollers are rotatably mounted on arms 39 pivoted on collars 40 fixed to the shaft 15, and are pressed against the casing 10 by springs 23. The rollers may be arranged in line with, or obliquely to, the axis of the pulverising-chamber. Instead of pivotally mounting the pads and rollers, they may be formed with stems 43, Fig. 6, slidable in radial pockets 42 in collars 41 on the shaft; springs 44 at the bottoms of the pockets press the pads &c. against the casing. The casing 10 and the cover 11 are provided with water jackets 45, 47 for cooling purposes.