WO1997026974A1

WO1997026974A1 - Disk filter

Info

Publication number: WO1997026974A1
Application number: PCT/EP1997/000231
Authority: WO
Inventors: Josef Ziller
Original assignee: Schenk Filterbau Gesellschaft mit beschränkter Haftung
Priority date: 1996-01-24
Filing date: 1997-01-18
Publication date: 1997-07-31
Also published as: DE19602348C1

Abstract

The invention concerns a filter for the layered filtration of suspension such as juice, wine, beer etc. A container (3) contains a filter set (28) comprising stacked filter elements (25) in the form of plates. Each filter element (25) has a hub (26) which is held in place by a shaft (12) projecting through the filter set (28). The hubs (26) contain an axial supply conduit (36) for the unfiltered part (18) and have several supply channels (46) equally distributed around the periphery of each hub (26) and directed radially outwards. These supply channels (46) are supplied from the supply conduit (36) and guide the unfiltered part (18) into the space (29) between neighbouring filter elements (25). Each filter element (25) also has at least an output channel (31) for the filtrate ending in the hub (26). In order to keep down the material and processing costs of the hub (26), the hub (26) comprises an inner ring (76) and an outer ring (86) lying concentrically to one another at a radial distance (b). The annular space (70) between the inner ring (76) and the outer ring (86) forms the conduit for the non-filtered part.

Description

Disc filter

The invention relates to a filter for sweat filtration of suspensions, in particular juice, wine, beer, chemical liquids or the like. According to the preamble of claim 1.

Such a disc filter is known from DE 35 29 706 C3, the unfiltrate is fed radially branching inlet channels via feed lines formed in the hub, which lead into a distributor ring space which is formed below the filter plate of a filter element. From this distributor ring space, the axially opposite filter element is flowed directly, as a result of which a uniform flow distribution is achieved in order to build up a homogeneous filter cake. The filtrate is discharged through filtrate drainage channels that lead to the center of the hub. This well-known disc filter ensures good filtration results with a high degree of utilization of the filter aids.

In order to ensure a flow-free supply of the unfiltrate for the precoat filtration, the hub must be of complex design. In the known disk filter, the hub is made from a solid ring disk. A large number of axial bores are to be drilled over the circumference thereof as a feed line for the unfiltrate, with feed channels from these individual bores for feeding the unfiltrate into the space between adjacent Branch off the beard filter elements. Since each axial bore of a hub has to connect liquid-tight to a congruent axial bore in the hub of an adjacent filter element, a sealing surface or a receiving groove for a sealing ring must be formed at the axial ends of the bore. Since the axial bores lie at a radial distance from the hub axis, the end faces of the axial bores can only be machined by milling with a head mill, which is very time-consuming and labor-intensive.

To center the filter element on a common shaft, spacers must be welded into the hub opening, which spacers must also be connected to the shaft in a rotationally fixed manner by means of a feather key. When assembling the filter pack, a sealing ring for pressure-tight connection to the axial bore of an adjacent hub is to be arranged on one end of each axial bore. The effort for the production of the sealing surfaces and receiving grooves and the effort for the required number of seals is very large.

The invention is based on the object of designing a filter element for a disc filter in such a way that the hub to be threaded onto a shaft of the filter pack and lying in the center of a filter plate is simple to manufacture with little use of material and low processing outlay.

The object is achieved according to the characterizing features of claim 1.

Both the inner ring and the outer ring are easy to manufacture, and the annular space formed between the inner ring and the outer ring can be used as a feed line due to the concentric arrangement with one another. It Therefore, the axial bores with the special sealing surfaces and the large number of sealing rings, which are otherwise to be formed to form the supply line for the unfiltrate, are eliminated.

The feed line is rotationally symmetrical to the hub axis, so that the machining of the end faces necessary for the pressure-tight connection to adjacent hubs of other filter elements is possible to form a sealing surface or a receiving groove for a sealing ring by turning. In this case, only two receiving grooves or corresponding annular sealing surfaces are to be produced on the respective end face.

The inner ring and the outer ring are preferably rigidly connected to one another by at least three radial bolts, the radial bolts being able to be easily fitted into corresponding bores in the inner ring and the outer ring. Simply by inserting the radial bolts into the corresponding mounting holes, a concentric and axially aligned rigid assembly of components of the inner ring and outer ring is created, which can be achieved by e.g. B. welding the bolts to the rings or z. B. is permanently fixed by a press fit. The radial bolts, which penetrate the inner ring in a liquid-tight manner and interact as a spacer with the shaft jacket, allow the hub to be aligned coaxially with the shaft. A non-rotatable connection between the shaft and each individual filter element can also be achieved in a simple manner via the radial bolts abutting the shaft jacket.

If the radial bolts are formed by hollow tubes, they can be used as filtrate drain channels penetrating the hub. For the safe drainage of the filtrate from the hollow tube, the end face of the radial bolt which is designed as a hollow tube and faces the shaft jacket bevelled at least in a partial area at an angle of preferably 45 ° to the shaft jacket.

Further features of the invention result from the further claims, the description and the drawing, in which an embodiment of the invention described in detail is shown below. Show it:

1 is a schematic representation of a partial section through a disc filter designed as a centrifugal filter,

Fig. 2 in plan view a threaded on a shaft

Hub of a filter element of the filter pack of a disc filter according to FIG. 1,

Fig. 3 in partial section of the concentric rings

Hub of a filter element connecting hollow tube,

4 shows a partial top view of the hub of a filter element,

5 shows a section through the hubs of two filter elements lying one on top of the other along the line V-V in FIG. 4 with inlet channels shown offset;

6 shows a partial section through a sleeve which delimits a distributor annular space.

The disc filter shown in FIG. 1 is intended for the filtration of liquids such as juice, wine, beer, chemical liquids and the like and is designed, for example, as a centrifugal cleaning filter. This consists of a container 3 supported on legs 4 of a stand and closed by a removable cover 5 which is fixed pressure-tight on the container 3 by means of pressure closures 6. A sight glass 7 is arranged on one side of the container 3.

Below the container 3, an electric drive motor 8 with a fluid coupling 9 is provided in the exemplary embodiment, which drives a shaft 12 via an angular gear 10 and a shaft coupling 11, which extends coaxially to the vertical axis 2 of the container 3.

Above the shaft coupling 11, the shaft 12 is held in a bearing 13; An inlet connection 16, which is arranged centrally on the bottom 15 of the container 13 and to which the liquid to be filtered, the unfiltrate 18, is supplied in the direction of the arrow, is connected via an inlet tube 17 via a sealing housing 14.

Furthermore, a drain pipe 19 is provided under the bottom 15 of the container 3, through which residual filtrate can be removed. In addition, an obliquely downwardly directed pipe socket 20 with a shut-off valve 21 is arranged in the bottom 15 of the container 3 for draining off filtrate residues and filter aids.

A central drain connection 22 is connected to the cover 5 of the container 3, through which the cleaned liquid, the filtrate 23, is discharged. The drain connector 22 is also formed as a bearing for the upper end of the shaft 12. A vent 24 is also provided on the cover 5.

A filter packet 28 made of stacked, plate-shaped filter elements 25 is arranged in the container 3. Each filter element 25 consists of a hub 26 arranged in the center of a filter plate 32, through the central opening 35 of which the shaft 12 projects. As in particular Fig. 2 shows, the hub 26 consists of an inner ring 76 and an outer ring 86, which are rigidly connected to one another via radial bolts 77. The radial bolts 77 preferably penetrate the inner ring 76 and protrude with an end section 78 into the central opening 35 of the hub 26. Provided over the circumference of the hub 26 are a plurality of radial bolts 77 which are arranged at the same distance from one another, at least three radial bolts being provided for fixing the position of the hub 26 relative to the shaft 12; In the exemplary embodiment shown, six radial bolts 77 are arranged, which are at a circumferential angle of 60 ^β to one another. Two radial bolts 77 each lie diametrically opposite to the shaft axis l? A. The end sections 78 of the radial bolts 77 protruding into the hub opening 35 have the same length 1 and cooperate with the shaft jacket 12b in order to align the hub 26 coaxially with the shaft axis 12a, which is also the vertical axis 2 of the container 3. The hub 26 is held centered on the shaft 12 by the projecting end sections 78 of the radial bolts 77; In the circumferential direction, the end sections 78 can cooperate with longitudinal ribs 12c of the shaft 12, which creates a rotationally fixed connection between the shaft 12 and the filter element 25 (FIG. 4).

The radial bolts 77 protrude up to the outer hub shell 27 into the outer ring 86 and are fixed there in a liquid-tight manner. Since the radial bolt 77 is also kept liquid-tight in the inner ring 76, the annular space 70 can be used as the feed line 36 which supplies the unfiltrate 18. The unfiltrate is branched off through inlet channels 46 which are formed in the outer ring 86 and are shown schematically with their longitudinal axis in FIG. 2.

Are the radial bolts 77 through hollow tubes 88 {Fig. 3), which in particular can have a cylindrical cross-section, can pass through the tube 88 from the outer hub jacket 27 liquid flow out through the annular space 70 carrying the unfiltrate into the annular channel 30 discharging the filtrate. Since the inner end of the hollow tube 88 bears against the shaft jacket 12b or is at a short distance from it, the axial end face 89 of the hollow tube 88 facing the shaft jacket 12b is chamfered at least in a partial area for trouble-free liquid drainage, as shown in FIG. 3. In the exemplary embodiment according to FIG. 3, one half 81 of the end face 89 lies in a plane 79 tangential to the shaft jacket 12b, while the other half 80 of the end face 89 lies at an angle 82 of preferably 45 * to this plane 79.

As can be seen from the illustration in FIG. 4 in conjunction with FIG. 5, a circumferential sealing ring 64 and 65 is arranged on an axial end face 90 of the hub 26 on the inner edges of the annular space 70. In the unloaded state shown in FIG. 5, the essentially rectangular sealing rings 64 and 65 protrude beyond the end face 90 of the hub 26. On the opposite end face 91, an essentially flat sealing ring 63 is arranged in the area of the outer edge of the outer ring 86, which can slightly protrude beyond the outer edge of the outer ring 86. The sealing ring 63 is embedded in a countersink in the end face 91 of the hub 26.

The outer ring 86 is formed in its outer circumference with essentially three sections of different diameters. The first section 71, which is the largest in diameter, holds a sleeve 60 which is essentially L-shaped in section and which surrounds the hub 26. With a foot section 66 and a section 72 with a reduced diameter, it delimits a chamber 52 which is advantageously designed as an annular chamber running over the circumference of the hub. This chamber 52 serves to calm the inflowing unfiltrate. Above the annular chamber 52 is the smallest in diameter Section 73 formed a ring step 75 on which the funnel-shaped inner edge 37 of a filter plate 32 is seated. The inner edge 37 is welded onto the ring step 75, the annular disk-like filter plate 32 being at right angles to the hub axis 38. The funnel-shaped inner collar 37 delimits, with the section 73 of the smallest diameter, a filtrate drainage space 39 which extends over the entire circumference of the hub 26 and is approximately triangular in cross section. A drainage mat 33 rests on the filter plate 32 and is received on its inner edge in a countersink 92 of the end face 90 of the hub 26. The drainage mat 33 thus closes the filtrate outlet space 39. A filter fabric 34, preferably made of stainless steel, is placed on the drainage mat 33, on which the filter cake is built up.

The hollow tube 88 forming the radial bolt 77 lies in the section 73 of the smallest diameter of the outer ring 86 and, as the filtrate outlet channel 31, guides the filtrate from the filtrate outlet chamber 39 into the annular channel 30 discharging the filtrate between the shaft 12 and the inner ring 76. The radial bolt 77 or that Hollow tube 88 lies in a plane parallel to the filter plate 32 at right angles to the hub axis 38.

Between the sleeve 60, the outer ring 86 and the filter plate 32, a distributor ring space 47 is formed, which adjoins the ring-shaped calming chamber 52 axially approximately at the level of the inner edge 37 of the filter plate 32. The distributor ring space 47 opens into an outlet gap 45 which is formed between the filter plate 32 and the leg of the sleeve 60 lying parallel to it. The collar 61 lying below the filter plate 32 and forming an end section of the sleeve 60 has embossments 62 rising up to the filter plate 32, which - as shown in FIG. 4 - extend over a partial circumference of the collar 61 and on the filter plate 32 issue. Partitions 48 are formed by these embossments 62, which are distributed uniformly over the circumference, an outlet passage 49 for the filtrate being formed between adjacent embossments 60. The partition walls 48 can lie both radially and in the circumferential direction at a distance a from the hub shell 27. Seen in plan view of a filter element 25 (FIG. 4), the partition walls 48 or the embossments 60 of the collar 61 lie in the circumferential direction between two adjacent inlet channels 46. It may be expedient to place the partition walls 48 at a radial distance from the mouth 44 of the To provide inlet channel 46 within the hub circumference.

The unfiltrate supplied via the feed line 36 flows into the settling chamber 52 via the feed channel 46, the wall section 51 of the sleeve 60 forming a wall 50 on which the inlet flow impinges. The inlet channel 46 branches off from a housing pocket 43 which is formed in the inner wall 87 of the outer ring 86. The housing pocket 43 is open to the annular space 70 and is preferably designed as a circumferential groove in the inner wall 87. Between the inlet channel 46 and the housing pocket 43, a constriction 41 is preferably formed, with which, on the one hand, an excessively high pressure drop in the feed line 36 and, on the other hand, an adapted volume flow are obtained. Since the unfiltrate flows in at the arrow 40 at high speed, the housing pocket 43 designed as a circumferential groove ensures the avoidance of an injector effect at the inlet opening of the constriction 41 facing the annular space 70.

Filter elements designed in this way are threaded onto the shaft 12 (FIGS. 1, 2) and stacked one above the other form the filter package 28, the seals 64 and 65 ensuring a tight connection of the partial sections 36 'to form an annular feed line 36 and the flat seal 63 on the Filter fabric 34 or the Filter mat 33 for liquid-tight covering of the filtrate outlet space 39 rests. The non-filtrate flowing in in the direction of arrow 40 is thus distributed over the height of the filter package 28 to the inlet channels 46 of the individual hubs 26 and enters the calming chambers 52 in order from there via the distributor ring space 47 and the outlet passages 49 formed between the embossments 60 flow out the non-filtrate space 29 between adjacent filter elements 25. The outlet flow 40 is located radially and approximately parallel to the filter element to be flown; the flow that is formed in the direction of the filter element is achieved by the pressure drop between the unfiltrate chamber 29 and the filtrate outlet chambers 39.

As FIG. 6 shows, the cuff 60 is approximately L-shaped in section. The foot section 66 forming the baffle 50 can lie at an angle 67 to the central axis 68 of the sleeve 60. The angle 67 is approximately 4 ° in the exemplary embodiment. The collar portion 61 of the cuff, which is essentially perpendicular to the central axis 68

60 can advantageously be designed to rise to its free end. The pitch angle 69 is only a few degrees; in the exemplary embodiment, the pitch angle 69 is approximately 2 ^* . The foot section 66 with the collar section

61 connecting transition section lies at an angle to the central axis 68. The angle is 25 * in the exemplary embodiment.

Claims

Expectations

Filters for precoat filtration of suspensions, in particular juice, wine, beer, chemical liquids or the like, with plate-shaped filter elements (25) stacked on top of one another in a container (3) to form a filter pack (28), each filter element (25) having a hub (26), which is aligned in its position by a shaft (12) projecting through the filter pack (28), with a feed line (36) axially penetrating the hubs (26) for the unfiltrate (18) and several in the circumferential direction of each Hub (26) lying in an evenly distributed manner, essentially radially outwardly leading inlet channels (46), which are fed by the feed line (36) and lead the unfiltrate (18) into the space (29) between adjacent filter elements (25) and each filter element (25) has at least one filtrate drain channel (31) leading into the hub (26), characterized in that the hub (26) is composed of an inner ring (76) and an outer ring (86) which are spaced apart radially ( b) are concentric with one another, and the annular space (70) delimited by the inner ring (76) and the outer ring (86) forms the feed line (36).

Filter according to claim 1, characterized in that the inner ring (76) and the Outer ring (86) are rigidly connected to one another by at least three radial bolts (77).

3. Filter according to claim 2, characterized in that the radial bolts (77) project through the inner ring (76) in a liquid-tight manner and cooperate as a spacer with the shaft jacket (12b) in order to align the hub (26) coaxially with the shaft (12).

4. Filter according to claim 2 or 3, characterized in that the radial bolts (77) are designed as hollow tubes (88) which form the filtrate discharge channels (31) penetrating the hub (26).

5. Filter according to claim 4, characterized in that the hollow tube (88) in the hub (26) forming rings (76, 86) is liquid-tightly connected.

6. Filter according to one of claims 2 to 5, characterized in that the end face (89) of the radial bolt (77, 88) facing the shaft jacket (12b) is at least in a partial region (81) tangential to the shaft jacket (12b).

7. Filter according to one of claims 2 to 6, characterized in that the end face (89) of the radial bolt (77, 88) facing the shaft jacket (12b) at least in a partial region (80) at an angle (82) of preferably 45 " to the wave jacket (12b).

8. Filter according to one of claims 1 to 7, characterized in that the inlet channel (46) branches off a housing pocket (43) which is formed in the wall (87) of the feed line (36).

9. Filter according to claim 8, characterized in that the housing pocket (43) is designed as an inner circumferential groove in the outer ring (86).

10. Filter according to claim 8 or 9, characterized in that a constriction (41) is formed between the housing pocket (43) and the feed line (36) in the inlet channel (46).

11. Filter according to one of claims 1 to 10, characterized in that the inlet channels (46) of a hub (26) open into a common, annular chamber (52) to which the distributor ring space (47) connects.

12. Filter according to claim 11, characterized in that the chamber (52) and the distributor ring space (47) by a hub (26), surrounding sleeve (60) are limited.

13. Filter according to one of claims 1 to 12, characterized in that the distributor ring space (47) opens into an outlet gap (45) which is divided over its circumference by partitions (48) into a plurality of outlet lanes (49).

14. Filter according to claim 13, characterized in that the partition (48) as an embossing (62) in a collar portion (61) of the sleeve (60) are formed.