US2196642A - Apparatus for pulverizing materials - Google Patents

Description

' April 9, 1940. c 5 RAMSEY 2,196,642

I APPARATUS FOR PULVERIZING MATERIALS Filed April 12, 1938 4 Sheets-Sheet 1 Attorneys April 9, 1940.

c s. RAMSEY 2,196,642

APPARATUS FOR PULVERIZING MATERIALS Filed April 12, 1938 4 Sheets-Sheet 2 m N Q a fa me n tar CLARENCE 8. IPA/war flttarn eya April 1940- c. s. RAMSEY 2,196,642

APPARATUS FOR PULVERIZING MATERIALS Filed April 12, 1938 {sheets-sheet s fizz/antar- CLAEENCE 8. Ramsay m pm;

Attorney's April 9, 1940. c. s. RAMSEY APPARATUS FOR PULVERIZING MATERIALS Filed Aprii 12, 1938 4 Sheets-Sheet 4 Attorney-s- Patented Apr. 9 1940 UNIT-E 15 MP'ARATUS FOR 'PULVERIZJNG MATERIALS, Ciai'ence "s; :eeiesey, feet-emit; one

ee meetten AI-sen 12, 1938, 1 Serial xmeoiis'zs Q 2 Gimme. (Gifts-4 5 r This intention r'eiat'es {to the pulirer'izing *and fine "gfindirigfo'f lh aid mateifial's seem-es ors, limestone, rock fertilizer, frocks from which cemen-tis made, and emnler materials whese per- 5 tielesize lies-to be reduced. inventien may aisqbe utilized fer the pulverizingpr grinding of light *weight materials "such as cei'e'als, farina-a' ceous seeds, taint pigments, cosmetib: powders,

coal, etc.

1'6" Iii-t e partiexflar eb jecteftnis invention to provide an eeonomibal means of grindingmr piiiver 'zi meteri eis without theu'seof water,

and fcl'assi'fj ing the. r1151;teria'ls pulverized Withp 0111: the of stifeens. v 15" It is a-T urther abject-of :thi's invention to-avoid th'effise "of intricate return Circuits and'imneeessaiy fegi'inding, Thematerial to be pulverized is fed to "the mill, crushed. 'to the proper size I when necessary, the fih'lyjblflvrized materia t formed in the mi11"being"in'1ir'iediate1y and co'n 1 It is a *fiir ther object of this invention to p 'o t'ct en -tneteering fromthe abrasive action of thedust wage, and to 'p'rovid-e e 16w stem 5 me ter'qe ena lew; 615'- eiatidnr Inthisfirian eh Iy-emeiemie eeetpmve izmg-ueviee; m nded.

It is "a fnithei' fob'jec' this invention to vice 1e'nt1y agitate "the matena in the min "in eraer 7 etheg the finely"piiiveiiiegi mateiiai' may be m m'editel'y f'arid in tenuyremeved-trem the min, and further to new the {me-tenet being my verized injeoiitatit withfithe grinding balls, *torevent me the nee-grin ficienuy repiaf-to A fr'e'e bali's s o "that they will: iotaltehn' their own ex'ee jtherety met-e sin their jeiiishfing force 4; in gditijen' t their weightyandto. furtheroompelthe 'iie'e lialls tb 'iid'E'inthe fiber-periphery er (in of tunmu race.

this invention to re a rialfcontimious'ly n'd orineddrem tlie by fewe t t iinpaiftbentiifiigal rq ee to the sweeps the ban rac ef and comes into intimate I centae't with thepulverize'd. material in entraini i'ig' and femov'ing it. v itiis afui'therobject of this inventionfto make use of a low' 'eostmea'ns-for operating the 'pul- I! ve fiiing or grinding device. For instance one-; fiafffifthe reai' axle "of an automobile or'truck" together with the driving shaft may be utilized aea unit to tfansmit power'iore rotatingthe pul verizing device. Thus an oil sealed transmission meansis r'ea'di-lymade available for -running in I --'I n the accompanying drawings forming a part of "this specification: i

a e'fess eeemeneil-deteii View 6f a. '5

Fight "5 "is -a jzir'bss se'dtional View in detail :Of the baliifac and a't'icbriipanyingeasing p'assage- 31) way snewi the pammes bemg cla's 'si fi ed therein andfithe melteiia eeingpuiv rized. 'Thepulyefizing ball'isfshewnin the position it takes in tiie'fiaee "the ptilveii'zihg operation? i igiires "6" fidfleirie-dtiil c-roes 'sectional views 35: similar tb ge-e-e,--eh wing the-attached; agiem 15 afg'eifiieinsj" and Figure-'8 isa erase 'seiitiohal' detai-l jii-iew ofjthe ball, and scraper arrangement shown in Figure.

WS. thfe urawmg s detail, whereerences ifidieate the same viewsb The Wm er east ateizen aleng the lihe fl aplookiri in th 41') t w nding device l. *Lomis attached to the plate 24 as indicated at 22a,

driven by the motor I2 by means of the belt l3" as illustrated in Figure 1. V

The housing 1 of the vertical drive shaft 6 is rigidly bolted to the member by means of the collar l4 and plate I5 and bolts l6 and 1, as illustrated in Figures 2 and 3.. The base of the rotatable shaft 6 is provided with appropriate thrust bearings 1a and roller bearings as indicated at points l8 and I9 of Figure 2.

At the top of the shaft 6 and housing is a hub 6 which is keyed to the drive shaft 6 at 1'. At'20' bolted to the hub 6' are a plurality of downwardly extending arms 20, which are arranged to enter the ball race 2 and. contact the freely movable ball 3. There may be as many arms as is desirable radiating from the hub 6 to the ball race, depending largely upon the diameter of the ball race. A compartment or space is thus formed in the ball race between the arms in which one or more balls may be placed.

On the under surface of at least two vof the arms 20 are rigidly attached agitator or particle discharger means such as 22 and 23, as shown in Figure 3, extending from thearm to near the bottom of the ball race, so shaped to conform to the contour of the ball race, and just escaping contact with the race. The discharger member 22 is formed to provide a plow shaped surface so as to lift the material to be pulverized from the internal and bottom portion of the ball race and throw it to the external portion of the race so that it will come in contact with the rotating balls passing therealong. The agitator means 23 will be attached to another arm and so shaped as to conform to the contour of the ball race, just escaping the ball race surface, and formed so as to lift the material being pulverized from the surface of the ball race and violently agitate it. The discharger means 22 and the opposite end is attached to the arm' 20 as at 2222, as illustrated in Figure 1., The agitatormember 23 may be bolted to the portion of the arm member 20 which extends into the race at 23a and 23b, as illustrated in Figure 6. In each case the members 22 and 23 are disposed so'that they will not drag the bottom of the ball race.

There may be one, two, or more, particle dis-. charger and agitator means installed, dependingupon the requirements of the material to be pulverized. Ifonly two particle discharger and agitator means are installed, the best results may be obtained if they are installed on opposite arms such as indicated in Figure 3, one of the discharger means being of the agitator type such as 23, illustrated in Figure 6, whereas the other particle discharger means 22, illustrated in Figure 7 is of the type heretofore indicated which lifts the material being pulverized from the'bottom portion of the ball race and throws it in the path of the rotating balls. however, the agitators or particle discharger members are protected from contact with the the balls rotating therein.

In all cases,

balls since they are attached to the arm or extending rotating parts connected thereto.

It is, however, an essential feature of this device that the material being pulverized is constantly lifted from the surface of the ball race so that the finely pulverized material may be instantly and continuously removed from the mill, and the-material left is thrown to the periphery of the ball race in order that it may come in contact with the balls. 7 The arms 20 have a ring member 2| attached to each arm over the ball race in a manner so as to prohibit the balls from jumping out of the race. This is accomplished by attaching the ring 2| to the extremities of the arms 20 such that the distance between the ring and the outer wall of the race is slightly less than the diameter of The ring member 2| is positioned so that ordinarily it is not in contact with the grinding balls during the rotation thereof. This ringmember strengthens the rotating member of the device and aids in supporting the attachments thereto.

Rigidlyattached and hermetically sealed to the under surface of the'ring 2| is a plate 24 extending completelyaroundthe same, and di- 2, provides a passageway to permit air. or gases to be drawn therethrough into the mill between the plate and the inner wall of the ball race. The. plate 24 or partitionis also. attached and hermetically sealed to the arms 2|] at their junction with the ring so that air can only enter the ball race throughthe space 25 between the lower edge of the plate and the bottom'of the inner portion of the ball race.

The base of a cone'shaped hood 26 is attached and hermetically sealed to the outer upper surface of the ring and arms, andthe apexextended above the hub 6', onthe vertical shaft, so that the hub, shaft and easing, including the arms on the hub for removal andadjustment.

External to the above cone shaped hood is a second cone shaped hood 21, the base of which corresponds to the outersurface of the ball race and is bolted to the outer circular flange surface portion 28, which corresponds to the thickness of the outer wall ofv the ball race.- This outer hood is so formed that it completely covers the ball race andapproaches an apex over the center of the ball race and the inner hood which covers the vertical shaft, casing, hub and arms, as illustrated in Figure 2. An opening is pro vided in the apex of the external cone shaped hood 21, as at 29. The opening 29 is connected to theiintake30 of the centrifugal blower or suction fan means 3| which is of the conventional type. The intake 30 is hermetically sealed to the apex opening 29, and the fan is arranged to force the gas and entrained particles entering the passageway 29 and 30 the conduit 32 into the centrifugal collector 33.

-The-collector 33' is provided with a circular therealong through 45 and the open spaces between the arms,'will be r part, as at 251). In

grease 35. The upper end is connected to the exit pipe 36 for removing the-air'or. gas after the entrained particles have been removed. The entrained pulverized material is "drawn off "through the hopper 3'1.

The external hood means?! is so. shaped that its sides are not parallel to'the inner hood .26,

as illustrated in Figures 2 and 5. There is thus. distance between the two provided a greater hoods at the apex than at the base, thereby decreasing the velocity of the gas flowing upward toward the apex as compared with the velocity of the gas at the base over the ball race and through the restricted throat passageway 25a at the base of the cone shaped hood members 26 and 2'1. In this manner the relatively coarse particles'38 of the materiaL'which have not been sufficiently pulverized, entrained by the gas and discharged through the passageway 25a into the gradually enlarging exit chamber 29, will gravitate downward along the surface of the inner cone 26 and fall back into the ball race 2. The finely ground and pulverized particles 39 of the desired size are entrained by the gas and carried upward through the exit 29 and thence into the collector 33, as more clearly indicated in Figure 5.

The distance 25a is of such dimension that the total cross sectional area of the circular throat exit passageway ly less than the circular cross sectional area defined by the cones 26 and 21 in the uppermost this manner the velocity of the gas and entrained particles moving from the throat 25a upward to the enlarged section 25b is effectively reduced so that the larger particles drop out and gravitate back into the pulverizing section of the mill, as indicated in Figure 2.

It will be understood that by varying the cross sectional area ratio, illustrated at 25a and 252), the differential velocity of the gas passing therealong may be adjusted in accordance with the nature of the material being pulverized. The velocity of the air moving through the top portion of the cone 21 is ordinarily maintained substantially constant so that the particles of the desired uniform size will be removed and collected.

The volume of the air or gas drawn through more ports M that may be opened or closed at will, either by rubber dams secured over the top of the port or by any other convenient sealing means. These ports may be as many as desirable, spaced around the hood. Preferably they should be circular in iorm' for convenience. The ports ll may be opened for permitting more air to enter the ball race or for inspection, and one or more may be used for feeding material into the mill.

It will be noted that there are open spaces between the inner wall of the ball race and the transmission case, such as indicated at 4, Figure 2. The space 4 may be left'open or screened or partially closed by a cone shaped hood approaching the transmission case, or by any other suitable means. Sumcient space must be left,

25a will be substantialthrough by means of the suction fan.

however, for allowing ready access, of air or gas which is to be drawn through the mill to the suction fan and collector means.

The suction fan shouldbe operated by a sep arate motor so that it' will operate at normal speed at all times. If the fan'is-operated from apulley running if the mill transmission, then in the event the mill is overloaded, slowing down, thefan would also be slowed down and conseguently the mill "would become clogged. On the other'hand, if the'fan is'operated with its own motor and running at normal speed, the simple procedure of ceasing to feedjthe mill at the first sign of overloading will avoid the difiiculty mentioned.

' It will be noted that when the fan is in operation, air orgas canlbe drawninto the mill through one place only, namely thespace be tween the internal wall of the ballrace and the bottom of the plate 24, as indicated by the character reference 25 on Figure 2. then is drawn througnthe bottom of the ball race, and passes between the inner and outer hood tothe fan,'asillustrated in Figure 2..

Theoperation of the mill is as follower.

.The suction fan 3| is actuated and when it to the propersize is fed into the mill through one or more of the ports 4! situateddirectly over the ball race. The material introduced falls into the ball race and comes in contact with the balls running freely therein.

The particular discharger members 22 and 23 function to prevent the material from settling in the dependent portion of the ball race and throw the material to the periphery of the race indirect path of the rotating balls. At the same time during this agitation and distribution of the material, the finely pulverized material is entrained by the air currents drawn there- The "air current must pass .under the edge of the plate or partition in the ball race which further agitates the material and sweeps the internal side and. bottom of the ball race and continues towards the external and upper portion of the ball race. This functions to aid in lifting the material from the bottom of the race and carrying it into intimate contact with the rotating balls.

The air may be so placed that the bottom of the ball race will be dragged but this will be undesirable because of the excessive wear on both the members and the walls ofthe'ball race. Aside from this the starting torque would be muchhigherand the.

loss of power by friction during operation would be greatly increased. This, of course, is not desired. I

It is understood that my invention isnot to be limited to the exact details of construction,

since obvious modifications within the scope of this invention may be made by those skilled in the art. Having thus fully described my invention desire to secure by Letball race extending around the rim thereof, freely rotatable balls in the race, a cone-shaped hood disposed over and hermetically sealed to the bowlshaped member enclosing the ball race, a-verticallyv disposed rotatable drive shaft extended through the central opening of the bowl-shaped member, a cone-shaped hood fixed to the drive shaft and rotatable therewith, the wall of said hood'extending into the race at an angle less than the wall of the first named hood to define a restricted throat passage-way, a circumscribing plate connected to the lower edge of the Wall of the second named cone and extended at right angles thereto, said plate stopping short of the inner wall of the race defining an air passage, means for rotating the drive shaft, said drive shaft having a plurality of circumferentially spaced arms extended into the race for moving the ballsaround the race, and said first named hoodhaving an opening for connection with a suction means.

2. In a pulverizing mill the combination of a bowl-shaped member havinga central opening for rpassage of air, said bowl-shaped member having a circular runway extending around the rim thereof,;freely rotatable balls in the runway, a vertically disposed rotatable shaft extended through the central opening of the bowlshaped member, a hub fixed to theupper end of the shaft, circumferentially spaced downwardly extended arms fixed to the hub, said arms terminating within the runway to engage and move the balls under rotation of the shaft, a conical casing fixed to the arms, the wall of the casing being extended into the runway and having a right angular circu mscribing plate, the free edge of the plate stopping short of the inner wall of the runway defining an air passage way in communication with the central opening of the bowl-shaped member, means for rotating the shaft, agitator and discharge means carried by the arms and positioned within the runway, a second conical casing enclosing the first casing andhermetically sealed around the runway, said second named casing having a wall disposed at an angle greater than the wall of the first named casing defining a restricted throat above the runway, and said second named casing having an opening in its apex for connection with a suction means.

CLARENCE S. RAMSEY.

Images