US1583324A - Pulverizing mill - Google Patents

Description

May 4 1926.`

C. B. STRACHAN PULVERIZING MILL fill @N+ f, I@

May 4 1926. 1,583,324

a c. B. sTRAcHAN PULVERI Z ING MI LL Filed May 25. 1925 4 2 Sheets-Sheet 2 Patented May 4, 1926.

H AUlxrlruo'STA TES PATENT oFrIcEy. @if

VCHARLES BooTHE STRACHAN, 0E lvrascor, TENNESSEE, AssrGNoR ,To STEACHAN TUBE MILL COMPANY, A GOREOEATION OF TENNESSEE. 1 Y

.'PULVERIZING- MILL.

Application led May 25, 1925. vSerial No. 32,792.`

of America, and a resident of 'Mascot, in

the county of Knox, State` of Tennessee, have invented new and useful Improvements 1n Pulverizing Mills, 'which invention is fully set forth in the following specification.l

This invention relates to grinding-or -p'ulf verizing mills of the character ordinarily used for crushing ore, stone or the like, and has for its object to provide a mill of such character and constructionv thatk thesame may be operated by a minimum expenditure of power, producing a uniform character of y product and a lminimum amounto-f shines, y

A further object of the invention isjto provide for the. ready separation (if-the ground product from that which has notbeen sufficiently pulverized and without, complicating theapparatus by theprovision of conveyors, separators and the like.

In the present invention, the ore or stone" being acted upon which has not ,been crushed or pulverized kto thedesired condition is separated from the properlyl reduced ,mate rial by centrifugal force, and this requires a high speed to bev imparted tothe mill, which speed, in turn, requires that the lparts thereof shall be sucientlymassivenotto have their grinding and separating opera: tions interfered with by centrifugal action which is employed to lseparate the ground from the unground material.- f With these objects in view, the invention consists of a strong, longitudinallyextending cylindrical shell whose ends are closed by heads through one of which :the material to be crushed is fed and throughtheother of. which the material finds its vexit-1 'Said head pieces have on thefinterior sides thereof circular chambers whose interior. walls are composed of perforated diaphragms lirmly secured to the head pieces, and "between these diaphragms are'placed a series of unitary massive cylinders, one within. the other, the diameters of thecylinders being such as to leave a very material :spacing between the outer vwall'of the interior cylinder and the interior wall of the next adjacent cylinder, thczinnermost.cylinder being preferably in the form of va solid cylindrical mass. These cylinders vare of uniform length and are retained by the diaphragms of the respective head pieces so as to just centto the center there `forthe gro-und material.

leave suiiicient play for them to roll freely onejwithin -thevother when the mill as a wholeA isl rapidlyrevolved. `The high speed at which .the mill isrevolved servestothrow the heavier .,unground particles outward from the center .Y while .the finelyy ground particles remain near theycenter, and. adja- Preferablyythoughnot necessarily, the

several cylinders have openings or perforations extending therethrough, to the end that the material under vtreatment r will'jpass through said openings'. l

y The" inventive ideal .is illustrated in the accompanying, drawings, which drawings are for fthe purposeof illustration'only, and in l vF ig. ll is a kcentral longitudinal section through a mill embodying the invention; v

. Fig. 2 is a vertical section on the line 2 2 of Fig. 1, looking in the,y direction of the arrow and Fig. is: avertical section on the line 3&3 of Fig. 1, also looking in the directionof the IH-OW,e n

-f K Referring. to the. drawings, in which n like reference rnumerals indicate likel-parts throughout the lseveral views, 4; isv a strong cylindrical metallshell,- the ends ofV which are closed by an inlet' head 5 andan outlet head- 6, said heads being heldsuiciently againstl the' ends ofthe `cylinder by rods 7 are formed exitsv passing through-openings in thehead and v to leave an open cylindrical chamber 1 6,

which, in turn,`,is` in free andopencommunication with the channel llvformed in the bearing portion 9. Thefdiaphragm 14:y is secured in position on the head 5 by means of suitable bolts 17 as willbe readily understood from the drawings.

f .The outlet head Gis provided with acenor `otherwise secured l.a shaft 19 taking bears .tral' hub. portion .-18 jwithin which is f keyed ll'O ing in a suitable support or pier 20, and

havingthereon suitable means, as a pulley 21, for connection to a source of power.

Surrounding the head piece on the hub 18 is a cylindrical chamber 22 from which lead.

diameter ofthe casing 4; The cylinder 28 ispreferably of aunitary pieoefof metal and offjustsuicient length to enable it to fit freely between` the diaphragms 14 and 26,A so that theA cylinder28 rests with itslentire weight'on the bottom ofthe interiorof casing 4. In like manner, a plural-ity of other cylinders 29, 30 and 31, each of sufficiently less diameterthan' the next exterior one to leave a free space when itrests upon the interior wall-of the next exterior cylinder. Within the cylinder/31 is-placed a cylinder 32 which, as here shown', is a solid cylindrical mass of metal. All of the cylinders 28 to `82', inclusive, areof uniform length and, asbefore stated, of sufficient length sothatthey are retained iii-place byt the diaphragme 14 and-261while at the same-time being able to roll the millfis revolved on its horizontal longitudinal axis.

In operation, the head pieces and casingarerevolved at la highv rate of speed, causing the-cylinder 28 to* roll withinthe casing 4, the cylinder 29 Vtoroll withinL cylinder 28,- cylinder` 3()l toroll; within the cylinder 29., cylinder 31 to 'roll ywithin the cylinder 30, and the solid cylindei32'to-rol1 within the cylinderllsl As each ofthe cylinders is a unitary piece, and vhence of 1 great mass or 1 weight, this -high rateofspeedis maintained without anyv material effect in decreasing the crushingy actionI between-the adjacent surfaces of the respective cylinders. The material to be crushed vis fed in throughithe intake hopper f12 in such size=as to readily passfth'rough the openings 15`ofithe screen 14,` and by reason of the .unobstructed chamberl, thelarger and heavier particles will enter through-the exterior perforations 15 while the smaller ones will pass through those nearer the center. Wheinpieces of material enter intofthe openings between the respective cylinders, they are subjected. to the-.great crushingl weight of thatcylinder plusthe cylinders within it, this ,weight being applied by the -minimum consumption of power by reason of the fact that each cylinder rrollson approximately its -own axis, andwithinthe next adjacent exterior cylinder; There is thus applied avery great discharge one within the other when' bined'weight ofall of the cylinders-28432,

inclusive. If desired, openingsimay be formed through the several hollow cylinders so as to permit the material to passkthrough said openings and into the space between thecylinders.

It will 'be observed that they entire mill-is formed of parts of great strength and massive weight which permits the-sa1neto -be driven at a. high rateof speed while-atthe same time taking ample advantage of theweight of the grinding orfcrushi-ng-- elements to efficiently perform this function, and this without the use of any elevators-or other device. This is in marked:- contrastf with previous structures in .which the grinding. or. crushmg elements are such that, lffthe machineweredriven at a high rate of speed;

centrifugal action: would reduce the crush'- lng effect of theparts. Moreover, by lreason ofthe fact-that the *centraliy cylinder 32-is solid and thatV alldthe cylinders rollvoneV within therother,vr thelarge'ungroundpartiey cles canV pass through-the millonly by entering between thezcylinders at points above the lowermost of the exit openings' .and being subjected to the-crushing action `asthe cylinders roll rone withinxthe other..l Furthermore, it will be observedthatthe exits from themill arenot -in itsaxis, but onfy the contrary there areaplurality of exitopeningsbetweeny the axis of the mill and the periphery of. the chamber 26.. The .result fof this is that centrifugal actionl throws' the larger particles outward in said chamber; thereby crowding the finelyA ground'lpartis cles toward the center wherethey yfind exitl through lt'he openings 23 in theL head'z.: And forfthesame reasonl the 'largerparti's cles inthe exist chamber'22 are` crowded back through the diaphragm and enterfthe open spaces betweenl therolls to befurther ground.

1. The combination `of a cylindrical .casing, oppositely disposed heads' securedto the respective ends of said casing,linterio'rly projecting annular flangesone on.eachV head piece, a perforated diaphragm.secured#to each flange whereby a cylindrical chamber is formeel in each head piece', anda 'series of cylinders of .progressively decreasing diameters within said casing rolling one within the other and of a length extending from diaphragm to diaphragm.

2. The combination of a cylindrical casing, two oppositely disposed head pieces having radial flanges bolted against lthe opposite ends of said casing and annular flanges projecting within said casing, a perforated diaphragm secured Vto each flange within the casing, and a series of cylindrical rollers of progressively decreasing diamev ters rolling one within the other and extending from one diaphragm to the other.

3. The combination of a head piece havingan outwardly extending hollow hub and an 4inwardly extending annular flange, a bearing for said hub and a perforated diaphragm secured to said flange, with an oppositely disposed head piece having a hub portion and an interiorly extending annular flange, a perforated diaphragm secured to said last-named flange, an outwardly projecting shaft connected to said hub, a bearing for said shaft, a casing extending between said head pieces, and a series of cylinders of progressively decreasing diameters within said casing rolling one within the other and extending from diaphragm to diaphragm. l

4. The combination of a cylindrical casing, a series of cylindrical rollers of uniform length and of progressively decreasing dib5 of said casing, a perforated diaphragm forming the interior wall of said chamber,

and a `series of rollers of progressively decreasing diameters one within the other with their end portions abutting said diaphragm and closing the perforations of said. iaphragm tothe passage of unground material through an extended arc below the axis ofsaid casing.

6. The combination of a cylindrical casing, a chambered head piece at each end of said casing, a perforated diaphragm forming the interior wall of the two chambers, and a series Vof cylindrical rollers of progressively decreasing diameters one within the other rolling within said v casing with their ends abutting* said diaphragms and closing the perforations in said diaphragms against the passage of unground material through an extended arc below the axis of said casing,

In testimony whereof I have signed this specification.

CHARLES BOOTHE STRACHAN.'

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