US2168087A - Mill - Google Patents

Description

Patented Aug. 1, 1939 UNITED STATES PATENT f orrlc Massachusetts Application December 31, 1934, Serial No. 759,905

9 Claims.'

My invention relates to material crushing and pulverizing apparatus, from one aspect relating to improved rock-crushing apparatus, from another to improved material pulverizing apparatus and from a third aspect to a combination of these.

' An object of my invention is to provide an irnproved mill for..crushing various materials such as rock, coal, ore, clinkers, residue from refining processes, like coke and petroleum coke, products from various industrial processes, and like materials. Another object of my invention is to provide improved means for pulverizing materials of the type just 'enumerated after they have been crushed to appropriate initial sizes. A third object of my invention is to provide an improved apparatus for performing both a crushing and a pulverizing function, and in itself adapted to replace gyratory or like Crushers. Still another object of my invention, from one of its aspects, is

to provide an improved material crushing apparatus in which freely traveling impact members of various sizes may each be segregated ,in chambers individual thereto and move in paths so constrained that superpositioning of bodies one upon another is prevented. More specifically an object of my invention from the aspect last mentioned is to provide an improved crusher in which the freely moving crushing elements are confined and controlled in such manner that a far more efiicient crushing action is accomplished than has heretofore been possible with apparatus of remotely comparable size. From another aspect, an object of my invention is to provide a pulverizing apparatus, in which the pulverizing medium 35 is provided with a relatively long path, restricted however in a direction at right angles to-its general direction of movement so that the material to be reduced can not escape the action of the pulverizing medium. From a further aspect, an lobject of my invention is to provide a single, moving, material-reducing-chamber-providing member, suitably partitioned, and segregating in different portions thereof crushing media of different sizes, with automatic feed of material being processed from chamber to chamber, so that material of. relatively large sizes may enter the compartment containing the largest crushing medium and progressively pass through other compartments until ultimately a nely pulverized product is delivered. From another aspect, it is an object of my invention tc provide improved feeding means delivering material to be crushed automatically in the most advantageousrelation to the relatively moving parts between which a crushing action is to be eifectcd. Still another object of my invention is to provide an oscillatory type mill in which 4there is provision for continuous feed and discharge of the material. Still another object of my invention is to provide an improved crusher equally well adapted to the wet and dry grinding and crushing of the materials for whose reduction it is adapted. Other objects and advantages of my invention will hereinafter more fully appear.

From one aspect, my invention comprises a plural-chambered mill element, relatively movable crushing media associated with each chamber thereof, and means' for effecting relative movement between the chambered element and associated media involving reversals of movement. Preferably, rapid oscillatory movement will be provided, and, very desirably, pivotal move-.

ment of the chambered element will be selected. Arcuate chamber form and graduated size of the relatively movable crushing media are very advantageous. While, obviously, diilerent pivot 1ocations may be selected for the chambered element, a pivot location near the point of initial material ingress facilitates feed; and a top pivot improves smoothness of operation and makes easier the discharge of processed material. Arcuate chamber form in conjunction with pivotal chamber movement increases size reduction by attritionand conserves power. The use of large media and sharp impact for crushing, and large quantities of small to fine media for pulverizing increases number of impacts more or less proportionately to increase in number of material particles. Chamber oscillation, as compared with oscillation of the internal crushing media facilitates drive and simplifies mechanical construction. All these advantages are available with my invention, and all the features disclosed in the discussion of preferred constructions are Within the contemplation of my invention from its several aspects.

In the accompanying drawing, in which for purposes of illustration one form which my invention may assume in practice has been shown:

Fig. 1 is a central vertical section through a mill constructed in accordance with the illustrative embodiment.

Fig. 2 is a vertical transverse section on a plane corresponding to the line 2--2 of Fig. 1.

Fig. 3 is a top view of the mill, with parts broken away. y

Referring to the drawing, it will be observed that a frame I comprising transverse body member: 2,v 2 integrally supporting suitably reinforced side members l, 3, joined by an upper transverse frame 4, later more fully described, constitutes the main support and body of the machine. y The side members provide journals or bearings 5, 5 at their upper ends. At one end of the frame members 3l 3 there is provided suitable support, as at '6, for a pair of journal blocks 1, in which there is rotatably mounted a powerdriven cranklshaft 8 carrying at one end thereof a heavy combined ywheel and driving pulley 9 and having a crank I0, which is connected by a pitman or connecting rod II to drive the movable mem-- ber of the mill.

Supported in the bearings 5 are transverse stub shafts I3, from which there depends a casing I4 elongated in form and having its interior divided into a plurality of mutually superimposed chambers, as will shortly be described. Within the casing I provide a series of vertically super'- imposed compartments I5, I6, I1. Herein these compartments are arcuate, and their curvature I ,primary crusher chamber, chamber I6 a secondary crusher chamber, and chamber 'I1 a pulverizer chamber. Chambers I5 and I6 are shown as provided with a curved end wall so as to provide for a greater crushing effect due to the closer, conformity in shape of these end walls to the shape of the crushing media which are confined to movement within the several chambers. The lowest chamber I1 also has concave end walls and has its bottom formed by suitablemiean's providing adequate rigidity and at the same time providing suitably sized openings for the passage of material reduced to the requisite amount, consisting, as illustrated, of a perforated wall 23 having openings 24 therethrough preferably of slightly larger size than the free openings 26 through a liner 25. Obviously any suitable form of construction which will insure the necessary reduction in size of the material being pulverized prior' to attaining entrance to the openings formed in the reinforcing structure, may be employed. 'Ihe pulverizing chamber receives crushed material through spaced openings 21, 21 from the 'secondary' crushing chamber I6, and the lastnamed chamber receives initially crushed. material, through an opening or openings 28, from the initial chamber I5. The chamber I5 has a supply or feed inlet opening 29, and each of the upper chambers is shown with an appropriate liner, as at 30. A stationary feed chute 3l supported by the transverse element 4 and extending well down-into a top chamber 32 in the member I4 serves to permit access of the material to be processed,- at all times into the reducing chambers. 'I'he connecting rod II is connected to a wrist pin 33 supported on suitable brackets 34, carried by one of the chamber ends, so that rotation of the crankshaft 8 effects a suitable oscillation of the member I4. The lengths of the several chambers I5, I6, I1 may be varied, both absolutely, and relatively with respect to each other, and their radial dimensions will be so fixed that the chambers I5 and I 6 will be slightly fdeeper than their contained crushing media, while chamber I1 may desirably be proportioned to insure packing of its contained material from top to bottom in each end as member I4 swings.

Thechamber I5 will be noted to contain a relatively freely movable crushing medium, herein in the form of a single relatively large and heavy ball 35 of suitable material such as steel, alloy steel, or any other material of adequate Weight, hardness, and resistance to fracture.

This crushing medium is herein confined as to vertical movement by the top of chamber- I5 in such manner that the movement of said member isl substantially restricted as regards deviation from a relatively true arcuate path. It must, therefore, positively engage and crush the-unbroken masses of material fed into its path.

Compartment I6 may be provided with one or more free crushing media of smaller size than element 35, if desired, but it is here shown as containing a single material-breaking element 36 of like size to element 35. Chamber I1, whose construction has previously been described, contains a substantial (a relatively large) number of crushing elements 31 of much smaller size, ranging from something less than an inch down to even one thirty-second of one inch'in diameter. While a single series of differently vertically positioned reducing compartments or chambers is shown in the rocker element I4 in the illustrative embodiment described, it will be appreciated that one or more parallel series of such chambers may be provided in a single, so to speak, pendulum element, and thereby doubled, trebled, or otherwise multiplied capacity provided. Obviously also, if desired, a single frame may support a plural crank drive shaft, and vibration be markedly reduced by providing a pluralitypf pendulums with cranks spaced say 180 apart, or

at some other suitable angle, actuating in opposite phase relation the different pendulums.

Reference has been made to the differences in chamber dimension. With a plural stage grinding and pulverizing unt,`ideal operating conditions for the various stages call for variations in chamber dimensions. The principles upon which crushing and pulverizing chamber dimension may be laid out are more fully set forth in my applications, executed of even date herewith, for crushers and for pulverizers but they will be briefly explained herein. It will be evident that the maximum velocity of any given point in any chamber wall may readily be determined graphically or by comparatively simple calculations when effective pendulum length and crank throw and R. P. M. are known. Having determined the force necessary to effect the crushing at each stage and selected suitable means for th crushing media, and suitable sizes thereof, calculations will occasion little difficulty. 'Rebound being substantially discounted as a factor by reason of the presence of material to be crushed between these moving bodies andthe ends of the chambers,-

which largely eliminates rebound, the maximum velocity of chamber contents is easily computed. Theoretically the maximum kinetic energy may be made availabe by proportionlng the length of any individua chamber so that the end wall of that chamber/toward which the moving crushing media is moving will be traveling at -maximum velocity at the moment that the material between ,the crushing member and that wall is simultaneously engaged onits opposite sides by the wall and the crushingmember. This result can be secured, approximately, by using a chamber of a length approximately equal to' 11/2M-l-15/2S+B;

where M=maximum size of entering material 75 length increased so that the energy is applied with diminished sharp impact and more attrition and pressure crushing. In the event `of reduction in the sizeof the crushing members in succeeding chambers the need for increased chamber length for increased radial distance from pivot axis lessens;l and sharp impact may be decreasingly necessary, also, in the later stages.

The mode of operation ofthe construction de.

scribed can now be briefly summarized. The mar, terial is fed in any suitable way and at any appropriate rate to the chute 3l, and passes via 32 and 29 alternately to the opposite sides of the member 35 when the latter is at one endy or the other of its path of travel. It will be appreciated that as the material which has thus entered the chamber is struck blows from opposite sides, as it were, by the headr of the chamber I5 and the free crushing medium 35, there will result a number of substantial sized fragments, many of smaller size, and some dust. Accordingly, a p art of the material broken in th'e first chamber may need little further crushing. 'I'he larger fragments and particles will be subjected to a further crushing action by the crushing member 36 in chamber I6. Material crushed by this member will, in the last chamber I1, be ground to a powder. In this last chamber, it will be appreciated that the entire mass of material, and balls or the like, will be iiung back and forth-from end to end of the chamber, and not only willthe kinetic energy of the moving mass result in pulverization due to impact, but there will be a substantial grinding action due to attrition.

From the foregoing description it will be ap- 4parent that the embodiment described is very simple in mechanical construction, is adapted to t crush, grind and pulverize relatively large quantities of material in a comparatively short period, will combine in one structure the functions of secondary crushing and of grinding, and is` adapted to permit the obtaining of a very eifective crushing eiect due to the generation and the use of kinetic energy, all the energy not actually used in the crushing of rock or in the relatively small generation of heat which takes place during the grinding operation, being returned to the iiywheel and there stored for reuse in actuation of the oscillating grinding' chamber member.

While I have in this application specifically described one form which my invention may assume in practice, it will be understood that this form is shown for purposes of illustration only, and that the invention may be modied and embodied in various other forms without departing from its spirit or the` scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

l. In a mill, a chamber forming element supported for pivotal movement upon a. substantially horizontal axis and providing at least two generally arcuate, elongated size-reducing chambers, each of which in the mid-swing position of said chamber-forming-element is disposed below a horizontal plane in which the pivot axis lies, and leach having upper and lower curved Walls and each spaced from said pivotal axis and each of substantially uniform cross sectional area,- on.v planes normal to its respective curvature and in' cluding the` axis of pivotal movement of said element through the major portions of its length,

means for introducing material to be reduced into one of said chambers, means for delivering it therefrom after size-reduction'therein to the other, and means for the escape of the material from the latter chamber after size-reduction therein, the chamber last mentioned the more remot from said horizontal axis, and means for rapi y positively oscillating said chambers through an angle less than the angle of their respective arcs.

2. In a mill, a chamberforming element providing a plurality of generally arcuate, elongated, size-reducing chambers arranged in serial communication with each/other and'supported for pivotal movement about a substantially horizontal axis, all of said 'chambers disposed, in the midswing positionof said element, below a horizontal plane in which the pivot axis lies and each having upper and lower curved walls, both spaced from said pivotalaxis, and each, further, ofsubstant'ially uniform cross section on planes Vincluding said axis, throughout4 the major portions `of its length, and means for rapidly positively oscillat-v ing said chambers through an angle less than the angles of their respective arcs. l,

3. In a mill, a chamber-forming element having a pivotal mounting and providing below its pivot a plurality of vertically-serially-arranged v size-reducing chambers each generally arcuate and all arranged in a sector of less than 180 inclusion havingits center in'said pivot, and of progressively increasing length Vas they are more remote from said pivot, and each of substantially uniform cross section on planes including said axis, and means for effecting rapidly repeatedA oscillation on said pivot.

4.' In a mill, a chamber-forming element having a pivotal mounting and providing below its pivot a plurality of vertically-serfally-arranged sizereducing chambers each generally arcuate and/ conforming in curvature to arcs struck from a center in the pivot axis and all arranged in a sector of less than 180 inclusion having its center in said pivot, and of progressively increasing length as they are moreV remote from said pivot and each of substantially uniform cross section on planes including said axis, and means for effecting rapidly repeated oscillation on said pivot of less angularextent than the angle of arc of any of said chambers, said chambers having size-reducing media therein of progressively diminishing size as the chambers lie more remotely fromsaid p pivot.

5'. In combination, in a mill, a frame member, a member pivotally supported by said frame member and providing at one side of its pivot 'only a series of chambers of increasing dimension transversely of said member from its pivbtahaxis. and

size-reducing media in said chambers, the size-v diiferent lengths, 'freely moving size-reducing media in the several chambers of said chambered -mill element. and means. for oscillating said element about its pivot. l

'1. In4 combination, in a mill. a frame member, a pendulum member pivotally supported by said frame member and providing a-plurality of arcuate chambers diierently spaced irom'the pendulum pivot and serially communicating with each other in the order of their relative`distances from said pivot and each containing a free-moving sizereducing medium and of a length to effect coaction between each chamber end and the chamber contents in material-size-reduction' atleast once in each complete cycle of pendulum oscillation and each of such dimension normal to its pathv of oscillation that at'opposite ends of its pendulum move- `ment filling from top to bottom occurs at one end.

and means for oscillating said pendulum at a rapid rate.

'8. In a mill, a chamber-forming member, means for supporting the same for pivotal movement, said chamber-forming member having an arcuate chamber therein and providing discharge means for the discharge during chamber movement"of`sizereduced material, a charge of free size-reducing :media in said chamber, spaced feed openings into said chamber each spaced from the longitudinal center 'of the chamber and 'so disposed that one of them is between saldlongitudinal center and each end of said chamber, andV means for swinging said chamber-forming member oppositely through a restricted arc at a rate to eilect alternate compacting of the chamber contents at the opposite ends' of the chamber, said openings so located and the length, depth and movement of said chamber so determined that the opening' remote fromy the end of the chamber in whlchthe chamber contents are compacted may serve for feed ingress during such compacti'ng of the contents.

9. In combination, in a. mill, a frame member, a pendulum member'- pivotally supported by said frame member, and means for oscillating said pendulum member at a rapid "ate, said pendulum member providing a plurality of arcuate chambers each of a dimension normal to its arc less than its mean radius and each containing a free-movingand of a length to effect coaction between each chamber end and the chamber contents during material size-reduction at least once in each complete cycle of pendulum oscillation and each further of such dimension normalto its path of oscillation that at opposite ends oi its contents movement illling from-top'to bottom occurs for at least half of its length.

Images