GB336776A - Improved pulverizing machine - Google Patents

Abstract

336,776. Hirsch, P. A. Nov. 15, 1928, [Convention date.]. Impact pulverizers.-In a beater mill barriers or walls confine the material being ground to the peripheral zone of the beaters and within such zone one or more separating means in the form of vanes are located between or follow the beaters so as to throw back the heavier particles. As shown, three discs 47, 55 and 55a are mounted on a shaft 32 rotatable in a casing 11, the material being fed in to the first ring of beaters through a conduit 18 and orifice 19 and the ground material being discharged in a cold or preheated blast of air drawn in through a duct 28 by a fan 38, 41 and discharged through a conduit 26. Each disc is provided with pivoted hammers, the disc 47 which comprises two plates having a single row 50 pivoted between them whilst the discs 55, 55<a> are supplied with a double row 58, 59 and 58<a>, 59<a> respectively. The hammers 50 rotate in an annular ring formed by a diaphragm 67, wear plates 49 fixed to the disc, and a peripheral ring of sectional plates 94. The diaphragm 67 is perforated with an annular ring of ports, through which the ground material passes to the next ring of beaters 58, 59. The webs 61 in the ports may be axially inclined to throw heavy particles of coal &c. back to the beaters 50. The hammers 58, 59 similarly revolve in an annular ring formed by a lip 66 of the diaphragm 67, sectional plates 94 and lip 76 of an annular ring of ports which communicate with the third ring of hammers 58<a>, 59<a>. The webs 71 in these ports are also inclined in order to throw back heavy particles into the ring of beaters 58, 59. The coal &c. finally passes to the third row of beaters 58<a>, 59<a>, which rotate in a closed annular space, and is ejected against a ring of fixed vanes 81, Fig. 5, some of which are radially extended at 81<b> to direct the coal to the fan 38. The vanes 81<b> register with vanes 91 on a wear plate 90 so as to extend completely across the discharge passage. The annular rings of ports 61, 71 are held in the casing 11 by screws 64 and the casing is in halves with hinges at each side so that after removing one hinge pin the casing may be pivoted about the other. The sectional plates 94 are held in grooves in the casing by stop plates 95 (Fig. 2, not shown), and certain of these plates at the bottom of the casing are removed so that metal particles &c. may be discharged into recesses formed in the supporting feet 14. An outlet 20 is also formed in the conduit 18 for the discharge of metal particles from the beaters 50. The axial inclination of the webs in the ports may be varied and the webs may be of arrow head shape in plan. Specification 221,124 is referred to.