WO2013182193A1

WO2013182193A1 - Filtering device for fluids

Info

Publication number: WO2013182193A1
Application number: PCT/DE2013/100204
Authority: WO
Inventors: Robert Middler
Original assignee: Kreyenborg Verwaltungen Und Beteiligungen Gmbh & Co. Kg
Priority date: 2012-06-06
Filing date: 2013-06-06
Publication date: 2013-12-12
Also published as: DE102012104924A1

Abstract

The invention relates to a filtering device (100) for fluids, which is designed as a screen piston exchanger. Said filtering device comprises a housing (10) having two displaceably mounted screen pistons (20, 30). The housing comprises at least one backwashing channel (41, 42, 43, 44) leading from the outer side of the housing to a housing bore (11, 12), which joins in a backwashing position of a screen piston (20, 30) in one of the screen cavities (21, 22, 31, 32). The backwashing channel (41, 42, 43, 44) for the screen cavity (21, 22, 31, 32) of one of the screen pistons (20, 30) arranged in the backwashing position is guided by means of a backwashing deviation channel (35, 36, 25, 26) on or in the respective other screen piston (30, 20) located in the production position.

Description

Filtration device for fluids

The invention relates to a filtering device for fluids, comprising a housing having at least two Gehäusebohrun ^¬ gene in which two axially displaceable screen plunger are integrally ^¬ assigns each have at least one screen cavity on ^¬, in which a filter medium is to be placed, and comprising:

at least one inlet part channel per screen cavity; at least one outlet channel per Siebkavität; and at least one of the housing outside in the Ge ^¬ housing bore leading backwash channel, which opens in at least one backwash position of a screen pin in a Siebkavität.

Such a filtering device is known from PCT / WO2004 / 026432 AI. This makes it possible to keep a continu ^¬ ous production operation to continue, even if one of the four screen cavities must be cleaned. By dividing the fluid flow to two Screening studs, each with two screen cavities, can constantly maintain 50% of the total filter area in production operation, while the other screen areas are backwashed or completely replaced. In a preferred embodiment of the known filter device, it is even possible to 75% of the total filter area in the production plant to hal ^¬ th, while only one of the four screen cavities carried backwashing or replacement of the filter media.

The advantageous effect of the known filtering device, namely to keep three quarters of the filter surface constantly in production, based on special ^¬ ren geometric conditions of the inlet and outlet part channels as well as the screen pin, which allow it to play together ^¬ , on the same screen pin the one Flushing screen cavity while the other is still flowing through the production plant. Due to the narrow axi ^¬ alen distances of the subchannels, the different

Flow paths, which are illustrated in Figures 1-5 of PCT / WO2004 / 026432 AI, allow, it is often ^¬ times no longer possible to provide a so-called locking position for the preparation of the backwashing, ie an axial position of the screen bolt, at the screen cavity on its clean side is already connected to an outlet ^¬ partial channel, but is still completely shut off on the dirty side of all flow paths. Without the shut-off but a pressure build-up, which is necessary for the effective ^¬ ve cleaning, not possible.

Thus, it is then necessary to shut off the so-called backwash channel, which establishes a connection between the dirty side of a screen cavity and the outside of the housing, with a valve, so that the screen Initially, from the clean side ago with the fluid, in particular ^¬ the plastic melt, can be acted upon. Thereafter, the valve is opened, so that solved by the high back pressure of the fluid to the filter element festsit ^¬ dividing particles and are washed away through the backwash to Ge ^¬ housing outside back. Such From ^¬ off valve increases the production costs and also must be kept constantly hot in the filtration of molten plastic so that it leftover Schmel ^¬ ze does not freeze. Since the valve is usually attached to the outside of the housing, it must be additionally ^¬ heats and / or insulated.

Object of the present invention is to improve a filtration device of the type mentioned so that the backwash channel without an external valve is shut off ^¬ bar.

This object is achieved by a filtering device having the features of patent claim 1.

The invention is based on in the backwashing of the screen plunger channel positions the Rückspülkanäle no longer directly from any screen cavity to the outside of Ge ^¬ häuses to lead and to install a valve at the mouth, but the respective other screen plunger, which is located in its production position, to use as a valve.

A backwash inlet channel, which leads away from the screen cavity to be washed, leads within the housing to the housing bore for the respective other screen bolt and first opens onto its lateral surface. Also a ^further part of the backwash channel, namely a backwash passage channel, which leads to an opening at the Gehäuseausßensei ^¬ te, opens at the lateral surface of the second Siebbol ^¬ Zen, whereby the backwash channel is interrupted altogether. As a result, a pressure can build up in the screen cavity of the first screen bolt to be flushed, which jams against the jacket surface of the second screen bolt. By ei ^¬ nen small axial stroke of the second screen pin a groove introduced on the circumference is moved to the mouths of the two sections of the backwash channel, so that they are connected together. Thus, the flow path for the screen cavity to be purged on the first screen plunger is free ge ^¬. The axial stroke on the second screen pin only needs a little more than the width of the circumferential groove, which according to a preferred embodiment forms the deflection point in the backwashing channel. The on ^¬ production operation on the second screen pin is not affected.

Particularly advantageous is also that it is possible in each of two sections in the OF INVENTION ^¬ to the invention separation of the Rückspülkanäle that the one above the other lie ^¬ constricting screen cavities in the adjacent screen plunger have a common backwash, depending on which of the two adjacent screen cavities being rinsed , leads to the deflection channel on one or the other screen pin. This already achieves a manufacturing advantage. The symmetrical design avoids an axial offset of individual flow paths and thus makes it possible to form the deflection channels on both screen bolts the same and to arrange them at the same axial position. The diversion channels can be internal channels within ei ^¬ nes screen plunger whose mouths then each end so that they spülaustrittskanal with the backwash inlet and return a continuous flow path ausbil ^¬.

Preferably, the deflection channels are formed as simple circumferential grooves on the outside of the screen pins. Since the screen plunger is sealingly guided in the housing bore, also results in an outward abgeschlosse ^¬ ner channel.

In particular, the common backwash may be formed by two portions which are zuei ^¬ Nander made V-shaped and which intersect at a point on the outside of the housing, the backwash ^¬ inlet channel is closed at the intersection by a shut-off again. The sections can thus be easily formed by two oblique, introduced from the outside of the housing forth holes.

Although each can be individually connected to the backwash outlet Gehäu ^¬ seaußenseite. Preferably, however, the Rückspülaustrittskanal is formed from two V-shaped each other employed Rückspülteilaustrittskanälen that lead to a common end of a backwash or equal to a common outlet opening on the outside of the housing. This allows a particularly space-saving design of the flow paths, which in particular makes it possible to arrange the common outlet opening at the end face of the housing between the housing bores. However, the particular advantage of the common backwash inlet channel described above lies in the fact that an internal flow connection can be formed between the respective dirt sides of the adjacent screen cavities, which is completely independent of the backwashing function described above. This flow connection via the common backwash inlet channel makes it possible to refill a cleaned and emptied sieve cavity from the dirty side with fluid, in particular plastic melt, and thereby vent it.

In the filtration apparatus known from the prior art, the filling always takes place from the outlet side, but where due to the pressure drop at the filtration device itself or too low a system pressure in the downstream processing machines, the fluid flow is too low to achieve a fast filling and venting and to return the affected screen cavity to the production position as soon as possible.

The double benefit of the formation of the backwashing channel according to the invention is achieved in that the Siebkavi- täten each have in addition to the known vent channel, which extends in the venting position of a screen pin from the respective top of Siebkavität to the housing outside, a preflow channel, which also from Edge of the Siebkavität runs in the direction of the outside of the housing, but extends axially less far than the vent channel and does not lead out of the housing in the venting position. As a result, the pre-flow channel is without function in the venting ^¬ the Siebkavität. At the neighboring screen On the other screen pin, which is located in a special axial position, the prefilter channel establishes a connection between the screen cavity there and the common backwash inlet channel. Wei ^¬ terhin in this position the screen cavity local in a compound having at least one of Eintrittska ^¬ ducts in the housing.

The flow path in the filling and venting thus results as follows: the fluid flows through one of the A ^¬ occurs partial channels of the housing into a screen cavity of the egg ^¬ NEN screen plunger and flows from there via the Vorflutkanal and the common Rückspülkanaleintrittskanal in the adjacent screen cavity of the other screen plunger , The Siebkavität fills quickly due to the pressure prevailing at the inlet side high pressure. The displaced air escapes upwardly through the vent channel to Gehäu ^¬ seaußenseite. After complete venting both screen bolts return to the production position. So any compounds of venting ducts for Ge ^¬ häuseaußenseite as well as the Vorflutkanäle to the common ^¬ seed backwash be interrupted. The backwashing ^¬ channels themselves are also interrupted because the backwash inlet channels open directly again on the lateral surface of the screen pin.

An additional valve for closing the backwashing channel can additionally be provided in order to be able to carry out a backwashing even if the screen bolt which has the deflection channel according to the invention is repaired or is being serviced or can not be moved into the position for other reasons, in which he should complete the backwash with his backwash diverting channel. The invention will be explained in more detail with reference to the drawing ^¬ tion. The figures show in detail:

1 shows a filtration device in the backwash position in a side view of the ^{Eintrittssei ¬} te;

FIG. 2 shows a filter device in the venting position in a side view of the inlet side; FIG.

FIG. 3 shows the filtration device according to FIG. 1 in top view; FIG.

Fig. 4, the filtering device according to Figure 1 in one

Detail of a perspective view;

Fig. 5 is an enlargement of the view of Figure 4; and

Fig. 6, the filtering device according to Figure 2 in one

Detail of a perspective view.

1 shows a Filtriervorrich ^¬ device 100 according to the invention with a housing 10 with two housing bores 11, 12, in which screen pins 20, 30 are mounted axially displaceable. Each screen pin 20, 30 has in the illustrated embodiment ^¬ two screen cavities 21, 22, 31, 32. These are fed by inlet part channels 13.1, 13.2, 13.3, 13.4, which branch off from a common inlet opening 13 on the housing 10.

In the left-hand image area, circumferential grooves 25, 35 can be seen on the mutually facing sides of the projecting ends of the screen pins 20, 30, which are required for the backwashing process described below. The sieve Bolt 20, 30 are formed symmetrically with respect to a vertical axis, so that correspondingly on the other Be ^¬ te the filtering device, at the respective other end of the screen pins 20, 30 and circumferential grooves 26, 36 are provided.

In the housing 10, a common backwash inlet channel 41, 42 is provided for each pair of superposed Siebkavitäten 21, 31 and 22, 32, which extends within the housing 10. Per pair in each case a backwash outlet 43, 44 is also provided, which branches from egg ^¬ ner common mouth at the outside of the housing into two portions 43.1, 43.2 (see. Fig. 4), each ^¬ weils to one of the screen cavities 21, 31 and 22, 32 lead.

Each of the screen cavities 21, 22, 31, 32 has at least one ventilation channel 21.2, 22.2, 31.2, 32.2 in the upper area. Furthermore, each of the screen cavities 21, 22, 31, 32 each has at least one bleed channel 21.1, 31.1, which is arranged close to the housing center axis, so that a connection with the mouths of the backwash inlet channels 41 and 42 can be established.

In Figure 1 there is according to the invention said filtration ^¬ device 100 with the upper screen plunger 20 in one backwashing position for flushing the upper left Siebkavi- ty 21st

The lower screen pin 30 with its screen cavities 31, 32 is in a production position, although it is not arranged exactly in the center with respect to the central inlet ^¬ opening 13. Nevertheless, the two screen cavities 31, 32 of the lower screen pin 30 by each because two inlet sub-channels 13.3 flowed. The ge ^¬ rings axial displacement of the lower screen pin 30 from the center position is necessary to bring the circumferential groove 35 in coincidence with the mouths of the Rückspüleintrittska- channel 41 and the Rückspülaustrittskanals 43 and thus to open the flow path for the fluid.

FIG. 3 shows the filtration device 100 in the backwash position in a view from above. The position of the screen plunger 20, 30 is, as shown in the side view of Figure 1, that is, the OBE ^¬ re screen plunger 20 is shifted to the left.

The right Siebkavität 22 of the upper screen pin 20 is flowed through from the inlet opening 13 ago. On the outlet side, the fluid via one of the housing designs passes occurs partial channels 14.1, 14.2 into the back of the left screen ^¬ cavity 21, from there through the backwash inlet 41 through which not visible here circumferential groove at the lower screen plunger 30 and above finally enters channel in the Rückspülaus- 43rd

FIG. 4 again shows the backwashing position, specifically in an enlarged detail of a perspective view. It becomes clear that the backwashing ^inlet channel 41 consists of two sections 41.1, 41.2 which are set in a V-shape relative to one another and have been manufactured from a common point of intersection 41.3 on the outside of the housing. The intersection has subsequently been sealed again with a closure element. The back spülaustrittskanal 43 is similarly made: from a common intersection point on the housing outside of Zvi ^¬ rule the screen plunger 20, 30 are two oblique bores 43.1, 43.2 introduced in the direction of the respective Siebkavitäten 21, 31. However, the intersection remains open here, because it forms the common Rückspülkanal- outlet 43.3.

At the lower screen plunger 30 is between the end of the rear spüleintrittskanals 41.2 and the circumferential groove seen the end of the passage channel Rückspülaus ^¬ 43.2 35 through wel ^¬ che the Rückspüleintritts- and -austrittskanäle 41.2, 43.2 in the position shown, the lower sieve pin 30 connected to one another have been brought.

FIG. 5 shows a further enlarged detail from FIG. 4. Therein, the flow path is shown with the dot-dash line.

During the backwashing, the plastic melt flows from the rear, ie from the clean side, into the upper left Siebkavität 21, and through the filter element not shown here into the Rücklüleintrittskanal 41. It then enters the circumferential groove 35 on the upper side of the lower screen pin 30 and about this in the lower portion 43.2 of the backwash outlet channel 43 to the outlet opening 43.3 on the housing 10th

The other portion 43.2 of Rückspülaustrittskanals 43 opens at the lateral surface of the upper screen pin 20 and is thus closed off. Without function is in the Darge ^¬ set position of the upper Siebkavität 21 and the pre-flood channel 21.1.

FIG. 2 again shows the filtration device 100 in a side view of the inlet side. In the Darge ^¬ presented position of the screen pin 20,30 is the filling and venting the previously cleaned, left upper Siebkavität 21 reached. Compared with the position in FIGS. 1, 4 and 5, the upper screen bolt 20 has been displaced even further to the left, so that the venting channel 21. 2 now ends outside the housing 10. It should be noted that the pre-flow channel 21.1, which is not required for the venting of its own Siebkavität 21, ends just before the housing edge.

At the lower screen pin 30, the right sieve ^¬ cavity 32 is in production. It is still fed by one of the inlet subchannels. The left Siebkavität 31 is still just in overlap with the inlet part channel 13.3, so that melt can flow into the Siebkavität 31. The preflow channel 31.1 of the screen cavity 31 is in communication with the common backwash inlet channel 41 of the two adjacent screen cavities 21, 31.

It is clearly visible that the circumferential grooves 25, 35 both lie outside the housing 10, so that no Ver ^¬ bond between the backwash inlet 41 and the backwash outlet 43 is. The backwash ^{inlet ¬} channel 41 is used in this position solely the internal transfer of the fluid from the lower Siebkavität 31 in the upper Siebkavität 21st

In Figure 6, the flow path in the venting position is shown as a dashed line. The fluid passes from the inlet opening 13 in one of the inlet part channels 13.3 and above in the lower Siebkavität 31. About the Vorflutkanal 31.1 is a connection between the Siebkavität 31 and the common backwash inlet channel 41 produced. Via the backwash inlet channel 41 as a bridge, the upper left Siebkavität 21 is reached and filled with fluid. The displaced air escapes upwards via the venting channel 21. 2 as well as via ^further venting channels to the outside of the housing 10.

The Vorflutkanal 31.1 also serves as a throttle to achieve a very slow filling, which allows even with highly viscous liquids a uniform, bubble-free loading ^¬ filling. The preflow channel is therefore preferably wedge-shaped, so that its opening cross-section can be varied by fine tuning of the axial position of the screen pin.

Claims

Patent claims:

1. Filtering device (100) for fluids, with a housing (10) with at least two housing bores (11, 12), in which two axially displaceable sieve bolts (20, 30) are arranged, each of which has at least one sieve cavity (21, 22 , 31, 32) in which a filter medium is to be arranged, as well as with:

at least one inlet channel (13.1, 13.2, 13.3) per screen cavity (21, 22, 31, 32);

at least one outlet channel per sieve cavity (21, 22, 31, 32); and

at least one backwash channel (41, 42, 43, 44) leading from the outside of the housing into the housing bore (11, 12), which opens into a screen cavity (21, 22, 31, 32) in at least one backwash position of a screen bolt (20, 30). , characterized in that the backwash channel (41, 42, 43, 44) for a screen cavity (21, 22, 31, 32) of the one screen bolt (20, 30) located in the backwash position via a backwash deflection channel (35, 36, 25, 26) on or in the other screen bolt (30, 20) located in the ^production position.

2. Filtering device (100) according to claim 1, characterized in that the backwash channels (41, 42) for the sieve cavities (21, 22, 31, 32) each comprise at least: a backwash inlet channel (41, 42), which in a backwash position of one of the screen bolts (20, 30) opens with one end into the screen cavity (21, 22, 31, 32) to be backwashed and which has the other end in the housing bore ( 11, 12) for the other sieve bolt (20, 30);

a backwash deflection channel (25, 26, 35, 36) on the other screen bolt (20, 30), which connects to the backwash inlet channel (41, 42) in at least one axial position of the other screen bolt (20, 30);

a backwash outlet channel (43, 44), which leads from the housing bore of the other sieve bolt (20, 30) to the outside of the housing (10) and which in the mentioned axial position of the other sieve bolt (20, 30) on the backwash deflection channel (25, 26 , 35, 36).

Filtering device according to claim 2, characterized in that the sieve cavities (21, 31, 22, 32) of adjacent sieve bolts (20, 30) arranged one above the other ^have a common backwash inlet channel (41).

Filtering device (100) according to at least one of claims 1 to 3, characterized in that on the outside of the sieve bolt (20, 30) from each sieve cavity (21, 22, 31, 32) towards the outside of the housing (10). at least one ^ventilation channel (21.2, 22.2, 31.2) and at least one pre-flood channel (21.1, 31.1) extend, the axial extent of which does not extend further than that of the ventilation channel (21.2, 22.2, 31.2), wherein the ventilation channel (21.2, 22.2, 31.2) extends from a sieve cavity (21, 22, 31, 32) to beyond the outside of the housing (10) in a venting position of a sieve bolt (20, 30).

and at the same time, in the case of the other screen bolt (20, 30), the screen cavity (21, 22, 31, 32) is connected to an inlet sub ^- channel (13.1, 13.3) and to the pre-flood channel (21.1, 31.1) and the pre-flood channel

(21.1, 31.1) connects to the backwash inlet channel (41, 42), which is connected to the screen cavity to be vented

(21, 22, 31, 32) flows.

5. Filtering device (100 ^Λ ) according to at least one of claims 2 to 4, characterized in that the backwash outlet channel (43 ^Λ , 44 ^Λ ) can be closed with a valve (50 ^Λ ) or the backwash inlet ^channel (41, 42) through a Valve needs to be interrupted.

6. Filtering device according to at least one of claims 2 to 5, claim, characterized in that the backwashing inlet channel (41, 42) is formed from two V-shaped backwashing part inlet channels (41.1, 41.2) which are located at a point (41.3). the outside of the housing (10), the backwash inlet channel (41, 42) being closed at the ^intersection point by a shut-off element or interrupted by a valve.

7. Filtering device according to at least one of the preceding claims, characterized in that the backwashing outlet channel (43, 44) is formed from two V-shaped backwashing part outlet channels (43.1, 43.2) which are positioned towards ^one another and which form a common one Lead the outlet opening on the outside of the housing (10).

8. Filtering device according to claim 7, characterized in that the outlet opening is arranged on the end face of the housing (10) between the housing bores (11, 12).

9. Filtering device according to at least one of the preceding claims 1 to 8, characterized in that the backwash deflection channel (25, 26, 35, 36) is designed as a circumferential groove made on the outer surface of the sieve bolts (20, 30).

10. Filtering device according to at least one of the preceding claims 1 to 8, characterized in that at least one backwash deflection channel is formed within the sieve bolts and has two openings on the outside.

11. Filter device according to at least one of the preceding claims, characterized in

that each sieve bolt has at least two sieve cavities (21, 22, 31, 32), in each of which a filter medium is to be arranged,

that the inlet channel (13) is branched into at least one inlet sub-channel (13.1...13.4) per screen cavity (21, 22, 31, 32);

that the outlet channel is branched into at least one outlet sub-channel (14.1, 14.2) per sieve cavity (21, 22, 31, 32).