US2611590A - Method and apparatus for stage kneading - Google Patents

Description

Sept. 23, 1952 R. H. JEBENs METHOD AND APPARATUS FOR STAGE KNEADING Filed Oct. 14, 1950 INVENTOR fiqyvza/m f7. J'Je/Vs BY fun/1|? fAmoudA ,W U Tm FEM ATTORNEYS Sept. 23, 1952 v R. FifJEBENs METHOD AND APPARATUS FOR STAGE KflEADING Filed- Oct. 14, 1950 FIG. 5

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- BY 4 Fwkjmmw M FEM um -ATTORNEY$ C R. H. JEBENS METHOD AND APPARATUS FOR STAGE KNEADING Sept, 23, 1952 4 She'ets-She et 3 Filed Oct. 14, 1950 FIG. I?

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' INVENTOR Payin /m djf/vs fimii, Zdflmeini infirm 50mm I ATTORNEYS Sept. 23, 1952 R. H. JEBE-NS 2,611,590

' METHOD AND APPARATUS FOR STAGBKNEADING Filed 001;. 14, 1950 4 Sheets-Sheet 4 INVE TO I. Raymond/iii eras a mi zadmmiflffiiffiamm ATTORNEYS Patented Sept. 23, 1952 KNEADIN RaymondH. Jebrens, Wellsville, Ohio, assignor to The Patterson? Foundry & Machine 00., East Liverpool, Ohio, a corporation of Ohio Application October 14, 19 50, S eria1 No. 190,095

This invention relates to "the kneading of various materials such as plastics, pastes, liquids, granular or crumbly materials, and the like in a continuous operation, and provides an improved method and al p latus for this purpose. Kneading includes such operations as dispersing, blending, masticatin g, smearing, mixing etc. The invention provides an integrated continuous method of kneading the material in several adjoining zonesin whichthe-material is smeared in a succession oi lgack and forth; movements in each zone, the material remaining in each zone and continuing to undergo such kneading therein unless other materialbe adde'd tothe operation to eiiect its movement I fromv one zone to an adjoining zone, and moving thefmaterial progressively from zone te -zone by adding-material at one zone and removing it at another -zone.

The invention provides an improvedcombination of apparatus comprising, at least two oppositely rotatable internieshing blades; each blade having a plurality of helically disposed leading edges and escape openings andeacdbla'de being mounted to rotate in a cylindrically shaped trough, and means for continuously'introducing material into the trough and removing kneaded material fromthe trough. y I1 An'important feature of the inventionjis'the provision of two similar, preferably identical, blades arranged in reversed end-,for-en'd' relation, each blade includingseveral blade units comprising two end units andone or more intermediate units, each unit having at least two leading edges equidistant from the rotary axis and substantially diametrically opposite each.

other, the edges being'helically shaped and arranged so that the'corre'sp'onding 'edges'of adjacent units converge towards each other. The end of each'unit has 'a cut-out portion embracing one of the edges and the units are so arranged in the blades that the cut-out portions adjoin and form! escape openingsin theblades at the edges between the units for the. flow therethrough of the material undergoing kneading. The edges on each side of the blades embrace a sort of undulating wave withcorresponding points on the edges of the two blades in the same radial plane. The edges; of the units in each blade are more than-one-half, preferably about two-thirds, the length of the unit and therefore overlap the corresponding edges of .the other unit. The blades may be unitary or assembled by mounting several units on a single Shafts. I V 7.

lZQIaims. (01. 259-104) In an advantageous and preferred embodiment, the unit profiles forwardly of each'edgewith'respect to the, direction oi rotation are constructed as an involute curve to intensify progressively the pressure of the material between the blades and on the troughs as'the'bladesrotate. The involute profile preferably follows-the curve of the edge in its helical direction. a

'1 The two troughs are preferably of identical cylindrical shapeand are connected together longitudinally to form a'ridgeorsaddle extending the/length of the blades." The-blades'fare 'sojmounted in the troughs that the edges and profiles clear' the. inner cylindrical surfaces and each other 'at'rany selected 'distance;and the edge's'and profiles'of the blades; are so shaped that they force the material against the troughs and 'each'other effecting a pressing, rolling'and smearing ofthe material while a150 moving some of the material axially'in the troughs to theescape openings wherea part of thematerial escapes from the edges of one blade and i's-then positioned to'be engaged by the edges of the opposite blade. v

The blades form a series "of kneading stages and zones, each zone comprising two stages and four'blade units with an; escape openingi'n each blade ofeach stage. In the kneading stages the fmaterialis retainediwhile kneading and'only displaced by added fresh [iced materialj' When the feed of material is stopped, the material in the trough undergoingkne'ading remains in its particular stage'and may ,mix indefinitely in each stage until displaced by new"material or released.

' he kneading blades of the"invention are so constructed and arranged in the troughs and with respect to' their profiles, edges and escape openings that the added material will'be'conveyed axially in different'direction's at the same time in each of the several stages. Diiririgbporation, one edge of one'unit moves some of the material axially one direction" towards an escape opening while one edge of the adjacent unit; moves some of the material axially in the opposite direction towards another e'seapelopeningwhere it can be picked upby an edge of a unit of the other blade, thus avoiding the circumferential movement of the entire mass of the material under treatment. The blades'permit some of the'material to'es'cape fromthe adjacent edges of one blade into the path of movement of the adjacent edges of the other blade, reversing", theaxial and" circumferential" move- 'fnefnt ofthe material, By suitably regulating-the the following discussion taken in conjunction with the accompanying drawings, in which:

Fig. 1 is an elevational view ofkneading apparatus of the invention with parts removed;

Fig. 2 is a plan view of the apparatus of Fig.1

with parts removed;

Fig. 3 is a view at the discharge end of Fig 1;

Fig. 4 is an enlarged side view of one pairof adjacent blade units of the invention;

Fig. 5 is a. sectional view at 5-5 of Fig.2;

7 Figs. 6 to 12 are sectional views at lines 5-43 T f to [2-12 respectively of Fig. 4; I Fig. 13 is a perspective of the units illustrated in Fig. 4;

Fig. 14 is a plan view of another form of kneading apparatus which may be used in practicing lmyinvention, and

7 Figs. 15, 16 and 1'7 are sectional views at iii- 13, 18-46 and ll--ll of Fig. 14 respectively;

The kneading apparatus illustrated in Figs. 1 to 13 comprises a horizontally disposed trough member I formed or two partly cylindrical troughs 2 and 3 joined togetheralong'their longitudinally contacting edges to form a centrally disposed saddle 4. The trough is formed ofany suitable metal, with or without a heating or cooling means, and is securely mounted in any suitable manner as on thelegs L. The kneading blades'5 and Bare of identical construction and are mounted in reversed end -for-end relation on shafts l and 8 which are concentrically mounted in the troughs 2 and 3 respectively. At the discharge end, the blades are mounted in bearings it and H and at thefeed end they are mounted in bearings l2 and I31 Blade 6 is driven by the kneaded and the trough 23 is for the discharge of the kneaded material from the trough member i. Any suitable means may be provided for spraying liquids or adding gases to the material in the trough, and other openings for the discharge of material may be provided in the bottom or sides of the cylindrical troughs.

A kneading apparatus employing the individual kneading units U of the blades is described and claimed in the copending application of Eardley Harry Ford, Serial No. 5,301, filed January 30, 1948, now Patent 2,559,418, granted July 3, 1951. These units are preferably hollow and have hub portions 24; 25 at their ends for engaging the shafts 7 and 8. The shafts 1 and 8 make tight contact with the hubs 24 and 25 of the blade units. The shafts may be hollow, as in Figs. 4 and 13, and holes may be provided in the shafts for the passage from the central opening of the shaft of a heating or cooling fluid into the hollow portion of the units to heat or cool the units, as the case may be. By reason of the relatively large surface of the units, they provide a very efieotive heat transfer medium.

Each blade unit of shaft 1 has two leading edges and SI helically and concentrically disposed with respect to the axis of its shaft and two arcuate cuts 32 and 33. The adjoining units being in reversed end-for-end relation, the mating arcuate cuts 32 and 33 form escape openings E. The end 34 of edge 38 is approximately 4 to more or less in advance of point 35 with respect to the direction of rotation. The blade portions forwardly of the leading edges have profiles 36 and 3? of pronounced curvatures, preferably as involute curves. The profile curves 36 and?! follow the curves of their respective helical edges. I

ihe blade units of shaft 8 are identical with the units of shaft '1, having similar leading edges 39' and 31', arcuate cuts 32' and 33', edge ends ar. and 35, involute curves 36' and 31, and

- escape openings E (Fig. 1).

- It will be noted that leading edges 30 and 3B are diametrically opposite edges 34 and 3!, re-

spectively, but are longitudinally displaced, as

shown in Figs. 1 and 4. The edges of the blades generate a cylinder on rotation and the edges are over one-haif, preferably about two-thirds, the length of the blade so that the end portions at theescape openings overlap. The adjacent units on the shaft are so positioned that-ii the leading edges were continuous they would form a sort "of undulating waveor sine-like curve. The units of bothshafts are inalternate reversed endforgend relation. Each pair of units as in Fig. in combination with its opposing pair of units diametrically opposite and contained within the overall length as Fig. 4 forms a zone Z which in turn comprises two stages of mixing.

\ It will be noted with-referencefto Figs. 1, 2,

d,, and '13 that leading edges adjacent the escape openings converge in the sense that they move the @material towards the escape opening while the continuous'leading edges oithe other blade at right angles thereto diverge in the sense that they'cause the material to move divergingly from the center point of the edges.

The shafts of the two blades are so positioned with respect to each other and to the troughs that the edges and involute surfaces on rotation clear each other. and the troughbut a small fraction of an inch for dispersing or kneading most materials. 1 I-Ioweventhe clearance may be adjusted as desired. v n

In carrying out a method of the invention with the apparatus of Figs. 1 to 13, the kneading of the material in any one zone will be described since similar kneading will be carried out simultaneously in the other zones. As the two kneading blades rotate in the direction of the arrows.

the material contacted by the leading edges 39, 31,38 and 3| and'the involute surfaces 36, 31, 3S and 31' is squeezed and smeared with progressively increasing pressure against the troughs 2 and 3 to the point of minimum clearance at the edges 3t, 3!, 30' and 3|. It is also squeezed and smeared with progressively increasing pressure between the involute surfaces 3 6, 31, and 361-32.

By reason of "the helical shape of the surfaces and edges and their relation to each other, the material is wiped and smearedin repeated back and'forth movements and some of the material is moved axially from bothunits of each zone toward the escape openings E and E. The escape openings .E' in edges '33 of blade 5, for

" example, are in a transverse plane to the crests of the abutting; edges 31' of the corresponding units of the same stage of blade 6 (Fig. 2). The

material-forced into the escape openings E is thus positioned to'be engaged by the converging or abutting edges 3i of blade 8 from which it is moved from the center in opposite axial directions; The material similarly forced through the escape openings E is positioned to be engaged by the edges 3| of blade 5. The material is accordingly moved convergingly by one blade towards and through an escape opening and then diverginglyiby the leading edges of the-opposite blad in a succession of similar operations.

The material undergoing pronounced mastica-- used in carrying out the method of my invention.

The apparatus comprises a horizontally disposed trough member 40 formed of two partly cylindrical troughs 4i and 42 joined together along their longitudinal contacting edge to form a centrally disposed saddle or ridge 43. The trough is formed of any suitable metal and may be provided with heating or cooling means. The mixing or kneading blades 44 and 45 are of identical construction and are mounted in reversed endfor-end relation in the end bearing members 46 and 41. The blades are driven in synchronism in the direction ofthe arrows by any well known means. The material to be kneaded may be added at the right end, as viewed in Fig. 14, or at any intermediate place, and is removed through the opening 48.

The mixing or kneading blades may also be formed of five blade units U connected together at the junctions J by welding or otherwise to form the continuous kneading blades. The blades may be formed as unitary members and can have any suitable number of units. Ducts D for a heating or cooling fluid are provided in the blades. The adjoining units are connected together in reversed end-for-end relation and the corresponding blade units of one dispersion blade overlap those of the other, as best shown in Fig. 14. The apparatus of Fig. 14 comprises two zones Z and a half-zone Z. Each zone includes four blade units so arranged that the two units of one blade form a stage and converge towards the junction while the two units of the other blade form another stage and diverge at the Junction.

The blade units U' have cross-sectional areas, as shown in Figs. 15, 16 and 17, with leading edges 50 and 5| which on rotation clear the troughs 4| and 42 by but a fraction of an inch. The blade units are in intermeshing relation but do not come into close contact. The leading edges of the units are helically disposed but do not continue in the same direction throughout the blades. The direction of the leading edges and blades reverses at each junction, and the corresponding parts of the units of one blade. are displaced longitudinally with respect to the units of the opposite blade whereby there is an appreciable overlapping as seen by comparing point 52 of blade 44 with point 53 of blade 45.

. In carrying out an operation of the invention in the apparatus of Figs. 14 to 17, the material to be kneaded is fed from above into the trough member at the right end with reference to Fig. 14 and if it is continuously added it will be moved along the trough from zone to zone and be discharged at 48. The blade units of one blade kneadthe material against the trough while .causing it to m'ovelongitudinally in one direction. I Each unitof both blades having the same helical direction moves the materialin the same direction. Each unit of the blade which is helically disposed in the oppositedirection also forces.

the material against the.trough but moves the ,material in the opposite longitudinal. direction.

With reference to any zone, the units of blade 45 move the material converginglytoward the junction J in opposite directions while the units of blade 44 move the materialin both directions divergingly from juncture J in opposite directions In each zone there are two stages of mixing, the material of each stage tending to remain separate until material is fed into one stage, when part of the material in that stage is forced into the other stage. At the'JunctionJ' material from either side approaches this junction and is thrown backlto remain inthat stage'which corresponds to one blade unit length. Thematerial which is converged by one blade is positioned to'be met by the opposite blade which moves it divergingly. As a consequence the material undergoes a series of back and forth movements in the trough and will continue to be kneaded in each zone more or less indefinitely unless it be displaced by added material.

I claim:

1. The methodv of kneading material in an integrated continuous operation which comprises kneading the material in several adjoining zones each of which comprise two stages in which the material is kneaded in a successionof back and forth movements in each zone, the material remaining in each stage of each zone and continuing to undergo such kneading therein unless other material be added to the operation to effect its movement from one stage to an adjoining stage, and from one zone to another zone, and moving the material progressively from stage to stage and zone to zone by adding fresh feed material at one stage and removing it at another stage during the kneading operation.

2. In the method of claim 1, adding material to the material being kneaded at an intermediate stage.

3. The method of kneading material in an integrated continuous operation which comprises kneading-the material in several adjoining zones and stages including an inlet zone, at least one intermediate zone and an outletizone in each of which zones the material is moved axially convergingly and divergingly with back and forth movements, the material undergoing kneading remaining in each stage of each zone indefinitely unlessdisplaced by added material, and displacing the material from each stage of each zone by adding fresh feed material at the inlet zone and removing kneaded material at the outlet stage during the kneading operation.

' 4. The method of kneading material in an integrated continuous operation which comprises moving in one direction in'one stage .while another part of the material is moving in the opposite direction in the stage, whereby the material will remain indefinitely in each stage unless additional material be added, and moving the material undergoing kneading from the inlet zone through thcinte edia e pneto the outlet zone 9 10 material, and means for adding material at the UNITED STATES PATENTS inlet zone and removing the material at the out- Number Name 534,968 Pfleiderer Feb'. 26, 1895 RAYMOND JEBENS- 5 2,095,907 Beken out. 12, 1931' 2,215,976 Robinson Sept. 24, 1940 REFERENCES CITED 2,231,911 Hitt et a1 Feb. 18, 1941 The following references are of record in the 2,434,707 Marshall Jan. 20, 1948 file of this patent: 2,559,418 Ford July 3, 1951

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