Filter-plate element made of metal for a chamber filter press

Abstract

A filter-plate element (1) made of metal for a chamber filter press for the solid / liquid separation of suspensions has an element frame (2) and two half-shells (3), which bear against the element frame (2) on mutually opposite sides (4). The element frame (2) has formed in it at least one drainage channel (9), via which a liquid flowing into the drainage channel (9) through at least one through-opening (8) in the half-shell (3) can be discharged from the filter-plate element (1). The element frame (2) has a frame-corner element which is produced from a metal profile and has at least two frame limbs which are oriented at an angle of between more than 0° and less than 180° in relation to one another and are each designed in the form of a frame-limb hollow profile. The frame-corner element can be produced in one piece, wherein the two frame-limb hollow profiles are connected to one another via an angled metal-profile strip extending over a corner of the filter-plate element.

Description

[0001] Metal filter plate element for a chamber filter press

[0002] The invention relates to a metal filter plate element for a chamber filter press for solid-liquid separation of suspensions, comprising an element frame and two half-shells which abut each other on opposite sides of the element frame, wherein at least one drainage channel is formed in the element frame, through which a liquid flowing into the drainage channel through at least one opening in the half-shell can be discharged from the filter plate element.

[0003] A chamber filter press is a device for solid-liquid separation used in various industries such as chemicals, food production, and wastewater treatment. It consists of a series of filter plate elements, typically covered with filter cloths and compressed into a bundle to form chambers between the filter plate elements. The suspension to be filtered is pumped through these chambers, with the solids being retained by the filter cloths and the filtrate flowing out of the filter plate elements. The filter plate elements are usually made of plastic or metal and have a ribbed structure within the chambers to facilitate the filtration process through the filter cloths and to ease liquid drainage. Chamber filter presses and suitable filter plate elements are known in numerous designs and for a wide range of practical applications.

[0004] Filter plate elements made from suitable plastic materials can be used in numerous applications. These filter plate elements, manufactured using processes such as pressing, extrusion, or injection molding, are lightweight and have comparatively low production costs.

[0005] Filter plate elements made of metal or predominantly metal offer several advantages over plastic filter plate elements. Metal filter plate elements are robust and resistant to mechanical, chemical, and thermal stresses, resulting in a longer service life. Filter plate elements can be made of or coated with special alloys that exhibit high resistance to aggressive chemicals, enabling their use in corrosive environments. Metal filter plate elements can withstand high or very low temperatures, making them suitable for processes that take place at such extreme temperatures.

[0006] The comparatively high strength of metal compared to plastics allows for the production of thinner filter plate elements with complex structures without compromising integrity, which can lead to improved filtration efficiency. They are easy to clean and reusable, reducing operating costs. These advantages make metal filter plate elements particularly suitable for demanding applications in the chemical and pharmaceutical industries, as well as in other sectors that place high demands on material properties.

[0007] However, the metal filter plate elements commonly used in practice are often very expensive to manufacture and frequently require machining of individual metal components. They typically have a high weight, placing high demands on the mechanical stability of the chamber filter press, which compresses the filter plate elements during operation. Consequently, the design effort, manufacturing costs, and operating costs for such a chamber filter press with metal filter plate elements are comparatively high.

[0008] It is therefore considered an object of the present invention to design a metal filter plate element with the aforementioned features in such a way that the advantageous material properties of the metal can be utilized for the filtration process and the filter plate element can be manufactured as cost-effectively as possible. Optionally, the filter plate element should also have the lowest possible weight.

[0009] This problem is solved according to the invention by the fact that the element frame has a frame corner element made of a metal profile, which has at least two frame legs that are aligned at an angle between more than 0° and less than 180° to each other and which are each designed as a hollow frame leg profile. A frame leg designed as a hollow profile has a low dead weight compared to a conventional frame leg made of solid material without a cavity, without necessarily reducing the mechanical load-bearing capacity of the element frame excessively. The two hollow frame leg profiles can be assembled into a frame corner element without being directly fixed to each other, solely by means of their respective fixings to the half-shells that abut the element frame and thus also the frame corner element from both sides.It is also conceivable that the two frame legs are connected and, for example, welded together to form a joined frame corner element, independent of any additional possible fixing to the half-shells.

[0010] The element frame can be assembled from a frame corner element extending over several corners, or from several interconnected frame corner elements, and optionally from additional sections of frame leg hollow profiles arranged between frame corner elements. It is optionally possible for the element frame to have a continuous frame cavity along a frame perimeter line.

[0011] According to the invention, the element frame can be designed such that it exhibits advantageous properties with regard to mechanical stability and thermal resistance, while simultaneously having a low weight compared to conventional filter elements. For example, a conventional stainless steel filter plate element with comparable dimensions can have a total weight of approximately 250 kg, and an aluminum element element approximately 85 kg. In contrast, a stainless steel filter plate element with an element frame designed according to the invention has a total weight of only about 50 kg and is therefore only slightly heavier than a plastic filter plate element with a total weight of approximately 35 kg.In contrast to the already known filter plate elements, the element frame designed according to the invention and the half-shells attached to it can be manufactured simply and cost-effectively, which will be explained in more detail below.

[0012] According to a particularly advantageous embodiment of the invention, the frame corner element can be manufactured in one piece, and the two frame leg hollow profiles can be connected to each other via a bent metal profile strip extending over a corner of the filter plate element. Such a frame corner element can be manufactured cost-effectively without machining. The two frame legs, connected to each other via a metal profile strip over a corner of the filter plate element, can initially be manufactured straight and aligned with each other. The metal profile strip connecting the two frame legs can then be formed or bent using a suitable forming process to create the frame corner element with the two frame legs aligned at an angle to each other.A complex assembly process involving two separately manufactured frame legs, which then need to be aligned at a predetermined angle and connected, is unnecessary. Such a frame corner element can have comparatively short frame legs that extend essentially over a small area of ​​the corresponding corner of the filter plate element. Frame corner elements forming two adjacent corners of the filter frame element can be connected to each other with a straight-line frame edge element. A straight-line frame edge element can also be manufactured cost-effectively. For example, the frame edge element can be produced by forming a flat sheet metal blank and then bent into a straight-line hollow profile.It is also conceivable that the frame edge element is manufactured as a hollow profile by extrusion or rolling. A frame edge element designed as a hollow profile has a lower dead weight compared to a frame element made of solid material without a cavity. The element frame can advantageously be composed of several, and optionally differently designed, frame corner elements and elongated or straight frame edge elements.

[0013] It is conceivable that the frame corner element is initially produced as a continuous hollow profile, for example by extrusion, and that subsequently a wedge-shaped recess is made in an area between the two frame legs, so that the hollow profile can be bent in the area of ​​the recess and formed into the frame corner element. According to a particularly advantageous embodiment of the invention, the frame corner element is produced from a flat sheet metal blank, which is bent multiple times in the area of ​​each frame leg, forming a hollow frame leg profile in each case. Such a frame corner element can be produced cost-effectively and without machining from a single flat sheet metal blank using a suitable forming process.It is advantageous to first form the frame leg hollow profiles, which can be done particularly quickly and cost-effectively by simultaneously bending the metal sheet blank over all areas of the frame legs.

[0014] To achieve maximum mechanical strength, the multiply bent sheet metal blank in the area of ​​the frame legs completely surrounds a cavity formed by the bent sheet metal blank in a circumferential direction that runs perpendicular to the orientation of the respective frame leg. Two opposing edges of the sheet metal blank in a region of the frame legs can be positively or butt-fittedly joined after forming to increase the mechanical strength of the resulting hollow frame leg profile. Subsequently, two adjacent frame legs or hollow frame leg profiles, connected by a metal profile strip, can also be bent in a forming step to create the frame corner element produced from a single, flat sheet metal blank.The manufacturing effort required for producing the element frame can be further reduced by forming the element frame from a single frame corner element with multiple frame legs, wherein each pair of adjacent frame legs is aligned at an angle between more than 0° and less than 180° to each other. The element frame can, for example, be triangular, square, or have five or more corners. For most applications, rectangular or square element frames are generally considered particularly advantageous. A square element frame can be produced from a single-piece, flat sheet metal blank having four frame leg regions, wherein adjacent frame leg regions are each connected to each other by a metal profile strip.The four frame leg sections can each be simultaneously and jointly formed into a hollow frame leg profile. Subsequently, the metal profile strips between the four frame leg sections can be bent, and the frame corner element can be formed into a square frame. The two adjacent end faces of the formed frame corner profile can then be joined together and, for example, butt-fit or form-fit. In this way, a mechanically robust element frame can be produced from a flat sheet metal blank with just a few forming steps. Compared to a conventional element frame assembled from several solid profile sections, this frame has a very low weight. Furthermore, no complex machining is required for its production.

[0015] Optionally, each half-shell may have a stepped edge strip along at least two opposing side edges, so that each half-shell rests against an outer surface of the element frame associated with that half-shell. If two or more filter plate elements are joined to form a filter plate element assembly and pressed together in a chamber filter press, the individual filter plate elements rest against each other with their respective outer surfaces of the element frame facing each other.This clamps the edge strip of the half-shell, which rests on this outer surface of the element frame, between the two opposing outer surfaces of the two element frames, which are arranged adjacent to each other in the chamber filter press and are pressed together. This clamping action secures the edge strip between the two element frames and thus provides additional protection against unwanted slippage or detachment from the element frame. Furthermore, the edge strip can also be advantageously used to seal a filter chamber and can be designed accordingly, so that a gap between two filter plate elements, which are pressed together along the respective element frames, is sealed by the edge strips resting against the element frames.

[0016] The stepped edge strip can be formed by two bends or deformations performed in opposite directions. By appropriately arranging and shaping the stepped edge strips, which abut the element frame on opposite sides, the half-shell can be fixed in the desired position by the edge strips alone or in addition to other measures. To reduce mechanical stress on a filter fabric or filter cloth fixed within the half-shell, a stepped strip connecting the edge strip to the half-shell base has an acute angle of more than 0° and less than 90° to the half-shell base or to the edge strip. Alternatively, a suitable forming process can be used to create transitions between the half-shell base and the edge strip that are as continuous as possible.

[0017] According to a particularly advantageous embodiment of the invention, it is provided that each half-shell has a stepped edge strip along each side edge, and that the half-shell is made in one piece from a flat filter plate blank with a corner between adjacent side edges and with a recess in a region of each corner, the shape of which is adapted to the stepped edge strip, so that after forming the edge strips of the adjacent side edges, the two stepped edge strips merge flush into each other.The stepped edge strips formed along all sides give the half-shell a trough-like shape, which is advantageous for use in chamber filter presses. This is because a filter chamber is formed between two facing trough-shaped half-shells of adjacent filter plate elements in the press, the volume of which is comprised of the volumes of the two trough-shaped half-shells. The trough-shaped half-shell designed in this way can also be manufactured from a flat sheet metal blank without any machining. Only a few forming steps, specifically two bends along the respective side edges, are required, making the production of a trough-shaped half-shell very quick and cost-effective.Unlike conventional manufacturing processes, no costly tools or molds are required that are individually designed for each tub design, as would be necessary, for example, for a deep drawing process.

[0018] The filter plate element according to the invention can, for the desired solid-liquid separation of the suspension introduced into the individual filter chambers in the chamber filter press, comprise a textile filter fabric or a filter cloth, which is inserted or clamped in the trough-shaped interior of a half-shell in such a way that the suspension, which has been introduced through a feed opening into the filter chamber formed by two adjacent filter plate elements, must flow through the filter fabric or filter cloth before exiting through the outlet channel, and the solid particles that do not fit through the small openings in the filter fabric or filter cloth are retained by the filter fabric or filter cloth in the filter chamber. The particles that gradually accumulate in the filter chamber thereby form a filter cake of solid residues over time.The filter cake must then be removed from the filter chamber at regular intervals by opening the chamber filter press and separating the two adjacent filter plate elements, which form the filter chamber between themselves or between the two facing half-shells, until a gap between the two filter plate elements allows the filter cake to be removed through this gap.

[0019] To ensure optimal temperature resistance of the filter plate element, the filter cloth can also be made of a metal mesh. Alternatively, a flat metal filter element can be used, which may be designed not as a metal mesh, but, for example, as a metal knit or a perforated plate. A metal mesh or a flat metal filter element can significantly extend the service life of the filter plate element, particularly in abrasive filtration processes or those carried out at extreme temperatures.

[0020] To maximize the filtration efficiency of the filter plate element during filtration, it can be advantageous to position a filter mesh on a half-shell, preferably between a feed opening and the outlet channel, such that any suspension fed through the feed opening must pass through the filter mesh before exiting the filter plate element. A filter fabric or filter cloth can be attached to the filter mesh on one or both sides, thereby providing mechanical support and reducing the risk of damage, such as tearing, during operation of the chamber filter press. The filter mesh facilitates the drainage of the filtrate between the half-shell and the filter fabric or filter cloth. The filter mesh can, for example, be designed as a metal grid with intersecting metal bars.The filter mesh can also be designed as a support structure with a shape that, on the one hand, defines and creates a distance between a filter fabric or filter cloth that may be in contact with the filter mesh and the associated half-shell of the filter plate element, and on the other hand, enables efficient drainage of the filtrate through the drainage channel.

[0021] Various materials are known from practice, and filter fabrics or filter cloths are commercially available that have high temperature resistance and can be used even at temperatures above 100 ° Celsius and can exert the desired filtering effect.

[0022] To enable the use of the filter plate element even at particularly high temperatures well above 200° Celsius and, if necessary, above 500° Celsius or even above 600° Celsius, the filter mesh is optionally designed to achieve a predetermined retention effect for solid particles in a suspension as this suspension flows through the filter mesh. For example, the filter mesh can have an average mesh size corresponding to the average particle size of the solid components of the suspension that are to be retained during the solid-liquid separation of the suspension in the filter chamber, while particles with a smaller average particle size can pass through the filter mesh and leave the filter chamber without being retained.Various types and configurations of wire mesh with different mesh sizes are known from practical experience and are suitable for use in a chamber filter press. The filter mesh can extend essentially completely over the outer surface of each half-shell, away from the element frame. It is also possible, and potentially advantageous, for the filter mesh to extend largely over the outer surface of the half-shell, but not over the stepped edge strips of the half-shell, which are clamped and compressed between two adjacent element frames during operation of the chamber filter press. Such compression could damage a filter mesh that is also clamped and compressed between two element frames and could impair the sealing effect of the compressed element frames.

[0023] According to a particularly advantageous embodiment of the invention, the filter mesh is made of metal, and a metal filter screen element is arranged on the outer surface of the filter mesh. Both the filter mesh and the filter screen element then exhibit very high temperature resistance and can be used with the filter plate element for extended periods or essentially indefinitely. Advantageously, the filter screen element can be permanently or inseparably bonded to the filter mesh. The filter screen element can expediently be sintered onto the filter mesh. It is also possible for the filter screen element and / or the filter mesh to be manufactured in separate manufacturing steps or as a single piece using a 3D printer or another additive manufacturing process.The filter screen element can, for example, be designed as a metal fleece or as a metal thread fabric.

[0024] It is also conceivable that the filter mesh is designed in multiple layers. For example, the filter mesh can have several layers of mesh, each with a different mesh size. Thus, the filter mesh can be composed of two, three, or more layers of mesh stacked on top of each other. The mesh size of each layer can decrease or increase with increasing distance from the corresponding half-shell. It is also conceivable that several layers of differently designed filter screen elements are combined and stacked on top of each other in a layered fashion within the filter mesh. Optionally, it can also be provided that individual layers of mesh and layers of a filter screen element alternate with each other, and that a layer of a filter screen element is covered on both sides by a layer of mesh.

[0025] According to one embodiment of the invention, it can advantageously be provided that the two half-shells abutting the element frame define a cavity between the two half-shells, surrounded by the element frame. Temperature control devices can, for example, be arranged in this cavity, with which the filter plate element is brought to and maintained at a predetermined temperature during use. Stiffening elements can also be arranged in the cavity to support the two half-shells in an area surrounded by the element frame and to ensure the mechanical load-bearing capacity of the filter plate element.

[0026] The portions of the suspension fed into a filter chamber formed between two adjacent filter plate elements via the feed opening and not retained in the filter chamber can usually penetrate through one or more openings in the half-shell into the cavity between the two half-shells of a filter plate element and from there be discharged from the filter plate element via a drain channel or via several drain channels formed in the element frame.

[0027] To ensure the most reliable drainage of the portions of the suspension not retained in the filter chamber from the filter plate element, an optional feature can be provided: a through-opening is formed in at least one corner of at least one half-shell of the filter plate element, and a discharge channel is arranged within the cavity. This channel connects the through-opening in the half-shell to the discharge channel in the element frame, directing any liquid entering through the through-opening to the discharge channel in the element frame without allowing the liquid to enter the cavity beyond the discharge channel. The discharge channel in the cavity effectively prevents uncontrolled entry of the suspension into the cavity, thus preventing the accumulation of solid particles.

[0028] The drainage channel can have a tubular section extending from the opening in the half-shell to laterally beyond the element frame. To allow the drainage channel to pass through the element frame, bores can be arranged or created in opposing frame walls of one frame leg of the element frame during or after its manufacture, such that the drainage channel can extend through these bores. Alternatively, the drainage channel can be inserted from the outside through the element frame and the bores formed therein until a first opening of the drainage channel is completely overlapping with the opening. The drainage channel can then be fixed in this position.In this way, simple design means can ensure that a section of the element frame designed as a frame leg hollow profile is not contaminated by a suspension unintentionally penetrating the frame leg hollow profile and that the previously penetrated suspension must be removed from the frame leg hollow profile by additional measures if necessary.

[0029] According to a further embodiment of the invention, at least one half-shell may have a cavity opening in at least one corner region of the half-shell, through which the cavity outside the filter chamber is accessible. Through these cavity openings, the cavity is accessible from outside a filter chamber, so that, for example, a temperature control medium such as a heat transfer fluid or a fluid coolant can enter the cavity through these openings and flow through the cavity to release or absorb heat. Sensors or other components may also be arranged in the cavity and accessible via these cavity openings, or be supplied with energy or connected for data transmission.

[0030] At least one half-shell can also have a cavity opening accessible from the filter chamber, located in a corner area of ​​the half-shell. By appropriately arranging and designing this cavity opening, it can, for example, also be used additionally or exclusively as a feed opening or as a passage opening for the suspension to be filtered.

[0031] Advantageously, at least one half-shell may also have a base with a three-dimensionally structured surface. The three-dimensionally structured surface may, for example, have a number of regularly or irregularly distributed, protruding features. These features may be knob-shaped or groove-shaped. This surface structuring can be produced from a flat sheet metal blank by suitable forming processes.With a suitably three-dimensionally structured surface, a filter mesh may be unnecessary, since the three-dimensional structuring prevents a filter cloth from lying flat and sealing against the surface, but rather allows sufficient drainage and removal of the portions of the suspension not retained by the filter cloth in the filter chamber through cavity structures between the filter cloth and the three-dimensionally structured surface.

[0032] To achieve the most precise possible temperature control of the suspension during filtration with the filter plate element, at least one half-shell can be connected, or connectable, to a temperature control device for heat transfer. A temperature control device located on or in the filter plate element can, for example, be located on or in the element frame or, if applicable, in the cavity between the two half-shells. This device could, for example, be a Peltier element or a heat pipe. It is also conceivable that one or both half-shells are connected for heat transfer to heat channels, which are located, for example, in the cavity between the half-shells or in the element frame, and that a temperature-controlled heat transfer fluid can be supplied to these heat channels from an externally located temperature control device.

[0033] Optionally, the temperature control device may also include a flow-through device in a region of the cavity between the two half-shells, through which a heat transfer fluid can flow. The flow-through device may, for example, be designed as a continuous flow channel that meanders within the cavity between the two half-shells. The heat transfer fluid can flow into the flow channel via a heat transfer fluid inlet opening and out of the flow channel via a heat transfer fluid outlet opening. The flow channel is advantageously designed and arranged to ensure the most efficient possible heat transfer between the heat transfer fluid and the half-shells.

[0034] It is also conceivable that a heat transfer chamber or several interconnected heat transfer chambers are formed between the two half-shells, and that the heat transfer fluid can flow into the heat transfer chamber or one of the several heat transfer chambers via a heat transfer fluid inlet opening and flow out of the heat transfer chamber or one of the several heat transfer chambers again through a heat transfer fluid outlet opening arranged at a distance from it.

[0035] Water, steam, or oil, for example, can be used as the heat transfer fluid. Other fluids, mixtures, or suspensions can also be used to achieve the fastest possible temperature control of the half-shells. The element frame, assembled or manufactured from hollow profiles, can be filled with air or, advantageously, with a thermal insulation material, so that the element frame surrounding the flow-through device between the half-shells provides thermal insulation and thereby reduces unwanted heating or cooling of the temperature-controlled half-shells by the environment.

[0036] The following are exemplary implementation examples, which are illustrated in the drawings. It shows:

[0037] Fig. 1 shows a top view of a filter plate element, wherein a half-shell resting on an element frame is facing the viewer, and wherein no filter mesh is yet arranged on the half-shell.

[0038] Fig. 2 shows a side view of the filter plate element shown in Fig. 1.

[0039] Fig. 3 shows a perspective view of the filter plate element shown in Figs. 1 and 2.

[0040] Fig. 4 shows a perspective view of some components of the filter plate element shown in Fig. 3 in a stretched view.

[0041] Fig. 5 is a schematic sectional view of the filter plate element shown in Figs. 1 to 4 along a line VV in Fig. 2, Fig. 6 is a schematic sectional view of the filter plate element shown in Figs. 1 to 4 along a line VI-VI in Fig. 1,

[0042] Fig. 7 shows a top view of a flat metal sheet blank from which a frame corner element with two right-angled frame legs can be produced.

[0043] Fig. 8 shows a perspective view of a frame corner element not yet fully manufactured from the metal sheet blank shown in Fig. 7, with two frame leg hollow profiles still aligned in a straight line to each other.

[0044] Fig. 9 shows a perspective view of the finished frame corner element produced from the metal sheet blank shown in Fig. 7, with two frame legs arranged at right angles to each other, each of which is designed as a hollow frame leg profile.

[0045] Fig. 10 shows a top view of a flat sheet metal blank from which a trough-shaped half-shell can be produced.

[0046] Fig. 11 shows a partially cut detail view of an area of ​​a corner of a trough-shaped half-shell, which is made from the flat sheet metal blank shown in Fig. 10.

[0047] Fig. 12 shows a sectional view through a section of a filter plate element with an element frame, with trough-shaped half-shells adjoining the element frame and with components fixed to the half-shells.

[0048] wire mesh,

[0049] Fig. 13 shows a perspective view of a half-shell with cavity openings in its corner areas.

[0050] Fig. 14 shows a sectional view through a half-shell with a half-shell base that has a three-dimensionally structured surface.

[0051] Fig. 15 shows a sectional view through a section of a filter plate element with an element frame, with trough-shaped half-shells adjoining the element frame, and with a multi-layered filter mesh and a metal filter fleece fixed to it, arranged on each half-shell.

[0052] Fig. 16 shows a sectional view through a filter plate element with an element frame, with trough-shaped half-shells adjoining the element frame and heat transfer chambers formed between the half-shells, through which a heat transfer fluid can flow, and

[0053] Fig. 17 shows a perspective view of an element frame in which a meandering flow channel for a heat transfer fluid is formed in a cavity between two half-shells not shown in Fig. 17.

[0054] Figures 1 to 6 show different views of a metal filter plate element 1 for a chamber filter press. The filter plate element 1 has a square frame 2 and two half-shells 3 which abut and are fixed to the frame 2 on opposite outer sides 4, 5. The two half-shells 3, together with the frame 2, define a cavity 6 between the two half-shells 3.

[0055] Each of the two half-shells 3 has a feed opening 7 and two through-openings 8. A feed lance (not shown in the figures) for supplying a suspension into a filter chamber can be passed through the two overlapping feed openings 7 of the two half-shells 3. The filter chamber is formed between two adjacent filter plate elements 1, which are pressed together with the facing half-shells 3. A portion of the suspension not retained in the filter chamber can be discharged through the two through-openings 8 via a discharge channel 9, which leads to the outside through the cavity 6 and through the element frame 2.

[0056] Between the two half-shells 3, a spacer element 10, in the exemplary embodiment having a cross shape, is arranged in the cavity 6. This spacer element supports the two half-shells 3 against each other at a distance predetermined by the spacer element 10, even under the high pressure with which the suspension is forced through the filter chambers, and prevents undesired deformation of the half-shells 3 in an area within the element frame 2. Only in Fig. 12 is a filter mesh 12 arranged on an outwardly facing outer surface 11 of the half-shells 3, which, in an adjacent arrangement of filter plate elements 1, forms an inner wall of a filter chamber. This mesh covers the passage openings 8 and leaves the feed opening 7 clear.A suspension forced through the inlet opening 7 into a filter chamber formed between two pressed-together filter plate elements 1 must then flow through the filter mesh 12 before the portion of the suspension not retained by the filter mesh 12 can leave the filter chamber through the openings 8 and flow out of the filter plate element 1 through the outlet channels 9. A filter cloth or other flat filter element can also be arranged and fixed on the filter mesh 12, so that the filtering effect is essentially provided by the filter cloth and the filter mesh 12 serves to prevent the filter cloth from fully contacting the half-shell 3 and instead to enable drainage and effective discharge of the portions of the suspension not retained by the filter cloth in the filter chamber.

[0057] Figures 7 to 9 schematically illustrate the production of a frame corner element 14 from a flat sheet metal blank 15. Starting with the flat sheet metal blank 15 shown in Figure 7, a frame leg 18, designed as a frame leg hollow profile 17, is produced on each side of a metal profile strip 16. The two frame leg hollow profiles 17 are each produced together by several forming steps or bending of the flat sheet metal blank 15. The two side edges 19, 20 of the sheet metal blank 15, which abut each other in the area of ​​the two frame leg hollow profiles 17, are joined together and, for example, welded together, so that a dimensionally stable frame leg hollow profile 17 with low weight is produced cost-effectively with minimal material expenditure.

[0058] The two frame leg hollow profiles 17 shown in Fig. 8, which are initially aligned in a straight line to each other, can then be bent by folding the metal profile strip 16 and arranged and fixed at right angles to each other to form a frame corner element 14 shown in Fig. 9 with two frame legs 18 arranged at right angles to each other, each frame leg 18 being designed as a frame leg hollow profile 17. Optionally, the square element frame 2 can be manufactured from a single flat metal sheet blank 15 with four frame leg sections, requiring only a few forming steps or bends to produce a square element frame 2 with four frame legs 18 arranged at right angles to each other, each of which is designed as a frame leg hollow profile 17, from the flat metal sheet blank 15.

[0059] Figures 10 and 11 show two views of a half-shell 3 during its manufacture. The half-shell 3, like the element frame 2, can be manufactured from a flat sheet metal blank 21, which initially has a square base. A recess 23 is made in each of the corner areas 22. Subsequently, a stepped and arranged edge strip 25 is produced by double forming or bending along each side edge 24. The edge strip 25 is arranged at a distance from a central area 26 of the half-shell 3 and projects laterally outwards from the central area 26, parallel to it.The stepped edge strips 25, which rest on the respective associated outer sides 4, 5 of the element frame 2, fix the two half-shells 3 in their respective positions relative to the element frame 2 and, in the case of an arrangement of several filter plate elements 1 in a chamber filter press, clamp them between the respective adjacent element frames 2 and additionally fix them.

[0060] Figure 12 shows an exemplary edge region of a filter plate element 1 designed according to the invention. The two half-shells 3 each rest against and are fixed to the element frame 2 on an associated outer surface 4, 5. The spacer element 10 supports the two half-shells 3 against each other and holds them at a distance from each other determined by the spacer element 10. A cavity 6 is formed between the two half-shells 3, through which the drainage channels 9 run, allowing the portion of the suspension not retained in a filter chamber to be discharged from the filter chamber and from the filter plate element 1. A filter cloth (not shown) resting on the filter mesh 12 is supported by the filter mesh 12, so that solid particles that cannot pass through the filter cloth are retained by the filter cloth in the filter chamber and gradually form a

[0061] Filter cakes are formed, while the portion of the suspension not retained by the filter cloth can flow through the filter mesh 12 and be discharged from the filter chamber through the openings 8 in the half-shells 3 and subsequently through the discharge channels 9 from the filter plate elements 1.

[0062] Figure 13 shows a perspective view of a half-shell 3. In the trough-shaped half-shell 3, the central area 26 forms a base, which is surrounded and bounded by the edge strips 25 formed along a circumferential rim. In each of the corner areas 22, a corner area 27 is arranged, raised above the central area 26 and flush with the edge strips 25. In each corner area 27, a cavity opening 28 is arranged, through which the cavity 6 between the two half-shells 3, shown for example in Figure 4, is accessible. The cavity openings 28 are arranged outside of the filter chamber formed between two half-shells 3, so that the cavity 6 is accessible from outside the filter chamber through the cavity openings 28.

[0063] Figure 14 shows an exemplary and schematic cross-sectional view of a half-shell 3, which has a three-dimensionally structured surface 29 in the central area 26, which forms the base of the half-shell. This three-dimensional structuring of the surface 29 was carried out by a forming step after the production and shaping of the trough-shaped half-shell 3. Stepped strips 30 running obliquely or at an acute angle are formed between the base of the half-shell and the edge strips 25.

[0064] Figure 15 shows a sectional view through a section of a filter plate element 1 with an element frame 2 and with trough-shaped half-shells 3 abutting the element frame 2 on both sides. A filter mesh 12, composed of two braided layers 31, 32, is arranged on each half-shell 3. A filter screen element 34, designed as a metal filter fleece, is arranged on one of the outer surfaces 33 of the filter mesh 12 facing away from the opposite half-shell 3. The filter screen element 34 is permanently and inseparably bonded to the adjacent braided layer 32 of the filter mesh 12, for example by a sintering process. The two braid layers 31 and 32 can also be permanently connected to each other and form a single-piece manageable drainage and separation element which can be removed and cleaned as needed, but can be used for a long period of time.

[0065] Fig. 16 shows a sectional view through a filter plate element 1 with an element frame 2 and with trough-shaped half-shells 3 adjoining the element frame 2. Several heat transfer chambers 35 are formed between the half-shells 3, through which a heat transfer fluid (not shown in Fig. 16) can flow. The heat transfer fluid can flow into one of the heat transfer chambers 35 through a heat transfer fluid inlet opening 36 extending through the element frame 2 and flow out again on the opposite side of the element frame 2 through a heat transfer fluid outlet opening 37, also extending through the element frame 2. Fig. 17 shows, by way of example, a perspective view of the element frame 2, in which the cavity 6 between two [parts] in Fig. 16 is formed.In the 17 half-shells (not shown), a meandering flow channel 38 for a heat transfer fluid is formed. The flow channel 38 is connected at one end to the heat transfer fluid inlet opening 36 and at the opposite end to the heat transfer fluid outlet opening 37. The flow channel 38 simultaneously forms a spacer support element for the half-shells that abut the element frame 2 from both sides.

Claims

PATENT CLAIMS 1. Filter plate element (1) made of metal for a chamber filter press for solid-liquid separation of suspensions, comprising an element frame (2) and two half-shells (3) which abut the element frame (2) on opposite sides (4, 5), wherein at least one drain channel (9) is formed in the element frame (2) through which a liquid flowing through at least one through-opening (8) in the half-shell (3) into the drain channel (9) can be discharged from the filter plate element (1), characterized in that the element frame (2) has a frame corner element (14) made of a metal profile, which has at least two frame legs (18) which are aligned at an angle between more than 0° and less than 180° to each other and are each designed as a frame leg hollow profile (17).

2. Filter plate element (1) according to claim 1, characterized in that the frame corner element (14) is manufactured in one piece and that the two frame leg hollow profiles (17) are connected to each other via a bent metal profile strip (16) extending over a corner of the filter plate element (1).

3. Filter plate element (1) according to claim 1 or claim 2, characterized in that the frame corner element (14) is made from a flat metal sheet blank (15) which is multiply in the area of ​​the frame legs (18). is bent and each forms a frame leg hollow profile (17).

4. Filter plate element (1) according to one of the preceding claims, characterized in that the element frame (2) is formed from a single frame corner element (14) with several frame legs (18), wherein two adjacent frame legs (18) are aligned at an angle between more than 0° and less than 180° to each other.

5. Filter plate element (1) according to one of the preceding claims, characterized in that each half-shell (3) has a stepped edge strip (25) along at least two opposing side edges (24), so that each half-shell (3) with the stepped edge strip (25) abuts an outer surface (4, 5) of the element frame (2) associated with the half-shell (3).

6. Filter plate element (1) according to claim 5, characterized in that each half-shell (3) has a stepped edge strip (25) along each side edge (24), and that the half-shell (3) is made in one piece from a flat filter plate blank (21) with a corner (22) between adjacent side edges (24) and with a recess (23) in a region of each corner (22), the shape of which is adapted to the stepped edge strip (25), so that after forming the edge strips (25) of the adjacent side edges (24) the two The stepped edge strips (25) merge flush into one another.

7. Filter plate element (1) according to one of the preceding claims, characterized in that a half-shell (3) a filter mesh (12) is specified.

8. Filter plate element (1) according to claim 7, characterized in that the filter mesh (12) is designed in such a way that a predefinable retention effect for solid particles in a suspension can be achieved when this suspension flows through the filter mesh (12).

9. Filter plate element (1) according to claim 7 or claim 8, characterized in that the filter mesh (12) is made of metal, and that a filter sieve element (34) made of metal is arranged on an outer side (33) of the filter mesh (12).

10. Filter plate element (1) according to one of the preceding claims, characterized in that the two half-shells (3) adjoining the element frame (2) define a cavity (6) surrounded by the element frame (2) between the two half-shells (3).

11. Filter plate element (1) according to claim 10, characterized in that a passage opening (8) is formed in at least one half-shell (3) in at least one corner (22) of the filter plate element (1) and that a discharge channel (9) is arranged in the cavity (6), which connects the passage opening (8) in the half-shell (3) with the drain channel in the element frame in order to allow a discharge through the The passage opening (8) allows the incoming liquid to be directed to the drain channel in the element frame (2) without the liquid being able to enter the cavity (6) into an area outside the drain channel (9).

12. Filter plate element (1) according to one of the preceding claims 10 or 11, characterized in that at least one half-shell (3) has a cavity opening (27) in at least one corner region of the half-shell (3) through which the cavity (6) outside of the filter chamber is accessible.

13. Filter plate element (1) according to one of the preceding claims, characterized in that at least one half-shell (3) has a half-shell bottom with a three-dimensionally structured surface (29).

14. Filter plate element (1) according to one of the preceding claims, characterized in that at least one half-shell (3) is connected or connectable to a temperature control device in a heat-transferring manner.

15. Filter plate element (1) according to claim 10 and claim 14, characterized in that the temperature control device has a flow-through device in a region of the cavity (6) between the two half-shells (3) through which a heat transfer fluid can flow.

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