US2675969A - Impact apparatus for disintegrating solids - Google Patents

Description

April 20: 1954 A. STAUFFER IMPACT APPARATUS FOR DISINTEGRATING SOLIDS Filed Aug. 17, 1949 2 Sheets-Sheet 1 IN VEN TOR. ALFRED STAUFFER A TORNFY April 20, 1954 STAUFFER 2,675,969

IMPACT APPARATUS FOR DISINTEGRATING SOLIDS Filed Aug. 17,1949 2 Sheets-Sheet 2 INVENTOR. ALFRED STAUFFER ATTORNEY Patented Apr. 20, 1954 1 IMPACT APPARATUS FOR DISINTEGRATING SOLIDS Alfred Staufier, Honey Brook, Pa., assignor to Lukens Steel Company, a corporation of Pennsylvania Application August 17, 1949, Serial No. 110,699

12 Claims. 1

The present invention relates to comminution of stones, coal, ore lumps and substantially any other relatively inelastic solids and is particularly directed to a machine for disintegrating into fine particles the stones found in cultivated fields, irregular lumps of ores and other minerals as delivered from a mine or quarry, for producing dust from coal or for comminuting substantially any generally comparable material.

It has been the practice in reducing materials of this character to finely divided form to grind them between large rolls or otherwise subject them to localized heavy pressure to break them into smaller pieces, and in so reducing mined or quarried minerals it has been customary to employ a series of crushers or breakers adapted to receive the irregular pieces as they come from the mine or quarry and progressively break them to the proper size, each stage reducing a portion of the material thereto and leaving another portion insufficiently reduced and therefore requiring a further treatment, often after screening to separate the fines; this practice involving the use of cumbersome and expensive machinery not only consume considerable quantities of power but usually necessitates reprocessing at least once a major portion of the total tonnage fed to the first breaker.

In accordance with the present invention, however, reduction is effected by disintegration resultin from th sudden impact between the pieces or chunks and a comparatively non-yielding body which occurs at the interruption or substantial diminution of their high relative velocities as by projection of the pieces at high velocity against a substantially non-yielding surface of a fixed target positioned substantially normal to their path of movement or by impact of a rapidly moving object against the pieces while they are moving through space at relatively low speed, or both, whereby substantially entire reduction of each lump to relatively minute particles is accomplished very rapidly and with expenditure of a minimum of power, the apparatus preferably embodying means for automatically returning the relatively small proportion of oversize fragments which may be produced for a second and if necessary a third disintegrating treatment while they are commingled with the incoming feed of unprocessed material.

it is therefor a principal object of the invention to provide a machine adapted to induce between a relatively frangible solid body and a substantially non-yielding one high relative velocity followed by sudden contact between them where- 2 by the frangible body is disintegrated into comparatively small particles.

A further object is to provide a machine in which solids to be disintegrated are initially projected along a substantially rectilinear path, while in transit along said path suddenly engaged by a non-yielding body moving along a second path at substantially greater velocity and in a different direction and their travel then suddenly interrupted whereby the solids are disintegrated into small particles.

Other objects, purposes and advantages of the invention will hereinafter more fully appear or be understood from the following description of its practice with the aid of a machine constructed in accordance therewith and adapted for carrying out the method thereof, reference being had to the accompanying drawings in which:

Fig. 1 is a side elevation of the machine,

Fig. 2 is a fragmentary vertical section on a larger scale substantially on the line 2-2 in Fla 4,

Fig. 3 a rear perspective of the machin on substantially the same scale as Fig. 1,

Fig. 4 a fragmentary front elevation on a like scale partly broken away to show internal construction,

Fig. 5 a detail perspective of one of the rotors embodied in it,

Fig. 6 an enlarged fragmentary perspective showing the lintel bar of the machine, and

Fig. 7 is a diagrammatic fragmentary vertical section substantially on the line 1-1 in Fig. 4 showing the path of material and air in the machine.

Referring now more particularly to the drawings, the machine illustrated is provided with supporting wheels W (omitted from Fig. 4) which render it readily transportable as when secured by a hitch H at the rear of a tractor vehicle, the machine thus being specially suited to be drawn over a cultivated field by a potato harvester or similar mechanism to receive from the latter the stones separated thereby from the earth, which ar then reduced substantially to powder by operation of the machine and returned to the ground for incorporation in the soil as the machine progresses along a row. The capacity of the machine for operating successfully on material fed to it is not depedent upon its being drawn over the ground however since it is fully effective in operation as a stationary machine. Furthermore while the said machine is designed to be motor driven, any suitable source of power may be provided and therefore as it is unneces- 3 sary to a full understanding of the construction and operation of the machine, no prime mover for driving its working parts is shown in the drawmgs.

More particularly the illustrated. machine cornprises in general a frame supporting in suitable housings substantially similar rotatable impellers designed to operate at different speeds to progressively increase by separate stages the velocity of the pieces of material delivered for dis integration, the final stage of their acceleration suddenly and violently changing their direction of motion as well as their velocity whereby in some cases at least preliminary disintegration may occur. Thus the initial stage or low speed impeller 2 is mounted on an axle 3 disposed at a small angle to the vertical for rotation in a sub stantially cylindrical housing 4 having a tangential exit conduit 5, a bottom plate 6 and a cover shield T overlying the conduit and about one half of the cylindrical portion of the hous ing. The final stage or high speed impeller iii arranged to operate at a materially greater speed is rotatable on a substantially horizontal axle II and is enclosed in a generally similar housing I2 including front and back plates i3, i and provided with a tangential upwardly directed exit conduit !5 the upper end of which is obstructed by a. rigid non-yielding target it made of heavy, preferably hardened, steel plate or generally similar abrasion and shock-resistant material and disposed at a slight angle to planes normal to the direction of movement of the sciids in the conduit is.

An opening ii in the front plate oi the high speed impeller housing provides an entrance port to the latter which is aligned with the end oi exit conduit 5 of the low speed impeller housing, and a removable lintel bar i8 is secured at the top edge of this opening and presents an edge which in cooperation with the blades of impeller iii forms one jaw of a shear operative to sever large pieces of material or any which may be only partially entered in the housing through its entrance port ii.

The lintel bar i8 is desirably square but reduced in cross sectional dimensions at its ends by approximately the thickness of the front plate 13 whereby one face of its main central portion can be entered in the upper part or opening it into alignment with the inner face of plate and straps i9 bolted to the plate over the reduced ends of the bar then hold the latter in place. As the bar it is removably secured in position with respect to the opening ii any of its faces may form a continuation of the inner wall of plate i3 and it thus provides a pluraiit of shear jaw edges any one of which may be presented for cooperation with the blades of impeller iii. Consequently when one edge becomes worn and thus rounded or concave with respect to the opening iii, by removing the bolts holding the straps is in place and then giving the bar a quarter turn or otherwise manipulating it it may be replaced in a position oifering a new unworn edge as a shear jaw until all four corners and adjacent faces of the bar have become too badly worn to be serviceable; it may then be discarded and a new bar substituted for it. As this part is among those which may be subjected to most destructive wear, due to abrasion and impact of the pieces of material fed to the machine, it is of great advantage that it thus be provided with a plurality of shear edges and be readily replaceable as the operative life of the machine as a whole is thereby greatly extended, while the ease with which it may be positioned to present a fresh unworn edge, or replaced if necessary, greatly facilitates maintenance of the machine in the field at maximum operative efficiency.

The back plate iii of the high speed impeller housing is provided with an exit port is adjacent and just below the target it and to the rear 01' the area defined by the path of the high speed impeller and substantially aligned with port open ing il in the front plate an opening 2i is formed in the back plate through which oversized particles may be readmitted to the housing.

At the rear of the exit port it a screen comprising angularly positioned bars 22 disposed at intervals corresponding to the maximum acceptable minimum dimension for the comminuted particles of the feed is enclosed within a housing 23 to minimize the dissemination of dust and insure passage of the particles through the interstices in the screen and out of the housing, which is open at the bottom to provide a discharge port is whereby the finely divided material may be directed to the subiacent ground or to any suitable receiver positioned below this port, while due to its angular position the screen directs any oversize fragments by gravity toward and through rear opening iii in the high speed impeller housing whereby they are again presented to the high speed impeller for further treatment to reduce them to acceptable sizes.

Each of the impellers comprises a pair of blades 25 (Fig. 5) made of relatively rigid metal bar stock suitably bored and recessed to receive the driving axle to which the blades are preferably secured with the aid of a key 2E5 fitted in appropriate key ways in the axle and in one of the blades to hold these parts in operative non-rotational relation. Nuts 2'? and bolts 28 are provided for securing the blades together in such manner that when they are set up the blades tightly embrace their axle, and I have found a convenient way of insuring this result. Thus two bars of proper dimensions are provided with suitable bolt holes for reception of bolts 2% and are secured together thereby substantially in their ultimate operative operation but with a thin shim or similar spacer between their inter-engaging faces and nuts ii are then tightly set up on bolts 28 to hold the bars together; a hole corresponding to the diameter of the axle is then bored with half its diameter in each bar and at the proper point centrally of the assembly considered 1ongitudinally, after which the bars are disassembled, a hey-way formed in the semi-bore of one or both as desired and the finished bars then reassembled without the shim and in snugly embracing relation with the axle and key.

Axles 3 and ii, running suitable carried by the respective impeller housings are adapted to be driven from a prime mover shown) which may be mounted on the high sp d impeller housing or at any other convenient point for driving a reducer having a power take 011 shaft 3i preferably connected to th high speed impeller axle by a V-belt lit runnin over sheaves 35, 36 on the reducer shaft an axle respectively. Additional sheaves respectively on the said axle and a drive shaft 39 drive the latter through a V-beit ii? and drive shaft in turn through bevel, spiral or other suitable gears ii, 52 drives the low speed impelle; axle 3. Obviously other means may be provided for driving the axles if desired although with a view to minimizing damage to the parts of the machine in the event of accident I consider it t oi,

advantageous to employ belts in their drives rather than direct gearing alone.

I have found that when the low speed impeller 2 is operated at a speed of about 500 R. P. M. material to be disintegrated may be fed rapidly to it either automatically or by being shoveled manually through the open top of housing 4 around which a suitable shield may be positioned if desired. The impeller 2 in a machine of convenient size readily receives substantially any materials in lump form below about the size 01. so called one man stone and when operated at substantially th speed indicated projects them through exit conduit 5 and port I! into the housing I 2 to be acted upon by the high speed impeller ID. The latter is preferably rotated at about 3000 R. P. M. or more and it is essential the lumps be projected at fairly high speed into its housing 52 since otherwise the rapidity with which the blades of impeller l0 pass the entrance port I! may cause a high proportion of the lumps to be rejected through contact with the edges of the blades. Consequently, the employment of the low speed impeller 2 is of extreme advantags, as it projects the lumps at sufficient speed into the high speed impeller housing to prevent rejection of any material amount of them through collision with an edge of a high speed impeller blade.

Substantially inevitably, however, some lumps are contacted by the impeller blades in such manner as not to be thus fully rejected but instead are carried into engagement with lintel bar !8, which in cooperation with the blades may shear the lumps into fragments of which some are rejected while the others are projected by the blades, with or without the lumps fully received in the housing against the target I 6. The rejected fragments of the sheared lumps together with any lumps fully rejected by contact with an impeller blade edge then are either projected into the high speed housing by a new impetus imparted by succeeding lumps or fall forwardly into the low speed impeller housing where they again encounter the low speed impeller for reprojection into the high speed housing.

When the lumps and/or fragments have entered the latter, and in most cases while they are moving unsupported therein substantially normal to the direction of travel of the high speed impeller blades they are violently engaged by one of the latter; this instantly changes the direction of their movement from substantially horizontal to substantially vertical and greatly increases their velocity. It usually moreover induces an initial breaking of the lumps into intermediate sized fragments or sometimes even to ultimate fines and as the lumps, or the fragments thereof, then pass at greatly increased velocity in the new direction upwardly and into contact with target IS, the larger fragments and unbroken lumps particularly react violently and with almost explosive force against the target with resultant instant disintegration into minute particles while even relatively small particles produced initially by the previous treatment may be still further disintegrated into powder or dust.

The slight angularity of the target Hi to the horizontal tends to cause rebound of the particles contacting it in a direction sloping toward the exit port 20 and their motion in this direction is further promoted by the stream of air which the rotation of the high speed impeller acting substantially as a blower induces in the machine whereby the particles are carried rapidly into the exhaust housing 23, where they are in effect screened by bars 22, the smaller ones passing from the machine through discharge port 24 while any larger ones unable to pass through the interstices between adjacent bars 22, or in whatever other screening device may be substituted therefor, are re-directed into the high speed impeller housing without initial projection such as given by the low speed impeller, but aided by gravity as well as by the intake of air through rear opening 2|. Following their second subjection to the action of the high speed impeller and also ensuing projection against the target the reprocessed fragments normally are all reduced to sizes able to pass through the screen.

The impeller housings which have been described as substantially cylindrical are preferably so designed and constructed as to provide a slightly increasing radius of curvature of their inner cylindrical walls in the direction of rotation of the impeller blades from one edge of their exit openings to the other, as the possibility of the impellers becoming clogged or obstructed by fragments of the materials being processed is thereby substantially eliminated. Thus for example in a machine of the size of that herein described the radius of the cylindrical wall of each impeller housing may progressively increase from about A; to about greater than the radius of the impeller whereby any fragments which may be carried by an impeller blade past the exit opening of its housing are swept around the latter for discharge through the opening on the succeeding passage of the blade, the increasing clearance between the blade end and the housing wall which results from the increasing radius of the latter preventing such fragments becoming wedged or locked between the wall and the end of the blade so as to obstruct the free rotation of the latter.

The impeller blades for a machine of a convenient size may extend about 16" from their axis of rotation so that when the machine is in operation with the impellers rotating at 500 and 3,000 R. P. M. respectively the lumps fed to the low speed impeller are projected thereby into the path or" the high speed one at a velocity of the order of 70 feet per second; the high speed impeller, the extremities of which are moving in a direction substantially normal to the path of the lumps at the moment of impact and at a velocity of the order of 420 feet per second, engages them at substantially this relative velocity and usually thereby effects at least a partial disintegration of the lumps. It then projects them against the target it at substantially the velocity of its extremities, resulting in a rapid and substantially complete disintegration of frangible solids of practically any specific composition.

These impeller speeds in an experimental machine constructed substantially as herein described have been found effective to reduce stones such as occur in cultivated fields in agricultural areas in the eastern part of the United States to a mixture of powder, sand and grit and thus in desirable condition for return to the soil where minerals useful as fertilizer are released from them for beneficial efiects upon subsequent crops; the particles in these sizes may also improve the physical condition of the soil, particularly where it is of heavy clay texture. The elimination of stones from cultivated fields which is readily accomplished by the use of my machine in connection with a stone collecting machine of the potato harvester type is of further obvious advantage in reducing hazards to ground Working tools, interference with plant growth and injury particularly to root crops during harvestmg.

The said machine may also be used for other purposes however, and it has been shown to be capable of powdering glass, of reducing lumps of silicon sandstone and of manganese ore substantially to fine sand, of reducing or comminuting road ballast trap rock, fragments of manufactured cement blocks, flint ferro-silicon ore and the like to aggregates passing 100% through /4 mesh screen, with a major portion passing a much finer screen. Cob corn has been passed through it and recovered of particle texture similar to that of cracked corn and cob which is extensively utilized for stock feeding, and horseshoes fed into it have been delivered broken into small bits, although the power required for its operation is but a fraction of that consumed in comminuting materials in accordance with prior practices with which I am familiar.

While I have herein described and illustrated with considerable particularity one type of machine constructed in accordance with this invent-ion and which I prefer to employ many in stances it will be understood I do not desire or intend thereby to limit or confine myself specifically thereto as changes and modifications in the form, construction and arrangement of the several parts of the said machine as a whole, will readily occur to those skilled in the art and may be made if desired without departing from the spirit and scope of the invention as defined in the appended claims.

Having thus described my invention, I claim and desire to protect by Letters Patent of the United States:

1. A machine for reducing solids to finely divided condition comprising a rotatable impeller, a housing for the impeller providing entrance and exit ports, a second rotatable impeller, a hOllSll'lg therefor providing an entrance port aligned with the exit port of the first housing and an exit port spaced from and in a plane substantially parallel to the plane of said entrance port, a substantially non yielding target disposed substantially normal to said planes adjacent the exit port of the second housing adapted to obstruct the travel of solid objects projected thereagainst by the second impeller and means for rotating the impellers simultaneously at different speeds.

2. A machine for reducing solids to finely divided condition comprising a rotatable impeller, a housing for the impeller providing entrance and exit ports, a second rotatable impeller, a housing therefor providing an entrance port aligned with the exit port of the first housing and an exit port spaced from and in a plane substantially parallel to the plane of said entrance port, a substantially non-yielding target disposed substantially normal to said planes adjacent the exit port of the second housing adapted to obstruct the travel of solid objects projected there against by the second impeller and means for rotating the first impeller at a predetermined speed and the second impeller at a substantially greater speed to thereby progressively increase the velocity of objects introduced to the first housing and project them against said plate at a velocity sufiicient to effect their disintegration.

A machine for reducing solids to finely divided condition comprising a rotatable impeller, a housing for the impeller providing entrance and exit ports, a second rotatable impeller, a housing therefor providing an entrance port aligned with the exit port of the first housing, an exit port spaced from and in a plane substan tially parallel to the plane of said entrance port, and a second entrance port remote from the first entrance port, a substantially non-yielding target disposed substantially normal to said planes adjacent the exit port of the second housing adapted to obstruct the travel of solid objects projected thereagainst by the second impeller, means for rotating the impellers simultaneously at different speeds and means disposed adjacent the exit port of the second housing adapted to direct particles of greater than predetermined maximum size issuing from said exit port into the second hOIlSlIlg through said second entrance port.

i. A machine for disintegrating solids comprising a pair of substantially cylindrical housin s disposed with their axes approximately normal to each other, means forming a passage extendin between the housings tangentially of one of them and generally in the direction of the axis of the other, said last mentioned housing having a passage extending tangentially thereof and an exit port lying in a plane substantially normal to the housing axis, an impeller in each housing rotatable about the axis thereof, means for rotating the impellers at different speeds, and a target obstructing the second passage adjacent port.

5. A machine for disintegrating solids comprising a pair of substantially cylindrical housings disposed with their axes approximately norma o each other, means forming a passage extend-1 between the housings tangentially of one of them and generally in the direction of the axis of the other, said last mentioned housing having a pas sage extending tangentially thereof and an port lying in a plane substantially normal to the housing axis, an impeller in each housing rotatable about the axis thereof, a substantially nonyielding target disposed adjacent said exit port substantially normal to the path of solids projected by the impeller in the second housing through the passage extending tangentially therefrom, and means for rotating the first impeller at a predetermined speed and the second impeller at a substantially higher speed.

6. In a machine for reducing solids to finely divided condition, a pair of impellers rotata respectively on axes substantially normal to ea. other and each comprising a plurality of blades, housings for the impellers, means interconnecting the housings providing a passageway for material projected by one of the impellers into i e path of the blades of the other, said passagew extending tangentially from the first impeller and delivering to the second at a zone adjacent the periphery of path and means for continuously rotating the impellers simultaneously at different speeds, the second at a higher rate of speed than the first.

'7. The construction of claim 6 wherein the J impeller is positioned to rotate: in a substantially horizontal path about a generally upright axis 8. The construction of claim 6 wherein said first impeller is arranged to rotate about a generally upright axis and is centered at a. level lower than the center of said second impeller.

9. The construction of claim 6 wherein the second impeller is positioned to rotate about a generally horizontal axis and the first impeller is positioned to rotate about a generally upright but somewhat tilted axis, and the housing for the said first impeller has an inlet adjacent its lower portion.

10. The construction of claim 6 wherein the housing of the second impeller is provided with a peripheral discharge port.

11. In a machine for reducing solids to finely divided condition, a pair of rotatable impellers respectively defining by their rotation substantially cylindrical spaces, means forming a passageway interconnecting said spaces extending substantially tangentially to one space and angularly to an end of the other space at a zone radially outward from its axis, and means for continuously rotating the impeller defining the first space at a predetermined speed adequate to forcibly project said solids into the path of said second impeller and for simultaneously rotating said second impeller at a substantially higher speed.

12. The construction of claim 11 including means substantially enclosing the space defined 10 by said second impeller and providing a. peripheral outlet therefrom for materials discharged from said second impeller.

References Cited in the file of this patent UNITED STATES PATENTS

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