GB209829A - Improvements in mills for reducing paints, colours and pigments - Google Patents

Abstract

209,829. Torrance, J. R. Oct. 17, 1922. Roller mills.-In a mill in which the grinding takes place between rollers having different peripheral speeds, the material is passed between a high-speed roll and a low-speed roll, the difference in the peripheral speeds of which is considerable so that the material on the highspeed roll is carried away from the grinding region with a strong centrifugal action and a directional controlled removal of the material from the high-speed roll is effected by a scraper or like collector set near to the nip of the rollers. As shown in Figs. 1 and 2, the rolls c, d are set at an inclination, and the ends of the roll spindles f, g project into a gear-box e in which the main driving-shaft h is mounted. The fast roll d is driven from the shaft h by equal-size wheels i, j, and the slow roll c is driven by a speed-decreasing wheel-train k, l, n, o. One roll may receive an axial reciprocatory movement by means of a gear such as that described in Specification 25988/09. The axis of the intermediate gears h, n may be adjustable round the axis of the pinion k as described in Specification 21573/09. Adjusting-screws q are provided for effecting a contacting or non-contacting setting of the rolls c, d; for non-contacting settings, the adjustment described in Specification 218,752, is preferred. The scraper r, which may be covered in and provided with two or morepairs of converging sides s leading to valvecontrolled outlets t, is carried by arms x rotatable on a rod w carried by arms u mounted to turn on an horizontal axis within the limits of a pin-andslot control v. Stops y on the arms x contact with screws z to keep the scraper in proper contact with the rolls d. The low-speed roll c may be provided with a scraper. When treating paints and like fluids, the feed-hopper 1 is fitted with a screen 2 to keep back foreign matter.. The rolls may be of chilled iron and hollow with heating or cooling provision, or they may be of granite &c. Fig. 4 shows a mill with superimposed pairs of rolls 3, 4, and 5, 6, a scraper 7 collecting from the fast roll 4 and delivering to the lower pair of rolls 5, 6, whence a scraper 8 collects from the fast roll 6 and delivers to a receptacle below. In another arrangement, Fig. 5, with one slow roll 9 and two fast rolls 10, 11, a scraper 12 collects from the fast roll 10 and delivers to the fast roll 11 which is provided with a scraper 13. A small idle roller, which may be plain or grooved, may be arranged in the uppervee between the grinding-rolls to assist the feed. The mill is applicable for reducing paints,. colours, pigments, pastes, powders, cocoa, chocolate, &c.