Patent GB-230438-A (GB)
Title: Improvements in or relating to pulverizing mills
IPC: B02C15/08
Filed: 1925-02-21
Abstract: 230,438. Fuller-Lehigh Co., (Assignees of Breerwood, C. H.). March 7, 1924, [Convention date]. Ball-and-ring mills. -In a puverizing mill with balls operating in a grinding-ring as described in Specifications 4290/12 and 139,511, the yoke which operates the balls comprises a series of rotatably-mounted vertical arms connected together at the upper ends and extending into the grinding-zone, each of the arms carrying a single means for propelling the balls and for dislodging the ground material from the surface of the raceway. The carrier 19, Fig. 1, mounted on the vertical shaft 16 and co-operating with the grinding-ring 18 to form a raceway for the grinding-balls 20 has a hub 21 extending upwardly into the hub 24 of the yoke 23 which has radiating arms connected by means of a ring 26. The arms 28, Fig. 2, carrying the ploughs and pushers depend from the ring 26 and have flat inner and outer faces with lateral tapering walls and terminate in square shanks 29 to which the pushers &c. are secured. Upwardly and rearwardly extending lifting-blades 30 are bolted to the outer faces of the arms 28 or are formed integral therewith. The fan-blades 31 which float the material lifted by the blades 30 against the screen 14 are carried by brackets 32 extending upwardly from the ring 26. The brackets 32 are placed between the radiating arms of the yoke so that each fan-blade is to the rear of one of the lifting-blades. A connecting-ring 33 supports the upper ends of the brackets 32. Fig. 8 shows a modification in which the fan is formed as a separate unit. The hub 47 of the fan has a recess 48 in its lower face into which a reduced portion 46 of the hub 38 of the yoke extends. The ends of the radial arms of the hub 47 are connected by a ring 51 having upward extensions 52, and a fan-blade 53 is secured to or, preferably, formed integral with each extension 52. The opening 49 in the hub 47 to receive the spindle 37 is so formed that the fan-blades alternate with the lifting-blades. Figs. 4 and 6 show a plough-pusher consisting of a body portion 42 having a vertical socket 41 to receive the square shank 29 on an arm 28 of the yoke. A concave surface 54 in the front face of the body 42 engages the grinding-ball and beneath this surface the body is cut away to form a vertical ridge 61 from which extends towards the inner face of the body a rearwardly inclined face 62. Another inclined surface 64 extends rearwardly toward the outer face of the body, and extending outwardly from the lower end of the ridge 61 is a blade 65 which tapers toward the rear. The outer wall of the bodv is cut awav to form a channel with which the inclined surfaces communicates. In operation, the material that would normally be packed down in the raceway by the passage of the ball is dislodged therefrom by the inclined' surfaces and part of it is thrown towards the centre of the mill, while part passes through the channel in the body and is discharged in the path of travel of the following ball. The plough-pushers described in Specification 230,427 may be used in the mill; or some of the depending arms 28 of the yoke may carry pushers for the grinding-balls and the remainder be equipped with ploughs.