EP0520321B1 - Centrifuge - Google Patents
Centrifuge Download PDFInfo
- Publication number
- EP0520321B1 EP0520321B1 EP92110303A EP92110303A EP0520321B1 EP 0520321 B1 EP0520321 B1 EP 0520321B1 EP 92110303 A EP92110303 A EP 92110303A EP 92110303 A EP92110303 A EP 92110303A EP 0520321 B1 EP0520321 B1 EP 0520321B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- oblong
- formations
- screw
- centrifuge according
- suspension
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
- B04B—CENTRIFUGES
- B04B1/00—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles
- B04B1/20—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
- B04B—CENTRIFUGES
- B04B1/00—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles
- B04B1/20—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl
- B04B2001/205—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl with special construction of screw thread, e.g. segments, height
Definitions
- the invention relates to a solid bowl screw centrifuge for the separation of a suspension into a solid phase and at least one liquid phase, in particular with a downstream separator or the like with a screw rotating around its shell with a differential speed, the helix of which on the course of the inner surface of the shell, in particular for solids discharge seen at least over a partial longitudinal area is conically narrowed, adapted at a short distance and between which the screw hub and the casing the separation space is formed, into which the suspension is fed through a cavity in the screw hub, with at least a partial area of the longitudinal extension of the screw hub Elongated structures distributed over the circumference are provided, which extend from the worm hub approximately radially to the separating space.
- Centrifuges for the separation of a liquid containing solids a so-called suspension into a solid phase and one or more liquid phases are known.
- the suspension is accelerated in the interior of the rotating centrifuge jacket, so that the solids, which are heavier than the clear liquid, settle towards the inside surface of the jacket.
- the solid is usually composed of a large number of particles of different sizes and / or weights. While the sedimentation of the coarse and heavy particles hardly causes any problems, this becomes more and more difficult or lengthy in the direction of the small, light particles.
- the invention has for its object to improve centrifuges of the type mentioned in terms of their separation result in terms of quality and quantity, especially in terms of saving time and material and to improve such centrifuges in such a way that blockages due to coarse solid particles are avoided.
- this object is achieved in that the elongated structures are designed in the manner of threads or bristles which are flexible transversely to their longitudinal extent when larger solid particles are attacked and which, at the latest under the action of centrifugal force when the centrifuge is in operation, struts approximately radially from the screw hub in extend the separation space.
- cross-sectional shape or a change in shape seen in the longitudinal direction of the structures can be shaped differently and possibly adapted to the separation task, the simplest form being a round, constant cross-section is to be selected.
- band-shaped cross sections and / or tapering in the longitudinal direction can also be considered.
- the elongated structures help to accelerate the liquid in the direction of circulation, which also serves a better separation result, because the flow turbulence occurring in the inlet area and its proximity impair the settling of the solid.
- the elongated structures can in principle be designed to be resilient in such a way that they are stiff to the extent that they increase their entrainment properties in the sense of the acceleration in circulation of the suspension, so that they assume their radial stripping direction from the worm hub on their own, i.e. also without centrifugal force.
- the structures would then have the character of elastic bristles.
- the elongated structures are designed in a particularly preferred embodiment in the manner of threads without resilient elastic properties, so that they only develop under the centrifugal force that occurs during operation of the centrifuge extend radially into the separation space and thus into the pond.
- threads and bristles there is every transition area of possible elongated structures to be used here, nor should threads and bristles be understood in such a way that a bristle-shaped character of the structures must necessarily be present in the inlet area and a thread-like character in the clarification area lying outside the inlet .
- a bristle-like, spring-elastic design of the elongated structures can very well be provided throughout or a thread-like structure continuously.
- Different structures can preferably be used, for example in the inlet area with a bristle-like character and in the separating area outside the inlet with a thread-like character.
- a change in the stiffness character, carried out continuously or in stages, from the slurry inlet is possible over the separation distance.
- the structures do not have to extend over the entire longitudinal region of the worm hub, they can also include partial regions, for example at least in the vicinity of the suspension inlet region the solids discharge.
- the screw spiral in this area, in particular in the clarification area facing away from the solids discharge in countercurrent centrifuges, in particular that between the suspension inlet and the clear liquid outlet, the screw spiral is interrupted, in such a way that the liquid can flow at least with a strong axial component, the spiral with regard to However, its task of transporting solids is maintained so that it is not interrupted with regard to its paint removal path.
- the threads which in principle can consist of any material, here chosen in view of the prevailing centrifugal forces and impingement of solids, preferably made of plastic, have a flexibility transversely to their longitudinal direction, which causes the elongated structures to yield to coarser solid particles, so that blockages accordingly be avoided.
- the attachment of the elongated structures to the worm hub is in principle arbitrary and can also be directed to holders which are arranged so as to be rotationally and centrifugally fixed relative to the worm hub.
- a loop shape is provided in such a way that the central region is fixed to the worm hub or the holder and the two striving subregions protrude into the separation space as two elongate structures.
- the figures show exemplary embodiments of solid-bowl screw centrifuges or their screws in a basically known design with a casing 1 and a screw 2, which is driven at a differential speed to the rapidly rotating casing 1, in accordance with the sense of pitch of the helix 4, which is from the outer circumference of the screw hub 3 is protruding, the plastic settling on the inner lateral surface is conveyed through the helix 4 to the solids discharge 13.
- the worm hub 3 and the casing 1 in the separation space 6 formed between the helices 4, the worm hub 3 and the casing 1, the level of the suspension fed through the inlet opening 10 from an inlet cavity in the worm hub is adjusted so that the radial thickness of the pond decreases from the suspension inlet 10 starting from the clear liquid outlet 14. Due to the resulting pressure difference between adjacent helical paths, a certain flow is established between the radial outer edge of the helix and the inner lateral surface, as a result of which solid matter deposited there can be partially whirled up again.
- the helix of the screw 2 shown there is designed to be interrupted in the axial region between the suspension inlet openings 10 and the end region of the clear liquid outflow which is provided for the conically narrowing end associated with the discharge of solids in such a way that helical sections 5 result , which are offset from one another in the axial direction, but seen in this direction do not release any gaps, so that the solid to be conveyed by the spiral sections is transported in a correspondingly stepped manner.
- the interrupted design of the helix 4 in sections 5 in this axial screw region creates an axial flow path between the sections for the liquid, so that the under-rinsing of the radially outer helix edges described with reference to FIG. 2 is omitted insofar as the pressure equalization takes place by means of axial flow.
- the screw region with an interrupted helical formation is also provided with a plurality of elongate structures 7 of thread-like character, as seen over the circumference of the screw hub. Since this is the clarifying section of a countercurrent centrifuge outside the slurry inlet, the result is finer solid particles - the coarser particles settle in or near predominantly from the inlet area - so that here the thread-like structures primarily have to fulfill their task of collecting fine solids and therefore have to be fine, preferably becoming finer when viewed from the clear liquid outlet.
- FIG. 3 shows the principle of a countercurrent centrifuge, i.e. the suspension is passed through an inlet pipe 11 into the longitudinal central region of the worm hub and is fed there via inlet openings 10 into the separation space 6, so that the coarser solid which settles in the inlet region is fed to the solids discharge 13 in a short way, while the one in particular Area between the inlet 10 and the clear liquid outlet 14 settling finer solid must cover the correspondingly longer transport route.
- the countercurrent centrifuge according to FIG.
- the suspension is fed in via the inlet pipe 12 and corresponding inlet openings 10 at the beginning of the entire conveying path of the screw 2, so that the solid settling in the inlet area has to cover a correspondingly long transport route.
- the clarified liquid is drained off in the longitudinal central region of the screw and fed to the clear liquid outlet 14. Both types are known and need no further explanation here.
- the supplied suspension must be accelerated in the circumferential direction, which was previously done in this area by the inner surface of the jacket.
- the elongated structures 8 now arranged in this inlet area according to FIGS. 3 and 4 serve primarily for acceleration and are therefore stiffer than outside this area.
- the entraining effect of the elongated structures in the suspension inlet area also has a particularly favorable effect in that the inner surface area otherwise causing acceleration of the suspension entered is spared in this area with regard to its abrasion.
Landscapes
- Centrifugal Separators (AREA)
Description
Die Erfindung bezieht sich auf eine Vollmantel-Schneckenzentrifuge für die Trennung einer Suspension in eine Feststoff- und wenigstens eine Flüssigkeitsphase, insbesondere mit nachgeschaltetem Separator oder dergleichen mit gegenüber ihrem Mantel mit Differenzdrehzahl umlaufender Schnecke, deren Wendel an den Verlauf der Mantelinnenfläche, die insbesondere zum Feststoffaustrag gesehen zumindest über einen Teillängsbereich sich konisch verengt, mit geringem Abstand angepaßt sind und zwischen denen, der Schneckennabe und dem Mantel der Trennraum gebildet ist, in den die Suspension durch einen Hohlraum in der Schneckennabe eingespeist wird, wobei über wenigstens einen Teilbereich der Längserstreckung der Schneckennabe über deren Umfang verteilt angeordnete längliche Gebilde vorgesehen sind, die sich von der Schneckennabe etwa radial abstrebend in den Trennraum erstrecken.The invention relates to a solid bowl screw centrifuge for the separation of a suspension into a solid phase and at least one liquid phase, in particular with a downstream separator or the like with a screw rotating around its shell with a differential speed, the helix of which on the course of the inner surface of the shell, in particular for solids discharge seen at least over a partial longitudinal area is conically narrowed, adapted at a short distance and between which the screw hub and the casing the separation space is formed, into which the suspension is fed through a cavity in the screw hub, with at least a partial area of the longitudinal extension of the screw hub Elongated structures distributed over the circumference are provided, which extend from the worm hub approximately radially to the separating space.
Zentrifugen für die Trennung einer Feststoff enthaltenden Flüssigkeit, einer sogenannten Suspension in eine Feststoffphase und eine oder mehrere Flüssigkeitsphasen sind bekannt. Die Suspension wird im Inneren des rotierenden Zentrifugenmantels beschleunigt` so daß sich die gegenüber der Klarflüssigkeit schwereren Feststoffe zur Mantelinnenfläche hin absetzen. Dabei setzt sich der Feststoff in der Regel aus einer Vielzahl von Partikeln unterschiedlicher Größe und/oder Gewichtes zusammen. Während die Sedimentation der groben und schweren Partikel kaum Probleme bereitet, wird dies in Richtung der kleinen, leichten Partikel immer schwieriger bzw. langwieriger. Zur Erzielung eines wünschenswert guten Trennergebnisses besteht natürlich das Bestreben, auch feinere bis feinste Feststoffpartikel auszuscheiden um somit die abzuführende Klarflüssigkeit sauberer zu gestalten und die abgeführte Feststoffmenge zu erhöhen, kurz das Trennergebnis zu optimieren.Centrifuges for the separation of a liquid containing solids, a so-called suspension into a solid phase and one or more liquid phases are known. The suspension is accelerated in the interior of the rotating centrifuge jacket, so that the solids, which are heavier than the clear liquid, settle towards the inside surface of the jacket. The solid is usually composed of a large number of particles of different sizes and / or weights. While the sedimentation of the coarse and heavy particles hardly causes any problems, this becomes more and more difficult or lengthy in the direction of the small, light particles. In order to achieve a desirably good separation result, there is of course the endeavor to separate even finer to finest solid particles in order to make the clear liquid to be discharged cleaner and to increase the amount of solid discharged, to briefly optimize the separation result.
Aus der SU-A-1,174,088 ist eine gattungsgemäße Vollmantel-Schneckenzentrifuge für die Trennung einer Suspension in eine Feststoff- und wenigstens eine Flüssigkeitsphase bekannt. Diese vorbekannte Zentrifuge weist eine Vielzahl von Stabelementen auf, die radial abstrebend an der Schneckennabe befestigt sind und sich in den Trennraum erstrecken. Bei diesen Starben handelt es sich um starre Gegenstände, die keinerlei Biegsamkeit aufweisen. Demzufolge haben diese Stäbe den Nachteil, daß zwischen den Stäben haftende gröbere Feststoffpartikel Verstopfungen verursachen. Ferner kann durch diese Stäbe eine Kavitationsgefahr hervorgerufen werden, die zu einem erheblichen Verschleiß innerhalb der Zentrifuge führt.From SU-A-1,174,088 a generic solid bowl screw centrifuge for the separation of a suspension into a solid and at least one liquid phase is known. This known centrifuge has a multiplicity of rod elements which are attached to the screw hub in a radially striving manner and extend into the separation space. These dead bodies are rigid objects that have no flexibility. As a result, these rods have the disadvantage that coarser solid particles adhering between the rods cause blockages. Furthermore, these rods can cause a risk of cavitation, which leads to considerable wear within the centrifuge.
Der Erfindung liegt die Aufgabe zugrunde, Zentrifugen der eingangs genannten Art hinsichtlich ihres Trennergebnisses der Qualität und der Quantität nach zu verbessern, dies insbesondere auch im Hinblick auf Einsparung an Zeit und Material und derartige Zentrifugen dahingehend zu verbessern, daß Verstopfungen durch gröbere Feststoffpartikel vermieden werden.The invention has for its object to improve centrifuges of the type mentioned in terms of their separation result in terms of quality and quantity, especially in terms of saving time and material and to improve such centrifuges in such a way that blockages due to coarse solid particles are avoided.
Erfindungsgemäß wird diese Aufgabe dadurch gelöst, daß die länglichen Gebilde nach Art von Fäden oder Borsten ausgebildet sind, die unter Angriff größerer Feststoffpartikel quer zu ihrer Längserstreckung nachgiebig sind und die sich spätestens unter Einwirkung von Fliehkraft bei Betrieb der Zentrifuge von der Schneckennabe etwa radial abstrebend in den Trennraum erstrecken.According to the invention, this object is achieved in that the elongated structures are designed in the manner of threads or bristles which are flexible transversely to their longitudinal extent when larger solid particles are attacked and which, at the latest under the action of centrifugal force when the centrifuge is in operation, struts approximately radially from the screw hub in extend the separation space.
Durch die Anordnung der nach Art von Fäden oder Borsten länglichen Gebilde von der Schneckennabe abstrebend und an dieser mehr oder weniger direkt befestigt erreicht man eine bessere Feststoffabscheidung auch kleinster Partikel dadurch, daß diese sich an den Oberflächen dieser Gebilde ansammeln und somit unter Fliehkraft entlang der Fäden besser und/oder schneller aus der Flüssigkeit abgeschieden und den gegebenenfalls bereits sedimentierten Feststoff an der Mantelinnenfläche der Zentrifuge zugeführt werden können. Das Ergebnis ist zunächst eine weitergehende Trennung als bisher möglich. Je nach Feststoff kann durch Wahl geeigneter Materialien für die länglichen Gebilde dieser "Sammel- oder Fangeffekt" für feine und feinste Feststoffpartikel zusätzlich beeinflußbar sein. Weiterhin kann die Querschnittsform oder auch eine Formänderung in Längsrichtung der Gebilde gesehen unterschiedlich und gegebenenfalls an die Trennaufgabe angepaßt ausgeformt sein, wobei als einfachste Form ein runder gleichbleibender Querschnitt zu wählen ist. Es kommen aber auch bandförmige und/oder sich in Längsrichtung verjüngende Querschnitte in Betracht.By arranging the elongated structures in the manner of threads or bristles striving from the worm hub and attached to them more or less directly, better solid separation of even the smallest particles is achieved in that they collect on the surfaces of these structures and thus under centrifugal force along the threads separated from the liquid better and / or faster and the possibly already sedimented solid can be fed to the inner surface of the centrifuge. The result is a further separation than was previously possible. Depending on the solids, this "gathering or catching effect" for fine and very fine solid particles can also be influenced by selecting suitable materials for the elongated structures. Furthermore, the cross-sectional shape or a change in shape seen in the longitudinal direction of the structures can be shaped differently and possibly adapted to the separation task, the simplest form being a round, constant cross-section is to be selected. However, band-shaped cross sections and / or tapering in the longitudinal direction can also be considered.
Insbesondere im Einlaufbereich der Suspension bzw. in dessen Nähe bewirken die länglichen Gebilde eine Hilfe für die notwendige Beschleunigung der Flüssigkeit in Umlaufrichtung, was ebenfalls einem besseren Trennergebnis dient, weil die ohne die Gebilde auftretenden Strömungsturbulenzen im Einlaufbereich und dessen Nähe das Absetzen des Feststoffes beeinträchtigen.In particular in the inlet area of the suspension or in its vicinity, the elongated structures help to accelerate the liquid in the direction of circulation, which also serves a better separation result, because the flow turbulence occurring in the inlet area and its proximity impair the settling of the solid.
Vor diesem Hintergrund wird deutlich, daß die länglichen Gebilde grundsätzlich federelastisch dergestalt ausgebildet sein können, daß sie im Sinne einer Erhöhung ihrer Mitnehmereigenschaft im Sinne der Umlaufbeschleunigung der Suspension insoweit steif sind, daß sie ihre radiale Abstreberichtung von der Schneckennabe von sich aus einnehmen, also auch ohne Einwirkung von Fliehkraft. Die Gebilde hätten dann den Charakter entsprechend elastischer Borsten. Vor allem aber im Bereich außerhalb des Suspensionseinlaufes, in dem die Klärung feinerer Feststoffpartikel im Vordergrund steht, sind die länglichen Gebilde in besonders bevorzugter Ausführung nach Art von Fäden ohne rückstellende elastische Eigenschaften ausgebildet, so daß sie sich erst unter der im Betrieb der Zentrifuge auftretenden Fliehkraft radial ausrichtend in den Trennraum und damit den Teich hinein erstrecken. Zwischen diesen beiden Ausbildungen - Borsten und Faden - gibt es jeden Übergangsbereich möglicher hier einzusetzender länglicher Gebilde, auch sollen Fäden und Borsten nicht so verstanden werden, daß notwendigerweise im Einlaufbereich ein borstenförmiger und im außerhalb des Einlaufs liegenden Klärbereich ein fadenförmiger Charakter der Gebilde vorhanden sein muß. Es kann sehr wohl eine borstenartige, federelastische Ausbildung der länglichen Gebilde durchgehend vorgesehen sein oder eben durchgehend ein fadenförmiges Gebilde. Vorzugsweise kann man verschiedene Gebilde einsetzen, so im Einlaufbereich mit borstenartigem Charakter und im Trennbereich außerhalb des Einlaufes mit fadenförmigem Charakter. Schließlich ist in weiterhin bevorzugter Ausführung eine kontinuierlich oder gestuft vorgenommene Änderung des Steifigkeitscharakters vom Suspensionseinlauf her gesehen über die Trennstrecke möglich. Desweiteren müssen sich die Gebilde nicht über den gesamten Längsbereich der Schneckennabe erstrecken, sie können auch Teilbereich umfassen, so zwischen dem Suspensionseinlaufbereich bishin zumindest in Nähe des Feststoffaustrages. Diese Wahlmöglichkeiten wird man insbesondere in Anpassung an die Bauart der Zentrifuge, hier insbesondere Gegenstromprinzip und Gleichstrompinzip ausnutzen. Desweiteren ist die erfindungsgemäße Lehre unabhängig davon, ob ein- oder mehrgängige Schneckenausbildungen vorgesehen sind.Against this background, it is clear that the elongated structures can in principle be designed to be resilient in such a way that they are stiff to the extent that they increase their entrainment properties in the sense of the acceleration in circulation of the suspension, so that they assume their radial stripping direction from the worm hub on their own, i.e. also without centrifugal force. The structures would then have the character of elastic bristles. Above all, however, in the area outside the suspension inlet, in which the clarification of finer solid particles is in the foreground, the elongated structures are designed in a particularly preferred embodiment in the manner of threads without resilient elastic properties, so that they only develop under the centrifugal force that occurs during operation of the centrifuge extend radially into the separation space and thus into the pond. Between these two designs - bristles and thread - there is every transition area of possible elongated structures to be used here, nor should threads and bristles be understood in such a way that a bristle-shaped character of the structures must necessarily be present in the inlet area and a thread-like character in the clarification area lying outside the inlet . A bristle-like, spring-elastic design of the elongated structures can very well be provided throughout or a thread-like structure continuously. Different structures can preferably be used, for example in the inlet area with a bristle-like character and in the separating area outside the inlet with a thread-like character. Finally, in a further preferred embodiment, a change in the stiffness character, carried out continuously or in stages, from the slurry inlet is possible over the separation distance. Furthermore, the structures do not have to extend over the entire longitudinal region of the worm hub, they can also include partial regions, for example at least in the vicinity of the suspension inlet region the solids discharge. These options will be used in particular in adaptation to the design of the centrifuge, in particular the countercurrent principle and the direct current principle. Furthermore, the teaching according to the invention is independent of whether single-screw or multi-screw designs are provided.
Bei durchgehender Wendel durchläuft die Flüssigkeit theoretisch den Schneckengang zwischen den benachbarten Wendeln und hat damit zwar eine verhältnismäßig lange Sidementationsstrecke bis zum Klarflüssigkeitsablauf, neigt aber aufgrund des Druckabfalles, der sich in axialer Richtung gesehen von Wendel zu Wendel ergibt, dazu, die Schneckenwendel zu unterspülen, d.h. zwischen der äußeren Kante der Schneckenwendel und der angrenzenden Innenwandung des Mantels hindurchzuströmen. Dabei wird dort abgesetzter feiner Feststoff wieder aufgewirbelt. In besonders bevorzugter Ausführung der Erfindung wird daher in diesem Bereich insbesondere in dem dem Feststoffaustrag abgewandten Klärbereich bei Gegenstromzentrifugen insbesondere derjenige zwischen Suspensionseinlauf und Klarflüssigkeitsablauf, die Schneckenwendel unterbrochen, und zwar derart, daß die Flüssigkeit zumindest mit einr starken axialen Komponente strömen kann, die Wendel hinsichtlich ihrer Aufgabe des Feststofftransportes jedoch derat aufrechterhalten bleibt, daß sie hinsichtlich ihres malen Abförderweges nicht unterbrochen wird. Zwischen den durch die Unterbrechung der Wendel geschaffenen, in Schneckenlängsrichtung gegeneinander versetzten Wendelabschnitten entsteht in Schneckenlängsrichtung und damit in Feststofförderrichtung gesehen keine Lücke, die Wendel können sich auch ein wenig überlappen, so daß der Feststofftransport lediglich gestuft von einem Wendelabschnitt zum nächsten weitergereicht wird.In the case of a continuous helix, the liquid theoretically passes through the screw flight between the adjacent helixes and thus has a relatively long section to the clear liquid outlet, but due to the pressure drop that results from helix to helix, seen in the axial direction, tends to rinse the helix, ie to flow between the outer edge of the screw helix and the adjacent inner wall of the shell. Thereby settled fine solid is whirled up again. In a particularly preferred embodiment of the invention, therefore, in this area, in particular in the clarification area facing away from the solids discharge in countercurrent centrifuges, in particular that between the suspension inlet and the clear liquid outlet, the screw spiral is interrupted, in such a way that the liquid can flow at least with a strong axial component, the spiral with regard to However, its task of transporting solids is maintained so that it is not interrupted with regard to its paint removal path. There is no gap in the longitudinal direction of the screw and thus seen in the solids conveying direction between the helical sections created by the interruption of the helix, which are offset with respect to one another in the longitudinal direction of the screw, the helixes can also overlap a little, so that the solids transport is only passed on in stages from one helical section to the next.
Die Fäden, die grundsätzlich aus beliebigem, hier angesichts der herrschenden Fliehkräfte und Feststoffbeaufschlagungen entsprechend widerstandsfähig gewählten Werkstoffen bestehen können, vorzugsweise aus Kunststoff, weisen eine Nachgiebigkeit quer zu ihrer Längsrichtung auf, die das Ausweichen der länglichen Gebilde gegenüber gröberen Feststoffpartikeln bewirken, so daß Verstopfungen entsprechend vermieden werden. Dies gilt sowohl für die federelastischen, borstenartigen Ausbildungen als auch für diejenigen, die keine eigene Ausrichtungsstabilität aufweisen, also fadenförmig sich erst unter Fliehkrafteinfluß ausrichten und damit besonders gut geeignet sind, unter dem Angriff größerer Feststoffpartikel nachgiebig zu reagieren und damit Verstopfungen zu vermeiden. Die Befestigung der länglichen Gebilde an der Schneckennabe ist grundsätzlich beliebig und kann auch auf relativ zur Schneckennabe dreh- und fliehkraftfest angeordnete Halterungen gerichtet sein. Insbesondere bei fadenförmigen Gebilden wird eine Schlingenform derart vorgesehen, daß der Mittelbereich an der Schneckennabe bzw. der Halterung festgelegt ist und die beiden abstrebenden Teilbereiche als zwei längliche Gebilde in den Trennraum hineinragen.The threads, which in principle can consist of any material, here chosen in view of the prevailing centrifugal forces and impingement of solids, preferably made of plastic, have a flexibility transversely to their longitudinal direction, which causes the elongated structures to yield to coarser solid particles, so that blockages accordingly be avoided. This applies both to the resilient, bristle-like designs and also to those that do not have their own alignment stability, that is to say that they align themselves under the influence of centrifugal force and are therefore particularly suitable under which To react flexibly to attack of larger solid particles and thus to avoid blockages The attachment of the elongated structures to the worm hub is in principle arbitrary and can also be directed to holders which are arranged so as to be rotationally and centrifugally fixed relative to the worm hub. In the case of thread-like structures in particular, a loop shape is provided in such a way that the central region is fixed to the worm hub or the holder and the two striving subregions protrude into the separation space as two elongate structures.
Diese und andere bevorzugte Ausführungen der Erfindung ergeben sich aus den Unteransprüchen, insbesondere unter Bezug auf die in der Zeichnung wiedergegebenen Ausführungsbeispiele, deren nachfolgende Beschreibung die Erfindung näher erläutert. Es zeigen
-
Figur 1
ein Ausführungsbeispiel einer Schnecke mit in einem Teilbereich angeordneten länglichen Gebilden in perspektivischer Darstellung; -
Figur 2
einen schematischen Längsschnitt durch eine Zentrifuge in hinsichtlich der Rotationsachse hälftiger Darstellung zur Erläuterung des Teichdruckgefälles Innerhalb des Trennraumes; -
Figur 3
einen schematischen Längsschnitt durch eine Vollmantel-Schneckenzentrifuge nach dem Gegenstromprinzip in Darstellungentsprechend Figur 2; -
Figur 4
einen schematischen Längsschnitt durch eine Vollmantel-Schneckenzentrifuge nach dem Gleichstromprinzip in Darstellungentsprechend Figur 2.
- Figure 1
an embodiment of a screw with elongated structures arranged in a partial area in a perspective view; - Figure 2
a schematic longitudinal section through a centrifuge in half with respect to the axis of rotation to explain the pond pressure gradient within the separation space; - Figure 3
a schematic longitudinal section through a solid bowl screw centrifuge according to the countercurrent principle in the representation corresponding to Figure 2; - Figure 4
3 shows a schematic longitudinal section through a solid-bowl screw centrifuge according to the direct current principle in a representation corresponding to FIG. 2.
Die Figuren zeigen Ausführungsbeispiele von Vollmantel-Schneckenzentrifugen bzw. deren Schnecken in grundsätzlich bekannter Bauart mit einem Mantel 1 und einer Schnecke 2, die mit Differenzdrehzahl zum schnellaufend angetriebenen Mantel 1 derart angetrieben ist, das entsprechend dem Steigungssinn der Wendel 4, die vom Außenumfang der Schneckennabe 3 abragend ausgebildet ist, der sich an der Innenmantelfläche absetzende Kunststoff durch die Wendel 4 zum Feststoffaustrag 13 gefördert wird. Wie insbesondere Figur 2 erkennen läßt, stellt sich in dem zwischen den Wendeln 4, der Schneckennabe 3 und dem Mantel 1 gebildeten Trennraum 6 der Spiegel der durch die Einlauföffnung 10 aus einem Zulauf-Hohlraum in der Schneckennabe zugeführten Suspension ein Gefälle ein, so daß die radiale Mächtigkeit des Teiches vom Suspensionseinlauf 10 ausgehend zum Klarflüssigkeitsablauf 14 gesehen abnimmt. Aufgrund des dadurch gegebenen Druckunterschiedes zwischen benachbarten Wendelgängen stellt sich eine gewisse Strömung zwischen der radialen Außenkante der Wendel und der Innenmantelfläche ein, wodurch dort abgesetzter Feststoff teilweise wieder aufgewirbelt werden kann.The figures show exemplary embodiments of solid-bowl screw centrifuges or their screws in a basically known design with a
Aus diesem Grunde ist bei dem Ausführungsbeispiel gemäß Figur 1 die Wendel der dort wiedergegebenen Schnecke 2 im axialen Bereich zwischen den Suspensions-Einlauföffnungen 10 und dem dem sich konisch verengenden, dem Feststoffaustrag zugeordnetne Ende gegenüberliegenden Endbereich vorgesehenen Klarflüssigkeitsablauf derart unterbrochen ausgebildet, daß sich Wendelabschnitte 5 ergeben, die in axialer Richtung gegeneinander versetzt sind, in dieser Richtung gesehen jedoch keine Lücken freigeben, so daß der von den Wendelabschnitten zu fördernde Feststoff entsprechend gestuft transportiert wird. Die unterbrochene Ausführung der Wendel 4 in Abschnitte 5 in diesem axialen Schneckenbereich schafft jedoch für die Flüssigkeit einen axialen Strömungsweg zwischen den Abschnitten, so daß die anhand von Figur 2 geschilderte Unterspülung der radial äußeren Wendelkanten insoweit unterbleibt, als der Druckausgleich durch axiale Strömung erfolgt.For this reason, in the exemplary embodiment according to FIG. 1, the helix of the
Beim Ausführungsbeispiel gemäß Figur 1 ist der Schneckenbereich mit unterbrochener Wendelausbildung zugleich über den Umfang der Schneckennabe hinweg gesehen mit einer Vielzahl von länglichen Gebilden 7 fadenförmigen Charakters versehen. Da es sich hier um die Klärstrecke einer Gegenstromzentrifuge außerhalb des Suspensionseinlaufes handelt, ist hier der Anfall an feineren Feststoffpartikeln - die gröberen setzen sich im oder nahe dem Einlaufbereich ab - entsprechend vorherrschend, so daß hier die fadenförmigen Gebilde vornehmlich ihre Aufgabe des Ansammelns feinen Feststoffes genügen müssen und daher fein, vorzugsweise zum Klarflüssigkeitsablauf hin gesehen feiner werdend, gerecht werden müssen.In the exemplary embodiment according to FIG. 1, the screw region with an interrupted helical formation is also provided with a plurality of
In den Ausführungsbeispielen nach den Figuren 3 und 4 erstrecken sich die länglichen Gebilde 7, 8 insoweit über den gesamten Klärbereich hinweg bzw. enden im sich konisch verengenden Mantelbereich vor dem Feststoffaustrag 13. Figur 3 zeigt das Prinzip einer Gegenstromzentrifuge, d.h. die Suspension wird über ein Einlaufrohr 11 bis in den Längsmittelbereich der Schneckennabe geleitet und dort über Einlauföffnungen 10 in den Trennraum 6 eingespeist, so daß der sich im Einlaufbereich absetzende Feststoff gröberer Natur auf kurzem Wege dem Feststoffaustrag 13 zugeführt wird, während vor allem der sich im Bereich zwischen dem Einlauf 10 und dem Klarflüssigkeitsablauf 14 absetzende feinere Feststoff den entsprechend längeren Transportweg zurücklegen muß. Bei der Gegenstrom-Zentrifuge gemäß Figur 4 wird die Suspension über das Einlaufrohr 12 und entsprechende Einlauföffnungen 10 zu Beginn der gesamten Förderstrecke der Schnecke 2 eingespeist, so daß der sich im Einlaufbereich absetzende Feststoff einen entsprechend langen Transportweg zurücklegen muß. Die geklärte Flüssigkeit wird im Längsmittelbereich der Schnecke abgeführt und dem Klarflüssigkeitsablauf 14 zugeleitet. Beide Typen sind bekannt und bedürfen hier keiner weiteren Erläuterung.In the exemplary embodiments according to FIGS. 3 and 4, the
Im jeweiligen Suspensionseinlaufbereich - Einlauföffnungen 10 - muß die zugeführte Suspension in Umlaufrichtung beschleunigt werden, was bislang durch die Mantelinnenfläche in diesem Bereich geschah. Die nach den Figuren 3 und 4 in diesem Einlaufbereich nunmehr angeordneten länglichen Gebilde 8 dienen vornehmlich der Beschleunigung und sind daher steifer ausgeführt als außerhalb dieses Bereiches. Man kann hier ein borstenförmiges, d.h. unter Federelastizität sich radial ausrichtendes Gebilde vorsehen, während im übrigen Trennraumbereich, insbesondere im Nahbereich des Klarflüssigkeitsabzuges, fadenförmige Gebilde angeordnet werden können. Die Mitnahmewirkung der länglichen Gebilde im Suspensionseinlaufbereich wirkt sich besonders günstig auch dadurch aus, daß die ansonsten die Beschleunigung der eingegebenen Suspension bewirkende Innenmantelfläche in diesem Bereich hinsichtlich ihrer Abbrasion geschont wird.In the respective suspension inlet area - inlet openings 10 - the supplied suspension must be accelerated in the circumferential direction, which was previously done in this area by the inner surface of the jacket. The
Claims (10)
- Solid bowl screw-type centrifuge for the separation of a suspension into a solid phase and at least one liquid phase, in particular with a downstream separator or similar means, having a screw rotating at a differential speed relative to its jacket (1), the spirals (4) thereof being adapted with a small distance to the course of the jacket inner surface which, particularly when viewed in the direction of the solid material discharge (13), tapers at least over an axial part-portion, between which spirals, the screw hub (3) and the jacket (1) the separation chamber (6) is formed into which the suspension is fed through a hollow space (10,11;10,12) in the screw hub (3), oblong formations (7,8) being provided over at least a part-portion of the longitudinal extension of the screw hub (3) and distributed over the circumference thereof, said oblong formations extending into the separation chamber (6) approximately radially projecting from the screw hub (3), characterized in that the oblong formations (7,8) are in the form of threads or bristles which under the attack of larger solid particles are yielding transversely of its longitudinal extension and which extend into the separation chamber (6) projecting radially form the screw hub (3) under the influence of centrifugal force during the operation of the centrifuge at the latest.
- Centrifuge according to claim 1, characterized in that the oblong formations in the nature of threads take their radial orientation, viewed around the hub circumference, only under centrifugal force.
- Centrifuge according to claim 1, characterized in that the oblong formations in the nature of bristles (8) are resilient.
- Centrifuge according to claim 2 or 3, characterized in that the oblong formations consist of plastics correspondingly able to take tensile loads, in particular of thread-like nylon.
- Centrifuge according to any one of the claims 1 to 4, characterized in that the spirals (4) are interrupted in the zone of the oblong formations (7,8) and consist of sections (5) which, viewed in the longitudinal direction of the screw hub (3), are offset and which are free of gaps or slightly overlap each other in this longitudinal direction with regard to the solid material transportation.
- Centrifuge according to any one of the claims 1 to 5, characterized in that the oblong formations (7,8), viewed in the longitudinal direction of the screw hub (3), are arranged to be limited to the zone between the suspension inflow (10) and the solid material discharge (13) and preferably terminate with a distance before the latter.
- Centrifuge according to any one of the claims 1 to 6, characterized in that in the zone of the suspension inflow (10) there are arranged oblong formations of higher rigidity, in particular resilient according to the nature of bristles (8).
- Centrifuge according to any one of the claims 1 to 7, characterized in that the oblong formations, viewed in the direction of the liquid phase outflow, are formed increasingly fine, respectively flexible and/or thin.
- Centrifuge according to any one of the claims 1 to 8, characterized in that the oblong formations - especially when in the nature of threads (7) - are formed as loops such that the central portion of a loop is fixed to the screw hub (3) and the two adjoining part-portions terminate as oblong formations in the separation chamber (6).
- Centrifuge according to anyone of the claims 1 to 9, characterized in that the oblong formations are formed as resilient bristles (8) in the inflow area (10) of the suspension and as slack threads (7) in the axially adjoining area or areas.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE4120565A DE4120565A1 (en) | 1991-06-21 | 1991-06-21 | CENTRIFUGE |
DE4120565 | 1991-06-21 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0520321A1 EP0520321A1 (en) | 1992-12-30 |
EP0520321B1 true EP0520321B1 (en) | 1995-09-20 |
Family
ID=6434473
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP92110303A Expired - Lifetime EP0520321B1 (en) | 1991-06-21 | 1992-06-17 | Centrifuge |
Country Status (4)
Country | Link |
---|---|
US (1) | US5222935A (en) |
EP (1) | EP0520321B1 (en) |
DE (2) | DE4120565A1 (en) |
DK (1) | DK0520321T3 (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE505557C2 (en) * | 1995-12-21 | 1997-09-15 | Alfa Laval Separation Ab | decanter |
BE1010851A3 (en) * | 1997-01-15 | 1999-02-02 | Atlas Copco Airpower Nv | LIQUID INJECTED COMPRESSOR at least two cooperating compressor elements. |
DE10055798A1 (en) * | 2000-11-10 | 2002-05-23 | Westfalia Separator Ind Gmbh | Screw used for a screw-type solid bowl centrifuge comprises additional leaf segments in some sections of a conveyor path between adjacent spirals, and in the area of the segments a screw leaf with recesses |
US20050082144A1 (en) * | 2003-10-14 | 2005-04-21 | Maupin Daniel D. | High speed food product peeling or cleaning machine and method |
US7527587B2 (en) * | 2007-04-17 | 2009-05-05 | Laughlin Henry J | Centrifugal separator and method for separating heavy and light matter in a substance |
CN106475234B (en) * | 2015-08-26 | 2018-10-26 | 苏州瑞威离心分离技术有限公司 | Horizontal spiral discharge sedimentation centrifuge |
CN114434686B (en) * | 2020-10-19 | 2023-07-11 | 中国石油化工股份有限公司 | Plastic crushing, cleaning and sorting equipment and application method |
Family Cites Families (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US165228A (en) * | 1875-07-06 | Improvement in driers | ||
DE138809C (en) * | ||||
US2184598A (en) * | 1939-12-26 | G jahn | ||
US692011A (en) * | 1901-09-09 | 1902-01-28 | Martin Hansen | Barley-bearder and cereal-polisher. |
FR324335A (en) * | 1902-09-10 | 1903-03-28 | Merckx Arthur | Device for separating centrifugal bowls |
US1529750A (en) * | 1918-04-15 | 1925-03-17 | Pehr G Sieurin | Apparatus for drying finely-divided material such as peat, etc. |
US1417965A (en) * | 1921-12-27 | 1922-05-30 | G H Davis | Oil-treating mixer |
US3260369A (en) * | 1962-12-14 | 1966-07-12 | Lou A Gruenewaelder | Means for centrifugally clarifying water containing sewage sludges and the like |
DE1279551B (en) * | 1963-07-11 | 1968-10-03 | Flottweg Motoren Werk Dr Georg | Solid bowl centrifuge |
US3644103A (en) * | 1967-10-06 | 1972-02-22 | Upjohn Co | Countercurrent solid-liquid contacting using flexible bristle scre flight means |
DE2907318A1 (en) * | 1979-02-24 | 1980-08-28 | Bayer Ag | Centrifuge drum with cylindrical and conical zones - where worm profile is designed for efficient sepn. of solids from liquids, esp. from liquids with high viscosity |
US4243779A (en) * | 1979-04-23 | 1981-01-06 | Mcalister Roy E | Polycarbonates stabilized by halohydrocarbon, halocarbon or silane groups |
SU1174088A1 (en) * | 1983-07-11 | 1985-08-23 | Предприятие П/Я В-2262 | Sedimentation scroll-discharge centrifuge |
DE3501341A1 (en) * | 1984-12-22 | 1986-07-03 | Klöckner-Humboldt-Deutz AG, 5000 Köln | Solid-bowl conveyor screw centrifuge |
GB2182869B (en) * | 1985-11-18 | 1989-05-04 | Decanter Pty Ltd | Decanter centrifuge |
-
1982
- 1982-06-17 US US07/900,158 patent/US5222935A/en not_active Expired - Fee Related
-
1991
- 1991-06-21 DE DE4120565A patent/DE4120565A1/en active Granted
-
1992
- 1992-06-17 EP EP92110303A patent/EP0520321B1/en not_active Expired - Lifetime
- 1992-06-17 DE DE59203723T patent/DE59203723D1/en not_active Expired - Lifetime
- 1992-06-17 DK DK92110303.2T patent/DK0520321T3/en active
Non-Patent Citations (1)
Title |
---|
London, GB; Class J01, AN 86-067725/10 * |
Also Published As
Publication number | Publication date |
---|---|
US5222935A (en) | 1993-06-29 |
DE4120565C2 (en) | 1993-05-06 |
DE4120565A1 (en) | 1992-12-24 |
DK0520321T3 (en) | 1995-11-06 |
EP0520321A1 (en) | 1992-12-30 |
DE59203723D1 (en) | 1995-10-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP1062047B1 (en) | Cyclone separator | |
DE2148422C3 (en) | Hydrocyclone | |
EP0322516A2 (en) | Solid bowl centrifuge | |
EP0520321B1 (en) | Centrifuge | |
EP1215335B1 (en) | Pressure screen for cleaning paper pulp containing impurities | |
EP0133460B1 (en) | Device for dehydrating and drying granulated synthetic material | |
DE3217824C2 (en) | Rotor for sorters for cleaning fiber suspensions, especially made of waste paper | |
EP1551526B1 (en) | Separating device, particularly for separating solids from liquids | |
DE19516636A1 (en) | Continuous centrifuge for sepg. 2 plastic waste fractions | |
EP1268074B1 (en) | Centrifuge having axially oriented separator surfaces | |
EP1137469B1 (en) | Device for separating waste water | |
EP1830001A2 (en) | Device for discharging heavy parts from an apparatus for treating a pulp suspension, in particular from a hydrocyclone which can be operated to clean a pulp suspension | |
DE1757368C3 (en) | Solid bowl screw centrifuge | |
DE3826454A1 (en) | Apparatus for separating off impurities from gas | |
EP0594167A1 (en) | Device for removing separable matter from a liquid flowing in a gutter | |
DE3335873A1 (en) | Solid bowl screw centrifuge for the separation of a solid-liquid mixture | |
DE19901655A1 (en) | Centrifuge for wet mechanical separation of solid mixtures | |
DE1297034B (en) | Solid bowl screw centrifuge | |
DE10104552A1 (en) | Device and method for peeling off a solid cake from a centrifuge drum | |
DE1442501A1 (en) | Process for separating foreign bodies from a fluid medium by means of a cyclone and a cyclone for carrying out the process | |
DE913880C (en) | Centrifugal separator | |
EP3238828A1 (en) | Helical conveyor centrifuge for the wet mechanical separation of solids | |
DE2244712A1 (en) | FULL CASE SCREW CENTRIFUGE | |
DE2355768C2 (en) | Sieving device for sorting suspensions | |
DE102019128562A1 (en) | Solid bowl screw centrifuge |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): DE DK FR GB IT SE |
|
17P | Request for examination filed |
Effective date: 19930127 |
|
17Q | First examination report despatched |
Effective date: 19940321 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): DE DK FR GB IT SE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRE;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.SCRIBED TIME-LIMIT Effective date: 19950920 |
|
ET | Fr: translation filed | ||
REF | Corresponds to: |
Ref document number: 59203723 Country of ref document: DE Date of ref document: 19951026 |
|
REG | Reference to a national code |
Ref country code: DK Ref legal event code: T3 |
|
GBT | Gb: translation of ep patent filed (gb section 77(6)(a)/1977) |
Effective date: 19951211 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
REG | Reference to a national code |
Ref country code: GB Ref legal event code: IF02 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20020613 Year of fee payment: 11 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20030617 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20030617 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20110630 Year of fee payment: 20 Ref country code: SE Payment date: 20110622 Year of fee payment: 20 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DK Payment date: 20110623 Year of fee payment: 20 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20110412 Year of fee payment: 20 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R082 Ref document number: 59203723 Country of ref document: DE Representative=s name: ROTHKOPF PATENT- UND RECHTSANWAELTE, DE |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R071 Ref document number: 59203723 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: DK Ref legal event code: EUP |
|
REG | Reference to a national code |
Ref country code: SE Ref legal event code: EUG |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION Effective date: 20120618 |