US1309212A - Roller-mill - Google Patents

Description

F. E. MARCY.

ROLLER MILL. APPLICATION FILED SEPT-26.1917 RENEWED OCT. 19'. I918.

Patented July 8, 1919."

3 SHEETS-SHEET I.

WITNESSES. 74.

. 0% N Q Q 0 m \E m E H o r I a F. E. MARCY ROLLER MILL. APPLICATION FILED SEPT-26, 1917- RENEWED PCT- 1 9 938- 1,309,212. Patented July 8, 1919.

3 SHEETS-SHEET 2.

WITNESSES: INVENTOR.

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F. E. MARCY.

ROLLER MILL! APPLICATION FILEQ SEPT-26. I917- RENEWED OCT. 19, 1918.

1 309,212, Patented Jul s; 1919.

3 $HtETS-SHEET 3- I WEmoR.

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" UNITED STATES PATENT UFFICE.

FRANK E. MAncY, F SALT LAKE crrY, UTAH.

ROLLER-MILL.

Application filed September 26, 1917, Serial No. 193,292. Renewed october 19, 1918. Serial No. 258,908.

To all whom it may concern:

Be it known that I, FRANK E. MARCY,

a citizen of the United States, residing at Salt Lake. City,'in the county of Salt Lake and State of Utah, have invented certain new and useful Improvements in Roller- Mills, of which the following is a full, .clear,

- the material is reduced toparticles of the desired size by means of freely moving crushing bodies in the form of longitudinally extended bars, rods, or rollers acting by impact and attrition upon the charge confined within a suitable tumbling barrel, drum, or equivalent tubular container or treatment vessel rotated about a fixed axis, the opposite 1 ends of the barrel being respectively provided with intake or feed, and discharge openings for the material. The present improvement is directed to that type of tum bling barrel or mill in which one end of the barrel is left open and unobstructed for the discharge of the material and for the direct insertion of the grinding rods into and their removal from the barrel, the advantages of such open end being apparent when we remember that the prevailing type of roller mill is provided with a head at each end, and that in order to gain access to the interior of the mill for purposes of repair or removal of worn out'and kinked rods, one

of the heads must :be removed, thereby entailing much labor and consuming valuable time. In my improvement the interior of the mill is at all times readily accessible, the construction being such that while the material is free to directly discharge through the open end, and the grinding rods are exposed to the opening at said end, they are nevertheless maintained permanently in the mill. The exposure of the contents of the mill to the open end necessarily results in considerable noise, and more or less splashing of the pulp under'tr'eatment (the material treated being usually wet). and one,

of the objects sought by the present im Patented July 8, 1919.

.p rovement is to deaden the nbise and prevent the splashing. A further object is to provide means at the discharge end for retaining the grinding bars or rods within the mill without depending solely on,the pitch or inclination of the walls of the crushing compartment, such inclination under the circumstances being reduced to a minimum degree. ate, in the present embodiment of my invention, toassist in building up the pulp line prior to the discharge of the finished product from the mill. A further object of the invention is to provide means for elevating the finished product after leaving the crushing compartment to a point from which it can flow under a proper head to any suitable classifier operating to return the coarse sands back to t e mill for further grinding or treatment. A further object is to dispose suitable lifters or equivalent devices on the inner walls of the crushing compartment which shall impart a special attrition movement to the grinding rods and in a measure operate to assist in keeping the rods in the crushing compartment of the mill. The in vention comprises a combination of features the advantages whereof will be fully apparent from the following detailed description in connection with the accompanying drawings in which Figure,1 represents a middle vertical longitudinal section of the mill showing my improvements; Fig. 2 is a vertical cross-section on the line 2-2 of Fig. 1, one-half of the head being removed to expose the interior, and the driving gear being broken away; Fig. 3 is an inner plan view of one of the wall liner sections'showing the preferred form of lifter; Fig. 4 is a cross-section on the line 44 of Fig. 3; Fig. 5 is a similar cross-section of a wall liner section showing a modified form of lifter; Fig. 6 is a diagrammatic middle horizontal section of the band or drum and a single grinding rod Fig, 6; Fig. 8 is a side elevation of the discharge end of the barrel shown in conjunc tion with a sound and splash arresting housing or casing; Fig. 9 is a front elevation of the housing, or a view at right angles to Fig. 8 looking toward the left; Fig.- 10 is a vertical cross-section of a barrel showing a bucket-supportingextension beyond the overflow ring over which the pulp discharges, and side elevationof the launder receiving the contents of the buckets; and Fig. 11 is an end view of Fig. 10 with parts broken away.

Referring to the drawings, and for the present to Figs. 1 to 4: inclusive, 1, represents a (preferably) cylindrical container, drum, tumbling barrel, or equivalent tubular member, the same being )rovided with a wall liner composed of a series of sections 2, the sections having formed thereon (or secured thereto) suitable ribs 3 which serve as lifters for the grinding rods or rollers 4. In the present embodiment of my invention the lifters 3 are warped, that is to say, they are disposed at an incline to the elements of the periphery of the drum, and necessarily, assume a spiral form where the drum is cylindrical. The lifters are so inclined that the ends nearest the feed end of the drum are in advance of, or precede the ends nearest the discharge end of the drum in the normal rotation of the drum (see arrows. Figs. 1, 2, 6, 7). This would bring the ends of the lifters which are nearest the feed end of the drum below the ends which are nearest the discharge end onthe descending half or side of the drum periphery (see arrow Fig. 1) while on the ascending side of the drum the feed ends of the litters would be above the discharge ends (Figs. 2, 7), the grinding rods 4 being of course lifted by the lifters only on their upward sweep. The action of the warped lifters on the rods is such as to keep the rods in the mill. as later herein more fully described: The lifters ter= minate some distance from each end of the liner sections as fully illustrated in the drawings. The feed end of the mill is closed by a head or cover 5 provided with a hollow feed or intake trunnion (3 to which the pulp is ,conveyed by a scoop-feeder 6', or otherw se, as well understood in the art, the head being protected by the end liner 7 against which bear the adjacent terminals of the wall liner sections 2. l The drive gear 8 in the present instance is at the feed end of the barrel.

In the present embodiment of my invention the open discharge end of the barrel or drum is provided with an annular .frustoconical diaphragm or ring 9, the pitch of the inner walls whereof isanywhere from fortyfive (45) to sixty (60) degrees to the base of I the frustuin or to a transverse plane through the aXis of the drum, said Walls sloping outwardly from the crushing compartment Got the drum and inwardly toward the aXis of the drum as shown to best advantage in Fig. 1 of the drawings. In other words the base of the tr'ustum faces the inside of the drum.

The said ring 9 has a two-fold fiinction. In

the first place it operates to build up the pulp line in the mill, and in the second place it assists in maintaining the grinding rods in the mill. The mill or drum is slightly pitched (the horizontal being indicated by the line 12 in Fig. 1) so as to cause the walls of the crushing compartment to. incline upwardly from the feed to the discharge end,

said inclination, together with the ring 9 and the lifters 3 cooperating to maintain the rods within the mill. It wlll be noted that the pitch of the mill is but slight; yet circumstances might arise where even this slight pitch could be dispensed with and the drum rotated about a horizontal axis. event the main reliance for keeping the grinding rods within the mill would have to be placed on the lifters 3 and on the diaphragm or ring 9. The finished product obviously discharges over the bottom portion of the inner edge of the ring 9, the level of the .pulp line being indicated by the refer-- .ing rods into, or their removal from. the

crushing compartment of the mill, the presence of the ring not materially reducing the size of the opening at the discharge end of the mill. In fact the ring 9 nay be considered as a fit nge directed inwardly or projecting toward the axis of the mill a suflicient distance from the walls of the crushing compartment to build up the pulp line, and to assist in a measure in preventing the rods from working out of the mill. As seen to best advantage in Fig. 2- (see also Fig. 7), y

the number of grinding rods employed is sufficient, to bring the center of gravity of the mass of rods opposite the opening to which they are exposed at the discharge end of the mill, the rods released from the lifters 3 with the rotation of the mill tumbling or being precipitated in paths opposite said opening and above the lower portion or half of the flange 9 the inner edge of which defines the available opening through which the finished product is free to flow. The cen- In that ter of gravity in the presentinstance is ob-' viously near the center of the figure representing the cross-section of the mass of rods.

preferred form of lifter 3 is that The shown in the figures referred to above, but

I do not wish to be understood as limiting myself tothis or any other specific form of lifter. In Fig..'5 for exznnple I show a wall liner section 2 with a-lifter or 'rib formation 3' somewhat less rounded and more angular in cross-section than the lifter 3. Other forms might be devised as clearly obvious to those skilled in the art.

In a mill of the character described, that is, a mill in which the discharge end is open and everything in the mill is exposed, the operation is necessarily attended with considerable noise, and more or less splashing of the pulp. To deaden the sound of the grinding action and arrest the splashing I may resort to the use of a stationary housing or casing 10 by which the discharge end of the drum 1 is loosely received and within which it terminates, access to the interior of the housing and hence to the interior of the mill beinghad through suitable doors D in the front wall'of the housing as shown in the modified structure illustrated in Figs. 8 and-9. No special construction of housing is claimed, that here shown being illustrated conventionally. The aplication of a housing to an open end type of mill however is believed to be new and I accordingly claim this as one of the novel features of the present invention. Where a housing is employed, the upper end of the launder 11 which receives the finished product terminates in the housing.

As well understood in the art, the coarser sands of the finished product of a grinding mill are usually returned to the mill for further grinding or regrinding. This return is generally effected through any well known type of classifier into which the overfiow or pulp from the mill is first discharged. A launder generally conducts the pulp from the point of overflow of the mill to the classifier; and since such a launder should have sufiicient pitch to impart the desired fiow or velocity to the pulp after the latter leaves the mill. the point of discharge from. the mill should be as high as possible to give the pulp the proper head.

In a mill having a trunnion overflow the head is manifestly much greater than in the case of a mill with an open discharge end where the pulp line or overflow is low or near the bottom of the mill and considerably below its rotation axis. This loss of head resulting from the use of a mill having an open discharge end is obviously a disadvantage when the mill is'used under the related circumstances but the objection in that regard is readily overcome by equipping the mill with suitable means for elevating the pulp to a plane above the rotation axis of the drum after the pulp has passed over the edge of the flange or ring 9. One form of such means is illustrated in the modified structure shown in Figs. 10 and 11. In this modification the shell or peripheral wall'of the drum 1 projects or extends beyond the ring 9, the said extension terminating in an inner flange 12 and having disposed on the inner face thereof and adjacent to the overflow edge of the ring, a series of buckets 13 which successively scoop or pick up the pulp as it flows over the edge of the ring at the bottom of the drum, the contents of the buckets being discharged at a point above the rotation axis of the drum into a box or receptacle l-l forming the upper terminal of a launder 15 which conducts the finished product to a suitable classifier (not shown) from which the coarse. sands are returned to the mill for regrinding.

The grinding operation of the mill does not differ materially from that of other mills of the general class or type here referred to, the pull) being fed to the crushing compartment of the mill through the hollow trunnion (5, the material being ground-by the crushing bodies 4 in said compartment. The Y finished product is discharged through the open discharge end of the mill, the pulp line being maintained substantially at the level .70 (Fig. l), the stream flowing over the lower edge of the ring or flange 9 as indicated by the arrow in Fig. 8 where the pulp is shown as being discharged into the launder 11. In a roller mill employing warped lifters such as 3 it is found that the end of the grinding rod 4 which is nearest the open discharge end of the mill is-the first to leaveor drop from the lifter by which it was picked up, the end of the rod thus released tending to swing inwardly or into the mill as indicated by the arrow a in the diagrammatic view in Fig. 6, the opposite end of the rod or that nearest the feed end being still supported on the lifter and serving as a. fulcrum about which the released end tends to oscillate. Thus the rod assumes an inclined position as shown by the bottom dotted illustration in Fig. 6; and when finally the end of the rod nearest the feed end of the mill is released or drops, the rod will cataract or roll down the mass of rods in the direction of the arrows a, a, (Fig. 6), that is to say in a direction parallel to itself and toward the feed-end liner 7 rather than toward the open end of the mill. The successive positions of the descending or, cataracting rod are shown re'spectivelyin plan and end views in Figs 6 and 7. The warped lifters thus tend to maintain the grinding rods in the mill during the rotation of the mill. In addition to the warped lifters we have the pitch of the mill which also assists in keeping the rods in the mill; and finally we have the inclined inner wall of the ring 9 whi h tends to direct any rod back into themill should the adjacent end of the rod impinge against said inclined wall. It is seldom that a rod would cataract or tumble in such a way as to project beyond the edge of the ring 9; but should it do so, it would immediately slip back into the mill. We thus have in the present embodiment of my invention three agencies which contribute to keeping the grinding rods within the mill, to-wit, (1) the warped lifters, (2)the pitch of the mill, and (3) the conical flange or ring 9. By terminating the lifters 3 a suitable distance from the feed end of the mill, that is to say from the discharge end of the feed trunnion 6-, so as to allow the grinding rods (which extend substantially the length of the crushing compartment (1) to project I crushing compartment of the mill, makes it perfectly safe to employ in conjunction with the mill ahousing such as 10 (Figs. 8, 9,) or the arrangement of. buckets 13v and launder 15 shown in Figs. 10 and 11, thei'e being no danger of the rods being projected outwardly and injuring any of these parts, or becoming jammed in the, housing. Obviously, the construction is susceptible of many changes without involving a departure from the spirit of theinvention. For example, the size of the discharge opening of the mill need not be as shown. The same may be varied by varying the width of the diaphragm or flange 9' relatively to the diameter of the crushing compartment C. By reducing the width of the flange the available opening will be correspondingly increased. By increasing the width of the flange the available opening will be correspondingly reduced; but in no sense must the discharge opening be reduced to the point where it would interfere with the free introduction of the grinding rods into, or

their removal from the mill; or to the point 7 where the. rods. would no' longer tumble or roll in front of, or be exposed to, said opening; or to the point-where the material was no longer free to discharge from the ends of the rods through the opening; orto the point where a full inspection of the grinding operation in the mill-while running was no longer possible. Such an undue reduction in the size of the discharge opening is foreign to the present invention. Again, the flange need not necessarily be frustoconical, or as shown. Neither do I wish to be understood as limiting myself to any particular means for causing an inward deflection of the grinding rods at the beginning of their tumbling movement to cause the rods toroll away from the open end ofthe mill. Any suitable means capable of so deflecting the rods are contemplated by the present invention. The foregoin changes are mentioned by way of example; others may suggest themselves to the skilled mechanic. Features shown but not alluded to are well understood in the art and require no description in the present connection.

Having described my invention what claim is: I

'1. In a mill of the character described, a

tumbling barrel having a feed end and a normally open discharge end, a plurality-of freely moving loose grinding rods 1n the barrel extended longitudinally substantially the length of the barrel and directly removable through said open end, and means in the barrel for imparting to the rods an inward deflection or oscillation at the beginning of their tumbling movement with successive rotations of the barrel.

2. In a mill of the character described, a tumbling barrel having a feed end and a normally open discharge end, a plurality of freely moving loose grinding rods in the barrelextended longitudinally substantially the length of the barrel and directly removable through said open end, and suitable. formations on the inner walls of the barrel for lifting the rods and subsequently releasing the same with each rotation of the barrel, and imparting to the rods at the moment of their release an inward oscillation or away from the open .end of the barrel.

3. In a mill of the character described, a tumbling barrel having a feed end and a normally open discharge end, longitudinally extended grinding rods therein, and means in the barrel for lifting the rods and subsequently releasing them first at the ends nearest the discharge endand then at the ends nearest the feed end of the mill, to cause the rods to roll away from the discharge end.

4. In a mill of the character described, a tumbling barrel having a feed end and an open discharge end, a diaphragm or flange at the discharge end projecting toward the axis of the barrel and defining the opening through which the material may discharge, a plurality of longitudinally extended grinding rods in the barrel, and means secured to said barrel for causing the rods to be lifted with the rdtation of the barrel 7 5. In a mill of the character described, a

tumbling barrel having a feed end and an open discharge end, an "inwardly projecting flange at the discharge end defining the opening through which the material may flow, longitudinally extendedloose, freely moving grinding rodsin the barrel massed to bring the center of gravity of the body 6. In a mill of the character described, a

tumbling barrel having a feed end and an open discharge end, an inwardly pro'ecting frusto-conical flange at the discha' geend having its base facing the crushing compartment and its smaller and'outer end defining the opening through which the material may flow, longitudinally extended loose, freely moving grinding. rods in the barrel massed oppositethe flange and opposite the discharge opening defined there y, the inclined walls ofthe flange operating to direct into the mill any rod impinging against said walls.

7. In a mill of the characterdescribed, a tumbling barrel having a feed end and an open. discharge end, an inwardly projecting flange at the discharge end defining the opening through which the material may discharge, longitudinally, extended loose,-

freely moving grinding rods in the barrel massed opposite the flange and opposite the discharge "opening defined thereby, and means in the barrel for causing the rods to tumble in paths opposite the discharge opening aforesaid.

8. In a mill of the character described, a

, tumbling barrel having a feed end and an o n discharge end, an inwardly rojectin ange or diaphragm at the disc \arge em l defining the opening through which the material may flow, a plurality of freely fallmg grinding rods in the barrel massed between the opposite ends thereof and extend substantially the full len h of the barand means in the barrel or causing the charge opening, upon rotation of the barrel. 9. In a' mill of the character described, a

tumbling barrel having a feed end and a normally open d scharge end, longitudinally v rods. in the barrel extending substantially thelengthof the crushing compartment of the barrel, the material being discharged from the ends of the rods directly exposed and opposite to the discharge opening of the barrel.

10. In a. mill of the character described, a tumbling barrel, a plurality of longitudinally extended grinding rods therein, one end of the barrel beingopen for the discharge of the material from the ends of the rods, and for the exposure of the rods and their direct removal from the mill, and lifters on'the inner walls of the barrel for releasing the end of a rod nearest the discharge end of the mill in advance of the opposite end of the rod, and to impart to the rod at the moment of said release a swing inwardly or away from the discharge end, whereby the tendency of the 'rod in its precipitation is to remain in the mill.

11. In a mill of the character described, a barrel rotatable about its longitudinal axis and having a feed end and a normally open discharge end disposed about saidaxis, a plurality of tumbling rods in the barrel extended longitudinally substantially the length-of the barrel and directly removable through said open end, devices contiguous to the open end of the barrel operating periodically below the pulp lineor plane of discharge of the outflowing material for catching said material, and subserfiently elevatingand discharging the same a ve said plane, and a diaphragm or flange disposed adjacent said devices on the side faclng the crushin com artment of the barre to protect said devices from the rods.

In testimon whereof I aflix my signature, in presence 0 two witnesses.

: FRANK E. -MAR1CY.

' Witnesses: 1

Vrom P. Dmzrsnan, Roam E. MARK.

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