US2218876A - Disk mill - Google Patents

Description

' 35 adhering thereto.

Pianeti-,maza 1946 i' .missili'Einen and Gusia'v'eiricii, ngremf f A n ,f Nordbaden,

i Applicationovembizl,iisssiserisino; 112,148 'i In Great Britain October g2;1936 y denim. (ci. ait-a)` VThis invention' relates to a process for'the production of a homogeneous, finefiibred Vor finely powdered material from fibrousor crustaceous substancesin the presence'of moisture or aliquid 1 5 and an apparatus forcarrying out the process.'

Substances, which can bejhomogenisedorcomminuted according tothe. process of thisinvention are,V rst of kall brous/'substances ofvegetable andV mineral origin,=as' we1l as liquids "coril taining the saine.y Y

lAccording to the process Yof this invention the initialmaterial is subjected in a disk millI tothe cleaving action of two counter-operating disks, which are provided'with radial or approximately l radial cutting ribs, which are so arranged that they are always parallel toy one another and ac Y shall`be introduced into the working 'zone of, the mill under pressure, depending onthe nature of the material under treatment and its behaviour 30 during treatment, on its propensity to form dust or crust-forming substances, which may give rise to smearing or choking. The nature andquantity ofthe liquid, water,` oil, etc., or vapours-de pend on the nature of the material and the liquid The function of the kagents introduced is to coolthe grinding discs with their cutting ribs, to keep thev latter open and'therebyl to maintain the width of the gaps between-the teeth unchanged during the passage of material 0- therethrough. The formation of. dust orsmall fragments which otherwise .occurs is thereby prel vented, since the gaps. between the cutting ribs are now no longer'i'llled with portions of themas terial being ground or deposits therefrom. Fibres 5 comminuted to the desired extent are directly re` 4moved from the working zone and cannot be further comminuted.

` The grinding disks are mounted so that one of them is stationary with the Supporting'structure,

so the otherA being rotatably'mounted on the supporting structure. The essential condition is that a. narrow gap should exist between the cutting'- ribs. The distribution of the ribs may be the same or different on both disks. The cutting ribs vIl themselves may be rectilinear and radial or may under treatment Individ Fig.' 4 shows a modification of the teeth of twovui Adisks,-`

be disposed not quitefradiaL but sl1ghtlyinc1in'ed,. in'whichvevent theangle otzin'clination on both' i f disks must be the -same,.so thatno tearingaction can takeplane,l as will lbe seem in Fig. 2a""of'the' kvaccoinpanying drawing The not'quite 'radial- 5 disposition' of fthe cutting-ribs in both disks slightly slows down the speed of the passage lof the material :undertreatmentv which is""an advantage Ior certainsubstances;r

Theteeth; ofv the cutting ribs may be serrated ih V transverse kcrosssection?amleacli rib maybe in the form ofk an isselesI or nonfisosceles-triangle.

, 'I'he grinding disks :are withfladvantage kprovided with inclined surfaces s'o as Ato Kforrifian'entr'y slot` Thefteeni maybe distributed uniformly ory non-l uniformly onfbth disks. The; cutting ribs on both disks must be disposed parallel toA one another and must not cross so-as to exclude a tearing action. g

The'liquid, vapour or air to be introduced, the 20 pressure -of which can be adjusted; is passedinto the workingrsurfacethrough a tubesystem." In Athe example shown a liquid reservoir is formed by x va widening ofthe grinding surfacesof the stationv ary disk inwardly, fromwhich reservoir additional liquid is pressed into the working zone by the action of centrifugal'force, the pressure of which is' '3 exerted in the direction of travel yof the material l arms, which eiect f prefcomminution of the material on sweeping over the exposed toothed portion of the stationary -disk, are provided on the narrower rotating `grind-K king disk.' The material discharging at the periphery of the disks can be ilung out of the casing by means roi' projecting blades.y 35` A few embodiments of apparatus according to n this invention are illustrated in the accompanying 'Y drawing, in which:v

a y Fig'. 1 is a ywerden iongitudinai section through one form of apparatus according to the invention, 40" Fig. 2 is a partial sectionshowing the rings inf detail,v

Fig. 3 is a half-ring of the working zone `with radiallydirected ribs according to Fig. 2,

Figs'. 5 to 'I ,illustrate tubesystems for the'f' liquid Iced. f K' Fig. 1 .illustrates an apparatus with grinding :rings k land ki'of equal external diameter, but 5l) v unequalwidtn.- `'The wide ring k1 on the casing e is stationary and the narrow rlngfk on the disk b i .is rotatable. Iheseworking rings are provided with cutting ribs i as shown in Fig. 3, ywhichlor example proceedr radiallyfor nearlyradially and `455 Cil rotation these ribs must be parallel to one another. "Furthermore the teeth of the rotating ring must align not with the vertical, but with the inclined, surfacesof the serrations of the stationary ring surface, so that long fibres or threads are formed. As shown in detail by Fig. 2, arms h are provided on the ring k, which sweep over the exposed toothed portion of the wide ring Ic, in order to` effect pre-comminution.

The liquid or the like is conveyed to the working zone through the hollow shaft a or the tube g with branches mounted therein. A plurality of tubes m, which are disposed at an inclination or vertically to the rotatable grindingv surface Ic.v

serve to feed the liquid to the stationary workingv surface. The discharge ends of the tube carry inclined or movable nozzles s (Figs. ,6 and 7), sor

that the injected liquid is fed as vvertically as p05-,

sible onto the working surface for the purpose of effecting a better cleansing action. -The same ap-y plies to the arms of the tube system g (Fig. l).

The finished product discharging between the grinding elements c, c, or k and k1 is flung out by projecting blades n.

bodies passing through, the zone slot widens.

In the figures the apparatus according to the invention isrshown with a horizontal shaft. It may be mentioned, that it is also possible to provide a verticalor inclined shaft. Y

We claim:

An apparatus forthe production of fine comminuted fibrous masses from vegetable or mineral substances containing fibrous materials, compris-v ing a support,` a fixed annular disk non-rotatably mounted on said support, said disk having at least one opening of substantial sizeextending through the face thereof adjacent its axis, means for feeding the substances to the working face of said disk i In the event of anyhard have a serrated cross-section (Figs. 3 and 4). On

through said opening, said working face having an inner surface and an outer surface, the outer surface being immediately inward of the periphery of said disk, said surfaces having a plurality of generally radial ribs of substantially triangular cross section and rectangular longitudinal section spaced therearound, a rotatable annular disk rotatably mounted on said support coaxially with the xed disk, means for rotating said rotatable disk, said rotatable disk having a working face opposed to that on the fixed disk, and having an outer surface kon said working face immediately opposite the outer surface' of the fixed disk, and having a plurality of generally radial ribs similar to and parallel, respectively, with those on the fixed disk, the disks being mounted, with respect to one another, to provide a relatively narrow operating zone between the cutting edges of the opposed ribs, the cutting edges on the respective outer surfaces being substantially parallel with one another, the radial extent of at least one of the outer surfaces being relatively small, a plurality of blade-like members mounted on said'rotatable disk inwardly` of said outer surface, said blade-like members being coplanar and radial comprising a plurality of substantially radially extending arms `mounted on the inner edge portion of said working face of the rotatable disk, the

' edges of said members operatively` opposed to the the periphery of the xed disk.

said rotatabledisk and extending outwardly of' JOSEPH EIRCH. GUSTAV EIRICH.

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