EP0642833A1 - Method of separating solids by means of flotation - Google Patents

Method of separating solids by means of flotation Download PDF

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Publication number
EP0642833A1
EP0642833A1 EP94110775A EP94110775A EP0642833A1 EP 0642833 A1 EP0642833 A1 EP 0642833A1 EP 94110775 A EP94110775 A EP 94110775A EP 94110775 A EP94110775 A EP 94110775A EP 0642833 A1 EP0642833 A1 EP 0642833A1
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EP
European Patent Office
Prior art keywords
flotation
suspension
air
flotation device
container
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.)
Granted
Application number
EP94110775A
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German (de)
French (fr)
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EP0642833B1 (en
Inventor
Herbert Britz
Alexander Peschl
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Voith Paper Fiber and Environmental Solutions GmbH and Co KG
Original Assignee
Escher Wyss GmbH
Voith Sulzer Stoffaufbereitung GmbH
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Publication of EP0642833A1 publication Critical patent/EP0642833A1/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
    • B03D1/00—Flotation
    • B03D1/14—Flotation machines
    • B03D1/1431—Dissolved air flotation machines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
    • B03D1/00—Flotation
    • B03D1/14—Flotation machines
    • B03D1/1418—Flotation machines using centrifugal forces
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
    • B03D1/00—Flotation
    • B03D1/14—Flotation machines
    • B03D1/1493—Flotation machines with means for establishing a specified flow pattern
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
    • B04C3/00—Apparatus in which the axial direction of the vortex flow following a screw-thread type line remains unchanged ; Devices in which one of the two discharge ducts returns centrally through the vortex chamber, a reverse-flow vortex being prevented by bulkheads in the central discharge duct
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
    • B04C3/00—Apparatus in which the axial direction of the vortex flow following a screw-thread type line remains unchanged ; Devices in which one of the two discharge ducts returns centrally through the vortex chamber, a reverse-flow vortex being prevented by bulkheads in the central discharge duct
    • B04C3/06—Construction of inlets or outlets to the vortex chamber
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
    • B03D1/00—Flotation
    • B03D1/14—Flotation machines
    • B03D1/1443—Feed or discharge mechanisms for flotation tanks
    • B03D1/1475—Flotation tanks having means for discharging the pulp, e.g. as a bleed stream
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
    • B03D1/00—Flotation
    • B03D1/14—Flotation machines
    • B03D1/24—Pneumatic
    • B03D1/245—Injecting gas through perforated or porous area

Definitions

  • the invention relates to a method for separating solids by flotation from a suspension according to the preamble of claim 1 and to an apparatus for performing the method.
  • Methods of the type mentioned are used to separate at least a portion of the solid particles suspended therein from a suspension.
  • the objective here can either be the removal of undesirable components of the suspension or the clarification of contaminated wastewater.
  • a foam or floating sludge containing the substances to be separated out is formed during flotation.
  • a typical application for the use of such a method is the preparation of a suspension made of printed waste paper, in which the ink particles have already been detached from the fibers, so that they can be selectively floated out (deinking flotation).
  • a flotation device which can already use the acceleration field caused by the rotational movement of the suspension.
  • the flotation foam is removed from the flotation device through an overhead tube, while the cleaned suspension flows off at the bottom. This means dividing the inflowing flow into axially opposing partial flows.
  • Such current routing is also common with hydrocyclones. It leads to a disproportionate increase in the centrifugal acceleration towards the center of the container in the form of a so-called potential vortex.
  • the invention had for its object to provide a method which, using a centrifugal field, an even better separation of the suspended Solid particles or the use of relatively compact flotation devices, or both.
  • the process according to the invention does not result in a deflection of the foam's transport direction in the flotation space. This specifically prevents the formation of a potential vortex.
  • Fig. 1 shows with dashed lines a clarification room 1, into which the suspension 2 is fed.
  • the suspension then performs a rotational movement, indicated by the arrow 3 about the axis 5.
  • a further movement, represented by the arrows 4, is superimposed on the rotational movement 3, which movement is essentially parallel run to the axis of rotation 5.
  • the flotated substances rise together with air bubbles against the effect of a gravitational field. Since the gravitational field arises as a centrifugal field as a result of the rotational movement 3, the floated parts move radially inwards.
  • the flotation foam thus accumulates in the radially inner region of the clarification chamber 1, a more or less sharp boundary 8 being formed between the flotation foam and the air escaping therefrom.
  • the method is carried out in such a way that the floated portions are transported essentially parallel to the axis of rotation 5 and in the same direction as that of the superimposed movement 4 (arrows 6).
  • the floated parts collected in this way are discharged from the clarification chamber 1, indicated here by the arrows 7, usually together with free air which has escaped from the suspension foam, arrow 10.
  • the part of the suspension from which the floated parts are removed emerges from the clarification room, arrow 11.
  • Air required for flotation is either added to the substance at the inlet, arrow 9, and / or through openings in the clarification room 1 during the actual flotation, arrows 9 '.
  • FIG. 2 shows a simplified section through a flotation container 12 with which the method can be carried out.
  • An inlet 13 and an outlet 14 (shown offset here) and the sludge pipe 15 can be seen.
  • a turbulence generating device 17 can be present in the inlet 13, here designed as a step diffuser, into which air is pumped in by an air line 16 in the vicinity of the step jump is sucked in.
  • a plurality of step diffusers are provided one above the other in the vertical direction and only one in the radial direction. Turbulence generation with the aid of step diffusers, even when entering flotation apparatus, is known per se, but offers particular advantages in connection with the other features of the method according to the invention. This is related to the task of achieving the best possible flotation effect in the smallest possible space. Controlled micro-vortices and a force field increased by rotation are therefore of great benefit.
  • Fig. 3 shows the apparatus of Fig. 2 as a view from above and in particular does tangential inlet 13 and outlet 14 visible.
  • FIG. 4 does not show a cylindrical but a slightly conical flotation container 12 '.
  • a measure allows the rotational movement to be accelerated without supplying any further energy, as a result of which friction losses could be compensated for.
  • the total volume of the suspension will be lower due to air flowing out into the center of the flotation container.
  • a further variation possibility not necessarily tied to the conical shape of the flotation container, is the ventilation of the suspension during the flotation through an air box 18 to which an air connection 19 is attached. In such a case, of course, suitable steps must be taken to allow the air to enter the suspension in the region of the wall 20, e.g. through porous or perforated designs.
  • FIG. 5 shows part of a further flotation device suitable for carrying out the method, namely the area of the sludge pipe 15 '.
  • This is designed as a concentric double tube, so that two different fractions of material accumulated in the central part of the flotation container can be drawn off. It can be particularly advantageous to separate a foam fraction 21 that is as concentrated as possible separately from a foam / suspension mixed fraction 22. A further separation step could then be obtained from the latter, e.g. unintentionally removed paper fibers.
  • Such a module unit can essentially consist of flotation tanks, as already described.

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Biotechnology (AREA)
  • Physical Water Treatments (AREA)

Abstract

The flotation method for separating off solids from a suspension takes place utilizing centrifugal forces. In the clarifying compartment (1), the suspension is set in rotation so that flotated portions are particularly effectively conducted towards the centre of the clarifying compartment (1) and concentrated. Viewed axially, flotated portions and the remainder of the suspension are conducted in the same direction and led off from the clarifying compartment. This flow guidance is advantageous to achieve a good separation effect particularly owing to the vortex avoided as a result. In addition, a plurality of apparatuses for carrying out the method are described. <IMAGE>

Description

Die Erfindung bezieht sich auf ein Verfahren zur Abtrennung von Feststoffen durch Flotation aus einer Suspension gemäß Oberbegriff des Anspruchs 1 sowie auf eine Vorrichtung zur Durchführung des Verfahrens.The invention relates to a method for separating solids by flotation from a suspension according to the preamble of claim 1 and to an apparatus for performing the method.

Verfahren der genannten Art werden verwendet, um aus einer Suspension zumindest einen Teil der darin suspendierten Feststoffteilchen auszuscheiden. Die Zielsetzung hierzu kann entweder die Entfernung von unerwünschten Bestandteilen der Suspension oder die Klärung von verschmutztem Abwasser sein. Bekanntlich wird bei einer Flotation ein die auszuscheidenden Stoffe enthaltender Schaum oder Schwimm-Schlamm gebildet.Methods of the type mentioned are used to separate at least a portion of the solid particles suspended therein from a suspension. The objective here can either be the removal of undesirable components of the suspension or the clarification of contaminated wastewater. As is known, a foam or floating sludge containing the substances to be separated out is formed during flotation.

Ein typischer Anwendungsfall für die Verwendung eines derartigen Verfahrens ist die Aufbereitung von einer aus bedrucktem Altpapier hergestellten Suspension, in der die Druckfarben-Partikel bereits von den Fasern abgelöst sind, so daß sie sich selektiv ausflotieren lassen (Deinking-Flotation).A typical application for the use of such a method is the preparation of a suspension made of printed waste paper, in which the ink particles have already been detached from the fibers, so that they can be selectively floated out (deinking flotation).

Aus der DE-OS 33 20 600 ist eine Flotationsvorrichtung bekannt, die bereits das durch Rotationsbewegung der Suspension verursachte Beschleunigungsfeld benutzen kann. Der Flotationsschaum wird dort durch ein obenliegendes Rohr aus der Flotationsvorrichtung entfernt, während die gereinigte Suspension unten abfließt. Das bedeutet eine Aufteilung der einfließenden Strömung in, axial gesehen, entgegengesetzt gerichtete Teilströme. Eine solche Stromführung ist auch bei Hydrozyklonen üblich. Sie führt zu einem überproportionalen Ansteigen der Zentrifugalbeschleunigung zur Behältermitte hin in Form eines sog. Potentialwirbels.From DE-OS 33 20 600 a flotation device is known which can already use the acceleration field caused by the rotational movement of the suspension. The flotation foam is removed from the flotation device through an overhead tube, while the cleaned suspension flows off at the bottom. This means dividing the inflowing flow into axially opposing partial flows. Such current routing is also common with hydrocyclones. It leads to a disproportionate increase in the centrifugal acceleration towards the center of the container in the form of a so-called potential vortex.

Der Erfindung lag die Aufgabe zugrunde, ein Verfahren zu schaffen, welches unter Ausnutzung von einem Zentrifugalfeld eine noch bessere Abtrennung der suspendierten Feststoffleilchen oder die Verwendung relativ kompakter Flotationsvorrichtungen oder beides gestattet.The invention had for its object to provide a method which, using a centrifugal field, an even better separation of the suspended Solid particles or the use of relatively compact flotation devices, or both.

Diese Aufgaben werden durch die im Kennzeichen des Anspruchs 1 genannten Merkmale gelöst.These tasks are solved by the features mentioned in the characterizing part of claim 1.

In den Unteransprüchen werden besonders vorteilhafte Ausführungsformen des Verfahrens sowie Vorrichtungen zur Durchführung des Verfahrens beschrieben.Particularly advantageous embodiments of the method and devices for carrying out the method are described in the subclaims.

Durch das erfindungsgemäße Verfahren erfolgt im Flotationsraum - axial betrachtet - keine Umlenkung der Transportrichtung des Schaumes. Dadurch wird gezielt die Ausbildung eines Potentialwirbels vermieden.From the axial point of view, the process according to the invention does not result in a deflection of the foam's transport direction in the flotation space. This specifically prevents the formation of a potential vortex.

In dem Bereich, wo sich der flotierte Stoff sammelt, wird so eine ungestörte Axialströmung des Schaumes in Richtung zum Schaumaustrag ermöglicht. Es können kaum noch störende Wirbel im Bereich der Trennung von Schaum und Suspension entstehen. Dieser Bereich ist besonders kritisch für die Reinheit des Flotations-Gutstoffes.In the area where the floated material collects, an undisturbed axial flow of the foam towards the foam discharge is made possible. There can hardly be any disturbing eddies in the area of the separation of foam and suspension. This area is particularly critical for the purity of the flotation material.

Die Erfindung wird erläutert anhand von Zeichnungen. Dabei zeigen:

Fig. 1
schematisch die wichtigsten Verfahrensschritte;
Fig. 2
schematisch eine geschnitten dargestellte mögliche Vorrichtung zur Durchführung des Verfahrens;
Fig. 3
eine Aufsicht des in Fig. 2 gezeigten Gegenstandes;
Fig. 4
eine weitere Vorrichtung zur Durchführung des Verfahrens;
Fig. 5
einen variierten Schaumaustrag.
The invention is explained with reference to drawings. Show:
Fig. 1
schematically the most important process steps;
Fig. 2
schematically shows a possible device shown in section for performing the method;
Fig. 3
a plan view of the object shown in Fig. 2;
Fig. 4
another device for performing the method;
Fig. 5
a varied foam discharge.

Fig. 1 zeigt mit gestrichelten Linien einen Klärraum 1, in den die Suspension 2 zugeführt wird. Die Suspension führt anschließend eine Rotationsbewegung, angedeutet durch den Pfeil 3 um die Achse 5 aus. Der Rotationsbewegung 3 wird eine weitere Bewegung, dargestellt durch die Pfeile 4, überlagert, welche im wesentlichen parallel zur Rotationsachse 5 verlaufen. Infolge des bekannten Mechanismus bei der Flotation steigen die flotierten Stoffe zusammen mit Luftblasen entgegen der Wirkung eines Schwerefeldes auf. Da das Schwerefeld als Zentrifugalfeld infolge der Rotationsbewegung 3 entsteht, bewegen sich die flotierten Anteile radial nach innen. Im radial inneren Bereich des Klärraumes 1 findet also die Ansammlung des Flotationsschaumes statt, wobei sich eine mehr oder weniger scharfe Grenze 8 zwischen dem Flotationsschaum und der daraus ausgetretenen Luft bildet. Erfindungsgemäß wird das Verfahren so durchgeführt, daß ein Transport der flotierten Anteile im wesentlichen parallel zur Rotationsachse 5 und in derselben Richtung wie die der überlagerten Bewegung 4 erfolgt (Pfeile 6). Die so gesammelten flotierten Anteile werden aus dem Klärraum 1 abgeführt, hier durch die Pfeile 7 angedeutet, in der Regel zusammen mit freier, aus dem Suspensionsschaum ausgetretenen Luft, Pfeil 10. Der Teil der Suspension, aus dem die flotierten Anteile entfernt sind, tritt aus dem Klärraum aus, Pfeil 11. Zur Flotation benötigte Luft wird entweder dem Stoff beim Einlauf zugegeben, Pfeil 9, und/oder durch Öffnungen im Klärraum 1 während der eigentlichen Flotation, Pfeile 9'.Fig. 1 shows with dashed lines a clarification room 1, into which the suspension 2 is fed. The suspension then performs a rotational movement, indicated by the arrow 3 about the axis 5. A further movement, represented by the arrows 4, is superimposed on the rotational movement 3, which movement is essentially parallel run to the axis of rotation 5. As a result of the known mechanism in flotation, the flotated substances rise together with air bubbles against the effect of a gravitational field. Since the gravitational field arises as a centrifugal field as a result of the rotational movement 3, the floated parts move radially inwards. The flotation foam thus accumulates in the radially inner region of the clarification chamber 1, a more or less sharp boundary 8 being formed between the flotation foam and the air escaping therefrom. According to the invention, the method is carried out in such a way that the floated portions are transported essentially parallel to the axis of rotation 5 and in the same direction as that of the superimposed movement 4 (arrows 6). The floated parts collected in this way are discharged from the clarification chamber 1, indicated here by the arrows 7, usually together with free air which has escaped from the suspension foam, arrow 10. The part of the suspension from which the floated parts are removed emerges from the clarification room, arrow 11. Air required for flotation is either added to the substance at the inlet, arrow 9, and / or through openings in the clarification room 1 during the actual flotation, arrows 9 '.

Fig. 2 zeigt vereinfacht den Schnitt durch einen Flotationsbehälter 12, mit dem das Verfahren ausgeführt werden kann. Man erkennt einen Einlauf 13 und einen Auslauf 14 (hier versetzt gezeichnet) sowie das Schlammrohr 15. Mit Vorteil kann im Einlauf 13 eine Turbulenzerzeugungsvorrichtung 17 vorhanden sein, hier als Stufendiffusor ausgebildet, in den in der Nähe des Stufensprunges Luft durch eine Luftleitung 16 zugepumpt oder angesaugt wird. Um einen möglichst breiten flachen Strahl zu erzeugen, sind in senkrechter Richtung mehrere Stufendiffusoren übereinander, in radialer Richtung nur einer vorgesehen. Die Turbulenzerzeugung mit Hilfe von Stufendiffusoren, auch beim Einlauf in Flotationsapparate, ist zwar an sich bekannt, bietet aber im Zusammenhang mit den übrigen Merkmalen des erfindungsgemäßen Verfahrens besondere Vorteile. Das hängt mit der Aufgabe zusammen, auf möglichst kleinem Raum eine möglichst gute Flotationswirkung zu erzielen. Daher sind kontrollierte Mikro-Wirbel und ein durch Rotationsbewegung erhöhtes Kraftfeld von großem Nutzen.FIG. 2 shows a simplified section through a flotation container 12 with which the method can be carried out. An inlet 13 and an outlet 14 (shown offset here) and the sludge pipe 15 can be seen. Advantageously, a turbulence generating device 17 can be present in the inlet 13, here designed as a step diffuser, into which air is pumped in by an air line 16 in the vicinity of the step jump is sucked in. In order to produce a flat jet as wide as possible, a plurality of step diffusers are provided one above the other in the vertical direction and only one in the radial direction. Turbulence generation with the aid of step diffusers, even when entering flotation apparatus, is known per se, but offers particular advantages in connection with the other features of the method according to the invention. This is related to the task of achieving the best possible flotation effect in the smallest possible space. Controlled micro-vortices and a force field increased by rotation are therefore of great benefit.

Fig. 3 zeigt den Apparat der Fig. 2 als Ansicht von oben und macht insbesondere den tangentialen Einlauf 13 und Auslauf 14 sichtbar.Fig. 3 shows the apparatus of Fig. 2 as a view from above and in particular does tangential inlet 13 and outlet 14 visible.

Fig. 4 zeigt im Gegensatz zu Fig. 2 keinen zylindrischen sondern einen leicht konischen Flotationsbehälter 12'. Bekanntlich kann durch eine solche Maßnahme die Rotationsbewegung beschleunigt werden, ohne weitere Energie zuzuführen, wodurch etwa Reibungsverluste ausgeglichen werden könnten. Ferner ist davon auszugehen, daß durch ausgeströmte Luft in die Mitte des Flotationsbehälters das Gesamtvolumen der Suspension geringer wird. Als weitere Variationsmöglichkeit, nicht unbedingt an die konische Form des Flotationsbehälters gebunden, ist die Belüftung der Suspension während der Flotation durch einen Luftkasten 18, an den ein Luftanschluß 19 angebracht ist. Natürlich müssen in so einem Falle geeignete Schritte unternommen werden, um im Bereich der Wandung 20 einen Eintritt der Luft in die Suspension zu ermöglichen, z.B. durch poröse oder gelochte Ausführungen.In contrast to FIG. 2, FIG. 4 does not show a cylindrical but a slightly conical flotation container 12 '. As is known, such a measure allows the rotational movement to be accelerated without supplying any further energy, as a result of which friction losses could be compensated for. Furthermore, it can be assumed that the total volume of the suspension will be lower due to air flowing out into the center of the flotation container. A further variation possibility, not necessarily tied to the conical shape of the flotation container, is the ventilation of the suspension during the flotation through an air box 18 to which an air connection 19 is attached. In such a case, of course, suitable steps must be taken to allow the air to enter the suspension in the region of the wall 20, e.g. through porous or perforated designs.

Fig. 5 zeigt einen Teil einer weiteren zur Durchführung des Verfahrens geeigneten Flotationsvorrichtung, und zwar den Bereich des Schlammrohres 15'. Dieses ist als konzentrisches Doppelrohr ausgebildet, so daß zwei verschiedene Fraktionen von im mittleren Teil des Flotationsbehälters angesammeltem Stoff abgezogen werden können. Es kann nämlich von besonderem Vorteil sein, eine möglichst konzentrierte Schaumfraktion 21 separat von einer Schaum/Suspensions-Mischfraktion 22 abzuziehen. Aus Letzterer wäre dann durch einen weiteren Trennschritt noch Verwertbares zu gewinnen, wie z.B. unbeabsichtigt abgeführte Papierfasern.5 shows part of a further flotation device suitable for carrying out the method, namely the area of the sludge pipe 15 '. This is designed as a concentric double tube, so that two different fractions of material accumulated in the central part of the flotation container can be drawn off. It can be particularly advantageous to separate a foam fraction 21 that is as concentrated as possible separately from a foam / suspension mixed fraction 22. A further separation step could then be obtained from the latter, e.g. unintentionally removed paper fibers.

Die Strömungsführung in dem Sinne, daß am oberen Teil des Flotationsbehälters eingeführt und am unteren Teil sowohl der Schaum als auch die gereinigte Suspension abgeführt wird, ist nicht zwingend. Auch eine gerade umgekehrte Strömungsführung ist denkbar und in besonderen Fällen von Vorteil.The flow guidance in the sense that the upper part of the flotation container is introduced and both the foam and the cleaned suspension are removed at the lower part is not mandatory. Reverse flow guidance is also conceivable and is advantageous in special cases.

Es ist ohne weiteres vorstellbar, eine Anzahl von Flotationsbehältern zu Modulen zusammenzusetzen, wodurch sich die gestellte Aufgabe einer kompakten Anordnung der gesamten Flotationsanlage noch besser lösen läßt. Eine solche Moduleneinheit kann im wesentlichen aus Flotationsbehältern, wie bereits beschrieben, bestehen.It is easily conceivable to assemble a number of flotation containers into modules, as a result of which the task of a compact arrangement of the entire flotation system can be solved even better. Such a module unit can essentially consist of flotation tanks, as already described.

Claims (25)

Verfahren zum Abtrennen von Feststoffen aus einer Suspension durch Flotation in einem Klärraum (1), wobei die Suspension während der Flotation eine Rotationsbewegung (3) ausführt, der sich eine weitere Bewegung (4) überlagert, die sich im wesentlichen in einer Richtung der Rotationsachse (5) erstreckt und wobei sich die flotierten Anteile radial nach innen bewegen,
dadurch gekennzeichnet,
daß sich die flotierten Anteile außerdem im wesentlichen in der Richtung der Rotationsachse (5) bewegen, die mit der Richtung der weiteren überlagerten Bewegung (4) der Suspension identisch ist.Method for separating solids from a suspension by flotation in a clarification chamber (1), the suspension executing a rotational movement (3) during the flotation, which is superimposed on a further movement (4) which is essentially in a direction of the axis of rotation ( 5) extends and the floated portions move radially inward,
characterized by
that the floated portions also move essentially in the direction of the axis of rotation (5), which is identical to the direction of the further superimposed movement (4) of the suspension. Verfahren nach Anspruch 1,
dadurch gekennzeichnet,
daß in der zugeführten Suspension (2), wie an sich bekannt, dicht am Einlauf in den Klärraum (1) Mikroturbulenzen erzeugt werden.Method according to claim 1,
characterized by
that, as is known per se, microturbulence is generated in the supplied suspension (2) close to the inlet into the clarification chamber (1). Verfahren nach Anspruch 1 oder 2,
dadurch gekennzeichnet,
daß der Klärraum (1) im wesentlichen zylindrisch mit vertikaler Achse (5) ist.The method of claim 1 or 2,
characterized by
that the clarification chamber (1) is essentially cylindrical with a vertical axis (5). Verfahren nach Anspruch 3
dadurch gekennzeichnet,
daß die überlagerte Bewegung (4) der Suspension im wesentlichen vertikal nach unten verläuft.Method according to claim 3
characterized by
that the superimposed movement (4) of the suspension runs essentially vertically downwards. Verfahren nach Anspruch 3,
dadurch gekennzeichnet,
daß der Einlauf der Suspension (2) tangential erfolgt.Method according to claim 3,
characterized by
that the inlet of the suspension (2) is tangential. Verfahren nach einem der voranstehenden Ansprüche,
dadurch gekennzeichnet,
daß der Auslauf der Suspension (11) tangential erfolgt.Method according to one of the preceding claims,
characterized by
that the outlet of the suspension (11) is tangential. Verfahren nach Anspruch 1 oder 2,
dadurch gekennzeichnet,
daß zur Flotation benötigte Luft (9) gemeinsam mit der Suspension in den Klärraum (1) gelangt.The method of claim 1 or 2,
characterized by
that air (9) required for flotation reaches the clarification chamber (1) together with the suspension. Verfahren nach Anspruch 2 und 7,
dadurch gekennzeichnet,
daß zur Flotation benötigte Luft (9) im Bereich der Mikroturbulenzen zugemischt wird.Method according to claims 2 and 7,
characterized by
that air (9) required for flotation is mixed in the area of the microturbulence. Verfahren nach Anspruch 1 oder 2,
dadurch gekennzeichnet,
daß zur Flotation benötigte Luft (9') im Klärraum (1) der Suspension zugegeben wird.The method of claim 1 or 2,
characterized by
that air (9 ') required for flotation is added to the suspension in the clarification chamber (1). Verfahren nach Anspruch 1 oder 2,
dadurch gekennzeichnet,
daß die zu flotierende Suspension (2) gelöste Luft enthält und zur Flotation benötigte Luftblasen durch Druckabfall in der Suspension erzeugt werden.The method of claim 1 or 2,
characterized by
that the suspension (2) to be floated contains dissolved air and air bubbles required for flotation are generated by a drop in pressure in the suspension. Verfahren nach Anspruch 1 oder 2,
dadurch gekennzeichnet,
daß flotierte Anteile in mehreren Fraktionen (21,22) aus dem Klärraum abgeführt werden.The method of claim 1 or 2,
characterized by
that floated portions in several fractions (21, 22) are removed from the clarification room. Verfahren nach Anspruch 11,
dadurch gekennzeichnet,
daß eine Fraktion (22) Stoffe enthält, die in einem nachgeschalteten Verfahrensschritt abgetrennt werden.A method according to claim 11,
characterized by
that a fraction (22) contains substances that are separated in a subsequent process step. Flotationsvorrichtung zur Durchführung des Verfahrens nach einem der voranstehenden Ansprüche mit einem im wesentlichen rotationssymmetrischen Flotationsbehälter (12,12'), mindestens einen tangentialen Einlauf (13) für die zuzuführende Suspension, Mitteln (16,17,18,19) zur Erzeugung und Verteilung von Luftblasen, mindestens einem tangentialen Auslauf (14) für die abzuführende Suspension sowie im zentralen Bereich des Flotationsbehälters (12,12') mindestens einem Schaumrohr (15,15') für die flotierten Anteile
dadurch gekennzeichnet,
daß das mindestens eine Schaumrohr (15,15'), axial betrachtet, an der Seite des Flotationsbehälters (12,12') angeordnet ist, an der sich auch der Auslauf (14) befindet.Flotation device for carrying out the method according to one of the preceding claims with an essentially rotationally symmetrical flotation container (12, 12 '), at least one tangential inlet (13) for the suspension to be supplied, means (16, 17, 18, 19) for generating and distributing Air bubbles, at least one tangential outlet (14) for the suspension to be removed and in the central area of the flotation container (12, 12 ') at least one foam tube (15, 15') for the flotated components
characterized by
that the at least one foam tube (15, 15 '), viewed axially, is arranged on the side of the flotation container (12, 12') on which the outlet (14) is also located. Flotationsvorrichtung nach Anspruch 9,
dadurch gekennzeichnet,
daß der Flotationsbehälter (12,12') im Betrieb im wesentlichen senkrecht steht.Flotation device according to claim 9,
characterized by
that the flotation container (12, 12 ') is essentially vertical during operation. Flotationsvorrichtungnach Anspruch 10,
dadurch gekennzeichnet, daß der Einlauf (13) im oberen Bereich des
Flotationsbehälters (12,12') angeordnet ist und Auslauf (14) und Schaumrohr (15,15') im unteren.Flotation device according to claim 10,
characterized in that the inlet (13) in the upper region of the
Flotation container (12, 12 ') is arranged and outlet (14) and foam tube (15, 15') in the lower. Flotationsvorrichtung nach Anspruch 13, 14 oder 15,
dadurch gekennzeichnet,
daß der Flotationsbehälter (12,12') kreiszylindrisch ist.Flotation device according to claim 13, 14 or 15,
characterized by
that the flotation tank (12, 12 ') is circular cylindrical. Flotationsvorrichtung nach Anspruch 13, 14 oder 15,
dadurch gekennzeichnet,
daß sich der Flotationsbehälter (12,12') zum Auslauf hin verjüngt.Flotation device according to claim 13, 14 or 15,
characterized by
that the flotation container (12, 12 ') tapers towards the outlet. Flotationsvorrichtung nach einem der Ansprüche 13 bis 17,
dadurch gekennzeichnet,
daß sich im Bereich des Einlaufes (13) ein Turbulenzerzeuger (17) befindet.Flotation device according to one of claims 13 to 17,
characterized by
that there is a turbulence generator (17) in the area of the inlet (13). Flotationsvorrichtung nach Anspruch 18,
dadurch gekennzeichnet,
daß der Turbulenzerzeuger (17) ein sich sprunghaft erweiternder Stufendiffusor ist.Flotation device according to claim 18,
characterized by
that the turbulence generator (17) is a step-widening step diffuser. Flotationsvorrichtung nach Anspruch 18 oder 19,
dadurch gekennzeichnet,
daß zur Flotation benötigte Luft in den Turbulenzerzeuger (17) zuführbar ist.Flotation device according to claim 18 or 19,
characterized by
that air required for flotation can be fed into the turbulence generator (17). Flotationsvorrichtung nach einem der Ansprüche 13 bis 20,
dadurch gekennzeichnet,
daß zur Flotation benötigte Luft aus einem Luftkasten (18) durch einen durchlässigen Wandungsabschnitt (20) des Flotationsbehälters (12,12') radial in diesen einführbar ist.Flotation device according to one of claims 13 to 20,
characterized by
that air required for flotation can be introduced radially into an air box (18) through a permeable wall section (20) of the flotation tank (12, 12 '). Flotationsvorrichtung nach einem der Ansprüche 13 bis 21,
dadurch gekennzeichnet,
daß zur Flotation benötigte Luftblasen mit Hilfe einer vor dem oder im Einlauf (13) befindlichen Drossel durch Drucksenkung in der Suspension erzeugbar sind.Flotation device according to one of claims 13 to 21,
characterized by
that air bubbles required for flotation can be generated with the aid of a throttle located in front of or in the inlet (13) by lowering the pressure in the suspension. Flotationsvorrichtung nach einem der Ansprüche 13 bis 22,
dadurch gekennzeichnet,
daß das Verhältnis des größten Innendurchmessers des Schaumrohres (15,15') zum größten Innendurchmesser des Flotationsbehälters (12,12') größer als 0,6 ist.Flotation device according to one of claims 13 to 22,
characterized by
that the ratio of the largest inner diameter of the foam tube (15, 15 ') to the largest inner diameter of the flotation container (12, 12') is greater than 0.6. Flotationsvorrichtung nach einem der Ansprüche 13 bis 23,
dadurch gekennzeichnet,
daß das Schaumrohr (15') mehrere, insbesondere zwei konzentrische, sich axial im wesentlichen deckende Rohre aufweist, so daß mehrere, insbesondere zwei verschiedene Fraktionen mit flotiertem Stoff ausgeleitet werden können.Flotation device according to one of claims 13 to 23,
characterized by
that the foam tube (15 ') has several, in particular two concentric, axially essentially overlapping tubes, so that several, in particular two different fractions with floated material can be discharged. Flotationsvorrichtung nach Anspruch 24,
dadurch gekennzeichnet,
daß wenigstens aus einem, insbesondere dem radial außenliegenden, der durch die konzentrischen Rohre gebildeten Räume ein tangentialer Auslauf besteht.Flotation device according to claim 24,
characterized by
that at least one, in particular the radially outer, the spaces formed by the concentric tubes has a tangential outlet.
EP94110775A 1993-09-10 1994-07-12 Method of separating solids by means of flotation Expired - Lifetime EP0642833B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4330635A DE4330635C2 (en) 1993-09-10 1993-09-10 Process for the separation of solids by flotation and flotation device
DE4330635 1993-09-10

Publications (2)

Publication Number Publication Date
EP0642833A1 true EP0642833A1 (en) 1995-03-15
EP0642833B1 EP0642833B1 (en) 1998-09-30

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US (2) US5690812A (en)
EP (1) EP0642833B1 (en)
DE (1) DE4330635C2 (en)

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Also Published As

Publication number Publication date
EP0642833B1 (en) 1998-09-30
DE4330635A1 (en) 1995-03-16
DE4330635C2 (en) 1996-07-11
US5690812A (en) 1997-11-25
US5916446A (en) 1999-06-29

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