DE1436296C

DE1436296C - Bag filter

Info

Publication number: DE1436296C
Authority: DE
Inventors: Ralph Derek St Austeil Cornwall Gwilham (Großbritannien)
Original assignee: English Clays Lovering Pochin & Co Ltd , St Austeil, Cornwall (Großbritan men)
Publication date: 1971-07-15

Description

Die Erfindung betrifft ein Beutelfilter, bestehend aus einem starren etwa zylinderförmigen Gehäuse, dessen Hauptachse in etwa lotrechter Ebene liegt und dessen unterer Deckel leicht zu öffnen ist, einem im Inneren mit seinem offenen unteren Ende am Gehäuseflansch befestigten Filterbeutel und einer ihn umhüllenden flüssigkeitsdurchlässigen in sich starren Abstützung mit einer Einrichtung zum Umstülpen des Filterbeutels zwecks Reinigung nach Wegnahme des Deckels und einer Zuführleitung für die Trübe ins Innere des Filterbeutels sowie einer Abführleitung für das Filtrat aus einem Filtratraum.The invention relates to a bag filter, consisting of a rigid, approximately cylindrical housing, whose main axis lies in an approximately vertical plane and whose lower cover is easy to open, one inside with its open lower end attached to the housing flange and one filter bag it enveloping liquid-permeable rigid support with a device for turning inside out the filter bag for cleaning after removing the lid and a supply line for the pulp into the interior of the filter bag and a discharge line for the filtrate from a filtrate chamber.

Es ist bereits ein Filter mit Filtertaschen und einem nahe der Wand des Gehäuses verlaufenden Filterbeutel bekannt, bei dem zwecks Reinigung die Filtertaschen zusammen mit dem Filterbeutel nach Wegschwenken der Bodenklappe mittels einer Kolbenstange nach unten aus dem Gehäuse herausgeschoben werden. Dabei wird der Filterbeutel umgestülpt. Das Wiedereinbringen der Filtertaschen und des Filterbeutels in das Gehäuse erfolgt wiederum mittels der Kolbenstange. Der Filterbeutel kann dabei auch von einer in sich starren Abstützung umgeben sein.It is already a filter with filter pockets and one that runs close to the wall of the housing Filter bag known, in which the filter bags together with the filter bag for the purpose of cleaning Pivoting the bottom flap pushed down and out of the housing by means of a piston rod will. The filter bag is turned inside out. The reintroduction of the filter bags and the filter bag into the housing takes place again by means of the piston rod. The filter bag can also be surrounded by a rigid support.

Im Gehäuse eines anderen bekannten Druckfilters ist ein Sack mit einem äußeren Membrankörper aus dichtem Neopren und mehreren inneren aus Filtermaterial bestehenden Lagen untergebracht. Der Membrankörper umschließt das Filtermaterial. Das Filtrat kann aus weiteren Auslässen, die zwischen dem Membrankörper und dem angrenzenden Filtriermaterial beginnen, abgehen. Der am Filtermaterial abgeschiedene Feststoff muß bei der Reinigung als Schlamm abgeführt werden.In the housing of another known pressure filter, a bag with an outer membrane body is made dense neoprene and several inner layers made of filter material. the The membrane body encloses the filter material. The filtrate can come from further outlets between the membrane body and the adjacent filter material begin to come off. The one on the filter material Separated solids must be removed as sludge during cleaning.

Der Erfindung liegt die Aufgabe zugrunde, ein für hohe Flüssigkeitsdrücke brauchbares Beutelfilter zu schaffen, bei dem sich der Filterkuchen nach Beendigung der Filtration leicht entfernen läßt und der bei der Filtration herrschende Druck über die ganze Oberfläche des Filterbeutels durch einen unter hohem Druck stehenden Membrankörper erfolgt. The invention is based on the object of a bag filter which can be used for high liquid pressures to create in which the filter cake can be easily removed after the filtration and the pressure prevailing during the filtration over the entire surface of the filter bag through a membrane body under high pressure takes place.

Hierzu schlägt die Erfindung vor, daß innerhalb des Filterbcutels ein an ein hydraulisches Druckmittel anschließbarer, etwa bis auf die Größe des Filterbeutels aufblähbarer, im wesentlichen geschlossener, dichter Membranhohlkörper angeordnet ist, der mit seinem offenen unteren Ende mit dem wegnehmbaren Deckel und einem Rohr verbunden ist, und daß der Filtratraum zwischen dem Filterbeutel und dem Gehäuse weiterhin über absperrbare Leitungen mit Druckluft oder Vakuum in Verbindung gebracht werden kann.For this purpose, the invention proposes that a hydraulic pressure medium within the Filterbcutels connectable, inflatable to about the size of the filter bag, essentially closed, dense membrane hollow body is arranged, which with its open lower end with the removable Lid and a tube is connected, and that the filtrate space between the filter bag and the housing is still connected to compressed air or vacuum via lockable lines can be.

Die Erfindung ist nunmehr an Hand eines Ausführungsbcispiels in der Zeichnung erläutert.The invention is now based on an exemplary embodiment explained in the drawing.

Die Zeichnung zeigt ein Beutelfilter nach der Erfindung in einem sxhematischen Längsschnitt.The drawing shows a bag filter according to the invention in a sxhematic longitudinal section.

Das gezeigte Beutelfilter besteht aus einem aufrecht stehenden zylindrischen Gehäuse 1, in dem gleichachsig damit ein gelochtes Stahlrohr als Abstützung! angeordnet ist. Diese Abstützung 2 ist an ihren Enden mit Flanschen 3 und 4 versehen, die zusammen mit den Flanschen des Gehäuses 1 befestigt sind.The bag filter shown consists of an upright cylindrical housing 1, in which a perforated steel tube is coaxial with it as a support! is arranged. This support 2 is provided at its ends with flanges 3 and 4 which are fastened together with the flanges of the housing 1.

Das Gehäuse I bildet einen Teil einer Filtrat-Kammer, die am oberen Ende durch einen Deckel 5 verschlossen ist. Am unteren Ende des Gehäuses ist ein Deckel 6 mit dem Flansch 4 durch Schraubverbindungen 7 druckdicht befestigt. Der Deckel 6 ist leicht abnehmbar und kann ebenso wieder verschlossen werden.The housing I forms part of a filtrate chamber, which is closed at the upper end by a cover 5. At the bottom of the case is a cover 6 is fastened to the flange 4 in a pressure-tight manner by screw connections 7. The cover 6 is easily removable and can also be closed again.

Das Rohr 2 dient zur Abstützung für einen flexiblen Filterbeutel 8 aus gewebtem Filtermaterial, der in diesem Rohr angeordnet ist, so daß zwischen dem Filterbeutel 8 und dem Gehäuse 1 ein Ringraum 9 vorhanden ist. Die Mündung des Filterbeutels 8 befindet sich an dessen unterem Ende, und das obereThe tube 2 is used to support a flexible filter bag 8 made of woven filter material, the is arranged in this tube so that an annular space 9 between the filter bag 8 and the housing 1 is available. The mouth of the filter bag 8 is at its lower end, and the upper one

ίο Ende des Beutels ist geschlossen; der Beutel ist an dem Rohr 2 nur längs des Randes seiner offenen Mündung befestigt. Der Filterbeutel 8 ist in ein hier nicht gezeigtes Schutz- und Stützgewebe aus Nylon eingeschlossen, das mechanische Beschädigungen des Filterbeutels, z. B. durch die Ränder der Löcher in dem Rohr 2, verhindert.ίο end of the bag is closed; the bag is on attached to the tube 2 only along the edge of its open mouth. The filter bag 8 is in a here Protective and supporting fabric made of nylon, not shown, included, the mechanical damage of the filter bag, e.g. B. by the edges of the holes in the tube 2, prevented.

Innerhalb des Filterbeutels 8 ist ein elastischer, nichtporöser Membranhohlkörper 10 aus stranggepreßtem Gummi oder Latex angeordnet, der dieInside the filter bag 8 is an elastic, non-porous hollow membrane body 10 made of extruded material Rubber or latex arranged that the

ao Gestalt eines Beutels hat und am oberen Ende geschlossen ist. Das offene Ende ist am vorspringenden Ende eines Rohrs 11 befestigt, daß sich durch die Mitte des abnehmbaren Deckels 6 erstreckt. Somit steht das Rohr Il in Verbindung mit dem Innenraum des Membranhohlkörpers 10. Außerdem ist das Gehäuse mit seinen Deckeln mit weiteren Öffnungen versehen, die durch Rohre 12,13 und 14 mit dem Filtratraum außerhalb des Beutels 8 und des Membranhohlkörpers 10 in Verbindung stehen. Ein weite-, res Rohr 15 mündet in dem Trüberaum zwischen dem Filterbeutel 8 und dem Membranhohlkörper 10. Das Rohr 11 kann mit einer Quelle für Druckwasser oder ein anderes hydraulisches Druckmittel verbunden werden, um den Membranhohlkörper 10 aufzublähen, wenn der abnehmbare Deckel befestigt ist. Das Rohr 12 ist an eine Quelle für Druckluft über ein Ventil 12 A angeschlossen, so daß man den Druck in dem Filtratraum auf der Außenseite des Filterbeutels 8 erhöhen kann. Der Kanal, über den das Rohr 12 mit dem Filtratraum in Verbindung steht, ist mit einem Rückschlagventil 12 B ausgerüstet. Alternativ zum Erhöhen des Drucks durch Einleiten von Druckluft über das Rohr 12 kann man den Druck in den Filtratraum dadurch herabsetzen, daß man das Rohr 13 über ein Ventil 13^4 mit einer Vakuumpumpe oder einem Ünterdruckbehälter verbindet, um Luft aus dem Filtratraum abzusaugen. Wie nachstehend beschrieben, bildet das Rohr 14 den Ablauf für das Filtrat. Dieses Filtrat kann über ein Ventil 14 A abgezogen werden. Ein weiteres Ventil 15 A regelt die Zufuhr der Trübe. Das Rohr 15 ist mit einem Rückschlagventil 15 B ausgerüstet, durch welches die Öffnung verschlossen wird, über die das Rohr mit dem Trüberaum in Verbindung steht.ao has the shape of a bag and is closed at the top. The open end is attached to the projecting end of a tube 11 that extends through the center of the removable cover 6. The tube II is thus in connection with the interior of the hollow membrane body 10. In addition, the housing with its covers is provided with further openings which are in connection with the filtrate space outside the bag 8 and the hollow membrane body 10 through tubes 12, 13 and 14. Another tube 15 opens into the sump between the filter bag 8 and the hollow membrane body 10. The tube 11 can be connected to a source of pressurized water or another hydraulic pressure medium in order to inflate the hollow membrane body 10 when the removable cover is attached. The pipe 12 is connected to a source of compressed air via a valve 12 A , so that the pressure in the filtrate space on the outside of the filter bag 8 can be increased. The channel over which the tube 12 communicates with the filtrate chamber in connection is equipped with a check valve 12 B. As an alternative to increasing the pressure by introducing compressed air through the pipe 12, the pressure in the filtrate space can be reduced by connecting the pipe 13 via a valve 13 ^ 4 to a vacuum pump or an underpressure container in order to suck air out of the filtrate space. As described below, the pipe 14 forms the outlet for the filtrate. This filtrate can 14 A are withdrawn via a valve. Another valve 15 A regulates the supply of the pulp. The pipe 15 is equipped with a check valve 15 B , through which the opening is closed through which the pipe is in communication with the fluid space.

Während des Betriebs ist das Beutelfilter gemäß der Zeichnung angeordnet, d, h. der Deckel 6 ist am Gehäuseflansch befestigt. Sämtliche Ventile sind geschlossen. Die Trübe, z. B. eine Tonaufschwemmung, wird durch öffnen des Ventils 15 A über das Rohr 15 in das Beutelfilter eingeleitet; hierauf wird das Ventil 15 A geschlossen. Druckwasser oder ein anderes hydraulisches Druckmittel wird über das Rohr 11 in den elastischen Membranhohlkörper 10 geleitet, um ihn aufzublähen. Während er sich ausdehnt, wird die Aufschwemmung gezwungen, das gewebte Filtertuch des Filterbeutels 8 zu durchdringen. Das Filtrat passiert den Filterbeutel 8, das Stützgewebe aus .,During operation the bag filter is arranged according to the drawing, i. E. the cover 6 is attached to the housing flange. All valves are closed. The turbidity, e.g. B. a Tonaufschwemmung, is initiated by opening the valve 15 A through the pipe 15 in the bag filter; the valve 15 A is then closed. Pressurized water or another hydraulic pressure medium is passed through the tube 11 into the elastic hollow membrane body 10 in order to inflate it. As it expands, the suspension is forced to penetrate the woven filter cloth of the filter bag 8. The filtrate passes through the filter bag 8, the supporting fabric from.,

Claims

3 43 4

Nylon (WZ) and the holes of the tube 2 to get into the. It has been shown that a filler bag with a

to reach the annular space 9 serving as the filtrate space. Diameter from about 140 to about 150mm for clay

The filtrate can at will via the valve 14 A slurries with a specific weight

subtracted from. The clay particles remain in about 1.050 which is suitable.

a layer as a filter cake under pressure between 5 The length of the filter bag does not have any significant

the filter bag 8 and the hollow membrane body 10. lent influence on the relationship between the

The hydraulic pressure medium is now over the bag volume and the filter surface, i. h., man

Tube 11 from the elastic hollow membrane body 10 can be a filter bag with the largest practical

drained; then the cover 6 is chosen together with a length that is still usable. However, it is

the membrane body 10 by loosening the screw io noticed that using one is too long

connections 7 removed. The filter bag 8 remains filter bag difficulties when turning inside out and

usually result together with the layer of the filter- removing the filter cake,

cake in its location. Compressed air is then passed in. It should also be noted that the woven filter bag

over the valve 12 A and the check valve 12 B must be as fine as possible in order to pass through

into the filtrate space so that the filter bag 8 will prevent over the »5 solid particles. Just the filter bag

after removing the cover 6, the free opening acts as a filter. And for economic reasons

is turned over. Since the filter bag 8 attaches to the housing, the filter cake must not become too thick,

is stigt, it is turned around here. The biggest . The holes in the support tube 2 have small ones

Part of the filter cake flakes off. The rest of the diameter, so that the filter bag at high

of the filter cake is not pushed through the holes by the compressed air from the pushing and through

The filter bag 8 is blown down so that the pores are damaged at their edges. As further protection

of the filter material become free. The filter cake measure against damage are the inlets

can be collected. . . on pipes 12 and 15 through the non-return

In order to protect the bag filter for the next batch of valves 12 B and 15 B in such a way that they are ready for filtration, the filtrate space will form smooth surfaces on the inside of the valve 13.4 on the inside of the valve 13.4 on a vacuum pump or on one side of the chamber via a closed state. .
Vacuum tank connected. The filter bag 8, the tube 2 can withstand high pressures, so it is sucked back into the filtration position so that the remaining liquid from the 'filter so that it can again squeeze out the cake shown in the drawing takes to an almost dry position. Finally, one proceeds to obtain the membrane product. It has been shown that the hollow body 10 reinserted and fastened the cover 6 using pressurized water or another on the housing. hydraulic pressure medium for applying the

It should be noted that the filtration performance of a pressure due to the expansion of the elastic membrane bag filter primarily on the surface of the hollow body offers a further advantage because of the filter bag. Given the surface area and the fact that the slurry can be pumped into the bag filter at low pressure directly in the case of a slurry with a certain amount, so that the solids content depends on the thickness of the filter cake which is known to be detrimental to a filtration process at high pressures of turbidity Wear and tear is not to be feared.
according to the volume of the slurry that is being filtered during the process. However, the advantage is that the filter bag is not scratched out or the time that is required to scrape a filter cake is not needed to produce the filter cake with the desired thickness, not to be removed directly. This makes the risk of being out of proportion to the thickness of the filter cake because of it. Plugging the pores of the filter cloth would largely take longer, a certain volume of the wrinkles. Particles of the filter cake can easily be filtered out of the pores with the aid of compressed air through a thick filter cake 45 with the aid of a slurry rather than just blown through the filter cloth,
alone. The minimum time during which the bag filter cannot be used for filtering, i.e. patent claims:
during which the filter cake is removed and that

Prepare the filter for the next filtration process. 5 ° 1. Bag filter for high pressure, consisting of tet is almost constant and changes with a rigid, roughly cylindrical housing, Changes in the filter cake thickness are not in one of the main axes of which lies in an approximately perpendicular plane noticeable extent. If you take into account the lower lid that is easy to open, one Pressing a certain amount of the slurry inside with its open lower end time required, as well as the filter bag 55 attached to the housing flange and one Filter cake required time, so it is possible to wrap it, liquid-permeable, in to determine the thickness of the filter cake, the rigid support, with a device every filtration process must arise if a. to turn the filter bag inside out for cleaning optimal Amount of the product can be obtained after removing the lid, and a supplement. This optimal volume of slurry 60 could lead the slurry into the interior of the filter naturally contained in a bag filter, bagged ice and a discharge line for the filtrate which can accommodate exactly this volume, so that from a filtrate space, thereby gekennsich a certain optimal diameter shows that within the filter bag (8) if one takes into account the fact that one also determined a connection to a hydraulic pressure medium Filter area and the desired volume, up to about the size of the filter bag men must be present. Before each filtration, inflatable, essentially closed, Process then the filter bag is completely arranged with a dense hollow membrane body (10), filled with the slurry. the one with its open, lower end with the

removable cover (6) and a tube (11) is connected. and that the formed as an annular space Filtrate space between the filter bag (8) and the housing (1) continues to be lockable Lines (12, 13) can be brought into connection with compressed air or vacuum.

2. Bag filter according to claim 1, characterized in that a check valve (15 B, 12B) is provided in the feed pipe (15) for the slurry and in the line (12) for the supply of compressed air, the valve cone of which is open in the closed state the side facing the interior of the housing has a smooth surface.

3. Bag filter according to claim 1 or 2, characterized in that between the filter bag (8) and the rigid support (2) another filter bag made of polyamide is provided.

1 sheet of drawings