EP0332031B1 - Zigzag sifter - Google Patents
Zigzag sifter Download PDFInfo
- Publication number
- EP0332031B1 EP0332031B1 EP89103544A EP89103544A EP0332031B1 EP 0332031 B1 EP0332031 B1 EP 0332031B1 EP 89103544 A EP89103544 A EP 89103544A EP 89103544 A EP89103544 A EP 89103544A EP 0332031 B1 EP0332031 B1 EP 0332031B1
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- EP
- European Patent Office
- Prior art keywords
- air
- zigzag
- sifting
- ducts
- channels
- 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
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- 238000009826 distribution Methods 0.000 claims description 14
- 238000011144 upstream manufacturing Methods 0.000 claims 1
- 239000000463 material Substances 0.000 description 10
- 239000007787 solid Substances 0.000 description 5
- 210000003027 ear inner Anatomy 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 238000000926 separation method Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 2
- 230000000007 visual effect Effects 0.000 description 2
- 230000033228 biological regulation Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
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Classifications
-
- 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
- B07B4/00—Separating solids from solids by subjecting their mixture to gas currents
- B07B4/02—Separating solids from solids by subjecting their mixture to gas currents while the mixtures fall
- B07B4/04—Separating solids from solids by subjecting their mixture to gas currents while the mixtures fall in cascades
Definitions
- the invention relates to a zigzag sifter with a multiplicity of fluidically connected, zigzag-shaped, compressed air-operated sifting air channels which are connected to a collecting channel under compressed air.
- This classifier is a simple, vertical, smooth tube with a rectangular cross-section that is alternately inclined to the right and to the left at the same angle to the vertical.
- the coarse portions of the feed slide down on the bottom wall of the channel. In doing so, they have to cross the visual air flow coming from below at the kinks. With each crossing there is a separation of fine parts, which in itself does not lead to a sharp classification. A multiple repetition can ultimately result in a very sharp separation of the fractions due to a multiplication effect.
- a multi-channel zigzag sifter with sifting air ducts connected in parallel in terms of flow, which are connected to a gas distributor, is described in EP-A-163 836.
- the construction principle of such a sifter package with many small channel cross-sections allows significantly lower overall heights with the same number of kinks.
- the number of kinks for one and the same desired separation result can also be reduced because the thickness of the material layer to be sifted is so small that a significantly better viewing process takes place at the individual kinks.
- CH-A-419 810 which has a group of sight tubes connected in parallel.
- This is a sifter cascade, in which the material to be sifted is passed one after the other under the feet of the individual viewing channels and is introduced into the individual viewing channels from below using visual air in the form of one or more sharp beams.
- the visible material on a conveyor belt is whirled up by the sharp line of sight air and blown into the sight pipes or sight channels.
- an airbed classifier For the dedusting of granular material at high throughputs, an airbed classifier was also developed, which e.g. is described in DE 1 507 686.
- This classifier combines a strongly fluidized fluidized bed with a system of parallel zigzag channels arranged above it. The feed bed moves through the fluidized bed in such a way that coarse material emerges from the bed at the end. The fine material is checked for its grain size in the zigzag channels and, if the size falls below a predetermined limit, is transferred from the classifying air to a separator. The coarse grain, on the other hand, falls back into bed.
- multi-channel zigzag sifters are on the market, in which the material to be sifted is fed evenly to the channels via a distributor screw. The visible air flows in undosed to the parallel channels.
- classifiers may only be operated with a low solids load.
- the invention has for its object to take precautions in a multi-channel zigzag sifter of low height and high selectivity, which ensure that all channels are supplied evenly and constantly with sifting air regardless of the respective loading with solid matter.
- the sifting air ducts each have an air distribution pipe for distributing the sifting air over the duct cross-sections and that in the individual air feeds branching off the collecting duct, sound restrictors with the same cross section are arranged, through which the sifting air flows at the speed of sound, so that in Each air distribution pipe receives an amount of air that is only determined by the cross section and the pressure in front of the sound throttle.
- Sound restrictors are perforated screens through which the visible air flows at sound speeds in their working area.
- a sound choke is therefore assigned to each viewing duct, so that all ducts have the same air throughput with the same cross section of the perforated screens. Since the parallel viewing channels are all fed from the same collecting channel, the pressure in the collecting channel can be used to vary the viewing air flow rate of all channels evenly.
- the cross sections of the ducts are advantageously narrowed below the feed point for the classifying air in such a way that the coarse grain of the desired size can just fall freely out of the classifying duct. Due to the particles falling out, the narrowing of the cross-section is fluidically increased the more particles pass the constriction. However, this leads to the desired stabilization of the flow distribution.
- the constriction is given the shape of a zigzag channel.
- zigzag channels have a particularly high resistance coefficient, which even exceeds that of labyrinth seals.
- a control device is provided in the zigzag sifter according to the invention which maintains such pressure in this space that no sifting air flows out of the channels downwards, but on the other hand also no air from the surroundings is sucked in by the ducts. This is achieved by a corresponding regulation for the extraction of the classifier exhaust air.
- the zigzag sifter shown schematically in FIG. 1 consists of a housing 1 with a collecting space 2 for the discharged material with the desired grain size, the zigzag sifter package and the collecting duct 4 for supplying the sifting air.
- the zigzag sifter package consists of a plurality of vertically arranged, fluidically parallel zigzag channels 5 with attached return shafts 6. Through the return shafts 6, the undersize may be thrown back into a material bed. They can have smooth or zigzag channel walls.
- the classifying air is fed to the air distribution pipe via a diaphragm or throttle (sound throttle) 11 through which the speed of sound flows (see also description of FIG. 3).
- labyrinths zigzag-shaped narrow points
- the labyrinth 12 ultimately serves to improve the selectivity if a different solids loading is to be expected in the classifier channels 5 and different pressure distributions result from this.
- the constrictions 12 counteract flow instabilities which result from such different pressure distributions.
- the air supply to the air distribution pipes 9 can be seen from FIG. 3.
- the sifting air flows for the channels 5 are branched off in parallel from the collecting channel 4.
- throttles 11 Due to the arranged in the individual feeds to the air distribution pipes 9 throttles 11 ensures that in each air distribution pipe 9, regardless of the pressure behind the sound throttle, an amount of air flows that is determined only by the cross section and the pressure in front of the sound throttle. With the same cross section of the sound restrictors, the air throughput for all classifier channels is also the same.
- the suction for the classifier exhaust air is provided with a control device which ensures that ambient pressure prevails in the collection space 2.
- the goods viewed are discharged from the collecting space 2 through a rotary valve.
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- Combined Means For Separation Of Solids (AREA)
- Separation By Low-Temperature Treatments (AREA)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
Description
Die Erfindung betrifft einen Zick-Zack-Sichter mit einer Vielzahl von strömungstechnisch parallel geschalteten, zick-zackförmigen, mit Druckluft beaufschlagten Sichtluftkanälen, die mit einem unter Druckluft stehenden Sammelkanal in Verbindung stehen.The invention relates to a zigzag sifter with a multiplicity of fluidically connected, zigzag-shaped, compressed air-operated sifting air channels which are connected to a collecting channel under compressed air.
Das Grundprinzip eines Zick-Zack-Sichters zur Steigrohrwindsichtung von körnigen Gütern wird in US-A-1 861 248 beschrieben.The basic principle of a zigzag sifter for rising pipe wind sifting of granular goods is described in US-A-1 861 248.
Bei diesem Sichter handelt es sich um ein einfaches, vertikales, innen glattes Rohr mit rechteckigem Querschnitt, das abwechselnd nach rechts und nach links unter dem gleichen Winkel zur Vertikalen geneigt ist. Die groben Anteile das Aufgabegutes rutschen auf der jeweils unteren Wand des Kanals nach unten. Dabei müssen sie an den Knickstellen den von unten kommenden Sichtluftstrom durchqueren. Bei jeder Durchquerung findet eine Abtrennung von Feinteilen statt, die für sich genommen nicht zu einer scharfen Klassierung führt. Durch eine vielfache Wiederholung kann aber aufgrund eines Multiplikationseffektes letzten Endes eine sehr scharfe Separierung der Fraktionen erreicht werden.This classifier is a simple, vertical, smooth tube with a rectangular cross-section that is alternately inclined to the right and to the left at the same angle to the vertical. The coarse portions of the feed slide down on the bottom wall of the channel. In doing so, they have to cross the visual air flow coming from below at the kinks. With each crossing there is a separation of fine parts, which in itself does not lead to a sharp classification. A multiple repetition can ultimately result in a very sharp separation of the fractions due to a multiplication effect.
Ein Mehrkanal-Zick-Zack-Sichter mit strömungstechnisch parallel geschalteten Sichtluftkanälen, die mit einem Gasverteiler in Verbindung stehen, wird in EP-A-163 836 beschrieben. Das Bauprinzip eines derartigen Sichterpakets mit vielen kleinen Kanalquerschnitten erlaubt bei einer gleichen Zahl von Knickstellen wesentlich geringere Bauhöhen. Darüber hinaus kann auch noch die Zahl der Knickstellen für ein und dasselbe angestrebte Trennergebnis reduziert werden, weil die Dicke der zu sichtenden Gutsschicht so gering ist, daß an den einzelnen Knickstellen ein deutlich besserer Sichtungsprozeß stattfindet.A multi-channel zigzag sifter with sifting air ducts connected in parallel in terms of flow, which are connected to a gas distributor, is described in EP-A-163 836. The construction principle of such a sifter package with many small channel cross-sections allows significantly lower overall heights with the same number of kinks. In addition, the number of kinks for one and the same desired separation result can also be reduced because the thickness of the material layer to be sifted is so small that a significantly better viewing process takes place at the individual kinks.
Weiterhin wird in CH-A-419 810 eine Sichtanlage beschrieben, die eine Gruppe von parallel geschalteten Sichtrohren aufweist. Dabei handelt es sich um eine Sichterkaskade, bei der das zu sichtende Gut nacheinander unter den Füßen der einzelnen Sichtkanäle vorbeigeführt und durch Sichtluft in Form von einem oder mehreren scharfen Strahlen von unten her in die einzelnen Sichtkanäle eingeführt wird. Durch den scharfen Sichtluftstrahl wird das auf einem Transportband befindliche Sichtgut aufgewirbelt und in die Sichtrohre bzw. Sichtkanäle eingeblasen.Furthermore, a sighting system is described in CH-A-419 810, which has a group of sight tubes connected in parallel. This is a sifter cascade, in which the material to be sifted is passed one after the other under the feet of the individual viewing channels and is introduced into the individual viewing channels from below using visual air in the form of one or more sharp beams. The visible material on a conveyor belt is whirled up by the sharp line of sight air and blown into the sight pipes or sight channels.
Für die Entstaubung von körnigem Gut bei hohen Durchsätzen wurde ferner ein Flugbettsichter entwickelt, der z.B. in DE 1 507 686 beschrieben wird. Bei diesem Sichter ist ein kräftig fluidisiertes Wirbelbett mit einem darüber angeordneten System paralleler Zick-Zack-Kanäle kombiniert. Das Aufgabebett wandert dabei so durch das Wirbelbett, daß am Schluß Grobgut aus dem Bett austritt. Das Feingut wird in den Zick-Zack-Kanälen auf seine Korngröße überprüft und, falls eine vorgegebene Grenzkorngröße unterschritten wird, von der Sichtluft in ein Abscheideorgan überführt. Das Grobkorn fällt dagegen ins Bett zurück.For the dedusting of granular material at high throughputs, an airbed classifier was also developed, which e.g. is described in DE 1 507 686. This classifier combines a strongly fluidized fluidized bed with a system of parallel zigzag channels arranged above it. The feed bed moves through the fluidized bed in such a way that coarse material emerges from the bed at the end. The fine material is checked for its grain size in the zigzag channels and, if the size falls below a predetermined limit, is transferred from the classifying air to a separator. The coarse grain, on the other hand, falls back into bed.
Außerdem sind mehrkanalige Zick-Zack-Sichter im Handel, bei denen das zu sichtende Gut den Kanälen über eine Verteilerschnecke gleichmäßig Zugeführt wird. Die Sichtluft strömt den parallelen Kanälen undosiert zu.In addition, multi-channel zigzag sifters are on the market, in which the material to be sifted is fed evenly to the channels via a distributor screw. The visible air flows in undosed to the parallel channels.
Um Instabilitäten zu vermeiden, dürfen solche Sichter nur mit geringer Feststoffbeladung betrieben werden.In order to avoid instabilities, such classifiers may only be operated with a low solids load.
Der Erfindung liegt die Aufgabe zugrunde, bei einem Mehrkanal-Zick-Zack-Sichter geringer Bauhöhe und hoher Trennschärfe Vorkehrungen zu treffen, die sicherstellen, daß alle Kanäle unabhängig von der jeweiligen Beladung mit Feststoff gleichmäßig und konstant mit Sichtluft versorgt werden.The invention has for its object to take precautions in a multi-channel zigzag sifter of low height and high selectivity, which ensure that all channels are supplied evenly and constantly with sifting air regardless of the respective loading with solid matter.
Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß die Sichtluftkanäle jeweils ein Luftverteilungsrohr zur Verteilung der Sichtluft über die Kanalquerschnitte aufweisen und daß in den einzelnen, vom Sammelkanal abzweigenden Luftzuführungen Schalldrosseln mit gleichem Querschnitt angeordnet sind, die von der Sichtluft mit Schallgeschwindigkeit durchströmt werden, so daß in jedes Luftverteilungsrohr eine Luftmenge einströmt, die nur vom Querschnitt und dem Druck vor der Schalldrossel bestimmt wird.This object is achieved in that the sifting air ducts each have an air distribution pipe for distributing the sifting air over the duct cross-sections and that in the individual air feeds branching off the collecting duct, sound restrictors with the same cross section are arranged, through which the sifting air flows at the speed of sound, so that in Each air distribution pipe receives an amount of air that is only determined by the cross section and the pressure in front of the sound throttle.
"Schalldrosseln" sind Lochblenden, die in ihrem Arbeitsbereich von der Sichtluft mit Schallgeschwindigkeiten durchströmt werden. Jedem Sichtkanal ist also eine Schalldrossel zugeordnet, so daß sämtliche Kanäle bei gleichem Querschnitt der Lochblenden den gleichen Luftdurchsatz haben. Da die parallelen Sichtkanäle alle aus dem gleichen Sammelkanal gespeist werden, kann über den Druck im Sammelkanal der Sichtluftdurchsatz aller Kanäle gleichmäßig variiert werden."Sound restrictors" are perforated screens through which the visible air flows at sound speeds in their working area. A sound choke is therefore assigned to each viewing duct, so that all ducts have the same air throughput with the same cross section of the perforated screens. Since the parallel viewing channels are all fed from the same collecting channel, the pressure in the collecting channel can be used to vary the viewing air flow rate of all channels evenly.
Die Sichtluft wird von unten in die Kanäle eingeblasen. Zu ihrer gleichmäßigen Verteilung über den Kanalquerschnitt ist vorteilhaft ein an der Oberseite perforiertes Luftverteilungsrohr vorgesehen, das um α = 5° bis 60° gegen die Horizontale geneigt ist. Auf diese Weise wird erreicht, daß oberhalb der Einspeisequelle die Strömungsgeschwindigkeit im Kanal zunimmt. Dies hat für die auszutragenden Partikel zur Folge, daß ihr Austrag durch eine in Fallrichtung abnehmende Anblasung nicht behindert wird.The visible air is blown into the ducts from below. For their uniform distribution over the channel cross section, an air distribution tube perforated on the upper side is advantageously provided, which is inclined by α = 5 ° to 60 ° to the horizontal. In this way it is achieved that the flow velocity in the channel increases above the feed source. For the particles to be discharged, this has the consequence that their discharge is not hindered by a blowing which decreases in the direction of the fall.
Im praktischen Betrieb des neuen Zick-Zack-Sichters kann es vorkommen, daß den einzelnen Kanälen unterschiedlich viele Feststoffpartikel zugeführt werden. Unterschiedliche Feststoffbeladungen in den Sichterkanälen haben aber unterschiedliche Druckverteilungen zur Folge, so daß Luft aus stärker beladenen Kanälen zurückströmt und dann ihren Weg durch weniger stark beladene Nachbarkanäle nimmt. Dies würde zu einem instabilen Verhalten des Sichterprozesses insgesamt und damit zu einem deutlichen Absenken der Trennschärfe führen. Um derartige Rückströmungen zu erschweren, sind die Kanäle vorteilhaft unterhalb der Einspeisestelle für die Sichtluft in ihrem Querschnitt so eingeengt, daß das Grobgutkorn mit der gewünschten Größe gerade noch ungehindert aus demSichtkanal herausfallen kann. Durch die herausfallenden Partikel wird die Querschnittsverengung strömungstechnisch umso mehr verstärkt, je mehr Partikel die Engstelle passieren. Dies führt aber gerade zu der gewünschten Stabilisierung der Strömungsverteilung.In practical operation of the new zigzag sifter, different numbers of solid particles can be supplied to the individual channels. Different solids loads in the classifier channels result in different pressure distributions, so that air flows back from more heavily loaded channels and then makes its way through less heavily loaded neighboring channels. This would lead to an unstable behavior of the classifier process as a whole and thus to a significant reduction in the selectivity. In order to make such backflows more difficult, the cross sections of the ducts are advantageously narrowed below the feed point for the classifying air in such a way that the coarse grain of the desired size can just fall freely out of the classifying duct. Due to the particles falling out, the narrowing of the cross-section is fluidically increased the more particles pass the constriction. However, this leads to the desired stabilization of the flow distribution.
Gemäß einer speziellen Ausbildung des erfindungsgemäßen Vorschlages wird der Engstelle die Form eines Zick-Zack-Kanales gegeben. Zick-Zack-Kanäle haben bekanntlich einen besonders hohen Widerstandsbeiwert, der selbst den von Labyrinthdichtungen übertrifft.According to a special embodiment of the proposal according to the invention, the constriction is given the shape of a zigzag channel. As is well known, zigzag channels have a particularly high resistance coefficient, which even exceeds that of labyrinth seals.
Am unteren Ende, wo alle parallelen Sichterkanäle in einen gemeinsamen Raum münden, ist bei dem erfindungsgemäßen Zick-Zack-Sichter eine Regelvorrichtung vorgesehen werden, die in diesem Raum einen solchen Druck aufrechterhält, daß aus den Kanälen keine Sichtluft nach unten ausströmt, aber andererseits auch keine Luft aus der Umgebung von den Kanälen angesaugt wird. Dies wird durch eine entsprechende Regelung für die Absaugung der Sichterabluft erreicht.At the lower end, where all parallel sifter channels open into a common space, a control device is provided in the zigzag sifter according to the invention which maintains such pressure in this space that no sifting air flows out of the channels downwards, but on the other hand also no air from the surroundings is sucked in by the ducts. This is achieved by a corresponding regulation for the extraction of the classifier exhaust air.
Im folgenden wird ein Ausführungsbeispiel der Erfindung anhand von Zeichnungen näher erläutert. Es zeigen:
- Fig. 1
- eine Aufrißdarstellung des Mehrkanal-Zick-Zack-Sichters,
- Fig. 2
- eine Seitenansicht und
- Fig. 3
- die Luftzuführung zu den Sichterkanälen.
- Fig. 1
- an elevation of the multi-channel zigzag sifter,
- Fig. 2
- a side view and
- Fig. 3
- the air supply to the classifier channels.
Der in Fig. 1 schematisch dargestellte Zick-Zack-Sichter besteht aus einem Gehäuse 1 mit einem Sammelraum 2 für das ausgetragene Gut mit der Wunschkorngröße, dem Zick-Zack-Sichterpaket und dem Sammelkanal 4 für die Zuführung der Sichtluft. Das Zick-Zack-Sichterpaket besteht aus einer Vielzahl vertikal angeordneter, strömungstechnisch parallel geschalteter zickzackförmiger Kanäle 5 mit aufgesetzten Rückführungsschächten 6. Durch die Rückführungsschächte 6 wird das Unterkorn gegebenenfalls in ein Gutbett zurückgeschleudert. Sie können glatte oder zick-zack-förmig ausgebildete Kanalwände haben.The zigzag sifter shown schematically in FIG. 1 consists of a housing 1 with a
Zu diesem Zweck ist am oberen Ende des Rückführungsschachtes 6 eine Öffnung 7 vorhanden (siehe Fig. 2). Das zu sichtende Gut wird über die Eintragsöffnung 8 am oberen Ende der Sichterkanäle 5 zugeführt. An ihrem unteren Ende sind die Kanäle 5, wie nachfolgend noch genauer beschrieben wird, mit dem Sammelkanal 4 für die Zuführung der Sichtluft verbunden. Jeder Sichtkanal 5 ist, wie aus Fig. 2 ersichtlich, mit einem Luftverteilungsrohr 9 ausgestattet, das z.B. unter einem Winkel von α = 45° gegen die Horizontale geneigt ist und an seiner Oberfläche Perforationen 10 für einen gleichmäßigen Luftaustritt aufweist. Die Sichtluft wird dem Luftverteilungsrohr über eine mit Schallgeschwindigkeit durchströmte Blende oder Drossel (Schalldrossel) 11 zugeführt (siehe auch Beschreibung zur Fig. 3). Unterhalb der Luftverteilungsrohre 9 sind zickzackförmige Engstellen (Labyrinthe) 12 angeordnet, deren Durchmesser nur geringfügig größer ist als der Durchmesser des auszutragenden gesichteten Guts (Wunschkorndurchmesser). Durch das Labyrinth 12 kann also das Grobgutkorn gerade noch ungehindert aus dem Sichtkanal 5 herausfallen. Das Labyrinth 12 dient letzten Endes zur Verbesserung dar Trennschärfe, wenn in den Sichterkanälen 5 mit einer unterschiedlichen Feststoffbeladung zu rechnen ist und daraus unterschiedliche Druckverteilungen resultieren. Die Engstellen 12 wirken Strömungsinstabilitäten entgegen, die sich aus solchen unterschiedlichen Druckverteilungen ergeben.For this purpose, an opening 7 is provided at the upper end of the return shaft 6 (see FIG. 2). The material to be sifted is fed through the entry opening 8 at the upper end of the
Aus Fig. 3 ist die Luftzuführung zu den Luftverteilungsrohren 9 ersichtlich. Aus dem Sammelkanal 4 werden parallel die Sichtluftströme für die Kanäle 5 abgezweigt. Durch die in den einzelnen Zuführungen zu den Luftverteilungsrohren 9 angeordneten Schalldrosseln 11 wird erreicht, daß in jedes Luftverteilungsrohr 9 unabhängig vom Druck hinter der Schalldrossel eine Luftmenge einströmt, die nur vom Querschnitt und dem Druck vor der Schalldrossel bestimmt wird. Bei gleichem Querschnitt der Schalldrosseln ist also auch der Luftdurchsatz für alle Sichterkanäle gleich groß.The air supply to the air distribution pipes 9 can be seen from FIG. 3. The sifting air flows for the
Um den Sichtluftdurchsatz aller Kanäle 5 gleichmäßig zu variieren, braucht also nur der Druck im Sammelkanal 4 entsprechend geändert zu werden.In order to vary the visible air throughput of all
Um sicherzustellen, daß durch den Sammelraum 2 unterhalb der Querschnittsverengung 12 weder Luft in die Kanäle ein- noch ausströmt, ist die Absaugung für die Sichterabluft mit einer Regeleinrichtung versehen, die dafür sorgt, daß im Sammelraum 2 Umgebungsdruck herrscht. Aus dem Sammelraum 2 wird das gesichtete Gut durch eine Zellenradschleuse ausgetragen.To ensure that neither air flows into or out of the channels through the
Claims (5)
- A zigzag sifter with a plurality of zigzag-shaped sifting air ducts (5), which are connected in parallel according to flow technology, are acted upon by compressed air and are connected to collecting ducts (4) similarly acted upon by compressed air, characterised in that the sifting air ducts (5) each comprise an air distribution pipe (9) for distributing the sifting air over the duct cross sections, and arranged in the individual air supply lines branching off from the collecting duct (4) are sound throttles (11), which have the same cross section and through which the sifting air flows at sonic speed, so that a quantity of air flows into each air distributing pipe (9) which is merely determined by the cross section and the pressure upstream of the sound throttle (11).
- A zigzag sifter according to claim 1, characterised in that the air distributing pipes (9) are perforated (10) on their upper side and are inclined relative to the horizontal through α = 5° to 60° in the direction of flow of the pipe.
- A zigzag sifter according to claims 1 to 2, characterised in that the ducts (5) are constricted (12) at their lower end in the region of the coarse grain outlet.
- A zigzag sifter according to claim 3, characterised in that the constriction (12) comprises zigzag-shaped duct walls.
- A zigzag sifter according to claims 1 to 4, characterised in that the exhaust for the exhaust sifting air is provided with a control device, which maintains such a pressure at the lower end of the ducts or constrictions that neither sifting air flows out nor air is drawn in from the environment at this point.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3808116A DE3808116A1 (en) | 1988-03-11 | 1988-03-11 | ZIGZAG SIFTER |
| DE3808116 | 1988-03-11 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| EP0332031A2 EP0332031A2 (en) | 1989-09-13 |
| EP0332031A3 EP0332031A3 (en) | 1991-07-31 |
| EP0332031B1 true EP0332031B1 (en) | 1994-01-26 |
Family
ID=6349469
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP89103544A Expired - Lifetime EP0332031B1 (en) | 1988-03-11 | 1989-03-01 | Zigzag sifter |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US4931174A (en) |
| EP (1) | EP0332031B1 (en) |
| JP (1) | JP2753848B2 (en) |
| DE (2) | DE3808116A1 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5213820A (en) * | 1984-02-27 | 1993-05-25 | Bayer Aktiengesellschaft | Process and device for fluidized bed spray granulation |
| DE4200821A1 (en) * | 1992-01-15 | 1993-07-22 | Bayer Ag | TASTE-MASKED PHARMACEUTICAL AGENTS |
| DE4304405A1 (en) * | 1993-02-15 | 1994-08-18 | Bayer Ag | Process for continuous fluidized bed agglomeration |
| US6213307B1 (en) * | 1995-11-15 | 2001-04-10 | Grana Inc. | Fluid-bed cleaner and grades sorter for particle form materials |
| EP0870537B1 (en) * | 1997-04-09 | 2004-10-06 | Symrise GmbH & Co. KG | Process for preparing alcohol-containing granules |
| PL1488712T3 (en) * | 2003-06-19 | 2011-07-29 | Hauni Maschinenbau Ag | Sifting means for sifting a product stream within a distributor apparatus |
| EP1958520A3 (en) | 2007-02-09 | 2013-04-03 | Symrise AG | Fluidised bed granulate with high fruit content |
| DE102010007593A1 (en) * | 2010-02-04 | 2011-08-04 | Hauni Maschinenbau AG, 21033 | Viewing means for viewing a product flow within a distributor device |
| DE102013215062A1 (en) * | 2013-07-31 | 2015-02-05 | Krones Ag | Zig-zag separator for separating separating material, for example plastic flakes, and method for separating separating material, for example plastic flakes, by means of a zig-zag separator |
| CN110074448B (en) * | 2019-06-19 | 2022-05-17 | 常德烟草机械有限责任公司 | Stem sorting unit |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1861248A (en) * | 1930-01-03 | 1932-05-31 | Albert H Stebbins | Air classifier |
| DE1135841B (en) * | 1960-06-09 | 1962-09-06 | Dr Theodor Eder | Method and device for separating granular material into at least two end fractions |
| DE1407846A1 (en) * | 1961-06-15 | 1969-04-10 | Alpine Ag | Use of the riser air separator according to patent 1270380 in the grain industry |
| DE1507686B1 (en) * | 1966-04-06 | 1972-05-25 | Alpine Ag | Riser air separator |
| NL136425C (en) * | 1966-07-11 | |||
| US3876419A (en) * | 1970-07-06 | 1975-04-08 | Lev Petrovich Brusov | Method of thermal and chemical treatment of solids of starting material not over 0.5 mm in size |
| DE2341363C3 (en) * | 1973-08-16 | 1979-05-31 | Kali-Chemie Ag, 3000 Hannover | Process for the preparation of a catalyst for the decomposition of hydrazine and its derivatives |
| US3925198A (en) * | 1975-01-29 | 1975-12-09 | Univ Utah | Apparatus and method of air classifying municipal solid wastes |
| DE2641068A1 (en) * | 1976-09-11 | 1978-03-16 | Alpine Ag | Air sifter for granular material - uses settling tank for conveying channels and removal of oversized particles |
| DE2804548A1 (en) * | 1978-02-03 | 1979-08-09 | Krauss Maffei Ag | Wet paper separation from refuse - uses stream of hot air introduced at refuse entry end with subsequent sifting |
| US4235707A (en) * | 1979-04-09 | 1980-11-25 | Burke, Davoud & Associates | Method and apparatus for treating solid municipal refuse and other cellulose containing material |
| JPS5616227U (en) * | 1979-07-11 | 1981-02-12 | ||
| SU906633A1 (en) * | 1980-06-20 | 1982-02-23 | Всесоюзный Научно-Исследовательский Институт Деревообрабатывающей Промышленности | Apparatus for sorting wooden particles |
| SU1265002A1 (en) * | 1984-02-03 | 1986-10-23 | Уральский политехнический институт им.С.М.Кирова | Pneumatic multicolumn classifier |
| EP0163836B1 (en) * | 1984-04-07 | 1988-10-12 | Bayer Ag | Process and apparatus for the production of granules |
| SU1268212A1 (en) * | 1985-06-17 | 1986-11-07 | Научно-исследовательский институт прикладной математики и механики при Томском государственном университете | Air separator |
| AT386362B (en) * | 1986-08-13 | 1988-08-10 | Uralsky Politekhn Inst | GRAVITY WINIFIFIER FOR SEPARATING SHEET MATERIALS |
| JPS6311067A (en) * | 1987-06-25 | 1988-01-18 | Victor Co Of Japan Ltd | Dc high voltage generating device |
-
1988
- 1988-03-11 DE DE3808116A patent/DE3808116A1/en not_active Withdrawn
-
1989
- 1989-02-27 US US07/316,368 patent/US4931174A/en not_active Expired - Lifetime
- 1989-03-01 DE DE89103544T patent/DE58906793D1/en not_active Expired - Lifetime
- 1989-03-01 EP EP89103544A patent/EP0332031B1/en not_active Expired - Lifetime
- 1989-03-10 JP JP1056571A patent/JP2753848B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| DE3808116A1 (en) | 1989-09-21 |
| JPH01274880A (en) | 1989-11-02 |
| EP0332031A2 (en) | 1989-09-13 |
| EP0332031A3 (en) | 1991-07-31 |
| DE58906793D1 (en) | 1994-03-10 |
| US4931174A (en) | 1990-06-05 |
| JP2753848B2 (en) | 1998-05-20 |
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