US1719164A - Ball mill - Google Patents

Description

July2, 1929. RBERNHARD 1,719,164

BALL MILL Filed April 30, 1928 5- Sheets-Sheet 1 I nuenl'or: Ric/land Bernhard, ,y w M W y 2, 1929- V R. BERNHARD 1,719,164

BALL mm.

Filed April '30. 1928' s Sheets-Sheet 2 l nven Z'or:

July 2, 1929.

R. BERNHARD BALL MILL 5 Sheets-Sheet 3 Filed April 30, 1928 Inventor:

R ichand Bernhard y .19 29. R.BERNHAR'D 1,719,164

BALL mm.

Filed A pril so, 1928 5 Sheets-Sheet 4 z I 2 2 b N a 6 2 6% Q 4 Q 2 a- 4 E fl v 2 V fi 1 b Inueni'or.

I I Jive/land Bernhard,

y 2, 1929- R. BERNHARD 1.719.164 BALL MILL Filed April 30, 1928 s Sheets-Sheet 5 lnueni'on' I is Richard Bernhard,

Patented Jul 2, 1929.

UNITED STATES PATENT orrica.

RICHARD BERNHABD, OF ALLENTOWN, PENNSYLVANIA, ASSIGNOR TO TRAYLOR ENGINEERING & MFG. COMPANY, OF .ALLENTOWN, PENNSYLVANIA, A. CQBPOBA- BALL MILL.

Application filed April 30, 1928. Serial No. 274,013.

I My present invention relates to nnprove-.

. new or PENNSYLVANIA.

ments in ball mills of the multiple grinding compartment type in which; the material ground in one compartment is sulnected to a screening action as the mill rotates and the oversize rejected, while the lines are delivered into asucceeding con'ipartment for further grinding.

The invention relates more particularly to thediaphragm, grate, and screen constructions and the way in which these are combined with the milldrum sect-ions and the manner in whichthe various parts are secured n place, all with a view to producing a null economical of production and assembly, one in which the parts will all be securely held in place, and properly protected. resulting in a mill which is durable and etticient in use.

W'ith these and other objects in view. which will hereinafter appear, the invention Includes the novel features of const rnct ion hereinafter described, the nature and scope of the invention being defined by the claims appended hereto. 2 \Vhat I at present. consider the preferred embodiment of the invention is illustrated in the accompanying drawings. in which:

Fig. 1 is a central longitudinal section through the adjacentport-ions of two null compartments embodying my invention.

Fi 2 is a transverse vertical section line 2-2 of Fig. l viewed as looking toward the left. a

Fig. 3 is a similar section through the coarse grinding compartment on line 3-3 of Fig. 1 and viewed looking toward the right.

Figs. 4 and 5 areenlarged developed fragmentary sectional views on lines 44, and 5-5 respectively of Fig. 1.

Fig. 6 is a sectional view similar to Fig. 1 showing a modification. Figs. 7, 7" and 7" are detail views of wedge -1neans. h Figs. 8, 8 and 8 are detail views of key means. and i Fig. 9 is a sectional view showing the wedge and key means juxtaposed.

In these drawings I have illustrated'but two portions of ad ace-nt mill compartments,

but it will be understood that as the end portions of the mill form no part. of the present invention illustration thereof is deemed unnecessary. It will also beapparent that the through the fine grinding compartment on drical shell of one grinding compartment and 1 the corresponding shell of the next sue ceeding compartment, which. in a two-stage mill, would be provided with suitable heads forming compartments A and A, closed except for the usual feed opening for compartment A and discharge opening for compartment A, these feed and discharge openings being usually arranged in the hollow trunnions of the mill which, as they form no part of the present invention and are well understood by those skilled in the art, are not shown herein. These shells, in the preferred embodiment shown, are made of different sizes whereby the finer grinding compartment A is of less internal'diameter than the coarser grinding compartment A. The connection between these two shell members if formed by a ring or annular member 2 which has an annular flange 2 to which the shell 1 is riveted or otherwise securely attached, and an oilsetannular flange 2" to whichthe shell 1 is similarly secured. Preferably the shell 1 is secured to the external periphery of the flange 2* while the shell 1 is secured to the inside faceof the. flange 2". This ring member 2 has an inwardly extending annular web or diaphragm 2 which. together with the lining or facing plates and closure and clamping member for the central opening thereof (hereinafter described), constitutes an imperforate p'artition separating the two mill compartment-s.

Said web or diaphragm 2 has extending from the face turned towards compartment- A and adjacent the central opening of the diaphragm. an annular flange 2 having at its free edge a rebate forming a support for the inner ends of the grate bars 3 as indicated at d. The annular ring port-ion 2' has. adj acent its free edge. an annular inwardly extending flange 2' having a thickened inner edge which 'is provided with an approximately broad V-shaped groove e to receive and support the outer ends of the grate bars.

, The grate bars are all duplicates of each other and eachcomprises a tapered bar 3 their ends in engagement with the seats (I and respectively, and when so placed will be self-sustaining by reason of-their forming a complete ring 0 truncated cone shape.

For forcing of the bars into close contact with each other and locking them firmly in place during-the operation ofthe'mill, I pro- Wldfl' wedging and key ng means m the shape with the plates 6, such zinc filling being inofwedge members 4 which are placed in position simultaneously with the grate bars, and key members 5, which are driven into placefrom the center of the mill and thereby crowd the grate members firmly together. These wedge and key members are shown in detail in Figs. 7 to 9 inclusive. 7

The key members 5 are preferably, of less thickness than the members 4 and are guided in their insertion by the flanges 4- of said members 4.

For protecting the outer ends of the grate bars and the face of the flange 2 which would otherwise be exposed to the action of the: balls and material in compartment A, I provide a plurality of segmental lining and wearing plates 6 (made in sections for convenience of insertion through the customary drum manholes) and which have thickened ends to overlie the face of said flange 2 and provide annular shoulders adjacent to the ends of the grate bars. The plates 6 may be bolted or otherwise secured in )osition and the spaces between their side edges and be tween their end edges and the flange 2, is filled with molten zinc, indicated at 7, which not only aids in holding the liner plates in position but closes up all gaps and prevents erosion. The outer edges of the 'ea r plates.

6 abut the usual shell liners 6, and the space between such shell liners and between the liners and the wear plates is likewise filled with molten zinc.

The face of the diaphragm or partition member 2 which is towards the compartment A is protected by segmental wear plates 8, the outer edges of which lie between the liner plates 9. and the diaphragm. 2, and the oint-s of which are filled with molten zinc in a manner similar to that described in connection dicated at 7.

The plates 8 at their inner edges are held by a disc member 10 having a rebated'edg& to receivethe corresponding rebated inner edges of the plates 8. .Said disc member 10 has a central recess to receive a locking bolt 11, the head 11 of which is seated in a' rebate o r{ ;;counter sink in the member and held against rotation by' key means, such as indirated at 11". The bolt has a fine thread which cooperates with the corresponding threads'of a clamping nut 12 which is seated in and bears against the recessed face of a holding and protecting plate 13, the which abuts the inner en s of the grate bars and edging and keying means therefor.

By sledging the nut onto the bolt by means of the ribs 12" the parts may be drawn very firmly together and securely held in place.

The space betweenthe grate bars 3 and the Pttl'tltlOIlfOl'lllS an annular compartment B to receive the material which is ground in chameripheral edge of her A to such size, as to pass the openings V between the grate bars. This material is sub;

jccted to a further sepa- 'ation by the means which will now be described.

The flange member 2" is provided at its edge with an annular outwardly extending flange 2 integral therewith and disposed in a plane perpendicular to the axis of the mill, and the shell 1 carries fast thereon a similar flange member 14,'these flanges having their peripheral edges .oquidist'ant from the'mill axis and preferablyrebated as shown. The

' edge faces of these flanges serve to support an annular screen 15, which is secured to the flanges by means such as bolts 20. Thus 1s formed between the screen and drum an annula-r chamber C which communicates with the chamber-B by means of the ports 16, 17 .and 18 arranged in staggered relation to each other, whereby, as the mill rotates, the material in chamber B will be delivered at various points into chamber C. Over-lying the screen 15 is an annular closure member 19 formed by sheet. metal segments having their abutting ends provided with angle iron reinforcements 19 Fig. 2 bolted together as indicated at 19". These sections are supported in ,spaccd relation to the screen 15 by Z-shaped irons 19 having their base flanges secured by the bolts 20 and their outer flanges rebated to form seats for .the closure members 19.

These members 19* and 19 form another annular chamber D outside the screen 15 which receives the material which is fine enough to passthrongh said screen. The material thus collected in chamber D, in the rotation of the mill, encounters the inclined deflectors 21 rigidly carried within the chamber D by which it is deflected towards the end of the said chamber D which overlies the adjacent end of the line grinding compartment A. As the mill rotates. said deflected fines encounter the eccentric deflector 22 by which they are deflected through screen openings 15 into compartments It having eccen tric walls 22 forming a continuation of deflectors 22, which deflect the fine material through passages 23 in the shell and lining into the fine grinding compartment A'..

The rejects in compartment C as the mill rotates, encounter the deflectors 24 (which are inclined rcversely to the deflectors 21) and are thereby deflected t0wards' the side of chamber C overlying the compartment A,

whence they'are delivered inte -pockets G formed at the sides of the compartment G and find their way through ports or passages.

r and partition arrangement may be used to partition 2 is formed integral therewith and has a central opening to which is applie advantage in a mill in which the-rejects are merely retained in the coarse grinding compart-ment by the grate and all the material passing through the grate enters directly-into the fine grinding compartment. Such an embodiment is shown in Fig. 6 in which A designates the coarse grinding compartment and A the tine grinding compartment.

In this form the annular member 2" is preferably formed of approximately wedge shape in cross section and hollow for lightness and carries at its thicker end a rebate forming a seat for the grate bar ends. The

a circular member which has a rebated edge which engages the inner ends of the weary plates 8 and clamps them to the web 2.

Said member 1O has a cross bridge 10 which has an opening for the passage of the bolt 11%.

The member for supporting the inner ends of the grate bars is in this case formed as a separate member 2 of dished form seated against the cross bridge and both the cross bridge and member 2 have ahned openings through which the bolt 11 passes as also it 'ing the ends of thegrate does through an opemng formed in the recessed central part of the holding and protecting plate 13", the parts being firmly clamped together by the nut 12".

.The outer ends 01. the grate bars are protected by wear plates 6 similar to the wear plates 6 heretofore described.

Having thus described my invention, what I claim is:

1. A multiple compartment ball mill ineluding a pair of adjacent grinding compartments, an annular member having a web forming a partition separating said compartments and prov1ded with a central opening,

from said web and grooved to provide a, seat, grate bars assembled in the form of a truncated cone and having their outer ends supported by said seat, and means supported by said web for'holding the inner ends of the grate bars. p

2; A .ball mill according to claim 1 in which wear plates are pnpvided for protectars.

3. A ball mill according to claim 1 in which a circular member is supported by the par;

- I tition web, the inner ends-oi the gratebars are seated in an annular groove in the edge of the circular member and held therein by a clamping" plate having means fqr' holding it clamping position.

lar laterally extending 4. A ball mill having a partition dividing it into two compartments, said partition hav-' ing a central opening, annular grate bar seats in one oi said com )artments arranged in parallel planes, grate ars having their ends supported by said seats, a holding and protecting plate engaging the inner ends of the grate ars, a circular member having a rebated edge bars, and having a recess in the central part.

thereof, a circular member havinga rebated d edge engaging the central opening in the partition, a bolt having its head countersunk in said circular member and projecting through the same and through the holding member, and a nut on said bolt seated in the recess in said holding member.

6. A ball mill having inner and outer annular flange members having seats for grate bar ends, saidseats being disposed in spaced apart parallel planes, radially arranged grate bars supported by said seats, wedge bars interposed at intervals between said bars, said wedge bars having their narrowest end portions towards the axis of the mill, and key means inserted between said wedge bars and the adjacent grate bars from the centenof the mill.

7. A multiple compartment ball mill including a. pair of cylinders of different diameter and partition and grate supporting means comprising an annular member having I stepped concen ric flanges to which the adjacent ends of the shells are respectively rigidly seeured.

8. A multiple compartment ball mill including a pair of juxtaposed cylinders, and an annular member having flanges to which d the adjacent ends of said cylinders are secured, said annular memberhaving an integrally extending partition member, an annular laterally extending grate supporting flange carried by said partition member, an inwardly extendm flange carried by said annular member a jacent the edge thereof which overlies the coarse grinding compartment and radially arran ed grate bars having t eir ends supported y said flange.

9. A multiple compartment ball mill including a pair of juxtaposed cylinders, and an annular member having flanges towhich the adjacent ends. of said cylinders are secured, said annular member having an integrally extending partition member, an annugrate supporting flange carried by said partition member, an inwardly extending flange carried by said allnular member adjacent the edge thereof which overlies the coarse rinding compartment, said laterally extendingflange having its edge located nearer the partition than the edge'of said inwardly extending flange,

the edges of said flan es being rovided with grooves, and a plurality of radially arranged grate bars having their ends seated in said grooves and forming a grate of truncated conical form.

10. A multiple compartment ball mill including a pair of juxtaposed cylinders, an annular men'iber'having flanges to which the adjacent ends of said cylinders are secured, said annular member having an inwardl extending partition member provided with a central opening, radially arranged grate members supported from said-annular member and partition 1n spaced relation to the latter,'a .plurality of segmental wear plates overlying said partition, and a closing plate for the central opening overlying the inner edges of the wearplates, wit-h means for holding said closing plate in position.

11. A multiplecompartment ball. mill in cluding apair of uxtaposed cylinders, an annular member having flanges to which the adjacent ends of said cylinders are secured, a transverse partition member carried by said annular member, having a central opening, an annular laterally extending flange carried by'said partition member adjacent said opening and having a rebated edge, radially arranged grate bars having their inner ends supported by saidrebated edge, means carriedby said annular member for supporting the outer ends of the grate bars, segmental wear plates covering the face of the partition member, a closure disc for the central opening having an edge for engaging and holding the inner edges of the segmental wear plates, at second disc member having its edge engaging portions of the inner ends of the grate bars, and means for drawing said discs together and locking them in position.

12.' ,A multiple compartment ball mill including a pair of juxtaposed cylinders, an annularauember having flanges to which the adjacent ends of said cylinders are secured, a transverse partition member carried by said annular member having a central opening, an annular laterally extending flange carried by said partition member adjacent said opening and having a rebated edge, radially arranged grate bars having their inner ends supported by said rebated edge, means carried by said annular member for supportin the outer ends of the grate bars, segmenta wear plates covering the face of the partition member, a closure disc for the central-opening having an edge for engaging and holding the inner edges ofthe se mental wear plates, 0. second disc member having its edge engaginw portions of the inner ends of the grate ars, said second disc member having a deflected central portion, a nut seated in the recess formed by such deflection, and a bolt passing through openings in the first and second discs and engaging said nuts. 13. A multiple compartment ball mill including a pair of juxtaposed cylinders, an annular member having flanges to which the ends of said cylinders are secured, a partition member having a laterally projecting annular flange adjacent the axis of the mill, radially arranged grate bars having their inner ends supported by said-flange, one of said cylinder -arrying flanges having, an inwardly extending flange having an edge adapted to support the outer ends of said grate bars, and segmental wear plates covering the face of said inwardly extending flange and protect ingthe outer ends of the grate bars. a

'14. In a ball mill of the'elass described having partition members, inner and outer flanges carried by said members having rebated edges to form grate end receiving grooves, radially disposed grate bars supported by said edges, locking wedges inter posed between certain of said grate bars and driven from the center outwardly to crowd said bars together, and locking and protect ing means overlying the inner edges of the bars and wedges.

15. In a'ball mill of the class described having partition members, inner and outer flanges carried by said members, said outer flange having an internal grooved edge to recci re and support grate bar ends, said inner flange having its edge disposed in a plane offset from the plane of the outer flange, and said edge having an annular shoulder, radially arranged grate bars having their outer ends seated in the groove of the outer flange and their inner ends supported by said shoulder, said inner ends being of greater depth than said shoulder, and wedging means driven from the center outwardly past said shoulder and between certain of the grate bars for crowding them together.

16. In a ball mill, a rotatable drum having a transverse screen partition forming coarse and fine grinding compartments, a grate spaced from said partition and providing'a collecting chamber for fines from the coarse grinding compartmel'lt, a chamber concentric to and rotatable with the drum having an annular screen partition separating the chamber into two concentric compartments, a duct placing one end of the inner compartment in communication with the coarse grinding compartments; opposite end of the outer of said concentric chambers in communication with the fine grinding compartment, said drum having ports leading from the collecting chamber centric compartment, and reversely inclined duct placing the to the intermediate portion of the inner con- .deflectorsarranged in said inner and outer concentric (.Oll'lPfil'tlllEIltS.

17. Apparatus according to claim 16, in which the ports leadlng from the collecting chamber are arranged in three rows and in staggered relation, the ports of the outer rows being inclined in opposite directions.

18. Apparatus according to claim 16 in which the inner commitment is formed by cirelnnferential flanges carried by the. drum to the outer edges of which flanges the an nular screen is secured, and the outer concentric compartment is formed by an annular trough-shaped member having its edges secured to the edges of said flanges.

19. In a multiple compartment ball mill,

.the combination with two drum sections of dm'erent size, of an integral reducer and connecting member having flanges to which the adjacent ends of said drum sections are secured, and a partition memner integral with saidcmmecting member.

.In testimony whereof, I aifix my signature.-

RICHARD BERN HARD.

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