DE2933034A1 - Membranes on alternate cloth-covered filters in series - with filters covered by cloth only - Google Patents

Abstract

The aligned axial passages for the flow of media in the tightly compressed edges of membrane filter plates have branches extending obliquely to filter chambers bounded by adjacent plates. These membrane-covered plates alternate with plates covered by cloth only, and have a support plate with a thickened edges on whose two faces is a frame which grips the membrane and has filtrate exit channels. Each filter plate has axial passages at all four corners, with one of these for delivering slurry connected to the filter cake cavity by troughs in the support plate. Diagonally opposite the slurry passage is a passage supplying pressurised media for compressing the filter cake. The frame is connected to the support plate by plastic plugs. The sealing difficulties involved in known membrane presses are overcome, so high pressures, e.g. 15 bar, can be used for filtering, compressing or washing. The presses are easier to mfr. than the type with adhesively-bonded or vulcanised membranes, and the generally diagonal flow of the washing water is beneficial.

Description

Filter press

The invention relates to a filter press alternating in the axial direction successive filter plates covered on both sides with filter cloth and off membrane filter plates covered on both sides with membranes and filter cloths, axial through-channels in the edge regions of the plates which are pressed tightly against one another for the supply and discharge of media are provided, from which through channels transversely directed branch channels to the filter chambers delimited by adjacent plates lead, Such filter presses are characterized by a high filter performance, because with them each filter cake space is limited on both sides by filter trays and as the filter cakes can still be re-pressed by means of the membranes. Further it is possible with the modern filter presses of this type that Filter cake Wash out with water. However, prepares in these known filter presses the arrangement of the membrane or the sealing between a filter cloth and a membrane-lying filtrate drain space considerable difficulties. So shows DE-PS 21 64 161 a filter press of the type discussed here, in which the membranes each with a thickened edge area for clamping between adjacent ones Plates are provided, while the membranes inward of the thickened edge area are provided with through holes, which the filtrate drainage spaces with within Connect the filtrate drainage channels provided for the membrane filter plates, in the area the through holes, however, result in significant sealing problems, which is why the membranes are either glued or vulcanized onto the memhran filter plates Need to become. However, when the membranes are repeatedly pressurized, they occur multiple leaks, as the areas to be sealed during operational Repressing is constantly subject to wear and tear.

ner invention is based on the object in one for repressing or washing the filter cake with a suitably designed filter press on both sides Filter cake spaces enclosed by filter cloths, the sealing and sealing areas described To fix wear problems with regard to the compression membranes and the application high pressures, e.g. B. 15 bar, when filtering, repress and, if necessary. Allow washing.

This object is achieved according to the invention by the following features achieved: (a) all axial through-channels are exclusively in the outer, clamped Edge area of the plates arranged; (b) the membranes are only clamped at their Edge area provided with openings for the axial through channels, the Membranes around their breakthroughs on both sides over a wide area between planes Contact surfaces are tightly clamped; (c) the membrane filter plates are made of one covered on both sides with the membranes, with a thickened tin clamping edge Support plate and two, on both sides on the thickened support plate edge under sealing Clamping of the membrane-attached frame in which the filtrate drain channels are formed are.

The invention offers a number of advantages. Through the division the membrane filter plate into a support plate spanned by the membranes and into It is now the frame that is attached to the support plate and encloses the membranes has become possible, each limited by a membrane by means of filtrate drainage spaces connect to the main filtrate drainage channel through the frames of channels passing through, while the membranes themselves are outside their constantly constrained edge areas no longer have any through holes. This eliminates the sealing and wear problems well-known urgent presses. In addition, the production of the filter press proves itself as much less critical, i no sticking or vulcanizing of the membranes or similar More sealing measures must be provided. Another advantage is that the channels provided in the frame when Washing process can be used for the washing water supply. After penetration of the filter cake, the washing water gets into each of a filter plate and a filtrate drainage space formed by a filter cloth, Qie to an axial passage channel are connected, which is diagonally opposite the channels formed in the frame.

Through this overall diagonally directed flow of the washing water thorough washing of the entire filter cake is guaranteed.

luach further features of the invention can be provided that the filter plates and the membrane filter plates at all four corners each with, axial through-channels forming bores are provided, one of which is a turbidity feed channel is. It can also be provided here that the turbidity feed channel Diagonally opposite through-channel can be connected to a post-press pressure medium source is and through side channels formed within the support plate with the pressure chambers is connected between the membranes and the support plate. As a result of these measures lie all supply and discharge channels within the filter plate package, and exclusively in the outer clamping edge area of the full, which is what the handling of the filter press at Move apart the plates simplified, a seal of the Filtering kitchen areas when moving the filter plate package perfectly guaranteed and the use of very high bridges in the supply of the sludge when pressing the filter cake as also allowed during the washing process.

According to a further feature of the invention it can be provided that the passage channel for the sludge supply through trough-shaped, in the filter plates provided side channels is connected to the filter cake space. These side channels are consequently when the filter plates are moved apart over their full length opened, eo that any deposits recognized and conveniently removed, z. B. by means of a automatic spray device can be rinsed off.

In a further embodiment of the invention it can be provided that all plates at their upper edge with holes forming an axial through-channel are provided, which can be connected to the atmosphere and through in the support plates trained branch channels with the pressure spaces between the membranes and the support plate connected is. These channels allow re-pressing by means of liquid pressure media to be carried out, using them as ventilation openings during the filling of the pressure chambers Serve, A repressing by means of a liquid pressure medium can be relatively high pressures run safely because, unlike when compressed air is applied, there is no pressure wave when a membrane or line bursts is caused in the installation hall of the filter press.

Finally, according to the invention, it can also be provided that the frame by plug-like plug-in links made of plastic with the support plates are connected. The plug-in links can be sunk into a frame recess lying head and elastic with a through hole in the support plate pinched, double-conical foot. This type of attachment is very inexpensive and allows a damaged membrane to be replaced quickly.

The object of the invention is explained below with reference to one in the Drawing illustrated embodiment described in more detail. In the drawing 1 shows a side view of a filter press according to the invention, FIG perspective exploded view of meiArere successive filter plates and membrane filter plates, each without filter cloths, Fi. 3 is a plan view of a Filter plate, 4 shows a section along the line IV-IV in Xig. 3, Fig. 5 shows a section along the line V-V in Fig. 3, ig. u a top view a membrane filter plate, FIGS. 7, 8, 9 and 10 each section according to the lines VII-VII, VIII-VIII, IX-IX and X-X in Fig. 6, Fig. 11 shows a section of the filter plate package in a perspective view with three partial sections lying in different planes, the filter chambers being shown during the "filtering" process, FIG. 12 a partial section through the filter plate package, which shows the status during the "filtering" process, 13 shows a section similar to FIG. 12, which shows the state during "pressing" and FIG. 14 shows a similar illustration for the "washing" process.

jig. 1 shows a filter press with two lying on stands 1, 2 I-beams 3 - only the front one can be seen - on the lower one, each on the outside lying flanges 4 a package of filter plates 5 and membrane filter plates 6 displaceable is suspended and can be compressed by a hydraulic cylinder 7. On the I-beams 3, a spraying device 8 is also movably mounted, which consists of a die I-beam 3 and the filter plate package enclosing rectangular frame consists of is provided with a ring of inwardly directed spray nozzles. Furthermore, Fig. 1 attached to the plate of the stand 1 connections 9, 10 for the sludge supply and the filtrate drainage. Two further connections are - in Fig. 1 through the connections 9, 10 hidden - on the back corners of the rat of the btanaer 1.

Furthermore, in Fig. 1 there is still a connecting pipe in the center of the stator plate shown with Abaperrhahn 11.

2, 3, 4 and 5 show the structure of the filter plates 5, the have a reinforced clamping edge 12 and inner Lalb of the reinforced clamping area on all four curls have a through hole 13, 14, 15, 16 and with similar Bores 177 18, 19, 20 of the adjacent membrane filter plates 6 (Fig. 6) are aligned. Lie bores 1, 17 in their entirety form an axial through-channel 21 (see also Fig. 11) via which the Tri-Fe is fed to the filter plates 5 are trough-shaped side channels 22, 23 shaped, which the axial through-channel 21 with the one lying within the thickened edge 12 Connect the interior of the filter plate 5. The filter plates 5 are on both sides with filter cloths 24, 25, which insert themselves into the platelet-shaped side channels 22, 23 and in each case through a cylindrical piece of filter cloth 26 penetrating through the bore 13 are tightly connected to each other.

The bore 14 of the plate 5 is through branch channels 27, 28 with the between the filter cloths 24, 25 and the knobbed surface of the filter plate 5 lying filtrate outflow spaces I (see also Fig. 12) connected. The holes 14, 18 form in their entirety an axial passage 29, which as one of two filtrate drainage channels during the filtering process and as a washing water discharge during the washing process is used.

The membrane filter plates 6 each consist of a support plate 30, which is spanned on both sides with a membrane 31, 32, and of two Frame 33, 34, the membranes 31, 32 under fin tension by means of plug-like Kunsttoff-teckglieder 35, 36 are connected to the support plate 30. The connecting links each have a head 37 and recessed in a recess in the frame a double-conical foot 38, which in a through hole of the support plate 30 is clamped elastically. The membranes 31, 32 are at ibien outer surfaces are provided with knobs and delimit together with the over the membrane filter plate 6 stretched filter cloths 39, 40 a second group of Filitrate drainage spaces II, which are formed by branch channels formed in the frame 33, 34 below 41, 42 with an axial through-channel formed by the plate bores 16, 20 43 are connected. This axial through-channel 43 serves as a filtrate discharge channel during the filtering process for the filtrate spaces II, while it is used as a water supply line during the washing process will.

The holes 17 diametrically opposite the sludge inflow holes 19 together with the bores 15 of the filter plates form an axial through-channel 44 for the supply of a Nachpref: -pressure medium, which via the branch channels 45 is connected to the pressure spaces between the support plate 30 and luenibranen 31, 32.

Furthermore, the filter plates 5 and filter membrane plates 6 are in the middle at the upper edge area provided with through holes 46, 47, one to the vent valve 11 leading axially through venting channel 48 and over into the membrane filter plates 6 provided branch channels 49 with the pressure spaces between the support plate 30 and the Membranes 31, 32 are connected.

Figures 11 and 12 illustrate the operation of filtering. The pulp runs over the channel 21 and the trough-shaped side channels 22, 23 in the filter cake spaces enclosed by two filter cloths 25, 39 and 40, 24 respectively 50.

The filtrate water, which the filter cloths assigned to the filter plates 5 24, 25 penetrates, runs through the filtrate chambers 1 and the branch channels 28 the axial through-channel 29 from. The filter cloths 39, 40 of the membrane filter plate 6 penetrating filtrate water runs over the filtrate spaces II, which are in the frame formed channels 41, 42 and the axial through-channel 43 from.

Following the filtering process, the pulp feed channel 21 is blocked, una through the diametrically opposite axial passage sign 44 is a Pressure medium, preferably water, into the pressure spaces 51 between the support plate 30 and membranes 31, 32, with the pressure chambers 51 via the channels 48, 49 Must first be vented using a bridge fluid. Flows when repressing the filtrate water as in the filtering process via the two described filtrate drainage paths away.

During the washing process (see also FIG. 14), the axial iurchgngskanal 43 and the channels 41, 42 wash water in the biium between each a membrane 31, 32 and a Filter cloth 39 or 40 passed. The wash water penetrates the filter cake and reaches the filtrate drain space I, from where it is delivered via channels 27, d, 29.

Claims (7)

Claims 1. Filter press from alternately in the axial direction successive filter plates covered on both sides with filter cloth and off Membrane filter plates covered on both sides with membranes and filter cloths, wherein in the tightly pressed edge areas of the plates, axial passage canals for supply and discharge of media is provided, from which through ducts transversely directed branch channels to the filter chambers delimited by adjacent plates lead, characterized by the combination of features (a) all axial through channels (21, 29, 4, 44, 43) are exclusively in the outer, machined edge area of the Plates (5, 6) arranged; (b) the membranes (31, 32) are only clamped at one of them Edge area provided with openings / for the axial through-channels, the Membranes around their breakthroughs on both sides over a wide area between planes Contact surfaces are used are clamped; (c) the membrane filter plates (6) exist e from one of them covered on both sides with the membranes (31, 32j, a thickened edge of the tin exposed base plate (30) and of two, on both sides of the thickened one Support plate edge under the sealing clamping of the membrane-attached frame (33, 34), in which filtrate drain channels (41, 42) are formed. 2. Filteriresse according to claim 1, characterized in that the Yilterplatten (5) and the membrane filter plates (6) at all four corners each with, axial passage channels (21, 29, 43, 44) forming bores (13/1 ?, 14/18, 15/19, 16/20) are provided, one of which (21) is a pulp feed channel. 3. Filter press according to claims 1 and 2, characterized in that that the passage channel (21) for the sludge supply through trough-shaped, in the filter plates (5) provided side channels (22, 23) is connected to the filter cake space (50). 4. Filter press according to claims 1 and 2, characterized in that daX the through channel (44) diagonally opposite the oil feed channel (21) can be connected to a Nachpreß-Druckmittelquelle and through itnerhalb the support plate (30) formed side channels (45) with the pressure spaces between membranes (31, 32) and support plate (30) is connected. 5. Filter press according to claims 1 to 4, characterized in that that all plates (5, 6) at their upper edge with an axial through-channel (48) forming bores (46, 47) are provided, which can be connected to the atmosphere and through branch channels (49) formed in the support plates (30) with the pressure chambers between membranes (31, 32) and support plate 30) is connected. 6. Filter press according to one or more of claims 1 to 5, characterized characterized in that the frame (33, 34) by plug-like plug-in members (35, 36) made of plastic with the support plates (30) are connected. 7. Filter press according to claim 6, characterized in that the plug-in links (35, 36) with a sunk head (37) and with a double-conical one that is elastically clamped in a through-hole in the support plate (5G) Foot (38) are provided.