GB881457A - Improvements in or relating to grinding mills - Google Patents

Abstract

881,457. Stuffing-box substitutes. MIT-- CHELL ENGINEERING Ltd. April 21, 1960 [April 24, 1959], No. 14049/59. Class 122 (5). In a rotary drum grinding mill the discharge end of the drum is sealed by pressure gas supplied to an annular chamber 32 surrounding the aperture 11a in the drum end 11 and sealed from the atmosphere by a sealing ring 20 resiliently urged axially towards a co-operating part 25. The sealing ring 20 is slidably mounted on and sealed by a rubber 0-ring 24 to a flange 19b of a gland ring 19 which encloses the chamber 32 and is formed in halves and bolted to the discharge box 14. The sealing face of the ring 20 is formed with a series of concentric grooves and the ring is urged towards the part 25, secured to the end 11, by leaf-springs 26, Fig. 4, and guided by hollow pins 27 which engage holes 28 in the ring 20 and act as passages for lubricant supplied to the grooved face of the ring. The gland ring 19 is axially located, prior to being clamped to the box 14, by adjustable cap nuts 30 on pegs 29. Compressed-air supplied through ports in the ring 19 passes through the clearance 15 between the end 11 and the box 14 to prevent escape of dust-laden gas through the clearance. A flange 25a on the part 25 deflects any escaping dust which is then removed through a hole (not shown) in the bottom of the gland ring 19. The feed end of the drum may be similarly sealed or, alternatively, as shown in Fig. 5, the sealing ring 41 may be secured to the gland ring 40; compressed-air being supplied to the chamber 42. In a modification, the sealing ring 20 may be slidably mounted in an annular channel and urged towards the part 25 by pressure gas instead of by springs. Reference has been directed by the Comptroller to Specification 817,341.