Note:Within nine months from the publication of the mention of the grant of the European patent,any person may give notice to the European Patent Office of opposition to the European patent granted.Notice of opposition shall be filed in a written reasoned statement.It shall not be deemed to have been filed until the opposition fee has been paid.(Art.99(1) European Patent Convention).
桔子的营养价值Europäisches Patentamt
European Patent Office Office européen des brevets
(19)
5
10
15
20
25
30
35
40
45
50
55
Description
[0001]The prent invention relates to a multi-shaft extruder according to the generic part of claim 1.
人生路遥[0002]From US 5,573,332such a screw element for an extrusion machine is known.The screw element has a teardrop shape in cross ction.Two screw elements are arranged next to each other on two shafts of a twin screw extruder.The flank of one screw rubs the oppos-ing flank of the other screw.This creates a high shear zone which in turn increas the bulk material temper-ature.Further there is a small degree of cross-channel flows.
[0003]Screw conveying bushings for twin-screw ex-truders are well known.Generally,the screw bushings are generally 2or 3-flighted bushings have 2to 3screw elements helically extending the length of the bushing.The crest of the screw elements are generally flat.The prior art screw bushings are manufactured such that side by side screw element crests generally mesh with each other when mounted in a twin screw extruder.The end walls of a standard screw bushing have flat sur-faces.The end wall flat surface has a central annular ction with two lobes extending diametrically opposite each other from the central ction.
[0004]Each of the lobes has a truncated crest.Gen-erally,two or more of the screw bushings are placed end to end to provide a continuous helical screw on each side by side twin screw extruder drive shaft.The screw bushings are generally ud for conveying mate-rials in the extruder.
[0005]A single flighted screw bushing is known for u to build up pressure generally at the end of the ex-truder.However,this type of screw bushing has a large arcuate crest that permits flow of product from one bush-ing to its side by side bushing as the above described 2and 3-flighted screw bushings do.Thus,this known sin-gle flighted bushing is generally not ud for the con-veying/mixing of material.
[0006]It is a problem of the prent invention to pro-vide a twin screw extruder with screw elements,which has little apex interaction and promotes better mixing.[0007]The problem is solved through the features of the characterizing part of claim 1.
[0008]It is an aspect of the invention that a single flighted extruder screw bushing,which both conveys and somewhat mixes the material,is conveyed in a twin or multi-screw extruder.This is hereinafter referred to as a single flighted screw conveying/mixing bushing.The twin screw conveying/mixing bushings have only one helical screw element extending the length of the bushings.The screw elements have an outer diameter and an inner diameter with the bushing having a bore to attach the bushing to a drive shaft.One end wall of the bushing has a cross-ction shape that has a central annular ction and only one lobe radially extending from the annular ction.The lobe has a truncated crest that extends for an angle of from 15…-30…and preferably
22… to 24….
[0009]Generally,two or more of the screw bushings are placed end to end on each side by side extruder drive shaft.When they are placed in a 0…orientation,all apex area interaction is eliminated and they provide a channel split for the material to divide and promote bet-ter mixing.
[0010]The screw bushings preferably have a ratio of the outer diameter to the inner diameter of from about 1.4to about 1.7and preferably 1.55,the screw element with a pitch of about 0.5to 2times the outer diameter,and the outer diameter being 25 to 380mm.
[0011]The materials that can be conveyed and mixed by the screw bushings are generally various types of polymers, starches and viscous substances.
[0012]The screw bushings are described as being applicable for a twin-screw extruder.However,the screw bushings may be ud with an extruder having more than two side by side screws or shafts (multi-screw or multi-shaft extruder).
[0013]The screw bushings are constructed such that when they are mounted on the shafts of the multi-shaft extruder,they are non-rotatable relative to their respec-tive shaft.This is done by splines or key joints on the bushing and the corresponding shaft.
[0014]Further aspects and advantages of the inven-tion will become apparent from the following embodi-ment taken in conjunction with the drawings.
Fig.1A is a perspective view of a pair of prior art twin screw bushings.
Figs.1B and 1C diagrammatically illustrate the working principles of the bushings of Fig. 1A.
Fig.2A is a planar view of the right side of one of the bushings of Fig. 1.
Fig.2B is a right side planar view of another prior art twin screw bushing.
Fig.2C is a right side planar view of still another prior art twin screw bushing.
Fig.3is a top view of prior art single flighted screw bushing.
Fig.4is an end diagrammatic view of the working screw bushings of Fig. 3.
Fig.5is a top perspective view of a multi-shaft ex-truder screw bushing of the prent invention.Fig. 6 is a planar view of the right side of Fig. 5.Fig.7corresponds to an embodiment of the prior art according to US 5 573 332.
Fig.8is an end planar view of a side by side pair of the screw bushings of Fig. 6 in 0° orientation.
Fig.9is a diagrammatic view of a multi-screw type extruder.
[0015]Fig.1illustrates a pair of prior art twin screw extruder screw bushing 11for conveying material in a twin screw extruder.The bushings are shown in a side-by-side relationship as if they were mounted on twin screw extruder shafts.The screw bushings 11are iden-
5
10
15
20
25工程部管理规章制度
30
35
40
45
50
55
tical to each other.The screw bushings 11are two flight-ed elements.That is,they have two helical screw ele-ments 12and 13.The helical screw elements 12and 13have flat helical crests 14 and 16 respectively.
[0016]The bushings 11have a central passageway or bore so as to be mounted on the drive shafts of an extruder.The bore has an appropriate mount to attach the bushing to the extruder drive shafts so that they do not rotate relative to their respective shafts.
[0017]Figs.1B and 1C diagrammatically illustrate the working principle of the conveying elements of the bush-ings 11when mounted at a 90°orientation and both ro-tated in the same direction.
[0018]Figs.2A-2C are only for illustrative purpos of some of the mounts ud with the screw bushi
ngs of the prior art and which mounts can be ud with my screw bushings which are described infra.Fig.2A illus-trates using 24involute spline teeth,Fig.2B illustrates using six straight sided splines,Fig.2C illustrates using two keys and Fig. 4 illustrates using a single key.
[0019]The are only some of the known drive shaft attachments and others may also be readily ud.The u of the multiple splines as shown in Fig.2A provide the most flexibility of orientating two or more screw bushings 11on appropriate extruder drive shafts relative to one another in both their end to end and side by side orientation.
[0020]As shown by Figs.2A-2C,the screw bushing 11has an annual center ction 20defining the bore.A pair of diametrically opposite lobes 21and 22extend from the annular center ction.Each lobe has a flat crest 23and 24respectively.The flat crest 23is diamet-rically opposite the flat crest 24.The screw element 12is part of the crest 23and the screw element 13is part of the crest 24.
[0021]Two or more screw bushings 11are mounted end to end on a first extruder shaft to provide continuous helical screw elements.Two or more screw bushings 11are mounted end to end on a cond extruder shaft to provide continuous helical screw elements.The first and cond shafts are in side by side relationship and the bushings on the cond shaft are mounted in a 90°ori-entation to the bushings on the first shaft to have the configuration as shown in Fig. 1.
[0022]The screw bushing 11has an axial length 26(Fig.1A),an outer or major diameter 27,an inner or mi-nor diameter 28.The length 26of bushing 11is equal to the pitch of each screw element That is,the screw elements 12and 13rotate over the length 26at an angle of about 360°.However,it is not a requirement that the pitch and length be equal.As shown in Fig.1A,the screw element 12of the right bushing 11wipes and in-termeshes with the screw element 13of the left bushing.[0023]Fig.3shows four identical single flighted screw bushings 31each having a screw element 32helically extending the length of their respective bushing.
[0024]The screw elements 32each have an arcuate crest 33.As shown in Fig.4,the arcuate crest extends
for an arc 34when measured along the circumference of the bushing's outer diameter 36or an angle of more than 100°.The upper two single flighted screw bushings as shown in Fig.3are at 0°orientation to the lower two single flighted screw bushings.This is,the crests 33of each side by side screw bushing faces in the same di-rection as is shown in Fig.4.The single flighted screw bushings of Figs.3and 4are generally ud at the end of an extruder to build up pressure to extrude the prod-uct.The single flighted screw bushings with their large arcuate crests only allows axial movement of the prod-uct and does not allow radial movement of the product to the adjacent bushing.
[0025]Therefore,the screw bushings are not gen-erally ud for conveying material in multi-shaft extruder and would not be ud in place of the 2-flighted screw bushings of Fig. 1A.
[0026]Figs.5and 6illustrate an improved multi-shaft extruder single flighted screw conveying/mixing bush-ings 41.This is ud for conveying and some mixing of the material in a twin or multi-screw extruder.The ma-terial as noted above is generally polymers,starches and any viscous substance.
[0027]The single flighted screw bushing 41has only one helical screw element 42versus the two or more screw elements of the prior art.The screw element 42has a flat helical crest 43.Screw bushing 41has an an-nular ba surface 44,a length 45,inner or minor diam-eter 46,and an outer or major diameter 47.The bush-ings 41have twenty four (24)inner splines for being joined to an appropriate extruder drive shaft having cor-responding splines.The bushing 41,of cour,can have any of the mounting configurations shown in Figs.2A-2C,4or which are commonly ud for this purpo.Screw bushing 41as shown in Fig.6has an annular center ction 48defining the bore with a center.A sin-gle lobe 49radially extends from the center ction.The lobe 49has a flat crest 50that extends for an angle 50a.The angle 50a is from the center 50b to each edge of the crest 50.The angle 50a is from 15°to 30°and pref-erably from 22° to 24°.
[0028]The bushing 41shown in Figs.5and 6has a pitch equal to the length 45and over the length,the screw element 42 rotates at an angle of 360°.
[0029]In a twin shaft extruder,more than two screw bushings 41are mounted end to end on the first extruder shaft to provide a continuous helical screw element and the same number of screw bushings 41are mounted end to end on the cond extruder shaft to provide a continuous helical screw element.
[0030]The first and cond extruder shafts are in side by side relationship so that the side by side bushings will convey and mix the material in the extruder.
[0031]Fig.7shows an end view of a pair of screw bushings 41mounted on the extruder side by side shafts such that the screw bushings are in 90°orientation.That is,the right screw element lobe crest 50faces the left screw bushing 41such that the left crest center line 51
5
10
15
20
25
30
什么流水成语35
40
45
50
55
intercts to the right crest center line 52at an angle of 90°.奇丽的近义词
[0032]Fig.8shows another orientation for the side by side screw bushings 41mounted on side by side twin extruder shafts.This embodiment shows a 0°orienta-tion which is my preferred orientation.That is,the lobes 49and have their respective crests 50facing in the same direction with their center lines
51and 52being parallel.
[0033]The bushing 41is such that it provides a new low energy conveying/mixing geometry.With the pair of screw bushings 41mounted on the extruder shafts as shown in Fig.7,there is minimal interaction and it opens up a path for better cross-channel material flow.
[0034]When the bushings 41are mounted on the ex-truder shafts as shown in Fig.8,with a 0°orientation,all apex interaction is eliminated and there is a channel split for the material in the extruder to divide and pro-mote better mixing.
[0035]The bushings 41preferably have an outer di-ameter of from about 25mm to about 380mm,a ratio of the outer diameter to the inner diameter for the 90°ori-entation shown in Fig.7of about 1.4to about 1.7and preferably about 1.55.The pitch of the screw element is preferably between 0.5 to 2 times the outer diameter.[0036]A screw-type extruding machine is diagram-matically shown in Fig.9.This screw-type extruding ma-chine has a housing 60having a plurality of ctions 61,62,63,64,65,which are dispod axially one behind the other and flanged to one another.Two shafts are located in the housing which are driven via a gearbox 67by a motor 66.A hopper 68discharges material to be procesd into the first housing ction 61.
[0037]Sections 61and 62contain three or more of the bushings 41on each of the shafts and they are ori-ented as shown in Figs.7and/or 8.Section 63contains kneading discs,and ctions 64and 65contain die bushings 41 as shown in Figs. 7 and/or 8.
Claims 1.
Twin screw extruder
a)having a pair of side by side drive shafts with at least two screw bushings (41)mounted end to end on a first drive shaft and a cond drive shaft,
b)said at least two screw bushings (41)on each shaft being identical bushings (41),
c)said identical bushings (41)having only one helical screw element (42)extending the length of said bushings (41),
d)said screw element (42)having an outer di-ameter (47) and an inner diameter (46),
e)said bushings (41)having a cross-ction shape having an annular ction (48)and a lobe (49),
g)said lobe (49)having a truncated crest (50),and
张优
h)said crest (50)having an angle (50a)meas-ured from the center (50b)of the bushing (41)to each edge of the crest (50)of from 15°to 30°,characterized in that
i)said at least two screw bushings (41)mount-ed end to end form a continuous helical screw clement on said first drive shaft and on said c-ond drive shaft,
j)said bushings (41)on said first drive shaft have a first crest center line (51)and said bush-ings (41)and said cond drive shaft have a cond crest center line (52) and
k)said first center line (51)and said cond center line (52) are parallel to each other.
2.
The extruder of claim 2,wherein said angle (50a)is from 22° to 24°.
3.
The extruder of claim 2,wherein a ratio of said outer diameter (47)to said inner diameter (46)is from about 1.4 to about 1.7.
4.
The extruder of claim 2,wherein the screw element (42)on each bushing (41)has a pitch of about 0.5to 2 times said outer diameter (47).
5.
The extruder of claim 4,wherein the outer diameter is from 25 to 380 mm.
Patentansprüche
1.Doppelschneckenextruder
a)mit einem Paar von nebeneinander angeord-neten Antriebswellen mit mindestens zwei Schneckenbüchn (41),die durchgehend an einer ersten Antriebswelle und einer zweiten Antriebswelle angebracht sind,
b)wobei die mindestens zwei Schneckenbüch-n (41)an jeder Welle identische Büchn (41) sind,
c)wobei die identischen Büchn (41)jeweils ein sich über die Länge der Büchn (41)er-streckendes,schraubenförmiges Schnecken-element (42) aufwein,
d)wobei das Schneckenelement (42)einen Au-ßendurchmesr (47)und einen Innendurch-mesr (46) hat,
e)wobei die Büchn (41)einen Querschnitt mit einem ringförmigen Abschnitt (48)und ei-nem Vorsprung (49) aufwein,
f)wobei der Vorsprung (49)einen abgestumpf-ten Kamm (50) aufweist und
h)wobei der Kamm (50)einen Winkel (50a)von 15°bis 30°gemesn vom Mittelpunkt (50b)
5
10
15
20
25
30
35
40
45
50
55
der Büch (41)zu jeder Kante des Kamms (50) aufweist,dadurch gekennzeichnet,
i)dass die durchgehend angeordneten,minde-stens zwei Schneckenbüchn (41)ein konti-nuierliches,schraubenförmiges Schnecken-element an der ersten Antriebswelle und an der zweiten Antriebswelle bilden,
j)wobei die Büchn (41)an der ersten An-triebswelle eine erste Kamm-Mittelebene und die Büchn (41)und die zweite Antriebswelle eine zweite Kamm-Mittelebene (52)aufwein und
k)wobei die erste Mittelebene (51)und die zweite Mittelebene (52)parallel zueinander verlaufen.
2.
Extruder nach Anspruch 2,wobei der Winkel (50a)zwischen 22° bis 24° beträgt.
3.
白鸽粥Extruder nach Anspruch 2,wobei ein Verhältnis von Außendurchmesr (47)zu Innendurchmesr (46)etwa 1,4 bis etwa 1,7 beträgt.
4.
Extruder nach Anspruch 2,wobei das Schnecken-element (42)an jeder Büch (41)eine Steigung von etwa dem 0,5-bis 2-fachen des Außendurch-mesr aufweist.
5.
Extruder nach Anspruch 4,wobei der Außendurch-mesr zwischen 25 bis 380 mm beträgt.
Revendications 1.
Extrudeu à double vis
a)possédant une paire d'arbres d'entraîne-ment bord àbord avec au moins deux douilles filetées (41)montées bout àbout sur un pre-mier arbre d'entraînement et un cond arbre d'entraînement,
b)lesdites au moins deux douilles filetées (41)sur chaque arbre étant des douilles identiques (41),
c)lesdites douilles identiques (41)possédant uniquement un élément formant vis hélicoïdale (42)s'étendant sur la longueur desdites douilles (41),
d)ledit élément formant vis (42)préntant un diamètre extérieur (47)et un diamètre intérieur (46),
e)lesdites douilles (41)préntant une coupe transversale possédant une ction annulaire (48) et un lobe (49),
f)ledit lobe (49)préntant un sommet tronqué(50), et
g)ledit sommet (50)préntant un angle (50a)mesuréàpartir du centre (50b)de la douille
栀子花扦插
(41)vers chaque bord du sommet (50)s'éche-lonnant entre 15°et 30°,caractérisée en ce que
h)lesdites au moins deux douilles (41)montées bout àbout forment un élément formant vis hé-licoïdale sur ledit premier arbre d'entraînement et sur ledit cond arbre d'entraînement,
i)lesdites douilles (41)sur ledit premier arbre d'entraînement préntent une première ligne moyenne de crête (51)et lesdites douilles (41)et ledit cond arbre d'entraînement prén-tent une conde ligne moyenne de crête (52)et
j)ladite première ligne moyenne de crête (51)et ladite conde ligne moyenne de crête (52)sont parallèles l'une à l'autre.
2.
Extrudeu lon la revendication 1,dans laquelle ledit angle (50a) est entre 22° et 24°.
3.
Extrudeu lon la revendication 2,dans laquelle un rapport dudit diamètre extérieur (47)sur ledit dia-mètre intérieur (46) est d'environ 1,4 à 1,7.4.
Extrudeu lon la revendication 2,dans laquelle l'élément formant vis (42)sur chaque douille (41)prénte un pas d'environ 0,5à2fois ledit diamètre extérieur (47).
5.
Extrudeu lon la revendication 4,dans laquelle le diamètre extérieur est entre 25 et 380 mm.
