EP0115057B1 - Pneumatic separator in the field of fine material - Google Patents

Pneumatic separator in the field of fine material Download PDF

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Publication number
EP0115057B1
EP0115057B1 EP83113017A EP83113017A EP0115057B1 EP 0115057 B1 EP0115057 B1 EP 0115057B1 EP 83113017 A EP83113017 A EP 83113017A EP 83113017 A EP83113017 A EP 83113017A EP 0115057 B1 EP0115057 B1 EP 0115057B1
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EP
European Patent Office
Prior art keywords
classifying
wheels
air
axis
air classifier
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EP83113017A
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German (de)
French (fr)
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EP0115057A2 (en
EP0115057A3 (en
Inventor
Roland Dr.-Ing. Nied
Herbert Dipl.-Ing. Horlamus
Fritz Kaiser
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Hosokawa Alpine AG
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Alpine AG
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Priority to AT83113017T priority Critical patent/ATE27556T1/en
Publication of EP0115057A2 publication Critical patent/EP0115057A2/en
Publication of EP0115057A3 publication Critical patent/EP0115057A3/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
    • B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
    • B07B7/00—Selective separation of solid materials carried by, or dispersed in, gas currents
    • B07B7/08—Selective separation of solid materials carried by, or dispersed in, gas currents using centrifugal force
    • B07B7/083—Selective separation of solid materials carried by, or dispersed in, gas currents using centrifugal force generated by rotating vanes, discs, drums, or brushes

Definitions

  • the invention relates to an air classifier, consisting of a vertical-axis viewing chamber with a cylindrical upper part and a funnel-shaped lower part and a viewing device arranged in the upper part with a rotating classifying wheel against the direction of centrifugation of the classifying air from the outside inwards, which is arranged in a ring shape and runs parallel to the axis of rotation Buckets has, the visual goods either together with the incoming air flowing through the lower opening of the lower part or directly into the viewing chamber, the coarse material is discharged through the lower opening of the lower part and the fine material together with the visible air from the classifying wheel through an upward from the Sifter emerging outlet connector is withdrawn.
  • DE-PS 1757582 shows a wind separator of the same type with direct feeding of the material to be classified into the viewing chamber.
  • the separation limit that can be achieved with such air classifiers depends essentially on the diameter and the peripheral speed of the classifying wheel. For a given size, the lower the separation limit, the higher the peripheral speed or speed of the classifying wheel is selected. Increasing the wheel speed also means a rapid increase in wear and energy consumption, so that economical work is only possible down to a certain separation limit.
  • the separation limit - if the circumferential speed of the classifying wheel and the radial speed of the classifying air are kept constant on entering the classifying wheel at the classifying wheel circumference - with increasing classifying wheel diameter and thus correspondingly increasing throughput, also larger, i.e. it is shifted to a larger grain area. Therefore, if a large classifying wheel is to cut just as finely as a small one, the peripheral speed must also be increased. However, this means that in addition to increased wear and energy consumption, strength and storage problems also arise.
  • the invention is therefore based on the object of providing an air classifier of the type required, with which high throughputs can be achieved economically, even in the finest range, while avoiding the disadvantages mentioned above.
  • This object is achieved in that at least two identical, individually driven classifying wheels designed for fine classifying are arranged as classifying devices in the classifying chamber of the air classifier.
  • the classifying wheels can be arranged in such a way that their axes of rotation are arranged in a plane perpendicular to the classifier axis or on the surface of an imaginary circular cone, the axis of which is the classifier axis.
  • the arrangement of a centrally located outlet connection for classifying air and fine material common to all classifying wheels is particularly simple.
  • an arrangement of the classifying wheels can also be advantageous, in which the axes of rotation of the classifying wheels run in a plane perpendicular to the classifying axis and parallel to one another and adjacent classifying wheels are arranged offset from one another by at least the classifying wheel height. Any number of classifying wheels can be accommodated in the smallest possible space without neighboring classifying wheels being able to influence each other through the coarse material they each throw off.
  • Classifying wheels are preferably used which, in a manner known per se, have a multiplicity of narrow blades which run radially or obliquely to the classifying wheel circumference, because their spraying grain strength and their insensitivity to fluctuations in the quantity and distribution of the task size make them particularly suitable for solving the task at hand.
  • the exemplary embodiment shows a wind sifter 1 with a vertical axis 2, the viewing chamber of which consists of the cylindrical upper part 3 and the funnel-shaped lower part 4.
  • a cylindrical container 5 connected to the funnel-shaped lower part 4 with an attached outlet funnel 6 is provided for the air supply, the outer diameter of which is larger than the diameter of the lower opening of the funnel-shaped lower part 4, and into which the classifying air line 14 opens tangentially.
  • four classifying wheels 7 are arranged in a star shape, the axes of rotation 8 of which lie in a plane perpendicular to the classifying axis 2 and extend radially to the latter.
  • the classifying wheels 7 are designed as paddle wheels det, which have a plurality of narrow, radially or obliquely to the sight wheel circumference blades 9. Each classifying wheel 7 is seated on a shaft 10 which is mounted in a bearing housing 11 which is laterally attached to the upper part 3. Each classifying wheel 7 is driven by a three-phase motor via pulleys (not shown here), all three-phase motors being controlled together by a frequency converter.
  • the flow pattern of the incoming sight air is determined by the guide vanes 15 which are aligned parallel to the classifier axis 2.
  • An airtight discharge element e.g. a cell lock (not shown) for the separated coarse material falling down is attached to the flange of the discharge funnel 6 during operation of the air classifier 1.
  • a guide surface 16 is arranged concentrically to the classifier axis within the sighting chamber 3, 4, which is designed at the bottom as a cylinder jacket and at the top as an upwardly widening truncated cone jacket, the upper edge of which runs at a distance from the classifying wheels 7.
  • the cylinder diameter corresponds to the diameter of the lower opening of the lower part 4.
  • the guide surface 16 is connected to the upper part 3 via three struts 17. A height adjustability to adapt to different operating conditions is not provided in the embodiment shown here.
  • the dosing screw 18 attached to the side of the upper part 3 is used for supplying visible material.
  • the upper part 3 is designed divided on the flange 19, so that the lower part of the upper part 3 with the guide surface 16, the lower part 4, the cylindrical container 5 and the discharge funnel 6 can be removed as a continuous component for inspection or cleaning purposes.
  • the fine classifier formed by the classifying wheels 7, the separating limit of which is set independently of the quantity and grain distribution of the goods offered, works together with a simple coarse classifier located in the area of the guide vanes 15, the separating limit of which depends very much on the material load in such a way that the separation limit moves into the fine range with increasing load and vice versa.
  • coarse material automatically accumulates in the viewing chamber until the separation limit of the coarse classifier corresponds to that of the classifying wheels under a certain good load, which means that the continuous operating state is reached.

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  • Combined Means For Separation Of Solids (AREA)
  • Cell Separators (AREA)

Abstract

A particle classifier comprising a casing, at least two separating wheels, a guide baffle, and a discharge conduit. The casing has a classification chamber and one or more openings that are provided to conduct air and particulate material into the classification chamber and to discharge course particles therefrom. The separating wheels are mounted in the classification chamber, and each wheel includes a multitude of blades forming openings for conducting fine particles into the interiors of the separating wheels. The guide baffle conducts air and particulate material entrained therewith upward to the separating wheels. The discharge conduit conducts from the separation chamber fine particles passing between the blade of the separating wheels.

Description

Die Erfindung bezieht sich auf einen Windsichter, bestehend aus einer vertikalachsigen Sichtkammer mit zylindrischem Oberteil und trichterförmigem Unterteil und aus einer im Oberteil angeordneten Sichtvorrichtung mit einem entgegen seiner Schleuderrichtung von der Sichtluft von aussen nach innen durchströmten rotierenden Sichtrad, welches kranzförmig angeordnete, parallel zur Rotationsachse verlaufende Schaufeln aufweist, wobei das Sichtgut entweder zusammen mit der durch die untere Öffnung des Unterteils einströmenden Sichtluft oder unmittelbar in die Sichtkammer zugeführt, das Grobgut durch die untere Öffnung des Unterteils abgeführt und das Feingut zusammen mit der Sichtluft aus dem Sichtrad durch einen nach oben aus dem Sichter austretenden Auslassstutzen abgezogen wird.The invention relates to an air classifier, consisting of a vertical-axis viewing chamber with a cylindrical upper part and a funnel-shaped lower part and a viewing device arranged in the upper part with a rotating classifying wheel against the direction of centrifugation of the classifying air from the outside inwards, which is arranged in a ring shape and runs parallel to the axis of rotation Buckets has, the visual goods either together with the incoming air flowing through the lower opening of the lower part or directly into the viewing chamber, the coarse material is discharged through the lower opening of the lower part and the fine material together with the visible air from the classifying wheel through an upward from the Sifter emerging outlet connector is withdrawn.

Ein Windsichter der vorstehend genannten Art, bei dem das Sichtgut in der Sichtluft dispergiert in die Sichtkammer zugeführt wird, ist z.B. in GB-PS 927876 beschrieben. Einen gattungsgleichen Windsichter mit unmittelbarer Zufuhr des Sichtgutes in die Sichtkammer zeigt DE-PS 1757582. Die mit solchen Windsichtern erzielbare Trenngrenze hängt im wesentlichen von dem Durchmesser und der Umfangsgeschwindigkeit des Sichtrades ab. Bei gegebener Baugrösse ergibt sich also eine um so kleinere Trenngrenze, je höher die Umfangsgeschwindigkeit bzw. Drehzahl des Sichtrades gewählt wird. Mit Erhöhung der Sichtraddrehzahl ist aber auch ein rasches Ansteigen von Verschleiss und Energiebedarf verbunden, so dass ein wirtschaftliches Arbeiten nur bis zu einer bestimmten Trenngrenze herab möglich ist. Andererseits wir die Trenngrenze - wenn die Umfangsgeschwindigkeit des Sichtrades und die Radialgeschwindigkeit der Sichtluft bei ihrem Eintritt in das Sichtrad am Sichtradumfang konstant gehalten werden - mit grösser werdendem Sichtraddurchmesser und damit entsprechend steigender Durchsatzmenge ebenfalls grösser, d.h. sie wird in einen grösseren Kornbereich verschoben. Soll daher ein grosses Sichtrad genauso fein trennen wie ein kleines, so muss zusätzlich die Umfangsgeschwindigkeit erhöht werden. Das bedeutet aber, dass neben verstärktem Verschleiss und Energiebedarf dann noch Festigkeits- und Lagerungsprobleme auftreten.A wind sifter of the type mentioned above, in which the material to be sifted is fed into the sifting chamber and is supplied, for example, in GB-PS 927876. DE-PS 1757582 shows a wind separator of the same type with direct feeding of the material to be classified into the viewing chamber. The separation limit that can be achieved with such air classifiers depends essentially on the diameter and the peripheral speed of the classifying wheel. For a given size, the lower the separation limit, the higher the peripheral speed or speed of the classifying wheel is selected. Increasing the wheel speed also means a rapid increase in wear and energy consumption, so that economical work is only possible down to a certain separation limit. On the other hand, the separation limit - if the circumferential speed of the classifying wheel and the radial speed of the classifying air are kept constant on entering the classifying wheel at the classifying wheel circumference - with increasing classifying wheel diameter and thus correspondingly increasing throughput, also larger, i.e. it is shifted to a larger grain area. Therefore, if a large classifying wheel is to cut just as finely as a small one, the peripheral speed must also be increased. However, this means that in addition to increased wear and energy consumption, strength and storage problems also arise.

Der Erfindung liegt daher die Aufgabe zugrunde, einen Windsichter der vorausgesetzten Art zu schaffen, mit dem bei Meidung der oben erwähnten Nachteile auch im Feinstbereich in wirtschaftlicher Weise hohe Durchsätze erzielt werden können. Diese Aufgabe wird dadurch gelöst, dass mindestens zwei gleichartige, für eine Feinsichtung ausgelegte, einzeln angetriebene Sichträder als Sichtvorrichtung in der Sichtkammer des Windsichters angeordnet werden.The invention is therefore based on the object of providing an air classifier of the type required, with which high throughputs can be achieved economically, even in the finest range, while avoiding the disadvantages mentioned above. This object is achieved in that at least two identical, individually driven classifying wheels designed for fine classifying are arranged as classifying devices in the classifying chamber of the air classifier.

Die Anordnung der Sichträder kann derart erfolgen, dass ihre Rotationsachsen in einer Ebene senkrecht zur Sichterachse oder auf dem Mantel eines gedachten Kreiskegels, dessen Achse die Sichterachse ist, angeordnet sind. In diesem Fall und bei radial zur Sichterachse verlaufenden Rotationsachsen der Sichträder im erstgenannten Fall ist die Anordnung eines allen Sichträdern gemeinsamen, zentral gelegenen Auslassstutzens für Sichtluft und Feingut besondes einfach.The classifying wheels can be arranged in such a way that their axes of rotation are arranged in a plane perpendicular to the classifier axis or on the surface of an imaginary circular cone, the axis of which is the classifier axis. In this case and with the axes of rotation of the classifying wheels running radially to the classifying axis, the arrangement of a centrally located outlet connection for classifying air and fine material common to all classifying wheels is particularly simple.

Zur Bewältigung besonders grosser Durchsatzmengen kann auch eine Anordnung der Sichträder von Vorteil sein, bei der die Rotationsachsen der Sichträder in einer Ebene senkrecht zur Sichterachse und parallel zueinander verlaufen und jeweils benachbarte Sichträder um mindestens die Sichtradhöhe gegeneinander versetzt angeordnet sind. Dabei lassen sich beliebig viele Sichträder auf möglichst kleinem Raum unterbringen, ohne dass sich benachbarte Sichträder durch das von ihnen jeweilig abgeschleuderte Grobgut gegenseitig beeinflussen können.To cope with particularly large throughputs, an arrangement of the classifying wheels can also be advantageous, in which the axes of rotation of the classifying wheels run in a plane perpendicular to the classifying axis and parallel to one another and adjacent classifying wheels are arranged offset from one another by at least the classifying wheel height. Any number of classifying wheels can be accommodated in the smallest possible space without neighboring classifying wheels being able to influence each other through the coarse material they each throw off.

Bevorzugt werden Sichträder verwendet, die in an sich bekannter Weise eine Vielzahl schmaler, radial oder schräg zum Sichtradumfang verlaufender Schaufeln aufweisen, denn durch ihre Spritzkornfestigkeit und ihre Unempfindlichkeit gegen Schwankungen der Aufgabemenge und -kornverteilung sind sie besonders zur Lösung der gestellten Aufgabe geeignet.Classifying wheels are preferably used which, in a manner known per se, have a multiplicity of narrow blades which run radially or obliquely to the classifying wheel circumference, because their spraying grain strength and their insensitivity to fluctuations in the quantity and distribution of the task size make them particularly suitable for solving the task at hand.

Der Betrieb mehrerer gleichartiger Sichträder in einer gemeinsamen Sichtkammer setzt natürlich voraus, dass alle Sichträder auf eine gleiche, durch die jeweils geforderte Trenngrenze bestimmte Drehzahl eingestellt werden können und die eingestellte Drehzahl konstant gehalten wird. Zweckmässig ist es deshalb, hierfür eine für alle Sichträder gemeinsame Steuereinrichtung vorzusehen, z.B. einen Frequenzumformer, über den die Antriebsmotoren aller Sichträder gemeinsam betrieben werden.The operation of several identical sight wheels in a common view chamber naturally presupposes that all sight wheels can be set to the same speed, determined by the separation limit required in each case, and that the set speed is kept constant. It is therefore advisable to provide a control device common to all classifying wheels, e.g. a frequency converter via which the drive motors of all classifying wheels are operated together.

Ein Ausführungsbeispiel der Erfindung ist in der Zeichnung dargestellt.

  • Fig. 1 zeigt einen Längsschnitt durch einen Windsichter mit vier Sichträdern,
  • Fig. 2 zeigt einen Querschnitt entlang der Linie I-I durch den Windsichter nach Fig. 1.
An embodiment of the invention is shown in the drawing.
  • 1 shows a longitudinal section through an air classifier with four classifying wheels,
  • FIG. 2 shows a cross section along line II through the air classifier according to FIG. 1.

Das Ausführungsbeispiel zeigt einen Windsichter 1 mit lotrechter Achse 2, dessen Sichtkammer aus dem zylindrischen Oberteil 3 und dem trichterförmigen Unterteil 4 besteht. Zur Verbesserung des Wirkungsgrades der Sichtung durch Nachsichtung des nach unten aus dem trichterförmigen Unterteil 4 der Sichtkammer austretenden Grobgutes ist für die Sichtluftzufuhr ein an das trichterförmige Unterteil 4 anschliessender zylindrischer Behälter 5 mit angesetztem Auslauftrichter 6 vorgesehen, dessen Aussendruchmesser grösser ist als der Durchmesser der unteren Öffnung des trichterförmigen Unterteils 4, und in den die Sichtluftleitung 14tangential mündet. Im Oberteil 3 sind sternförmig vier Sichträder 7 angeordnet, deren Rotationsachsen 8 in einer Ebene senkrecht zur Sichterachse 2 liegen und radial zu dieser verlaufen. Die Sichträder 7 sind als Schaufelräder ausgebildet, die eine Vielzahl schmaler, radial oder schräg zum Sichtradumfang verlaufender Schaufeln 9 aufweisen. Jedes Sichtrad 7 sitzt auf einer Welle 10, die in einem seitlich am Oberteil 3 befestigten Lagergehäuse 11 gelagert ist. Jedes Sichtrad 7 wird über hier nicht dargestellte Riemenscheiben von einem Drehstrommotor angetrieben, wobei alle Drehstrommotoren gemeinsam von einem Frequenzumformer gesteuert werden.The exemplary embodiment shows a wind sifter 1 with a vertical axis 2, the viewing chamber of which consists of the cylindrical upper part 3 and the funnel-shaped lower part 4. In order to improve the efficiency of the sighting by inspecting the coarse material emerging from the funnel-shaped lower part 4 of the viewing chamber, a cylindrical container 5 connected to the funnel-shaped lower part 4 with an attached outlet funnel 6 is provided for the air supply, the outer diameter of which is larger than the diameter of the lower opening of the funnel-shaped lower part 4, and into which the classifying air line 14 opens tangentially. In the upper part 3, four classifying wheels 7 are arranged in a star shape, the axes of rotation 8 of which lie in a plane perpendicular to the classifying axis 2 and extend radially to the latter. The classifying wheels 7 are designed as paddle wheels det, which have a plurality of narrow, radially or obliquely to the sight wheel circumference blades 9. Each classifying wheel 7 is seated on a shaft 10 which is mounted in a bearing housing 11 which is laterally attached to the upper part 3. Each classifying wheel 7 is driven by a three-phase motor via pulleys (not shown here), all three-phase motors being controlled together by a frequency converter.

Die Austrittsöffnungen an den Sichträdern 7 für die feingutbeladene Sichtluft münden über austauschbare Rohrstücke 12 in einen zentralen Auslassstutzen 13, an dem über eine nicht gezeichnete Rohrleitung ein Abscheider für das Feingut angeschlossen wird.The outlet openings on the classifying wheels 7 for the fine air laden visible air open via exchangeable pipe sections 12 into a central outlet connection 13, to which a separator for the fine material is connected via a pipe (not shown).

Den Strömungsverlauf der eintretenden Sichtluft bestimmen die parallel zur Sichterachse 2 ausgerichteten Leitschaufeln 15. Ein luftdichtes Austragsorgan, z.B. eine Zellenschleuse, (nicht dargestellt) für das ausgeschiedene, nach unten fallende Grobgut ist beim Betrieb des Windsichters 1 am Flansch des Auslauftrichters 6 befestigt.The flow pattern of the incoming sight air is determined by the guide vanes 15 which are aligned parallel to the classifier axis 2. An airtight discharge element, e.g. a cell lock (not shown) for the separated coarse material falling down is attached to the flange of the discharge funnel 6 during operation of the air classifier 1.

Zur weiteren Verbesserung des Wirkungsgrades der Sichtung ist konzentrisch zur Sichterachse innerhalb der Sichtkammer 3,4 eine Leitfläche 16 angeordnet, die unten als Zylindermantel und oben als sich nach oben erweiternder Kegelstumpfmantel, dessen Oberkante mit Abstand zu den Sichträdern 7 verläuft, ausgebildet ist. Der Zylinderdurchmesser entspricht dabei dem Durchmesser der unteren Öffnung von Unterteil 4. Über drei Streben 17 ist die Leitfläche 16 mit dem Oberteil 3 verbunden. Eine Höhenverstellbarkeit zur Anpassung an unterschiedliche Betriebsverhältnisse ist bei der hier gezeigten Ausführungsform nicht vorgesehen.To further improve the efficiency of the sighting, a guide surface 16 is arranged concentrically to the classifier axis within the sighting chamber 3, 4, which is designed at the bottom as a cylinder jacket and at the top as an upwardly widening truncated cone jacket, the upper edge of which runs at a distance from the classifying wheels 7. The cylinder diameter corresponds to the diameter of the lower opening of the lower part 4. The guide surface 16 is connected to the upper part 3 via three struts 17. A height adjustability to adapt to different operating conditions is not provided in the embodiment shown here.

Die seitlich am Oberteil 3 befestigte Dosierschnecke 18 dient zur Sichtgutzufuhr.The dosing screw 18 attached to the side of the upper part 3 is used for supplying visible material.

Das Oberteil 3 ist am Flansch 19 geteilt ausgeführt, so dass der untere Teil von Oberteil 3 mit Leitfläche 16, Unterteil 4, zylindrischem Behälter 5 und Auslauftrichter 6 als zusammenhängendes Bauteil für Inspektions- oder Reinigungszwecke abgenommen werden kann.The upper part 3 is designed divided on the flange 19, so that the lower part of the upper part 3 with the guide surface 16, the lower part 4, the cylindrical container 5 and the discharge funnel 6 can be removed as a continuous component for inspection or cleaning purposes.

Die Wirkungsweise des Windsichters ist folgende:

  • Das durch die Dosierschnecke 18 eingetragene Sichtgut fällt im Umfangsbereich der Sichtkammer 3,4 nach unten, wo es von der durch die Leitschaufeln 15 einströmenden Sichtluft kräftig durchgespült wird, was eine vollständige Auflösung von Kornagglomeraten bewirkt. Die gröbsten Gutteilchen fallen nach unten in den Auslauftrichter 6, das übrige Gut wird von der Sichtluft innerhalb der Leitfläche 16 nach oben mitgerissen und den Sichträdern 7 zugeführt. Entsprechend der durch die eingestellte Drehzahl der Sichträder 7 bestimmten Trenngrenze wird es hier nun in Feingut und Grobgut aufgetrennt. Das Feingut tritt mit der Sichtluft durch die Schaufeln 9 hindurch und wird durch die Rohrstücke 12 und den Auslassstutzen 13 abgeführt. Das durch die Schleuderwirkung der Schaufeln 9 abgewiesene 'Grobgut fällt im Umfangsbereich der Sichtkammern 3,4 ausserhalb der Leitfläche 16 wieder nach unten, wo es im Bereich der Leitschaufeln 15 von der Sichtluft erneut intensiv durchspült wird, so dass noch an den groben Teilchen haftende Feingutteilchen abgelöst werden. Ein Teil des Grobguts fällt nun in den Auslauftrichter 6 und wird von der darunter angeordneten Zellenschleuse ausgetragen, der Rest wird zusammen mit dem von der Dosierschnecke 18 eingetragenen Sichtgut wieder zu den Sichträdern 7 geführt.
The air classifier works as follows:
  • The visible material entered by the dosing screw 18 falls downward in the peripheral region of the visible chamber 3, 4, where it is flushed through by the visible air flowing in through the guide vanes 15, which causes a complete dissolution of grain agglomerates. The coarsest particles of good fall downward into the discharge funnel 6, the remaining good is carried upward by the classifying air within the guide surface 16 and fed to the classifying wheels 7. According to the separation limit determined by the set speed of the classifying wheels 7, it is now separated into fine and coarse material. The fine material passes through the blades 9 with the classifying air and is discharged through the pipe sections 12 and the outlet connection 13. The coarse material rejected by the centrifugal action of the blades 9 falls down again outside the guide surface 16 in the peripheral region of the viewing chambers 3, 4, where it is again intensively flushed by the visible air in the region of the guide blades 15, so that fine particles still adhering to the coarse particles be replaced. A part of the coarse material now falls into the discharge funnel 6 and is discharged from the cell lock arranged underneath, the rest is guided back to the classifying wheels 7 together with the visible material entered by the dosing screw 18.

Praktisch arbeitet hier also der von den Sichträdern 7 gebildete Feinsichter, dessen jeweils eingestellte Trenngrenze unabhängig ist von Menge und Kornverteilung des angebotenen Gutes, mit einem einfachen, im Bereich der Leitschaufeln 15 gelegenen Grobsichter zusammen, dessen Trenngrenze sehr stark von der Gutbelastung in der Weise abhängt, dass sich die Trenngrenze bei zunehmender Belastung in den Feinbereich bewegt und umgekehrt. Dies bewirkt, dass sich in der Anlaufphase in der Sichtkammer automatisch Grobgut solange anreichert bis bei einer bestimmten Gutbelastung die Trenngrenze des Grobsichters der der Sichträder entspricht, womit der Dauerbetriebszustand erreicht ist. Diese Eigenschaften des beschriebenen Windsichters tragen mit dazu bei, dass hohe Gutdurchsätze bei scharfer Trennung von Feingut und Grobgut bis in den Feinstbereich, d.h. Trenngrenzen kleiner 8 jim, erzielt werden können.In practice, the fine classifier formed by the classifying wheels 7, the separating limit of which is set independently of the quantity and grain distribution of the goods offered, works together with a simple coarse classifier located in the area of the guide vanes 15, the separating limit of which depends very much on the material load in such a way that the separation limit moves into the fine range with increasing load and vice versa. This means that during the start-up phase, coarse material automatically accumulates in the viewing chamber until the separation limit of the coarse classifier corresponds to that of the classifying wheels under a certain good load, which means that the continuous operating state is reached. These properties of the described air classifier contribute to the fact that high material throughputs with a sharp separation of fine material and coarse material down to the very finest range, i.e. Separation limits less than 8 jim can be achieved.

Claims (8)

1. Air classifier (1) comprising a classification chamber defining a vertical axis, having a cylindrical top part and a tapering bottom part, a particle classifying means mounted in the top part of the classification chamber, having a classifying wheel mounted for rotation about its axis and including a multitude of blades (9) positioned about the circumference of the wheel, extending parallel to its axis (8), this wheel being flown trough against its centrifugal action from its circumference to its interior by the classifying air, whereat the material to be classified being supplied to the classification chamber either directly or together with the classifying air entering through the lower opening of the bottom part, the coarse material being discharged through that lower opening of the bottom part and the fines being discharged together with the classifying air out from the classifying wheel and through the outlet conduit (13), characterized in that the classifying means consists of at least two classifying wheels (7), of the same shape and size qualified for fine classification, that wheels being placed in parallel with respect to their operational mode and driven individually.
2. Air classifier according to claim 1, characterized in that the rotational axes (8) of the classifying wheels (7) lie in a plane at right angles to the axis (2) of the classification chamber.
3. Air classifier according to claim 2, characterized in that the rotational axes (8) of the classifying wheels (7) extend radially relative to the axis (2) of the classification chamber.
4. Air classifier according to claim 1, characterized in that the rotational axes (8) of the classifying wheels (7) lie on the surface of an imaginary circular cone, the axis of the circular cone being the axis (2) of the classification chamber.
5. Air classifier according to claim 3 or 4, comprising a common outlet conduit (13) for the classifying air and the fines entrained therewith, centrally located relative to the classifying wheels (7).
6. Air classifier according to claim 2, characterized in that the rotational axes (8) of the classifying wheels (7) are parallel to each other, and adjacent classifying wheels are staggered relative to one another by at least the height of a classifying wheel.
7. Air classifier according to any one of claims 1 through 6, characterized in that the classifying wheels (7) have a multitude of narrow blades (9) extending radially or diagonally relative to the circumference of any one of the classifying wheels.
8. Air classifier according to any one of claims 1 through 7 comprising control means to adjust and maintain the rotational speed of the classifying wheels to be the same for all classifying wheels, as determined by the desired particle classification size.
EP83113017A 1983-01-29 1983-12-23 Pneumatic separator in the field of fine material Expired EP0115057B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT83113017T ATE27556T1 (en) 1983-01-29 1983-12-23 WINDSIFTER FOR THE FINEST AREA.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3303078A DE3303078C1 (en) 1983-01-29 1983-01-29 Air classifier for the fine area
DE3303078 1983-01-29

Publications (3)

Publication Number Publication Date
EP0115057A2 EP0115057A2 (en) 1984-08-08
EP0115057A3 EP0115057A3 (en) 1985-10-30
EP0115057B1 true EP0115057B1 (en) 1987-06-03

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ID=6189605

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83113017A Expired EP0115057B1 (en) 1983-01-29 1983-12-23 Pneumatic separator in the field of fine material

Country Status (5)

Country Link
US (1) US4528091A (en)
EP (1) EP0115057B1 (en)
JP (1) JPS59142877A (en)
AT (1) ATE27556T1 (en)
DE (1) DE3303078C1 (en)

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DE3521491A1 (en) * 1985-06-14 1986-12-18 Krupp Polysius Ag, 4720 Beckum METHOD AND SYSTEM FOR THE FINE SIZING OF GOODS
DE3521638C2 (en) * 1985-06-15 1994-03-31 Kloeckner Humboldt Deutz Ag Scattering classifier for classifying fine-grained material
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DE3621221A1 (en) * 1986-06-25 1988-01-14 Pfeiffer Fa Christian METHOD FOR WINDPROOFING AND WINIFIFIER
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US4793917A (en) * 1987-04-15 1988-12-27 Institut Khimii Tverdogo Tela I Pererabotki Mineralnogo Syrya Sibirskogo Otdelenia Akademii Nauk Ussr Centrifugal classifier for superfine powders
DE3838871C2 (en) * 1988-01-22 1994-10-27 Nied Roland Air classifier
DE3814458A1 (en) * 1988-04-28 1989-11-09 Krupp Polysius Ag Air separator
ATE109690T1 (en) * 1988-11-17 1994-08-15 Nied Roland WINDSIFTER.
EP0379711B1 (en) * 1988-12-27 1992-03-18 Roland Dr.-Ing. Nied Method of sifting fine materials, and apparatus for carrying out the method
DE4140656C1 (en) * 1991-12-10 1992-09-10 Alpine Ag, 8900 Augsburg, De
DE4326605A1 (en) * 1993-08-07 1995-02-09 Hosokawa Alpine Ag Method and device for separating a fine-grained solid into two grain fractions
NO300257B1 (en) * 1995-04-07 1997-05-05 Sinvent As Apparatus for sorting particulate material
DE29506015U1 (en) * 1995-04-07 1995-06-14 Hosokawa Alpine Ag, 86199 Augsburg Classification wheel for centrifugal wind classifiers
DE10151325B4 (en) * 2001-10-17 2006-07-27 Wester Tonbergbau Kg air classifier
DE60218156T2 (en) * 2002-09-12 2007-11-15 Ehinger Impianti S.R.L. particle sorter
DE102005001542B4 (en) 2005-01-13 2009-06-10 Lehigh Technologies, LLC, Naples Multi-wheel air classifier, separate classifying wheel unit and separate classifier unit
DE102006048850A1 (en) * 2006-10-16 2008-04-17 Evonik Degussa Gmbh Amorphous submicron particles
DE102006048865A1 (en) * 2006-10-16 2008-04-17 Roland Dr. Nied Process for the production of finest particles and jet mill therefor and air classifier and operating method thereof
DE102006048864A1 (en) * 2006-10-16 2008-04-17 Roland Dr. Nied Process for the production of finest particles and jet mill therefor and air classifier and operating method thereof
DE102013002237B3 (en) 2013-02-11 2014-05-22 Microtec Gmbh Classifier
DE202015009079U1 (en) 2015-08-27 2016-10-07 Josef Fischer Kryogenmahlvorrichtung
EP3135380B1 (en) 2015-08-27 2017-10-11 Josef Fischer Cryogenic grinding device and method

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Also Published As

Publication number Publication date
EP0115057A2 (en) 1984-08-08
EP0115057A3 (en) 1985-10-30
JPS59142877A (en) 1984-08-16
US4528091A (en) 1985-07-09
JPS6349548B2 (en) 1988-10-05
ATE27556T1 (en) 1987-06-15
DE3303078C1 (en) 1984-05-30

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