US2634915A - Centrifugal impact pulverizing apparatus - Google Patents

Description

R.' P.' FlsHl-:R- :rrr AL CENTRIFUGAL. mPAcT PULVERZING APPARATUS Filed Aug. l2, 1950 INVENTOR ROBERT P FsHER OR//LLEEWAJNG Patented Apr. 14, 1953 CENTRIFUGAL IMPACT PULVERIZING A APPARATUS Robert P. Fisher, Los Angeles, Calif., and Orville E. Walling, Beatty, Nev., assignors tol Paramount Mining and Milling CompanyyBeatty,

Nev., a copartnership Application August 12, 1950, Serial No.` 179,021

4 Claims.

This invention relates to apparatus" for pulverizing any type of material, including mineral matter, metals or like substances in either a dry or liquid phase, and is particularly directed to mechanism for thoroughly decimating such material whereby the latter may readily be separated into its component physical parts by means of suitable amalgamating or other equipment.

An object of the present invention is to provide simplified apparatus in which incoming material may be subjected to a combination of different forces and impacts all of which tend to thoroughly pulverize the same as it passes through the mechanism.

Another object of the invention is to provide apparatus of the type described for receiving and pulverizing hard solid material in a rapid continuous flow process with little or no danger of the apparatus jamming due to the reception of oversize pieces of material or from other yreasons and causes. l

A still further object of this invention is to provide a pulverizer of the aforementioned type in which the parts of the mechanism subjected to maximum wear and strain may easily be replaced without necessitating major overhaul or other costly operations.

Yet another object of the invention is to provide apparatus of the foregoing description in which means are provided to reduce the turbulence normally created by high speed rotors whereby the rotor eniciency is greatly increased and the centrifugal force utilized to hurl the incoming material against the rotor casing will be maintained at a substantially constant level.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of the preferred form of the invention which is illustrated in the drawing accompanying and forming part of the specification. It is to be understood, however, that variations in the showing made by the said drawing and description may be adopted within the scope of the invention as set forth in the claims.

Referring to the drawing:

Figure 1 is a front View, partly in section, of the apparatus of our invention, taken along the plane indicated by line I-I of Figure 2.

Figure 2 is a longitudinal cross-sectional view of the apparatus taken along the plane indicated by line 2-2 of Figure 1.

Figure 3 is a perspective View of one of the rotor blades used in the apparatus.

Figure l-is a perspective view ofthe rotor mounting element.

Figure 5 is a view similar to Figure 1 showing a modied form of outlet, portions of the view being cut away to conserve space in' the drawing.

Figure 6 is a view similar to Figure 2 showing the modied outlet arrangement, with portions of the view being cut away.

In broad terms, the apparatus of our invention is designed to receive a quantity of crushed rock or the like, rely on suction to assist in drawing the material into the mechanism, utilize rotor blades to strike the incoming ma'- terial, and centrifugally hurl the same against a hardened peripheral surface so as to pulverize the material, and remove theV pulverized material through a discharge passage for such further treatment as may be necessary.

Apparatus to carry out' the foregoing may assume a variety of forms, but we have found that mechanism of the type disclosed in the ydrawings will adequately serve the necessary functions and is able 'to pulverize material so that it is capable of passing a 900 to 1000 theoretical meshv screen of the Tyler standard, although in normalY operations, a 400 mesh material is suf- `iciently v'1l-lne' to :permit subsequent physical separation of desirable components of the material. As here shown, the apparatus comprises a rotor housing II which includes a )rectangular rear end wall i2, arectangular front end wall I3, and a substantially circular peripheral wall I4, such walls cooperating to provide a cylindrical chamber I6 in which the rotor blades are disposed, as will be'hereinafter described. Walls I2, I3 and I4 are preferably detachable so that access to chamber vI6 is readily available, and as indicated in the drawing, bolts I1 extend through apertures in walls I2 and I3, and suitable wing nuts I8 are threadedly engaged thereto to secure the walls in place. Peripheral wall I4 is disposed between the end walls and is arranged to be seated as. circumferentially extending shoulders I 9 and 2I provided in rear and front walls respectively. The housing II may be secured to any suitable base structure by means of angle clips 22 fastened to the lower edges of walls I2 and I3 by bolts 23, similar bolts 24 fastening the clips to the base material.

Rear wall i2 is provided with a rearwardly extending circular wall 26 of smaller diameter than the wa1I`I4 so as to provide a diametrically reduced second chamber 21 axially aligned with and in flow communication with main chamber I6. The rearmost end of chamber 21 is dened by a transverse wall member 28 formed integrally with wall 26, an axial extension 29 thereof being threaded at its distal end as at 3l to receive a cap member 32 similarly threaded as at 33- to form a closure for the previously described structure.

Mounted for rotation in the housing Il is an axially aligned shaft 34 which terminates at itsf forward end approximately at the rear end ina bearing 36 journaled in a suitable vertical support member 31 which may be secured to the aforesaid base structure by bolts 38. M Support bearings 39 are also provided alongV the length of the shaft to support the same, andrn order to eliminate axial movement inthe shaft as the latter is rotated, we provide a thrust bearing 4l engageable on one side by an inwardlygextending shoulder 42 of extension 29 and on the other side thereof by a nut 43 threadedly engaged to a threaded portion 440i the shaft disposed withincap-member 22. In this matter, the shaft will be rmly supported and prevented'from any undesirable end play. v

VvSuitable means may be provided for rotating .the shaft 3d, land as here shown, such means 'comprise a sheave 46 keyedvto the'shaft at 41, the sheavebeing rotatablethrough one or more V-belts connected to a motor of any desirableca- Vpacity. As such'belts andmotors arewell known inthe art, they .have not been shown in the draw- .ing for purposes yofsimplicity. Obviously, ifdesired, other means, suchas direct gearing, could be utilizedto impart lthe requisite rotary movement to the shaft.

VIn Aorder to insure `proper bearing lubrication, we prefer to'vutiliz'e a force-feed system, such system including :an yoil pump and a pressure conduit 48 entering the Ispace between bearings 39 4.by means of va fitting 49 secured to extension 29. Oil is permitted to return to the pumpV by means of conduit l which receives theoil from a fitting 5.2 at the end of can member 32' after it has passed through bearing l4l as well as bearing 39.

Mounted in the chamber 21 for rotation with shaft 334 by a key 50 is a substantially cylindrical solid rotor member 53 provided with a plurality of axially Y-extending rectangular grooves Ad4 fora purpose to be hereinafter described. It vwill be noted vthat shaft 34 and the front face I545 lof the rotor53 do not enter'the chamber'l' `Vfor any appreciable distance. thereby 4leen/'ing the chamber substantially unobstructed for receiving material and in whichthe latter may be pulverized. As here shown. four zgrooves are provided., but it will be evident that any suitable number may be'utilized, so long as they are eoually Aspaced and no unbalance will result Fixedly received in the grooves are a plurality of rotor blades 51, each of which comprises a mounting portion 1158 Vadapted to enter one of the grooves. Vsuch pore tion being transversely enlarged axially forward of face 5B to form the inner rotor blade portion 59. This latter portion is beveled along its lower edge El to provide a knife-like shearing edge, and includes Van axially extending groove 62 long its outer edge to receive the tongue b3 of the outer rotorblade portion 614. When the tongue and groove are in place, the inner and outer blade portions may be rsecured together by means of screws 66 preferably being countersunk so that the assembled blade portions will rpresent a .smooth unobstructed surface. 1t will be seen that the blades 451 extend into the chamber -lB 4 and are equally circumferentially spaced around the same.

After the blade portions 58 have been seated y torV assembly to' prevent unbalance and vibrations during operation.

' Front plate l 3 is provided with an axially aligned central aperture'l through which the material is fedinto-chamber I6, and to prevent the turbulenceA normally created at a fan inlet, as well as to prevent the blades 51t from whipping or becoming relatively displaced, an annular deilector plate ylilis secured to thefrontedees .of the blades.

Plate-68 is varranged to be'seated in Va-rmtcbed portionprovided at the'inner lfront portion of blade 59, the plate being vsecuredto thevblades by means of screws 1| extending into-'aperturev 12 ofblade 59.Y f

' As previously explained,.the thrust'bearing 4l is utilized to Vprevent axial movement of shaft'34, but as the rotor assembly extends beyond the forward end lof the shaft, -we have furtherprovided as econd thrust-bearing 16 having itsiiat face disposed against wall, and the balls-arranged to ride in grooves 11-in the rear edgeof blade portion 58 Aas well as on the rear face of rotor member 53. In this way, the rotorgassenibly is more securely arranged against displacementin either a radial or axial direction. Also. to insure .a smoother running apparatus, a -counterweightlll is secured to the shaft :by a key such weight tending to reducepthle exces- .sivetorque on the shaft created by the axiall.r

displaced rotor assembly.

Outlet means `for the material is provided, and Vas here shown, includes la conduit 18 provided with a flange 13s/hereby the `-conduit may be secured bybolts 8l or similar fastening means to krear wall l2. It will fbenoted that theconduit opens into the rear end of chamber I through an opening $2 provided'in wall I2 adjacent the periphery of the chamber so that al1 material enteringthe chamber will be required .to pass radially outwardly aswell as rearwardly before it may .enter the discharge .conduit, .andgthereby be subjected to a maximum amount ..ofj.pulverizing vaction duri-ng its travel through the apparatus. To `regulate the flow of air and .material inthe conduit .1.8, .a butterfly valve 83 is provided therein which may be .adjustably positioned by means of handleil. This value will also .serve to regulate suction in the chamber IB.

To protect .the .peripheral Wall i4 from being dented or injured by the material, We .prefer to yprow/ide a replaceable liner '86 which .leaf-ranged toflie on theinner surface .of wall I 4 in .contiguous relation thereto. Such Vliner .may be securedin place by set screws .81er other suitable members. It will be evident that the 4liner will protect the YVwall .I4 from actionof the material in thechamber, and .as it maybe .constructed of Va .hardened material, and as -itl is .readily replaceable, the vnor.- mal life vof the apparatus will be greatly vi-ncreased.

We will now discuss .the operation of the foregoing apparatus. Material .such .as quartz is 7'(5 fed 'toward the .inlet B1 Lby a gravity or screw conveyor or other suitable mechanism. Such` material, of course, must be of a size permitting the same to pass through the inlet opening, and it will 'bel understood that as the material is fed to the machine, the shaft, rotor member, and

rotor blades are in rotation, the lattercreating a partial vacuum in chamber It to aid in drawing material through inlet El. By varying the speed of the shaft or positioning of butterfly valve 83, the suction in chamber I6 may be controlled to .only permit materials of desired size to pass out with the discharging air stream. It will be seen from the drawing that the inner edges of deector 68 and blades 57 are disposed radially outwardly from the inlet opening thereby creating a large unobstructed areaV in chamber I6' extending rearwardly of the inlet. This will permit the entering material to be fed rapidly into the apparatus with little danger of jamming due to a localized accumulation of material.

As the pieces of material enter the chamber, they will be subjected toa plurality of forces, all of which combine thoroughly to break down and pulverize the same. The primary forces vare those created by the rotating blades, which mayV be described as impact or striking forces and centrifugal force. It is believed that a piece of material will rst'be struck by one or more of theblades whichV are preferably rotated at approximately 5,000 R. P. M. This impact will tend to shatter or otherwise break up the piece and also, due to the beveled surface on the inner edges of the blades, a piece striking the same will be sheared so as to further assist in the pulverization thereof. Then, because of the rapid rotation of the blades and the high centrifugal force the pieces of material will be hurled at very high velocities toward the liner 8S, and upon striking the same, will be further broken up. Although the exact action in the chamber cannot be readily observed, it is believed that the nely pulverized material will be blown out through the discharge conduit i8, while larger fragments will continue to be struck by the rotating blades until the air stream can pick up the pulverized particles and discharge the same.

As the rotor blades are made up of two pieces, it will be apparent that the outer portions 6ft which receive the maximum impact loads, can readily be replaced as they become worn. However, as the shaft and rotor element 53 are disposed rearwardly of chamber i6 in which the pulverizing takes place, these parts will not be subjected to undue impact loads, and can be used for extended periods of operation without requiring repairs of any nature. The elements receiving the maximum wear, namely, the rotor blades 5l and the liner 85 can be easily removed and replaced by opening the housing il.

In place of the heretofore described outlet, we have found that in pulverizing certain types of materials, a discharge opening provided in the peripheral wall lli is advantageous. Such an alternate arrangement is indicated in Figures 5 and 6 of the drawing, and includes a conduit 9| axially aligned with apertures 92 and 93 provided in peripheral wall i4 and liner 85 respectively. The conduit may be attached to the casing by means of a flange member 9d secured to wall i4 by means of screws or bolts 96. A butterfly valve 91 is operatively inserted in conduit SI for purposes previously set forth which may be adjusted by means of a handle 98.

For most operations, it is sufficient if the pulverized material is capable of passing a 400 mesh screen, but ifner or larger particles are desired, .therotor speed and'buttery opening in the selected discharge conduit can be adjusted only to permit particles of a selected size to be carried out with the discharge air stream.

It will be seen from the foregoing description that We have provided apparatus which is. extremely simple in construction, which will permit rapid pulverization of relatively large quantities of material whichmay be continuously fed to the apparatus, and which may be operated over long periods of time without requiring skilled attention or major overhaul.v

What is claimed is:

l. Apparatus of the character described comprising a substantially cylindrical housing hav-` of said blades with the opening thereof axially aligned with and of a larger diameter than said inlet opening, the outer edges of said blades extending radially outwardly from the outer peripheral surface of said deilector member, means forming an outlet opening adjacent said peripheral surface of said housing, and valve means operatively associated with said opening.

2. In a machine for decimating relatively hard solid material, a substantially cylindrical casing including a front end face having a centrally disposed aperture therein, said casing further having a rearward diametrically reduced portion provided with a rear end face, a shaft journaled for rotation in said casing and vterminating at the forward end of said reduced portion, a substantially solid rotor member secured to said shaft and being substantially entirely within said reduced portion, said rotor member being provided with axially extending equally spaced grooves, rotor blades mounted in said grooves and having portions thereof within said cylindrical casing, said blades having end portions thereof yadjacent said front end face, said blades having their outer edges extending axially of said casing adjacent the periphery of said casing and having their inner edges spaced radially outwardly from said central aperture and extending axially of said casing, -said inner edges further being provided with opposing relatively sharp blades for splitting the material in said casing, outer portions of said blades adjacent said periphery being removable from the other portions of the blades, and outlet means adjacent said periphery and the rear edges of the blades through which the material may be removed from the casing.

3. Pulverizing apparatus including a front end wall, rear end wall and peripheral side Wall, said walls cooperating to dene a substantially cylindrical material receiving chamber with the axis thereof extending in a generally horizontal direction, said front end wall including an axially aligned material inlet opening, means cooperating with said rear wall to define a second chamber in flow communication and |axially aligned with and of a smaller diameter than said receiving

Images