Plate for a filter press, filter press, use of the filter press and method for cleaning the filter press

Abstract

A plate for a filter press, a filter press, the use of such a filter press as well as a method of cleaning and sterilization of such a filter press. The plate for a filter press has a base body, consisting of a first material with a hardness H.sub.1 and having an outer circumferential surface, and a frame arranged on the outer circumferential surface, consisting of a second material with a hardness H.sub.2, where H.sub.2<H.sub.1, and wherein the frame has on at least one side surface at least one encircling seal protruding relative to the side surface.

Claims

1. A plate for a filter press, comprising: a base body, consisting of a first material with a hardness Hi and having an outer circumferential surface, a frame arranged on the outer circumferential surface, consisting of a second material with a hardness H.sub.2, where H.sub.2<H.sub.1, wherein the frame has an outer circumferential surface, an inner circumferential surface and two sides surfaces, wherein the frame has on at least one of the side surfaces at least one encircling seal protruding outwardly relative to the side surface, wherein the at least one encircling seal and the frame are made from a single piece of one material, wherein the encircling seal in the unloaded condition has a first protrusion which passes into a second protrusion, wherein the second protrusion is located further away from the side surface than the first protrusion, wherein the frame has at least one through borehole for the supply and drainage of cleaning agent and/or sterilization agent and at least one through borehole for venting, and wherein the through boreholes extend from one of the side surfaces of the frame to the other side surface of the frame.

2. The plate as claimed in claim 1, wherein the frame is joined by its inner circumferential surface to the outer circumferential surface of the base body.

3. The plate as claimed in claim 1, wherein the inner circumferential surface of the frame is welded to the outer circumferential surface of the base body.

4. The plate as claimed in claim 1, wherein the frame has a hardness H.sub.2 of 90 to 100 shore A.

5. The plate as claimed in claim 1, wherein the frame has a thermoplastic elastomer or consists of the thermoplastic elastomer.

6. The plate as claimed in claim 1, wherein the base body has a hardness H.sub.1 of 60 to 80 shore D.

7. The plate as claimed in claim 1, wherein the second protrusion extends beyond the first protrusion.

8. The plate as claimed in claim 1, wherein the first protrusion has an abutment surface oriented parallel to the side surface of the frame.

9. The plate as claimed in claim 1, wherein the first protrusion is arranged closer to the outer circumferential surface of the frame than the second protrusion.

10. The plate as claimed in claim 1, wherein the side surface having the seal has an encircling groove, and the groove is adjacent to the second protrusion.

11. The plate as claimed in claim 1, wherein the plate is a filter plate.

12. The plate as claimed in claim 1, wherein the plate is a membrane plate.

13. The plate as claimed in claim 1, wherein the plate is a frame plate.

14. The plate as claimed in claim 10, wherein the through boreholes are arranged in the encircling groove.

15. A filter press with a plate arrangement, having a plurality of plates arranged parallel to each other, wherein at least every second plate is a plate as claimed claim 1.

16. A method of using a filter press, comprising the steps of: obtaining a filter press as claimed in claim 15; and filtering blood plasma or manufacturing pharmaceutical products with the filter press.

17. A method for cleaning the plates of a filter press as claimed in claim 15, involving the following steps: (a) a first compressing of the plates, wherein only the second protrusion of the seal is compressed, (b) at least one rinsing procedure with a cleaning, rinsing and/or sterilization medium and (c) a second compressing of the plates, wherein both the second and also the first protrusion of the seal are entirely compressed.

18. The method as claimed in claim 17 for cleaning the plates of a filter press, wherein the following steps are performed in advance of steps (a), (b) and (c): (1) sliding apart the plate arrangement, (2) removal of the filter cake, (3) removal of the plates and separate cleaning (4) installing of the cleaned plates.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Sample embodiments of the invention shall be explained more closely below with the aid of the figures.

(2) FIG. 1 shows a perspective representation of a filter press,

(3) FIG. 2 shows a top view of a frame plate,

(4) FIG. 3 shows a top view of a membrane plate known in the prior art,

(5) FIG. 4 shows a top view of a filter plate known in the prior art,

(6) FIG. 5 shows a feature of a plate arrangement in cross section in the opened state of the filter press,

(7) FIG. 6 shows a feature of a plate arrangement in cross section in the cleaning state of the filter press,

(8) FIG. 7 shows a feature of a plate arrangement in cross section in the filter state of the filter press,

(9) FIG. 8 shows a partial cross section through a filter plate according to the invention, and

(10) FIG. 9 shows a partial cross section through a membrane plate according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(11) FIG. 1 shows a filter press 1 in perspective view. The filter press 1 has a mobile frame 2, having at either end a frame plate 3a, 3b, which are joined together by two support beams 4. On these support beams 4 there are hung the frame plates 20, membrane plates 30 and filter plates 40 by their retaining tabs 21, 31, 41 in a predetermined sequence to form a plate arrangement 9, being pressed against each other tightly by a pressing device. The membrane plates 30 have pressurized air ports 7′, to which hoses 7 are fastened, being led by a rod 8 to a common pressurized air supply (not shown).

(12) In the front part of the frame there are several connections 5 for nonfiltrate supply and filtrate drainage, being connected to filtrate and nonfiltrate channels situated inside the plate arrangement 9. In order to form these filtrate and nonfiltrate channels, appropriately dimensioned eyelets 28, 38, 48 are provided in the plates 20, 30 and 40 in the corner regions, being indicated in FIGS. 2, 3 and 4 for the aforementioned kinds of plates. The membrane plates and filter [plates] represented in FIGS. 3 and 4 are plates of the prior art, which are assembled together with the frame plates 20 according to the invention. FIGS. 8 and 9 show membrane and filter plates 30, 40 according to the design of the invention, which can be assembled with conventional frame plates, or frame plates without the seal according to the invention, to make a plate arrangement.

(13) The frame plate 20 represented in FIG. 2 is composed of a base body 10 and is made from a material with hardness H.sub.1 with an outer circumferential surface 11 and a frame 100 and is made from a material H.sub.2 with an outer circumferential surface 110, an inner circumferential surface 111 and two side surfaces 112. The frame 100 surrounds the outer circumferential surface 11 of the base body 10, the outer circumferential surface 11 of the base body 10 being welded to the inner circumferential surface 111 of the frame 100. On each side surface 112 of the frame 100 there is arranged an encircling, closed seal 101. Since FIG. 2 is a top view, only one side surface 112 can be seen.

(14) As can be seen in FIG. 5, the seal 101 has a steplike configuration and in the unloaded state which is shown it has a first protrusion 102 and a second protrusion 103, both protrusions 102, 103 bordering on each other and the second protrusion 103 extending beyond the first protrusion 102. The first protrusion 102 lies closer to the outer circumferential surface 110 of the frame 100 than the second protrusion 103 in the sample embodiment shown.

(15) At the inside of the seal 101 there runs a groove 104, which borders directly on the second protrusion 103 and can be milled from the frame material. In the groove 104 are found through boreholes 27, which serve for the supply and drainage of cleaning agent (see FIG. 2, not visible in FIG. 5). The through boreholes 27 are located, in terms of the installation state of the frame 20, in the lower part of the encircling groove 104. In the upper part of the groove 104 are found through boreholes 27′, which serve for venting of the chamber region during the cleaning procedure and ensure that the cleaning agent can reach all product-contacting regions.

(16) In the example shown, the frame plate 20 furthermore has boreholes 26 in the inner margin region of the encircling groove 104, which serve for receiving retaining pins 60 of adjacent membrane and filter plates 30, 40, serving for the fastening of filter cloths 50, 70 (see FIG. 5).

(17) For sake of completeness, FIGS. 3 and 4 show a membrane plate 30 and a filter plate 40 which are already known from the prior art and which can be used in conjunction with the frame plate of FIG. 2 in a filter press 1 according to the invention.

(18) FIG. 3 shows a top view of such a membrane plate 30, not showing the filter cloth 70 supported by retaining pins 60. The retaining pins 60 are arranged at a spacing from the outer circumferential surface 33 of the membrane plate 30 and lie substantially in the region of the connection line of the eyelets 38 which are situated in the corner regions of the membrane plate 30. Moreover, there can be seen a membrane 32, which lies in a recess 34. The membrane plate 30 furthermore has an annular groove 36, in which the filter cloth 70 terminates (see also FIG. 5).

(19) FIG. 4 shows a filter plate 40 which is configured in similar manner to the membrane plate 30 and which likewise has retaining elements 60 which are arranged at a spacing from the outer circumferential surface 43 of the filter plate 40 (see also FIG. 5). Here as well there is provided an annular groove 46, in which the filter cloth 50 terminates. The configuration of the annular groove 46 corresponds to that of the annular groove 36. Moreover, eyelets 48 are provided in the corner regions of the filter plate 40. The inner region of the filter plate 40 is provided with knobs 44, on which the filter cloth 50, not shown, is placed.

(20) FIGS. 5 to 7 each show a feature of the plate arrangement 9 in different operating states of the filter press 1 and should clarify the mode of operation of the invention.

(21) FIG. 5 shows the plate arrangement 9 with plates 20, 30, 40 in the opened state of the filter press 1, no pressing force being applied to the plates 20, 30, 40.

(22) The plate arrangement 9 has frame plates 20, membrane plates 30 and filter plates 40, with membrane and filter plates 30, 40 alternating and with a frame plate 20 situated between them each time, having a frame with the above described frame 100 and seal 101.

(23) The membrane plate 30 has a membrane 32 on each of its side surfaces, which is covered by a filter cloth 70. The filter cloth 70 is fastened by means of retaining pins 60 in the margin region of the membrane plate 30.

(24) The side surfaces of the filter plate 40 are likewise each fitted with a filter cloth which, as in the case of the membrane plate 30, is fastened by means of retaining pins 60 in the margin region of the filter plate 40.

(25) The frame plate 20 shown in cross section in FIGS. 5 to 7 corresponds to the frame plate 20 of FIG. 2 and therefore comprises the base body 10 and the flexible frame 100. On the side surfaces 112 of the frame 100 are situated the seals 101. The first protrusion 102 of the seal 101 has an abutment surface 113 parallel to the side surface 112. The second protrusion 103 is hump shaped in the example shown.

(26) FIG. 6 shows the plate arrangement 9 in the intermediate position in which the cleaning and sterilization of the plates 20, 30, 40 is performed.

(27) For the cleaning of all product-contacting regions of the plates 20, 30, 40, the plate arrangement 9 is compressed with a pressing force, which typically amounts to between 20 and 70 bar, until the membrane plate 30 and the frame plate 40 lie against the abutment surfaces 113 of the first protrusion 102 of the seals 101. Between the plates 20, 30, 40 are formed gaps 120 with a width of a few mm, into which the sterilization medium can penetrate. The gap width corresponds to the height of the first protrusion 102, which forms an end stop for the neighboring plates and ensures a uniform propagation of the pressing force over the entire plate arrangement 9 thanks to its good resistance to deformation.

(28) FIG. 7 shows a feature of the plate arrangement 9 from FIGS. 5 and 6 in filter mode. The plates are pressed entirely against each other with a large pressing force of around 240 bar. The flexible seal 101 is completely compressed, the displaced sealing material being taken up in the groove 104.

(29) FIG. 8 shows a filter plate 40 with the features according to the invention. The filter plate 40 comprises a base body 10, which is welded by its outer circumferential surface 11 to the inner circumferential surface 111 of the frame 100. The base body 10 consists of a material of hardness H.sub.1 while the material of the frame 100 has a hardness H.sub.2. Also in this embodiment, H.sub.2<H.sub.1. The retaining pins 60 in this embodiment are part of the base body 10. The design of the seal 101 protruding with respect to the side surface 112 corresponds to the design of the seal 101 of the frame plate 20 in FIG. 5. The seal 101 has a first protrusion 102 and a second protrusion 103, with the second protrusion 103 extending beyond the first protrusion 102. The first protrusion 102 has the parallel abutment surface 113. The groove 104 is situated adjacent to the second protrusion.

(30) FIG. 9 shows a membrane plate 30 with the features according to the invention. The membrane plate 30 has a base body 10 and a frame 100. The retaining pins 60 are likewise part of the base body 10. The base body 10 is welded by its outer circumferential surface 11 to the inner circumferential surface 111 of the frame 100. For the materials of base body 10 and frame 100, the same materials are used as for the base bodies 10 and frames 100 of the filter plate 40 and the frame plate 20. In this embodiment as well, the hardness H.sub.2 of the frame 100 is less than the hardness H.sub.1 of the base body. On both side surfaces 112 there is arranged a respective seal 101 according to the invention, while the sequence of first protrusion 102 and second protrusion 103 has been interchanged. This means that the first protrusion 102 is arranged on the inside and the second protrusion 103, which extends beyond the protrusion 102, faces the circumferential surface 33. Accordingly, the encircling groove 104 is also arranged between the circumferential surface 33 and the second protrusion 103.

LIST OF REFERENCE NUMBERS

(31) 1 Filter press 2 Mobile frame 3a, b Frame plate 4 Support beam 5 Connections 7 Hose 7′ Pressurized air port 8 Rod 9 Plate arrangement 10 Base body 11 Outer circumferential surface 20 Frame plate 21 Retaining tab 26 Borehole 27, 27′ Through borehole CIP 28 Eyelet 30 Membrane plate 31 Retaining tab 32 Membrane 33 Outer circumferential surface 34 Recess 36 Annular groove 38 Eyelet 40 Filter plate 41 Retaining tab 43 Outer circumferential surface 44 Knobs 46 Annular groove 48 Eyelet 50 Filter cloth 60 Retaining pins 70 Filter cloth 100 Frame 101 Seal 102 First protrusion 103 Second protrusion 104 Groove 110 Outer circumferential surface 111 Inner circumferential surface 112 Side surface 113 Abutment surface 120 Gap H.sub.1 Hardness of the base body 10 H.sub.2 Hardness of the frame 100