Insert element for membrane chamber plates

Abstract

A membrane chamber plate (1) is intended to replicate various operating modes as simply and cost-effectively as possible, and the service life of the membrane (6) is also to be extended. For this purpose, an insert element (14) is provided for detachable insertion into a filtrate drainage area of ​​a membrane chamber plate (1). The insert element (14) is arranged, in the direction of filtrate flow, between the membrane (6) and a filtrate drainage channel (10) in the filtrate drainage area of ​​the membrane (6).

Description

[0001] The invention relates to an insert element for detachable insertion into a filtrate discharge area of ​​a membrane chamber plate with a membrane chamber plate base body and a membrane; furthermore, the invention relates to a membrane chamber plate with such an insert element and a filter press with such membrane chamber plates.

[0002] Wet filtration is a process for separating solids from liquids. A liquid is passed through a filter medium that retains the solids, also called the filter cake, while allowing the purified liquid, also called the filtrate, to pass through. In wet filtration using filter presses, membrane chamber plates are used, among other things, to reduce the residual moisture in the filter cake. These plates further compress it through pressure. The membranes have a drainage surface for collecting the filtrate, as well as a filtrate outlet area for removing the filtrate or for introducing a liquid or gaseous medium for further treatment of the filter cake in the filter chambers. For this purpose, a filtrate outlet channel is provided in the filter plate, which is fluidically connected to the drainage surface of the membrane via the filtrate outlet area.

[0003] The filtrate drainage areas generally have a predefined geometry for the purpose described above and are an integral part of the membrane. These functions are generally activated by corresponding access channels in the membrane plate body, which are connected by open transitions on the membranes in the filtrate drainage area. Although the filtrate drainage area, as its name suggests, primarily serves to drain the filtrate from the membrane and thus provides corresponding channels for connecting the drainage area to the filtrate drainage channel, it is desirable for this area to fulfill other functions in other operating modes.For example, during filter cake treatment, it may be desirable to completely interrupt the connection between the drainage area and the filtrate drainage channel, or, conversely, to direct a medium via the filtrate drainage channel into the drainage area and to the filter cake for treatment, particularly to neutralize the pH, wash out undesirable substances from the filter cake, or blow dry. Depending on the operating modes of the membrane chamber plate, different designs of the filtrate drainage area are desirable.

[0004] But it may be desirable to change the filtrate drainage area not only when changing operating modes. For example, if the filter plate provides multiple filtrate drainage channels and individual filtrate drainage channels are now to be specifically controlled or a new filtrate drainage channel is selected.

[0005] However, all of this has so far only been possible through a complex and costly replacement of the entire membrane. Furthermore, this requires the provision and storage of specially manufactured membranes for each operating mode.

[0006] In addition, the filtrate drainage area of ​​membranes is generally subject to greater stress from outflowing media due to high flow velocities and the resulting abrasion, as well as thermal and chemical stress. Filter media (filter cloths) that are in direct contact with the outflowing or inflowing media in these areas therefore often wear out sooner in these areas than in other areas and therefore require complete replacement.

[0007] The object of the present invention is therefore to provide a membrane chamber plate and an insert element which can represent the various operating modes as simply and cost-effectively as possible and also extends the service life of a membrane.

[0008] The object is achieved according to the invention by claims 1 and 8. Advantageous embodiments are the subject of the subclaims.

[0009] The invention is based on the idea that the filtrate drainage area is physically separated from the membrane and provided as a separate insert element and spare part. This allows, on the one hand, to decouple the area of ​​the membrane that is usually the first to be damaged due to the higher stress, thus extending the membrane service life. On the other hand, by providing different insert elements, it is possible to cover all desired operating modes of the membrane chamber plate without having to maintain a large number of different membranes.

[0010] To further convey and introduce the filtrate into the filtrate drainage channel, the insert element advantageously comprises a drainage area that expands the drainage area of ​​the membrane. This drainage area is preferably formed by an arrangement of studs and / or webs. The drainage area is advantageously designed so that the filtrate is optimally guided into the filtrate drainage channel in terms of flow velocity and flow direction. For this purpose, supply channels or supply grooves can also be provided in the insert element further downstream of the flow path, which are directly connected to supply channels in the filter plate. These supply channels or supply grooves can also be designed with regard to their depth, width, gradient, cross-section, and diameter to ensure an optimal flow velocity of the filtrate.Also, webs and knobs that are partially defined by the membrane can be used to discharge the filtrate into the insert element.

[0011] In an alternative advantageous embodiment, the insert element can also be designed to close the filtrate drainage channel. This is achieved, in particular, by covering the supply channels in the filter plate with the insert element. In this case, however, the insert element can also have additional areas for filtrate guidance, in particular for returning it to the membrane area, for example, to prevent filtrate buildup or accumulation in the area of ​​the insert element.

[0012] To protect the membrane and support its retention, the insert elements, in a particularly preferred embodiment, comprise a number of vane elements extending from the base body of the insert element. These vane elements are positioned such that, when the insert element is in use, they rest on the membrane, and the membrane in this area is thus located between the vane elements of the insert element and the membrane chamber plate base body. Depending on the stiffness of the vane elements, the membrane is clamped and additionally held between the filter plate and the vane elements.

[0013] To be able to respond flexibly to constantly changing process conditions or specifications, the insert element is specifically designed to be detachably connected to the filter plate. For this purpose, the insert element comprises a number of fastening elements. These can, for example, be a number of fastening studs that clip into corresponding recesses in the filter plate. However, other detachable connection combinations are also possible.

[0014] The heavy material stress on the membrane in the filtrate outflow area is not initially eliminated by dividing it into an insert element and a membrane, but merely shifted from the membrane to the insert element. The use of an insert element, however, now makes it possible to approach the material selection independently and without regard to any material specifications for the membrane. The insert element is advantageously made at least partially, and preferably entirely, from a different material than the membrane. This is selected with particular regard to the chemical, thermal and dynamic-mechanical stresses. It is also possible to select the material depending on the filtrate or the intended use. Here, too, there is the advantage that several different insert elements can be kept in stock particularly easily and cost-effectively and these can be optimized, selected and used according to the intended use.The insert element is preferably manufactured by additive manufacturing processes, injection molding or mechanically.

[0015] The advantages achieved with the invention lie in the fact that the physical separation of the filtrate drain area, which is now essentially taken over by the insert element, and the membrane allows for particularly flexible response to changing process conditions. This means that, depending on the application, different insert elements can be provided which can be replaced quickly and cost-effectively, while the membrane can be used unchanged. Since precisely the area of ​​the membrane that was previously subject to the most severe stress and led to early replacement of the membrane is now transferred to a replaceable insert element, the service life of the membrane is significantly extended. Since the insert element also serves as a cover for the filtrate drain area, this also applies to any filter cloths used. These filter cloths also suffered the highest levels of abrasion, particularly in the filtrate drain area, and had to be replaced early.Thanks to the insert element, they are no longer in direct contact with the rapid filtrate flow in the filtrate drain area and the media introduced to treat the filter cake, especially air. They can therefore no longer be sucked in by the filter cake and even clog the filtrate drain channel.

[0016] The invention is further described with reference to the exemplary embodiments illustrated in the drawing figures. They show: Fig. 1 a membrane chamber plate with an insert element, Fig. 2 an excerpt from Fig. 1, Fig. 3 an insert element for forwarding the filtrate into the filtrate drain channel, Fig. 4 an insert element for closing the filtrate drain channel, Fig. 5 an insert element without wing elements.

[0017] The illustrations in the figures are partly simplified and schematic. Different views of parts may be scaled differently. Identical reference numbers are used for identical or similarly constructed parts.

[0018] An embodiment of a membrane chamber plate 1 is shown in the embodiment according to the Fig. 1. The membrane chamber plate comprises a membrane chamber base plate 2. The membrane chamber base plate 2 has a circumferential receiving groove 4 on all four edges for receiving and holding a membrane 6, which is arranged in the interior of the membrane chamber base plate 2. The membrane chamber base plate 2 according to Fig. 1 further comprises two holding elements 8, on which the membrane chamber plate 1 can be suspended within a filter press (not shown). A filtrate drainage channel 10 is shown in two corners of the membrane chamber base plate 2; however, depending on the design of the membrane chamber base plate 2, such a filtrate drainage channel 10 can also be provided in all or any number of corners. It is important that at least one filtrate drainage channel 10 is present to allow the filtrate to be drained from the membrane 6.

[0019] One corner of the membrane chamber base plate 2 to Fig. 1 is in Fig. 2 is shown in an enlarged view. Visible is the filtrate drainage channel 10 with two access channels 12 within the membrane chamber base plate 2, which provide a fluid connection between the membrane 6 and the filtrate drainage channel 10. A detachably inserted insert element 14 is also provided between the filtrate drainage channel 10 or between the access channels 12 and the membrane 6. This insert element 14 serves in particular to guide the filtrate from the membrane 6 into the access channels 12 or into the filtrate drainage channel 10. Depending on the design of the insert element 14, it can also be used to close the access channels 12.

[0020] Such an insert element 14, which is intended to guide the filtrate to the filtrate outlet channel 10, is in Fig. 3. The insert element 14 is shown in more detail in comparison to the Fig. 2 shown upside down. The top view in Fig. 3 is thus the underside of the insert element 14 in Fig. 2 and vice versa. The insert element 14 according to Fig. 3 also includes supply openings 16, which correspond to the position of the access channels 12, so that the filtrate can be guided into the filtrate outlet channel 10. In addition, the insert element 14 includes two wing elements 18, which protrude laterally from the elongated base body 20 and in the illustration of the Fig. 3 are arranged on the underside. These wing elements 18 are placed over the membrane 6 in use, so that the edge areas of the membrane 6 are located between the wing elements 18 and the membrane chamber base plate 2. On the upper side of the wing elements 18 according to Fig. 3 or inwards with respect to Fig. 2, a number of webs 22 are arranged, forming a drainage surface to guide the filtrate in a targeted manner toward the inlet openings 16. Alternatively or additionally, knobs may also be provided here.

[0021] In principle, numerous design variants of the insert element 14 are conceivable and desirable, especially with regard to the design of the drainage surface, the supply line to the access channels 12, the design of the wing elements 14, and the choice of material, since, as a modular insert element 14, it is specifically designed to be optimized for a specific application and to be exchanged depending on the application. To do so, the insert element 14 is simply removed from the membrane chamber base plate 2 and replaced with a new insert element 14.

[0022] In the example according to the Fig. 4 shows an alternative embodiment of an insert element 14. The insert element 14 according to the Fig. 4 serves specifically to close the filtrate drainage channel 10 or the access channels 12. Therefore, the insert element 14 lacks corresponding supply openings 16. The insert element 14 after the Fig. 4 also shows two fastening elements 24 in the form of circular protrusions, which can be clipped into corresponding openings of the membrane chamber base plate 2, whereby the insert element 14 can be fastened in the membrane chamber base plate 2. Such fastening elements 24 are of course also present in the embodiment according to the Fig. 3, even if not shown there.

[0023] In the example according to the Fig. 5 shows a further alternative embodiment of an insert element 14. This insert element 14 also serves to close the filtrate outlet channel 10 but does not have the Fig. 4 wing elements still shown 18. List of reference symbols 1 membrane chamber plate 2 membrane chamber base plate 4 grooves 6 Membran 8 Holding element 10 Filtrate drain channel 12 access channel 14 Insert element 16 Supply opening 18 wing element 20 basic bodies 22 bridges 24 fasteners

Claims

[1] Insert element (14) for detachable insertion into a filtrate drainage area of ​​a membrane chamber plate (1) with a membrane chamber plate base body (2) and a membrane (6), wherein the insert element (14) is arranged in the flow direction of the filtrate between the membrane (6) and a filtrate drainage channel (10) in the filtrate drainage area of ​​the membrane (6). [2] Insert element (14) according to claim 1, characterized by that the insert element (14) has a drainage area which guides the filtrate into the filtrate drainage channel (10) in the insert of the insert element (14). [3] Insert element (14) according to claim 2, characterized by that the drainage area has a number of knobs and / or webs (22). [4] Insert element (14) according to claim 1, characterized by that the insert element (14) is designed to close the filtrate drain channel (10). [5] Insert element (14) according to one of claims 1 to 4, characterized bythat the insert element (14) has wing surfaces (18) which at least partially cover the membrane (6) when the insert element (14) is in use. [6] Insert element (14) according to one of claims 1 to 5, characterized by a number of fastening elements (24) for fastening to the membrane chamber plate base body (2) of the membrane chamber plate (1). [7] Insert element (14) according to one of claims 1 to 6, characterized by that the insert element (14) is at least partially made of a different material than the membrane (6). [8] Membrane chamber plate (1) with a membrane chamber plate base body (2) and a membrane (6), comprising a filtrate drainage area, characterized by at least one insert element (14) according to one of claims 1 to 7 arranged in the flow direction of the filtrate between the membrane (6) and a filtrate outlet channel (10) of the membrane chamber base plate (2). [9] Membrane chamber plate (1) according to claim 8, characterized bythat the insert element (14) or the insert elements (14) functionally replace the filtrate drainage areas of the membrane (6). [10] Filter press with a number of membrane chamber plates (1), characterized by at least one membrane chamber plate (1) according to one of claims 8 and 9.

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