US1807034A - Universal rod mill - Google Patents

Description

y 1 H. HARDINGE 1,807,034

- UNIVERSAL HOD MILL Filed 25, 1927 2 Sheets-Sheet l Patented May 26, 1931 UNEE'ED mass 7 rat on rarest? OFFEQE v HARLOVIE 'HARDINGE, OF YORQ PENNSYLVANIA, ASSIGNOR TO HARDINGE COMPANY, INCORPORATED, F YORK, PENNSYLVANIA, A CORPORATION OF NEW YORK U'NIVERSAL ROD MILL Application filed February 25, 1927. Serial No. 170,763.

This invention relates to grinding mills and more particularly to rod mills grinding either with or without moisture.

Among the objects of the invention is to provide a universal grinding mill in which the pulp line may be varied'at will and in which liners may be used, as desired, for the purpose; in one case, of assisting the flow of comminuted material through the mill and toward the discharge outlets of the mill; and in another case, of prolonging the duration of time during which comminuted material which is'below the rods and in contact with the inner wall of the mill to be raised as the mill rotates and dropped upon the top of the pile of rods ashort distance farther away from the discharge end of the mill than its original position below the rods.

. Myinvention is shown in association with a rod mill of the type described in United States Patent No. 1,449,751 and it is applicable to the cylindrical type of rod mill which may or may not have both ends conical. In rod mills having a conical discharge end there is a tendency for the larger particles of the comminuted material to collect at the base end of the conical discharge portion and close to the ends of the rods which lay within the cylindrical portion of the mill. This condition is a result of the Stratification of the comminuted material within the-conical portion, as is well understood by those skilled in the art. The coarse particle-s gathered at this portion of the mill opposite the ends of the rods oftentimes are not ground fine enough for the purposes desired and, while they will, in time,- be worked and ground beneath the end portions of the rods, it is among the purposes of my'invention to make a more rapid disposal of this coarse material either bytaking it out of the mill for use in its exist-ing form or by leaving it in the mill and causing it to be fed back beneath'the ends of the rods and/or, while in contact with the wall of the mill, be raised as the mill is rotated and dropped upon the pile of rods in order that it may be subjected to further grinding action by the rods. In carrying out this phase of my invention I so construct the plate-s lining'the cylindrical portion of the mill in the vicinity of the conical portion as to permit the material opposite the ends of the lower rods and along the wallsto Work or be worked beneath the end portions of the rods so that it either may be discharged or a.

returned within the mill in the manner set forth hereinbefore, and, in either case, the lining plates are so constructed as to accommodate comminuted material beneath the rods without causing undue cushioning of the rods or elevation of the'ends of the rods, while at the same time increasing the grinding eficie-ncy at this portion of the mill.

Other advantages and objects will be pointed out hereinafter in the accompanying specification and in the drawings, in which: Fig. 1 illustrates a side elevation of a rod mill having, a plurality of outlet ports near its discharge end, i I 4 Fig. 2 is an enlarged View of the discharge '10, 11, preferably are of a conical or dished configuration. A plurality of cylindrical or other rods 12 are mounted with the grinding compartment and the conical or dished ends servethe purpose, among other purposes, of maintaining these rods out of contact with the ends of the mill and within the grinding compartment 9. Either or both ends may be conical in shape. The rods preferably are of substantially the same internal length as the cylindrical grinding compartment. Material is fed to the mill at one end 10 and through a passage within the trunnion 13. Due to the rotation of the mill, the rolling movement of the rods, and the impact of the rods against each other and on the bottom of the mill, the material is comminuted and lee 7 of the mill in this manner, there need be no tion or classification ofccomminuted mate-' rial against the sloping wall cf a conical ior dished end, reference may be had to the patent identified hereinbefore.

As in previous constructions, the mill disclosed inithe appended drawings 'is operative for discharging comminut-ed materials through a passage 14: within the trunnionlii at thedischarge end of the mill. In the use difference in the functioning of the mill unless the various features of the present in vention are utilized.

However, the tieldof use of the mill under theseconditions may be said to be limited and my proposed improvements accomplish the purpose of adapting such a mill for any field of use. That is, I am enabled to vary the pulp discharge level of the mill Without resorting to such expedients as raising or lowering one end of the mill or of removing a portion or all of the discharge end wall. I accomplish this by piercing the sloped wall 11 of the conical discharge end of the mill in such a manner as to provide a plurality of series of ports with each series of ports disposed at different distances from the axis of the mill, or, in other words, from the bottom of the mill. For example, in the present embodiment there are two series of "ports in the conical dlscharge end 11, each series ining capable, when opened, of forming an interrupted' annulus for permitting the dis- 7 charge of commmuted material from the mill; The ports are of sufiicient size and in sutficient number to freely discharge the material. For example 111 Fig. 2 the closures 16 of the series of ports 17 near the base-of the conical Wall 11 may be removed and, with the axis of a cylindrical mill in a horizontal position, the pulp line may be maintained just above the bottom line of the mill. V 7

Ports 17 typify a: style of port which has a .widthwise' measurement greater than its height, When not in use its closure, comprising a lining plate 16 completely covers the inside end of the port and also serves to fill out a practically uninterrupted inner surface of the end wall. A bolt 22 and bridge plate 23 maintain the lining plate in place.

The'second highest level of the pulp line is obtainable by closing the series of ports 17 and opening the next highest series of ports 24. The closures for these latter ports comprise the heads of bolts 25 and they are fitted to be removable at will. I What may be stated to have been the normal discharge level of the type of mill illustrated would be the discharge passage let through trunnion 15. Such a level maybe 6 taken to be the thirdhighest level of the pulp line and I propose a design of a mill whereby this level may be changed at will. For this purpose there is provided a plurality of circular plates having the same outside diameter but each plate being apertured with a hole havinga diameter different than any other plate. Byway of example I have illustrated in Figs. 6, .7 and 8 three such rings. It easily is understoodthat a use of any one of these apertured circular plates or rings 26inplace of none at all'or in place of any other will produce a variation in the discharge level through the trunnion. A selected ring 26 is positionable within passage 14: against an edge of a lining plate 27 as illustrated in Fig. 2. It is held in place by a sleeve 28 fitting within the trunnion and lining the same. This sleeve has a flared discharge end 29and studs 30 are provided for maintaining the sleeve in its assembled position. The flared portion of the sleeve has depressions cast "therein to permit the studs to hold the sleeve properly in place and, at the same time,.not interfere with the flow of the product discharged. By removing the nuts on the studs the sleeve may be removed and the ring 26 may be replaced by another ring having asmaller or larger aperture therein.

Uses other than the variation of the pulp line may be accomplished bythe use ofthe ports and rings just described as, for example, the withdrawing of comminuted material of difierent classification or coarser character than that dischargedat the higher level. Obviously any number ofsuch combinations and characterof discharge levels are obtainable.

The grinding compartmentof-the mill is lined with removable plates 31 which are maintained in position by bolts 32. Theseplates may be smooth as shownin Fig. 2 or maybe ribbed circumferentially, orsim'ilar to plates 131 illustrated in Fig. 3, or similar'to plates 231 illustrated in Fig. 4. No matter how these plates are finished I propose a construction by which the grinding compartment has a series of discharge ports 33 at its periphery and near to the end of the grinding compartment 9 and near to, yet beneath the end portion of the grinding rods 12. These ports may be used in conjunction with the ports in the conical end but they have a function entirely independent thereof. They perform one. function which also is peculiar to the ports in the conical end in that they permit the use of a'trunnion discharge mill of the type illustrated as an open ended mill when a high pulp line and the free comminuted ma' terial opposite the endsio'f the ro'dsand in the conical end, tends to cause the relatively ports 33 have other uses coarse material in the vicinity of the'base of the conical end to remain there. Some of this material is likely to get beneath the end portions of the rods and cause the hindrance of the passage of the material through. the

this vicinity is likely to be reduced to a pulp altogether too fine. With the last mentioned,

conditions prevailing I propose to make use of the ports 33 by opening them and removing the comminuted material at this point in the mill.

In the case where material is ground which is likely to gather and hinder the passage of the material through the mill or impair the grinding efiiciency of the mill in'the vicinity of the end portions of the mill by cushioning the impact of the rods, or in any other manner, some of the material may be removed through ports 33. This material then may be reintroduced into the mill for further reduction, if further reduction is desired. I have shown a launder 34, Fig. 1, for that purpose but automatic means may be utilized, such as is disclosed in the U. S. Patent No. 1,348,642. Illustrated in Fig. 2 there is a circumferential groove 35 for assisting the material to travel beneath the rods and towards a port 33.

i In Figs. 3 and 4 the plates 131 and 231 are wardly along the upwardly moving grooves.

grooved on a slant and these plates also permit the material to approach the ports 33.

Each of the ports 33 may be closed completely by a closure 36 held in place by a bolt and a bridge plate 37 If it is desired, perforated closure plates 38, such as the one shown in Fig. 5 may be provided for obtaining a total discharge area at any one port less than that of the open port. Of course, the same type of ports are capable of use on the conical end, Fig. 5. p

F 3 is intended to represent a plan development of a few slanting groove plates adjacent a discharge port 33. With the plates moving in the direction of the arrow (that is, clockwise as seen from the discharge end of the mill Fig. 2), the material at the base of the conical end is scooped or advanced toward theport 33,beneath the end portion of the rods. Material not encountering a discharge port 33 would be advanced back into the mill as the mill rotated, the material sliding down- The result of this latter action would be to drop the material thus raised upon the top of the pile of rods and further away from the discharge ports. In other words, the use of the plates illustrated in Fig. 3 would tend to retard the progress of the material through the mill and would be useful under conditions where wet grinding is in progress.

By rotating the mill in the opposite direction, these same plates would operate in a converse manner in so far as the effect upon the passage of the material through the mill is concerned. That is, the material would be assisted in its progress through the mill ant such a condition is desirable when certain classes of materials are ground and'especially, under dry grinding conditions. Plates having a reverse slant, Fig. 4, could be provided for this purpose and the direction of rotation of the mill would always be the same.

in any event the use of grooved plates, circumferential longitudinal grooves or slanting grooves serves to render possible the approach to ports 33, prevent the accumulating of material beneath the end portions of the rods, and assist in the discharge of material at this portion of the mill.

My invention is capable of a wide variation and relationship of parts without departure from the nature and principle there. of and I do not restrict myself unessentially in the foregoing or other particulars, but contemplate such alterations and modifications within the scope of the appended claims as may be found to be advisable.

I claim:

1. A grinding mill comprising in combination, a grinding compartment having an end wall at its discharge end pierced by a plurality of ports, a main discharge passage in open communication with said grinding compartment through said end wall, and means for controlling the level of discharge from said mill, said means including a plurality of closures for closing certain of said port-s at will and removable apertured rings for variously controlling the discharge level through said main passage. 1

2. A grinding mill comprising, in combination, a grinding compartment having an end wall at its discharge end pierced by a plurality of ports, a discharge passage in open communication with said grinding com partment through said end wall, means for closing any of said ports at will, a ring with in said discharge passage, and a sleeve for retaining said ring and for permitting said ring to be removed from retained position whereby the discharge level through said discharge passage is capable of adjustment.

3. A grinding mill comprising, in combination, a substantially cylindrical grinding compartment having a conical discharge end wall pierced by a plurality of port openings, a plurality of rods within said compartment and out of contact with said conical discharge end wall, the portion of the grinding mill beyond the ends of said rods and formed by said conical discharge end wall being free for permitting unrestrained approach and normal flow of pulp to said port openings, and means for closing certain of said port openings, whereby the open or closed condition of any of said port openings operates to regulate the pulp line discharge level from said grinding mill.

4..A grinding mill comprising,.in combination, a cgrindlng compartment, :a plurality of rods within said grinding compartment, a conical end wall at :the :discharge end of said compartment pierced :by aplurality of ports, said ports being arranged in a plurality of series of ports with each series of ports placedatfdifierentidistances from the axis of said grinding compartment and the lowest series of ports being near to the inner wall of said grinding compartment, and means for closing any of said ports whereby a pulp line level of discharge may be obtained near to'the'level of the inner Wall of said grinding compartment or at the level of any series-of ports. 7 g

5'. A grinding mill comprising, in combination, a grinding compartment having a wall at itsdi-scharge end pierced by a plural ity of ports, said grin-ding compartment havinga plurality of ports near to said Wall, and means for closing any number of said ports at will whereby certain of said ports which are not closed may discharge comminnted material.

6. A grinding mill comprising, in combination, a grinding compartment having a wall at its discharge end pierced by a plurality ofports, said grinding compartment'having a plurality of ports near to said wall, and means for closing any number of said ports, said means comprising a plurality of insert linings. y

7 A grinding mill comprisin in combination,,a grinding compartment having a Wall at its discharge end pierced by a plurality of ports, said grinding compartment having a plurality of ports near to said wan, perforated lining plates for controlling the size of product discharged through said ports, and means for permitting the removal of said plates at Will. u

8. A grinding mill comprising, in combination, a grinding compartment having a substantially cylindrical body portion and an inlet opening, an outwardly extending end wall at the discharge end of said compartment, a plurality of rods Within said compartment, and aplurality of ports placed cirumferentially about the cylindrical Wall binatioii, :a grinding compartment having a substantiallyicylindrical :body portion .and an zinlet' opening, anendWalhat'the discharge end :of-saidcompartment, a pluralityeof rods within said compartment, a plurality of ports :placed circumferentially about the cylindrical wall of :said compartment in the vicinity of the-end portions of-said rods, and grooved lining plates within said mill, :the grooves thereofserving as passages for permiliting the flow of material beneath said roc s.

11. The combination set forth inclaim in Which some of the grooves in said lining plates communicate 'Withsaid ports for facilitating the passage =of material to said ports and beneath :the rods.

' 12. A :grindingmill comprising, in combination, a rotatable gninding compartment of said compartment in the vicinity ofthe end portions of said rods. I V

9. A grinding mill comprising, in combination, a grinding compartmentfhaving a substantially cylindrical body portion and an inlet opening, an outwardly extending end Wall at the discharge end of said compartment, a plurality of ports through said end Wall, means for closing .any number of said ports,,.and a plurality of rods within said compartment, said compartment having a plurality of ports near to said, end wall and adapted to pass beneath-said rods upon rotation of the mill.

10. A grinding mill comprising, in com--

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