Patent GB-248347-A (GB)
Title: Improvements in pulverising mills
IPC: B02C13/26
Filed: 1926-02-10
Abstract: 248,347. Raymond Bros. Impact Pulverizer Co., (Assignees of Lauritzen, C. M., and Vogel, W. H.). March 2, 1925, [Convention date]. Impact pulverizers.-In a pulverizer comprising a substantially cylindrical heater-chamber within which hammers revolve, the lower corner of the pulverizing-chamber at the side remote from the outlet for the pulverized material is provided with a deflecting- member adapted to direct into the path of the hammers material thrown against it during the operation of the mill. The member may form part of a. ring mounted in close proximity to the path of the hammers. As shown, Fig. 1, the directing plate or ring 28 is formed integrally at one end of a liner plate or ring 29 of the beaterchamber 2, and preferably inclines inwardly towards the hammers 17, and outwardly from the driving-shaft 4 at an angle of about 45‹, with one edge substantially in line with the path of travel of the first series of hammers. By inserting shims 30, the plate 28 can be adjusted towards the hammers to compensate for wear; or the plate may have adjusting screws extending through the adjacent wall of the mill housing. A similar inclined deflecting- ring 32 adjustable by means of screws 33 is fitted at the other side of the. hammers. The plates 28, 32 serve to direct the coarse material thrown against them back into the path of the hammers 17. The material is fed through the inlet opening 14 of the chamber 2 by a pocketed feed-wheel 12 which is intermittently and adjustably driven from a shaft 15 driven through gearing and a belt 16 from the shaft 4. The hammers 17 are pivotally mounted at their inner ends 18 within a frame composed of a series of plates or discs 19 keyed on the shaft 4. Spacing-rings 20 separate the disc 19, and the discs and rings are clamped between a collar 21 and an adjustable nut 22 on the shaft 4. A fan 9 in the chamber 3 withdraws the pulverized material and drives the fuel-laden air through a conduit 24 to a storage bin or directly to the 'burners where it is consumed. Air is supplied to the chamber 2 from an inlet pipe 25, and additional air may be supplied to the fan chamber 3 through an adjustable inlet 26. A recess or air-pocket 34 may be provided at the top of the chamber 2 beyond the beating zone of the hammers. In a modification, the two rings 28, 32 are secured to or made integral with an annular connecting-member which is adjustable towards the sides of the chamber 2 by means of screws. Or the deflecting ring assembly may be fixed within that portion 38, Fig. 4, of the mill housing which encloses the chamber 2, and the portion 38 be bodily adjustable laterally. The walls 39 at one end of the casing 38 can slide along a cylindrical extension 40 of the fixed housing 41 at the inlet end of the mill, and the conical outlet portion 42 of the casing 38 has a cylindrical neck 43 which can slide within an opening 44 in the end wall 45 of the fan chamber 3. Screws 46. 47 or other suitable means are provided for adjusting the casing section 38. Or the entire casing may be fixed and the shaft 4 carrying the hammers be adjustable endwise. In the arrangement shown in Fig. 5, a regulator or whizzer 48 comprising a series of radial plates 49 is mounted on the shaft 4 adjacent the outlet 23. The outer ends 50 of the plates are preferably inclined and travel within a short distance of the conical ring 51. The coarser material thrown against the ring 51 is deflected back into the chamber 2. The regulator 48 may be adjustable along the shaft 4 towards or from the ring 51. When a regulator 48 is fitted, the inclined deflecting-ring 32 at the outlet end of the chamber 2 may be dispensed with, and only a ring 28 at the inlet end used. The material may be fed at the top or at one side of the mill.