CN1237114A

CN1237114A - pressure filter

Info

Publication number: CN1237114A
Application number: CN97198971A
Authority: CN
Inventors: 伯纳德·L·F·休伯特
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-10-18
Filing date: 1997-10-17
Publication date: 1999-12-01
Also published as: EP0946244A1; HUP0000241A2; FR2754758A1; BR9712335A; FR2754758B1; CA2268798A1; CZ138199A3; TR199901481T2; PL332829A1; JP2001502598A; AU4872097A; WO1998017367A1

Abstract

The invention relates to a pressure filter comprising at least two plates (1,2) having adjacent peripheral zones (1a,2a) defining a junction plane (7) and delimiting between them a filtering space (6) in which a membrane (8) extends and whose peripheral part (9) is engaged between the peripheral zones of the plates for at least part of its length so as to have a movable zone, on both sides of which a filtering chamber (10) and a pressure chamber (11) are delimited, means (23,26) for introducing a product to be filtered into the filtering chamber (10), means (39) for supplying a fluid to the pressure chamber (11) and means (20,29,37) for discharging the filtrate from the filtering chamber, the peripheral part (9) of the membrane (8) comprising at least one branch duct (25) engaged in the peripheral zones (1a,2a) in the meantime.

Description

Filter-press

The present invention relates to a kind of improvement to filter-press, filter-press is used in particular for concentrating various industrial mud and particularly wastewater treatments or reclaims contained juice in the substrate, particularly in sugar industry.

More specifically, the present invention relates to a kind of filter-press, it can comprise folded a plurality of plates, form filter space therebetween, diaphragm stretches in filter space, and these spaces are divided into filter chamber and balancing gate pit, treat filtrate introducing filter chamber, pressure fluid is introduced the balancing gate pit, and the fluid of introducing the balancing gate pit causes the compression of the displacement of diaphragm with realization introducing material, thereby therefrom extracts juice.

Purpose of the present invention is improved the air-proof condition of this filter pressure and installation, maintenance and the dismounting condition of improving diaphragm in particular, improves filtration and dwindles filtering bodies, and increase the mechanical strength of diaphragm.

Filter-press of the present invention preferably includes one and is stacked to few two boards, and described each plate comprises adjacent peripheral part, limits a composition surface and defines a filter space betwixt; One diaphragm extends in this space, and the peripheral part of diaphragm constrains between the peripheral part of described each plate along at least a portion of its length so that have a movable area, in the movable area delimited on either side one filter chamber and a balancing gate pit; Be used for article to be filtered are infeeded the device of described filter chamber; Be used for liquid is infeeded the device of described balancing gate pit; And the device that is used for discharging filtrate from described filter chamber.

According to the present invention, the above-mentioned peripheral part of described diaphragm preferably includes at least one minute lattice framing, and it constrains between the described peripheral part of described each plate.

According to the present invention, the peripheral part of at least one plate in described each plate preferably includes at least one flow-catheter, its lead to described filter chamber and be formed on above-mentioned minute lattice framing and the movable area of above-mentioned diaphragm between.

According to the present invention, advantageously, the extensible above-mentioned peripheral part that passes each plate of described flow-catheter, and at least one plate in described each plate comprises the passage that flows, it is described filter chamber of connection and described flow-catheter in the zone on above-mentioned composition surface.

According to the present invention, a plate is preferably pressured on a plate that is positioned at described flow passage area with the peripheral part of above-mentioned diaphragm.

According to the present invention, advantageously, described flow-catheter is extensible to be passed the peripheral part of above-mentioned diaphragm and leads to the filtrate flows conduit that is formed between diaphragm and the filter cloth.

According to the present invention, above-mentioned minute lattice framing preferably by on given length from the peripheral part of above-mentioned diaphragm cut from or isolated part form.

According to the present invention, the peripheral part of above-mentioned diaphragm preferably includes a peripheral frame, the part of peripheral frame on a given length, cut from or separate so that form above-mentioned minute lattice framing.

According to the present invention, advantageously, at least one plate in described each plate can comprise a major trough, and the frame of the above-mentioned peripheral part of diaphragm is bonded on wherein, and one second groove, and open to described major trough its each end, and lattice framing was bonded on wherein in above-mentioned minute.

One alternative embodiment according to the present invention, the peripheral part of above-mentioned diaphragm comprises a periphery sealing, it is bonded in the major trough of one of described plate, and comprise that one constrains in the frame between the peripheral part of described each plate, one outstanding diaphragm peripheral part is bonded in the circumferential groove of described sealing, and described sealing comprises above-mentioned minute lattice framing.

According to the present invention, described periphery sealing preferably includes an inner rim frame, is arranged on described diaphragm and has between the plate of described major trough.

According to the present invention, described periphery sealing preferably includes a lip, and it is close to described inner rim frame and is pressed on the plate with described major trough.

According to the present invention, described sealing has a U type section, and the edge of two arms of U type section comprises described frame.

Another alternative embodiment according to the present invention, the peripheral part of above-mentioned diaphragm comprises an outstanding peripheral part or a frame, it is bonded in the major trough of one of described plate and comprises that one constrains in the peripheral frame between the peripheral part of described each plate, and this ledge comprises above-mentioned minute lattice framing.

According to the present invention, the outstanding peripheral part of described diaphragm comprises a circumferential groove, is used for remaining on the wire of described major trough at its bottom joint one.

According to the present invention, advantageously, the peripheral frame of above-mentioned diaphragm can comprise a section enlarged, is bonded in the bottom that the section of described major trough enlarges.

According to the present invention, advantageously, one latallae can comprise the filtrate flows conduit in described filter chamber, and a filter cloth covers these conduits, and the periphery edge of this cloth is retrained by means of the periphery edge of diaphragm.

Another remodeling according to the present invention, at least the described plate and the described diaphragm that are positioned at described balancing gate pit one side have coaxial passage in above-mentioned movable area, one forms one and comprises an outstanding peripheral part with the coaxial confinement ring of described passage with described plate, the edge around its above-mentioned passage of diaphragm is constrained on the outstanding peripheral part of described ring and centering between the part of its above-mentioned passage of described plate, and at least one is communicated with inside and described filter chamber that the aperture connects described confinement ring.

According to the present invention, the outstanding peripheral part of described plate and described ring is preferably in and defines an endless groove between them, and a ring frame of above-mentioned diaphragm edge constrains in wherein.

According to the present invention, a connecting ring that is connected to described confinement ring by above-mentioned passage preferably includes an outstanding peripheral part against described plate opposite side, and described each ring constitutes an endless core.

According to the present invention, the above-mentioned ledge of the confinement ring of two adjacent panels and connecting ring preferably abuts against each other and forms described connection aperture.

According to the present invention, has coaxial waveform around its above-mentioned edge at described filter space interior diaphragm.

According to the present invention, diaphragm comprises the filtrate flows conduit in described filter chamber one side, and filter cloth covers these conduits and comprise a passage coaxial with described passage, and the edge of this passage of described cloth is retrained by the above-mentioned edge of diaphragm.

By following with reference to accompanying drawing to description as the filter-press of non-limiting example, the present invention will be better understood, wherein:

Fig. 1 represents front view according to the plate of first filter-press of the present invention with the ratio of dwindling, and it is equipped with diaphragm and cloth;

Fig. 2 illustrates the cross section along the II among Fig. 1-II line of two plates of filter-press;

Fig. 3 illustrates the front view of the exposure angle of described plate;

Fig. 4 illustrates this angle of the described plate that diaphragm and cloth are housed;

Fig. 5 is illustrated in the cross section of two plates of the described filter-press in this angle along the IV among Fig. 1-IV line;

Fig. 6 is illustrated in two plates of the described filter-press in this angle another cross section along the VI among Fig. 1-VI line;

Fig. 7 illustrates the front view of another exposure angle of described plate;

Fig. 8 illustrates this another angle of the described plate that diaphragm and cloth are housed;

Fig. 9 is illustrated in the cross section of two plates of the described filter-press in this another angle along the IX among Fig. 1-IX line;

Figure 10 illustrates the cross section of two plates of another embodiment of above-mentioned filter-press;

Figure 11 illustrates the cross section of middle body of another embodiment of described filter-press;

Figure 12 illustrates the part section corresponding to the amplification of another embodiment of the described filter-press of Fig. 2.

Referring to figs. 1 through Fig. 9, can see that show two

adjacent square plates

1 and 2 of filter-press, wherein filter-press is usually with label 3 expressions and comprise a plurality of stacked on top of each other and by the corresponding plate of side-line bar (not shown) constraint.

Plate

1 and 2 has recess area 4 respect to one another and 5, defines a filter space 6 betwixt, contacts along faying face 7 closings with 2a with 2 peripheral part 1a around the plate 1 in this space.

Filter-press 3 comprises a diaphragm 8, and it constrains between the peripheral part 1a and 2a of

plate

1 and 2 along filter space 6 extensions and its peripheral part 9, so that filter space 6 is divided into filter chamber 10 that is positioned at plate 2 sides and the balancing gate pit 11 that is positioned at plate 1 side.

The peripheral part 9 of diaphragm 8 comprises a peripheral part or frame 12, and it forms to such an extent that stretch out and be bonded in the main circumferential groove 13 of plate 1 perpendicular to faying face 7.This peripheral part 9 also comprises a sealing 14, is made by for example rubber, is arranged between the wall of this frame 12 and groove 13, and this sealing 14 is a U type section, and at one end comprises the circumferential groove 15 that forms perpendicular to faying face 7.

The bottom of the groove 13 of plate 1 has a section that enlarges, and the end of the frame 12 of diaphragm 8 has a horizontal boundary 16, so that the peripheral part 9 of diaphragm 8 constrains in wherein after in the groove 13 that distortion or compression by periphery sealing 14 enter plate 1.

Diaphragm 8 has a plurality of peaks 17 on it is positioned at the surface of filter chamber's 10 1 sides, limit flow gaps or conduit 18 therebetween.Be positioned at the displacement of the movable area within the filter space 6 for ease of it, 6 periphery also has coaxial waveform 19 to diaphragm in the space.

Filter-press 3 also comprises a filter cloth 20, and it extends in filter chamber 10 and is supported on the peak 17 of diaphragm 8 and the top of waveform 19.The peripheral part 20a of filter cloth 20 is by faying face 7 and be bonded in the groove 15 of periphery sealing 14, and walks around the outside of the peripheral frame 12 of diaphragm 8.

When assembling, the frame 12 of the circumferential edge 20a of cloth 20 and diaphragm 8 is introduced in the groove 15 of periphery sealing simultaneously.

On the edge of its neighboring arm, sealing 14 also has a frame 21, and it is arranged in the outer peripheral widened section 22 of groove 13 of plate 1.

As clearlying show that among Fig. 2, the periphery surface that the assembly that is made of the periphery of the peripheral part 9 of diaphragm 8 and filter cloth 20 is positioned at the plate 2 of faying face 7 remains in the groove 13 of plate 1, and frame 21 is on this surface.

At the angle 3, filter-press 3 has a flow passage 23 by

plate

1 and 2, and it extends and be formed on the outside of the groove 13 of the peripheral part 9 of diaphragm 8 and plate 1 perpendicular to faying face 7.

At this angle 3a, be positioned on the surface of faying face 7 at it, plate 1 has one second branch's groove 24, and it is walked around conduit 23 and its end in conduit 23 outsides with a determining deviation and opens and add broad edge 22 to its groove 13.

At its fringe region corresponding to branch's groove 24, the peripheral part 9 of diaphragm 8 has a continuous branch lattice framing 25, and it extends along this branch's groove 24.Divide lattice framing 25 to be made up of the counterpart of the frame 21 of periphery sealing 14, sealing 14 is extended and is arranged in branch's groove 24 towards outside tractive when diaphragm 8 is installed then between the end of branch's groove 24 such as isolated by cutting.

As clearlying show that in the Figure 4 and 5, thereby divide lattice framing 25 being arranged in the face constraint on the faying face 7 and being compressed in branch's groove 24 of plate 1 by plate 2.

This causes the continuous sealing in the periphery of filter-press 3, and it is formed by being arranged on frame 21 in the groove 13 and the bar 25 that is arranged in branch's groove 24.

Be communicated with for setting up between flow-catheter 23 and filter chamber 10, plate 1 has the sunk area 26 that is provided with respect to faying face 7.

Groove 13 has the part 13a of the peripheral part 9 of the hollow profile of deferring to sunk area 26 and diaphragm 8, divides lattice framing 25 to be partitioned into and to be out of shape to adapt to the profile of part 13a from the peripheral part 9 of diaphragm 8.

Be shown specifically as Fig. 3 to 6, use restraint for the zone of the peripheral part 9 that is suitable for diaphragm 8 and to it, be provided with a fuel plate 27, it adapts to the profile of sunk area and is fixed on the plate 1 by screw 28.

The sunk area 26 of flow-catheter 23 and plate 1 has constituted a flow-catheter like this, material to be filtered can be incorporated in the filter chamber 10 through this conduit.

Moreover the sealing of balancing gate pit 11 is sealed on its whole periphery by the periphery in the groove 13 of lead-in plate 1 and realizes.

At its angle 3b relative with angle 3a, illustrate especially as Fig. 7 and 9, filter-press 3 has another flow-catheter 29, and it extends through the peripheral part 1a and the 2a of plate 1 and plate 2, perpendicular to faying face 7 and be positioned at a distance in groove 13 outsides.

At this angle 3b, the peripheral part 9 of diaphragm 8 has a border 30, and it stretches out with respect to its peripheral frame 12 and is bonded in the part 31 of groove 13 sides that are formed on plate 1.

Along this border 30, the part of the frame 21 of periphery sealing 14 such as isolated so that constitutes and divide lattice framing 32 by cutting, its along groove 13 from its part 31 extended transverse branch parts 33 extensions.Thereby divide lattice framing 32 to be pressed into this part 33, walk around the part 32 of diaphragm 8 by the surface to faying face 7 extends of plate 2.

At the angle of filter-press 3 3b, plate 1 also has the conduit 34 that flows, its relatively its adjacent side extend with 45 ° and with flow-catheter 9 cross connections, the end 34 of this conduit terminates in

stopper

35 and 36.

Moreover plate 1 has a plurality of conduits 37, and it opens conductive pipe 34 on the one hand, opens on the other hand to groove 13.The peripheral part 9 of diaphragm 8 has a plurality of passages 38 that are positioned in the face of the conduit 37 of plate 1, and these passages 38 are opened below cloth 20.The flow gaps 18 of diaphragm 8 is therefore by flow-

catheter

37 and 38 and link to each other with flow-catheter 29 by flow-catheter 34, and these conduits are liquid the formation one mobile or discharge line for flowing through cloth 20 in the process that the movable area of diaphragm 8 moves towards the direction of plate 2.

Also have, as shown in Figure 2, plate 1 has a conduit 39, is used for feed fluid and enters balancing gate pit 11, and fluid under pressure is introduced this chamber and made that the movable area of diaphragm 8 can be towards the direction displacement of plate 2, so that the material of filter chamber 10 is introduced in compression.

Also have, the bottom of the sunk area 5 of plate 2 has a plurality of peaks 40, defines flow gaps therebetween or conduit 41, one filter cloths 42 are arranged in the filter chamber 10, is positioned at the top at peak 40.The peripheral part 43 of cloth 42 is fixed in the circumferential groove 44 that is formed on sunk area 5 bottoms.In aforesaid chamber 10 in the contained material compression process, thereby liquid also can be via the space 41 of plate 2, and the conduit 45 by the connecting duct on the plate 2 29 is discharged to the outside.

Referring now to Figure 10, as can be seen, show the diaphragm 46 of representing another embodiment of diaphragm 8 in the previous example.

In this example, diaphragm 46 is made by elastomeric material such as rubber, and as previous example, diaphragm 46 has a peripheral frame 47, and it is bonded in the circumferential groove 13 of plate 1 and has corresponding shape.Frame 47 has a circumferential groove 48, forms perpendicular to faying face 7, opens one side to plate 2a.In the bottom of groove, introduce a wire, it is substantially disposed in the center of the enlarged of groove 13.The periphery edge 20a of filter cloth 20 is introduced in the groove 48 and holds wire 49.

The peripheral part of diaphragm 46 and filter cloth 20 thereby be suitable for constrains in the groove 13 of plate 1 and example is the same as described above is pressed into this groove by the surface that is positioned at the plate 2 on the faying face 7.

Also have, diaphragm 46 has an outer perimeter 50, and it is corresponding to the outer perimeter 21 of the sealing of the periphery in the previous example 14.

Isolating on periphery 50 given length makes it possible to form a branch lattice framing that is equal to the branch lattice framing 25 in the previous example, or any other minute lattice framing that can be used for particularly realizing sealing on the faying face 7 of

plate

1 and 2.

With reference to Figure 11, as can be seen, show one and be used to supply with the alternative embodiment of material to be filtered to the device of the adjacent chamber 51 that separates by plate 53 of two of filter-press 54 and 52, its remaining part is corresponding to previous described filter-press.

Plate 53 heart position therein has a cylindrical channel 55.Circular cylinder shaped portion 56 and 57, two rings of being extended with two

rings

58 and 59 in this cylindrical channel 55 end-to-end have outstanding peripheral part or

peripheral shoulder

60 and 61 respectively, and the edge of the passage 55 of plate 53 extends betwixt.

One columned retainer ring 62 is bonded in the ring 58 and 59.It has a circumferential shoulder 63, is supported in ring 58 the interior circumferential recess 64 and is tightened on the circular cylinder shaped portion 57 of ring 59.

The diaphragm 65 that be arranged in the filter chamber 51, its neighboring part is supported by plate 53 has a centre gangway 66 and comprises a ring frame 67 around this passage, and ring frame 67 constrains in the shoulder and the groove 68 between the plate 53 that is formed on ring 58.Also have, a ring packing 69 is arranged in the space of cannelure 68, so that pressured ring frame 67 in diaphragm 65, plate 53 and encircle 58 circular cylinder shaped portion 56, the sealing of the balancing gate pit of realization between plate 53 and diaphragm 65 like this.

Also have, the filter cloth 70 that accompanies with diaphragm 65 has a centre gangway.The periphery 71 of this filter cloth 70 is constrained on the ring frame 67 of diaphragm 65 and encircles between 58 the shoulder 60.In addition, another surface support one filter cloth 72 of plate 53, the middle body of filter cloth has a passage, and its edge 73 is bonded on plate 53 and encircles between 59 the shoulder 61.

Ring 58 and encircle 59 end surface 74 and 75 and define vertical plane can support on it with the corresponding ring of adjacent panels, thereby whole folded formation one is perpendicular to the central flows conduit 76 of each plate of filter-press 54.

Ring 58 has a plurality of radial conduit 77, these conduits make it possible to set up between center conduit 76 and filter chamber 52 and are communicated with, and corresponding adjacent ring 59 is supported on the ring 58, have identical conduit, make it possible between center conduit 76 and filter chamber 51, set up connection.

So the center conduit 76 and the radial conduit 77 of the ring 59 that is associated with each plate 53 of filter-press 54 have constituted the adjacent chamber 51 of filter-press 54 and 52 supplying duct.

With reference to Figure 12, can see that show a periphery sealing 78, it has represented the alternative embodiment with reference to the described sealing 14 of Fig. 2.

This sealing 78, for the frame 12 of channel section and diaphragm 8 is bonded on wherein, the edge of peripheral within it arm 79 comprises the peripheral frame 80 of a compression, is arranged between the interior planar edge 81 of main circumferential groove 13 of the interior angle of frame 12 of diaphragm 8 and plate 1.

Also have, described sealing 78 comprises a contiguous frame 80 and is supported on compression seal lip 82 on the wall of groove 13 that this lip is along turning back in the opposite direction with the side that introduces sealing 78.

The invention is not restricted to example described above.Do not depart from the embodiment that appending claims institute restricted portion has many replacements.

Claims

1. A pressure filter comprising a stack of at least two plates (1, 2), said plates comprising adjacent peripheral portions (1a, 2a) defining a joint surface (7) and delimiting a filter space therebetween ( 6); a diaphragm (8) extending in this space, the peripheral portion (9) of the diaphragm being constrained between said peripheral portions of the plates along at least a part of its length so as to have a movable area, in A filter chamber (10) and a pressure chamber (11) are defined on both sides of the movable area; means (23, 26) for supplying the article to be filtered into said filter chamber (10); for supplying liquid into the device (39) of the pressure chamber (11); and the device (20,29,37) for discharging the filtrate from the filter chamber; characterized in that the above-mentioned peripheral portion of the diaphragm (8) ( 9) Comprising at least one branch strip (25) bound between said peripheral portions (1a, 2a) of said plates.

2. A pressure filter according to claim 1, characterized in that a peripheral portion of at least one of said plates comprises at least one flow duct (23, 26) leading to said filter chamber (10) and formed in said Between the branch bar (25) and the movable area of the above-mentioned diaphragm (8).

3. A pressure filter according to claim 2, characterized in that said flow conduit (23) extends through said peripheral portion of each plate, and at least one of said plates comprises a flow channel (26) which The filter chamber (10) and the flow conduit (23) are connected in the region of the aforementioned joint surface (7).

4. 3. A pressure filter according to claim 3, characterized in that a plate (27) presses the peripheral portion of said membrane against a plate in the region of said flow channel (26).

5. A pressure filter according to claim 2, characterized in that said flow conduit extends through the peripheral portion of said membrane and leads to a filtrate flow conduit (37) formed between the membrane (8) and the filter cloth (20). ).

6. A pressure filter according to any one of the preceding claims, characterized in that said branch strip (25) consists of a portion cut or separated from the peripheral portion of said membrane at a given length.

7. A pressure filter according to any one of the preceding claims, characterized in that the peripheral portion of said membrane comprises a peripheral frame (21), a part of which is cut off or separated over a given length to form said branch strips.

8. A pressure filter according to any of the preceding claims, characterized in that at least one of said plates comprises a main groove (13) in which the frame (21) of said peripheral portion (9) of the membrane engages, and a second groove (24), each end of which opens into said main groove, into which said branch strip (25) engages.

9. A pressure filter according to any one of the preceding claims, characterized in that the peripheral portion of said membrane comprises a peripheral seal (14) engaged in a main groove (13) of one of said plates and comprising a frame (21) between the peripheral parts of said plates, a protruding diaphragm peripheral part (12) engages in the peripheral groove of said seal (14), said seal (14) comprising said branch strips (25 ).

10. A pressure filter according to claim 9, characterized in that said peripheral seal comprises an inner peripheral frame (80) disposed between said membrane and a plate having said main groove (13).

11. The pressure filter of claim 10, wherein said peripheral seal includes a lip (82) adjacent said inner peripheral frame and pressed against the plate having said main groove.

12. A pressure filter according to any one of claims 9 to 11, characterized in that said seal has a U-shaped section, the edges of the two arms of which comprise said frame (25, 80).

13. A pressure filter according to any one of claims 1 to 8, characterized in that the peripheral portion of said membrane (46) comprises a protruding peripheral portion or frame (47) which engages in the In the main groove (13) and comprising a peripheral frame (50) bounded between the peripheral portions of said panels, this protruding portion includes the aforementioned branch strips.

14. A pressure filter according to claim 13, characterized in that the protruding peripheral portion (47) of said membrane (46) comprises a peripheral groove (48) engaging at its bottom a groove for holding in said main groove (13). ) in the wire (49).

15. A pressure filter according to any one of claims 8 to 14, characterized in that the peripheral frame of said membrane comprises an enlarged section engaging in the enlarged section bottom of said main groove (13).

16. A pressure filter according to any one of the preceding claims, characterized in that the membrane comprises filtrate flow conduits (18) on the filter chamber side, and a filter cloth (20) covering these conduits, the peripheral edge (20a of the cloth ) is constrained by means of the peripheral edge (9) of the diaphragm.

17. A pressure filter comprising a stack of at least two plates (1, 2), said plates comprising adjacent peripheral portions (1a, 2a) defining a joint surface (7) and delimiting a filter space (6) therebetween ), a diaphragm (8) extends in this space and its peripheral portion (9) is constrained between the peripheral portions of said plates along at least a part of its length so as to have a movable area in which Delimited on both sides is a filter chamber (10) and a pressure chamber (11), means (23, 26) for supplying items to be filtered to said filter chamber (10), for supplying liquid to said pressure chamber ( 11), and means (20, 29, 37) for discharging filtrate from said filter chamber, characterized in that said plate (53) at least on one side of said pressure chamber and said Said diaphragm (65) has a coaxial channel (76) in said movable region, and a confinement ring (58) integral with said plate and coaxial with said channel comprises a protruding peripheral portion (60) , the edge of the diaphragm around its above-mentioned passage is constrained between the protruding peripheral portion of the ring and the portion of the plate surrounding its above-mentioned passage, at least one communication orifice (77) connects the interior of the confinement ring and The filter chamber (51).

18. A pressure filter according to claim 17, characterized in that said plate and the protruding peripheral portion of said ring define an annular groove (68) between them, and an annular frame (67) at the edge of said membrane constrains in it.

19. A pressure filter according to claim 17 or 18, characterized in that a connecting ring (59) connected to said confinement ring (58) through said channel comprises a protruding peripheral portion abutting against the other side of said plate, The rings constitute an annular core.

20. 19. Pressure filter according to claim 19, characterized in that the above-mentioned protruding portions of the confinement ring (58) and the connection ring (59) of two adjacent plates abut against each other and form said communication orifice.

twenty one. A pressure filter according to any one of claims 13 to 20, characterized in that the membrane has coaxial undulations (19) around its above-mentioned edge in the filter space.

twenty two. A pressure filter according to any one of claims 17 to 21, characterized in that the membrane comprises filtrate flow conduits on one side of the filter chamber, and the filter cloth (70) covers these conduits and comprises a A coaxial channel, the edge (73) of this channel of the cloth is bounded by the aforementioned edge (67) of the membrane (65).