Measuring unit, filter plate, measuring arrangement, filter press, and method for monitoring condition of filter plate

Abstract

A measuring unit (1) for a filter press (50) comprises an elongated frame part (2) comprising an outer end part (3) at a first end and an inner end part (4) at a second end, and a middle part (5) extending between and coupled to the outer end part (3) and the inner end part (4). The measuring unit (1) also comprises a temperature detector (6) provided in connection with the frame part (2), and a strain detector (7) provided in connection with the frame part (2) in the area of the middle part (5) such that the strain detector (7) is arranged to detect deformation of the middle part (5). The cross-sectional area of the middle part (5) is smaller than cross-section area of the outer end part (3) and the inner end part (4).

Description

[0001] MEASURING UNIT, FILTER PLATE, MEASURING ARRANGEMENT, FILTER PRESS, AND METHOD FOR MONITORING CONDITION OF FILTER PLATE

[0002] FIELD OF THE DISCLOSURE

[0003] The present disclosure relates to filter presses, and particularly to a measuring unit, a filter plate, and a measuring arrangement. The present disclosure further concerns a method for monitoring condition of a filter plate.

[0004] BACKGROUND OF THE DISCLOSURE

[0005] Industrial filters, including filter presses, are commonly used for separating solids from liquids in various processes. The mix of these liquid and solid components is often called slurry.

[0006] Filter presses, especially horizontal filter presses, consist of a pack of filter plates arranged side by side and forming filter chambers between them. The filter plates may form recessed plate membrane filters forming vertically oriented filter chambers between them. The filter plate pack may be located between two rigid plates that are opened and closed by hydraulic cylinders. In the closed position, the filter plates form a solid filter plate pack of sealed filter chambers with two filter cloths between each pair of filter plates. The process liquids enter into the filter through slurry distribution channels that are formed when the plate pack is closed. The slurry is pumped into all filter chambers simultaneously to form a filter cake on both sides of the filter chamber. During filtration, the solids are captured by the filter cloth on both sides of the chamber to form a cake. The liquid components, on the other hand, pass through the filter cloth and are extracted through liquid distribution channels from the filter press. After completion of the filtration, the filter plate pack is opened, and the cake is discharged.

[0007] Operational conditions within the filter presses are typically very harsh with presence of high pressures, wet conditions added with slurry and often also with some chemicals. This kind of an environment is very challenging for typical detectors, such as different types of sensors. The harsh process environment within the filter presses thus affects the accuracy and durability of sensors, and even prevents certain types of measurements from being made with conventional detectors. The operational conditions may also be similar causing similar type of problems in other types of filter presses, such as tower presses, where plates in horizontal position are arranged on top of each other and where the build-up, such as the filter cake, is only provided on one side of each filter plate. Thus, the solution of this disclosure may also be beneficial in such filter presses.

[0008] BRIEF DESCRIPTION OF THE DISCLOSURE

[0009] An object of the present disclosure is to provide a new measuring unit, filter plate, measuring arrangement, filter press, and method for monitoring condition of a filter plate.

[0010] The object of the disclosure is achieved by the new measuring unit, filter plate, measuring arrangement, filter press, and method for monitoring condition of a filter plate which are characterized by what is stated in the independent claims. Some embodiments of the disclosure are disclosed in the dependent claims.

[0011] The disclosure is based on the idea of providing a measuring unit comprising a plurality of detectors and being designed to be placed in a cavity in a filter plate.

[0012] An advantage of the solution of the disclosure is that changeable and serviceable measuring unit is provided, which can be provided inside the filter plate such that the filter plate frame protects the detectors of the measuring unit from the harsh conditions within the filter press, while enabling measurements being made from the actual area of the filter chambers.

[0013] BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In the following the disclosure will be described in greater detail by means of preferred embodiments with reference to the accompanying drawings, in which:

[0015] Figure 1 illustrates schematically a filter press; Figure 2 illustrates schematically a measuring unit according to a first embodiment;

[0016] Figure 3 illustrates schematically a measuring unit according to a second embodiment;

[0017] Figure 4 illustrates schematically a filter plate according to an embodiment seen in perspective;

[0018] Figure 5 illustrates schematically a filter plate according to an embodiment seen in cross section seen from a side;

[0019] Figure 6 illustrates schematically a filter plate according to an embodiment seen in cross section seen from an end;

[0020] Figure 7 illustrates schematically a measuring arrangement according to an embodiment; and

[0021] Figure 8 illustrates schematically a method for monitoring condition of a filter plate.

[0022] The figures are for illustrative purposes only and are not shown in scale. Not all similar features are provided with reference signs in all the figures for the sake of clarity. Some features are exaggerated in some figures to better illustrate the features.

[0023] DETAILED DESCRIPTION OF THE DISCLOSURE

[0024] The disclosure relates to filter presses, and more particularly to measuring units for such filter presses.

[0025] Figure 1 illustrates schematically a filter press. The measuring units, filter plates, measuring arrangements, and methods described in this disclosure may be applied for instance to such a filter press, but are not limited to the type of a filter press illustrated in Figure 1. Instead, the measuring units, filter plates, measuring arrangement and methods in this disclosure may be applied to many types of filter presses comprising a pack of filter plates designed to form filter chambers between them.

[0026] A typical filter press 50, especially a horizontal filter press 50 such as the filter press of Figure 1, may comprise a frame 53 formed of two parallel horizontal side bars 54, a pack 58 of filter plates 30. The pack of filter plates 30 may comprise two end plates, one at each end of the pack of filter plates. A first one of these end plates may be fixed and the second one of these end plates may be movable with an actuator 55 in a longitudinal direction 56 of the filter press. The actuator 55 may be for instance a hydraulic cylinder-piston apparatus. The pack of filter plates 30 may be pressed together between the end plates by moving one of the end plates by the actuator 55. The filter plates 30 may be supported at the side bars 54, and the side bars 54 may be supported with vertical support bars 57 on the floor of the building.

[0027] As described above, according to an embodiment, the filter plates 30 may form for instance recessed plate membrane filters forming vertically oriented filter chambers between them. In some embodiments, the filter plates 30 may, however, not comprise membranes.

[0028] The filter plate pack 58 may be located between two rigid plates, the unmovable end plate 60 and the movable end plate 59, that are opened and closed by actuators 55, such as hydraulic cylinders. In the closed position, the filter plates 30 form a solid filter plate pack 58 of sealed filter chambers, typically with two filter cloths 39 between each pair of filter plates 30. The process liquids enter into the filter through slurry distribution channels (not shown) that are formed when the filter plate pack 58 is closed. The slurry is pumped into all filter chambers simultaneously to form a filter cake on both sides of the filter chamber. During filtration, the solids are thus captured by the filter cloth 39 on both sides of the filter chamber to form the filter cake. The liquid components, on the other hand, pass through the filter cloth and are extracted through liquid distribution channels from the filter press. After completion of the filtration, the filter plate pack 58 is opened and the cakes are discharged.

[0029] Although the filter plates 30 and the filter press 50 illustrated in the figures and in some embodiments of this disclosure are horizontal filter presses, in other embodiments, the filter press 50 may also comprise a vertical filter press, such as a tower press, and the filter plate 30 may comprise a filter plate of such a vertical filter press. Operating conditions in horizontal and vertical filter presses may be in many respects similar, although the filter plates are arranged in a different direction and the structure of the filter plates is typically different is some respects. Similarly, in some embodiments, the measuring unit 1, the measuring arrangement 40, and the method for monitoring condition of a filter plate 30, too, may be applied in connection with a vertical filter press.

[0030] Figure 2 illustrates schematically a measuring unit according to a first embodiment. Figure 3 illustrates schematically a measuring unit according to a second embodiment.

[0031] A measuring unit 1 for a filter press 50, such as a measuring unit 1 of Figure 2 or Figure 3, comprises an elongated frame part 2. The frame part 2 comprises an outer end part 3 at a first end of the frame part 2, an inner end part 4 at a second end of the frame part 2, and a middle part 5 extending between the outer end part 3 and the inner end part 4. The outer end part 3 and the inner end part 4 are coupled to the middle part 5. In other words, the middle part 5 is arranged to engage with the outer end part 3 and the inner end part 4, for instance to at least touch the outer end part 3 and the inner end part 4. According to an embodiment, the outer end part 3 and the inner end part 4 may be fixedly attached to the middle part 5 or the mutual movement of the middle part 5 in relation to the outer end part 3 and / or the inner end part 4 may be limited in the direction of one or more degrees of freedom in such a manner that it enables detecting one or more characteristics of the filtering process. In other words, the outer end part 3 and the inner end part 4 may be attached to the middle part 5 in such a way that possible movements and forces applied to the outer end part 3 and / or the inner end part 4 and designed to be detected are transferred to the middle part 5. According to an embodiment, the middle part 5 may be enabled to spin and / or move axially in at least one lateral direction in relation to the outer end part 3 and / or the inner end part 4, for instance in relation to one of the outer end part 3 and the inner end part 4. This may be beneficial for instance to enable thermal expansion of at least one of the outer end part 3, the inner end part 4, or the middle part 5. In such embodiments, the mutual movement of the middle part 5, the inner end part 3, and the outer end part 4 may be limited in some other manner, if and where needed, for instance as explained in connection with some embodiments of this disclosure. The frame part 2 of the measuring unit 1 having an elongated shape refers to a length 22 of the frame part 2 of the measuring unit 1 measured from the first end to the second being greater than the largest dimension of the frame part 2 of the measuring unit 1 measured in a transverse direction 17, preferably at least three times greater.

[0032] The measuring unit 1 also comprises a temperature detector 6 provided in connection with the frame part 2. In different embodiments, the temperature detector 6 may be for instance mounted to the frame part 2 fixedly or removably. According to an embodiment, the measuring unit 1 may comprise two or more temperature detectors 6. According to an embodiment, at least one temperature detector 6 may be configured to detect a measurable variable indicative of temperature of the slurry. According to an embodiment, at least one temperature detector 6 may be configured to detect a measurable variable indicative of temperature of the filter plate. A measurable variable being indicative of a characteristic, such as temperature of the slurry, refers to the measurable variable directly measuring the characteristic or enabling determining the characteristic on the basis of the measurable variable. According to an embodiment, the temperature detector(s) 6 may comprise at least one of an infrared sensor, a thermocouple, or the like.

[0033] In this disclosure, when a first structural part, such as the temperature detector 6, is provided in connection with a second structural part, such as the frame part 2, unless otherwise specified, it means that the first structural part may be for instance fixedly or movably connected to the second structural part, coupled with the second structural part, permanently or removably mounted to the second structural part, provided as a part of the second structural part, or arranged to the second structural part in any other suitable manner known as such.

[0034] The measuring unit 1 further comprises a strain detector 7 provided in connection with the frame part 2 in the area of the middle part 5 such that the strain detector 7 is arranged to detect deformation of the middle part 5. According to an embodiment, the strain detector 7 may be for instance mounted fixedly to the frame part 2 or formed as a part of the frame part 2 in the area of the middle part 5 such that the strain detector 7 is arranged to detect deformation of the middle part 5. In other words, the strain detector 7 may be mounted or attached to the frame part 2 in such a way that the strain detector 7 is capable of detecting strain applied to the frame part 2 due to external forces applied to the frame part 2. According to an embodiment, where the outer end part 3 and the inner end part 4 are provided in contact with the filter plate 30, the forces and strain applied to the filter plate 30 may, thus, be transferred to the frame part 2 and detected by the strain detector 7. According to an embodiment, the strain detector 7 may comprise for instance at least one of a strain gauge, a piezoelectric sensor, a fibre optic strain sensor, or a capacitive strain sensor. A strain gauge may comprise for instance an integrated pressure strain gauge, a load cell, a strain gauge pressure sensor, or another type of a strain gauge.

[0035] In the measuring unit 1, the cross-sectional area of the middle part 5 is smaller than the cross-sectional area of the outer end part 3 and the inner end part 4. In other words, the middle part 5 may be tapered or thinner than the outer end part 3 and the inner end part 4. The cross-sectional area of the middle part 5, the outer end part 3, and the inner end part 4 refers to the area of the cross section of the respective part in a transverse direction 17 of the measuring unit 1.

[0036] According to an embodiment, the outer end part 3, the inner end part 4, and the middle part 5 may be formed as separate pieces coupled with each other. According to an embodiment, at least one of the outer end part 3 or the inner end part 4 is fixedly coupled to the middle part 5. According to an embodiment, the middle part 5 may be formed as one piece with at least one of the outer end part 3 or the inner end part 4. According to a further embodiment, the outer end part 3, the inner end part 4, and the middle part 5 may be formed as one piece.

[0037] An advantage of such a measuring unit 1 is that it can be provided in a cavity 31, especially a cavity in a form of an elongated hole, provided in a filter plate 30, where the measuring unit 1 and the detectors, such as the temperature detector 6 and the strain detector 7, provided in the measuring unit 1 are isolated and protected from the surrounding operating conditions, such as external pressures, moist and the like. At the same time, such a measuring unit 1 may enable providing the temperature detector 6 at an optimal position along the frame part 2, for instance in view of the object to be measured, in other words in relation to the object, the temperature of which the temperature detector 6 is intended to measure. In addition, in such a measuring unit 1, the strain detector 7 may be arranged to measure strain applied to the filter plate 30, when the measuring unit 1 is connected filter plate 30. According to an embodiment, the strain detector 7 may be positioned at an optimal position to detect strain applied to the filter plate 30, such as deformation of the filter plate 30, for instance at a point where the highest change in the values can be detected.

[0038] According to an embodiment, the measuring unit 1 may be connected to the filter plate 30, for instance to the walls of the cavity 31, such as the walls of a drilled hole, at both the inner end part 4 and the outer end part 3. According to an embodiment, the measuring unit 1 may be connected to the cavity 31, for instance to a drilled hole, at one of its end parts, namely at the inner end part 4 or the outer end part 3, in a way preventing the movement of that end part 4 or 3 in relation to the filter plate 30 in the directions of all the degrees of freedom. According to an embodiment, the measuring unit 1 may be connected to the cavity 31 at the other one of its end parts, namely at the outer end part 3 or the inner end part 4, respectively, in a way preventing movement of that end part 3 or 4 in relation to the filter plate 30 at least in transverse direction 17 of the measuring unit 1.

[0039] According to an embodiment, the measuring unit 1 is connected to the filter plate 30 in such a way that the movement of one of the end parts 3, 4 of the measuring unit 1 in relation to the filter plate 30 is prevented in the directions of all the degrees of freedom, and that the movement of the other one of the end parts 4, 3 of the measuring unit 1 in relation to the filter plate 30 is prevented only in one transverse direction of the frame part 2 of the measuring unit 1 and not prevented in any other direction. According to an embodiment, the measuring unit 1 is connected to the filter plate 30 in such a way that the movement of one of the end parts 3, 4 of the measuring unit 1 in relation to the filter plate 30 is prevented in the directions of all the degrees of freedom, and that the movement of the other one of the end parts 4, 3 of the measuring unit 1 in relation to the filter plate 30 is prevented only in one transverse direction of the frame part 2 of the measuring unit 1 and in one rotational direction, which is the rotation about the longitudinal direction of the frame part 2, and not prevented in any other direction. According to an embodiment, the end part, the movement of which in relation to the filter plate 30 is prevented in the directions of all degrees of freedom is the inner end part 4.

[0040] According to an embodiment, one end part of the measuring unit 1, namely the outer end part 3 or the inner end part 4, may be connected to the cavity 31 in a manner enabling a mutual movement of the end part and the cavity in a direction of at least one degree of freedom. In such embodiments, the mutual movement of the end part, namely the outer end part 3 or the inner end part 4 of the measuring unit 1, and the filter plate 30 may be limited in other ways, such as by further structural parts. Similarly, the mutual movement of the other end part, namely the outer end part 4 or the inner end part 3, respectively, may also be limited in other ways, such as by plugging equipment or by further structural parts.

[0041] The cavity 31 in the filter plate 30, into which the measuring unit 1 may be provided, may preferably comprise an elongated hole, such as a drilled hole. Preferably, the cavity 31 may comprise a blind hole, in other words a hole that is closed at one end. However, in some embodiments, it may also comprise a different kind of a cavity, such as a through hole. According to an embodiment, the cavity 31 may be provided in the filter plate 30 by drilling the cavity 31, particularly in the form of an elongated hole, to the filter plate 30. However, it is clear for a person skilled in the art that the cavity 31 may also be provided in the filter plate 30 in another manner, for instance by casting or machining. Drilling the cavity 31 may, however, be particularly beneficial in embodiments, where the cavity 31 is provided in an existing filter plate 30 to provide it with a measuring unit 1, for instance as a retrofit.

[0042] According to an embodiment, the length 22 of the frame part 2 of the measuring unit 1 and a position of the measuring unit 1, when mounted in the cavity 31, is designed in such a way that the inner end part 4 is provided in the area of the filter chamber, when the measuring unit 1 is provided in the cavity 31, more particularly mounted to the cavity 31. According to an embodiment, the lengths 22 of the frame part 2 may be sufficiently long for the inner end part 4 being provided in the area of the filter chamber, when the measuring unit 1 is provided, more particularly mounted, in the cavity 31. According to an embodiment, the length 22 of the frame part 2 may be longer that the distance between an outer edge 32 of the cavity 31, which may be but is not necessarily equal to the edge 33 of the filter plate 30 around an open end of the cavity 31, and an outer end of a recess 36 provided in the filter plate 30 in order to form the filter chamber. This part of the filter plate 30, which surrounds the recess 36, may be called a frame 34 of the filter plate 30. The length 22 of the frame part 2 of the measuring unit 1 is, thus, preferably longer than the width 26 of the frame 34 of the filter plate 30 measured from an edge 33 of the filter plate 30 towards the centre of the filter plate 30 in a direction same or parallel to the direction of the length 22 of the frame part 2 of the measuring unit 1, when the measuring unit 1 is provided in the cavity 31. Thereby, at least the inner end part 4 of the measuring unit 1 may be provided in the area of the recess 36 and, thus, in the area of the filter chamber, when the measuring unit 1 is mounted to the cavity 31, also in case the outer end part 3 of the measuring unit 1 is mounted to the outer edge 32 of the cavity 31.

[0043] According to an embodiment, the outer edge 32 of the cavity 31 may be provided at an edge 33 of the filter plate 30.

[0044] According to an embodiment, the measuring unit 1 may further comprise at least one identification detector 8 provided in connection with the frame part 2, for instance mounted to the frame part 2. According to an embodiment, the identification detector 8 may comprise an identification detector configured to identify the filter plate 30, the membrane 38, and / or the filter cloth 39. According to an embodiment, the membrane 38 and / or the filter cloth 39 may comprise an identification tag 24, 25, such as an RFID tag or an NFC tag. According to an embodiment, at least one identification detector 8 may be configured to detect a measurable variable indicative of the identification related to the identification tag 24, such as the RFID tag or the NFC tag, of the membrane 38. According to an embodiment, at least one identification detector 8 may be configured to detect a measurable variable indicative of the identification related to the identification tag 25 of the filter cloth 39. According to an embodiment, an identification detector 8 may comprise for instance an antenna configured to read the identification tag 24, 25 of the membrane 38 or the filter cloth 39. According to an embodiment, the measuring unit 1 may comprise two or more identification detectors 8 connected to the frame part 2. According to an embodiment, these identification detectors 8 may be connected to different parts of the frame part 2. According to an embodiment, each identification detector 8 may be connected to the frame part 2 at an area optimal for reading the identification tag 24, 25 in question. According to an embodiment, such an optimal area may be located at a position closest to the identification tag 24, 25 and / or at a position where other structures, such as parts of the filter plate 30, cause the least amount of interference to the identification detector 8.

[0045] According to an embodiment, the measuring unit 1 may further comprise at least one of the following: a pressure detector, a leakage detector, a sound detector, a position detector, an acceleration detector, a gyroscope, or an inertial measurement unit (IMU). One or more of these detectors may be connected to the measuring unit 1, for instance to the frame part 2 or into an other part of the measuring unit 1. In this description, one or more of the temperature detector 6, strain detector 7, identification detector 8, and / or the above-listed detectors may be in general referred to as detector(s), where the specific type of detector is not relevant.

[0046] According to an embodiment, the measuring unit 1 may further comprise first connecting equipment 20 for transferring data from the detectors in a wired or wireless manner to a first data collecting unit 21. According to an embodiment, the first connecting equipment 20 may comprise one or more wires capable of transmitting data related to the characteristics and / or the measured variables from the detector(s) to the first data collecting unit 21. Such wires may be connected to one or more of the detectors at one end of the wire or along the length of the wire and to the first data collecting unit 21. According to an embodiment, first connecting equipment 20 may comprise devices capable of transmitting wirelessly data related to the characteristics and / or the measured variables from the detector(s) to the first data collecting unit 21, such as transmitters and receivers.

[0047] According to an embodiment, the first data collecting unit 21 may be provided in connection with the measuring unit 1. According to another embodiment, the first data collecting unit 21 may be provided in connection with the filter press 50. In such an embodiment, the first connecting equipment 20 may preferably be capable of transmitting the data wirelessly.

[0048] According to an embodiment, the inner end part 4 of the measuring unit 1 may comprise a threaded portion 14, as can be best seen in Figure 2. According to an embodiment, such a threaded portion 14 may be beneficial, as it can be used to mount the measuring unit 1 to the bottom of the cavity 31 in an unmovable manner. According to an embodiment, the threaded portion 14 may be removably mounted to the bottom of the cavity 31. According to an embodiment, the threaded portion 14 may be configured to be mounted permanently to the cavity 31 and the rest of the measuring unit 1 may be designed to be removable and replaceable. In other words, according to an embodiment, the threaded portion 14 may form a kind of anchoring inside the cavity, for instance on the bottom or at the closed end of the cavity 31 or along the length of the cavity 31, for removable and replaceable part of the measuring unit 1. According to other embodiments, the measuring unit 1 or a part of the measuring unit 1, such as the inner end part 4 may be designed to be correspondingly removably mounted in the cavity 31, or a part of the measuring unit 1, such as the inner end part 4, may be designed to be correspondingly permanently mounted in the cavity 31 by some other means than threading, such as by an expander, chemical anchoring, bayonet fixing, tight bushing and / or by a tight fit.

[0049] According to an embodiment, the bottom, in other words the closed end, of the cavity 31 may comprise a threaded portion (not shown) to which the threaded portion 14 of the measuring unit 1 may be configured to engage to, when the measuring unit 1 is mounted to the cavity 31. According to another embodiment, the threaded portion 14 of the measuring unit 1 may be designed to provide the closed end of the cavity 31 with threads. This may be implemented for instance by forming the threaded portion 14 of the measuring unit 1 from a suitable material, for instance a strong and rigid material.

[0050] According to an embodiment, the difference between the largest dimension 15 of the outer end part 3 in a transverse direction 17 of the measuring unit 1 and the largest dimension 16 of the inner end part 4 in the transverse direction 17 of the measuring unit 1 is less than or equal to 20 percent of the largest of the largest dimension 15 of the outer end part 3 and the largest dimension 16 of the inner end part 4. The percentage may, thus, be calculated comparing the difference to the larger one of the largest dimensions, namely the largest dimension 15 of the outer end part 3 and the largest dimension 16 of the inner end part 4. In other words, the outer end part 3 and the inner end part 4 may preferably comprise a same size, for instance a same diameter, or at least approximately same size. This may be beneficial in embodiments, where the hole in the filter plate 30, to which the measuring unit 1 is mounted, is made by drilling, whereby the diameter of the cavity 31 is typically approximately identical over the length of the cavity 31.

[0051] According to an embodiment, at least an outer edge 18 of the outer end part 3 may have a round cross section. According to other embodiments, at least an outer edge 18 of the outer end part 3 may have a cross section of another shape, such as an oval, rectangular, or polygonal cross section, for example.

[0052] According to an embodiment, the largest dimension 15 of the outer end part 3, more particularly the largest dimension of the cross section of the outer end part 3, may be provided at the outer edge 18 of the outer end part 3. According to an embodiment, where the cross section is round or oval, the largest dimension 15 of the outer end part 3 may comprise the largest diameter of the cross section of the outer end part 3 at the outer edge 18 of the outer end part 3. In other words, in such embodiments, the outer end part 3 may have the largest dimension 15 at the outer edge 18. Thereby the outer edge 18 of the outer end part 3 can be used for plugging the outer edge 32 of a cavity 31, when the measuring unit 1 is received in said cavity 31. Preferably, the diameter of the cavity 31 is, thus, equal to the diameter of the largest dimension 15 of the outer end part 3 to provide effective plugging of the cavity 31. According to an embodiment, the measuring unit 1 may further comprise at least one mounting member 19 in the area of the middle part 5 or the inner end part 4 for receiving at least one detector or other device mounted in the transverse direction 17 of the measuring unit 1. According to such an embodiment, a transverse hole 35 may be provided in the filter plate 30 for mounting the detector and / or other device(s). An example of such an embodiment is illustrated schematically in Figure 3.

[0053] Figure 4 illustrates schematically a filter plate according to an embodiment seen in perspective, Figure 5 illustrates schematically a filter plate according to an embodiment seen in cross section seen from a side, and Figure 6 illustrates schematically a filter plate according to an embodiment seen in cross section seen from an end.

[0054] According to an aspect, a filter plate 30, such as a filter plate 30 of one or more of the Figures 4, 5, and 6, comprises at least one measuring unit 1 according to an embodiment disclosed in this description and / or accompanying claims and / or drawings, or a combination of such embodiments.

[0055] According to an embodiment, the filter plate 30 may thus comprise a cavity 31. According to an embodiment, the cavity 31 may be a blind hole. According to an embodiment, the cavity 31 may have a different shape, for instance a through hole. According to an embodiment, the measuring unit 1 may be provided in the cavity 31 such that the inner end part 4 is directed towards the bottom of the cavity 31 and the outer end part 3 is directed towards an edge 33 of the filter plate 30. According to an embodiment, the cavity 31 may extend to the edge 33, namely to the outer surface of the filter plate 30. In other embodiments, the cavity 31 may be provide for instance in a groove, a hole, or similar provided on the surface of the filter plate 30.

[0056] According to an embodiment, the measuring unit 1 may be provided in the cavity 31 in such a manner that at least a part of the outer end part 3 extends outside the cavity 31. According to an embodiment, the measuring unit 1 may be provided in the cavity 31 in such a manner that at least a part of the outer end part 3 extends outside the edge 33 of the filter plate 30. According to an embodiment, the outer edge 18 of the outer end part 3 may be provided in a same level with the edge 33 of the filter plate 30. According to a further embodiment, the measuring unit 1 may be entirely embedded in the filter plate 30, such that the outer surface of the outer end of the outer end part 3 is spaced inwards from the edge 33 of the filter plate 30.

[0057] According to an embodiment, the filter plate 30 may comprises a recess 36 at least on one side 37 of the filter plate 30. This may be the same recess 36 already referred to in connections with the measuring unit 1 embodiments. According to an embodiment, such a recess or recesses of adjacent filter plates 30 in a filter plate pack 58 may accommodate the filter chambers, to where slurry is fed for filtration. According to an embodiment, the cavity 31, the length 22 of the frame part 2, and positioning of the detectors in relation to the frame part 2 may be designed such that at least the inner end part 4 and at least one detector are arranged within the filter plate 30, more particularly inside the cavity 31, in the area of the recess 36. Thereby, the inner end 4 and the at least one detector may be provided in the area of a filter chamber in the filter press 50, when the measuring unit 1 is provided in the cavity 31 and the filter plate pack 58 is formed.

[0058] According to an embodiment, the filter plate 30 may be provided with second data connecting equipment 41 for transferring data from the first data collecting unit 21 in a wired or wireless manner to a second data collecting unit 51 provided in connection with the filter press 50. The second data connecting equipment 41 may be similar or different from the first data connecting equipment 20. For instance, according to an embodiment, the first data connecting equipment 20 may provide a wired connection and the second connecting equipment 41 may provide a wireless connection.

[0059] According to an embodiment, the filter plate 30 further comprises plugging equipment 23 for plugging the cavity 31 at the outer edge 32 of the cavity 31. The plugging equipment 23 may comprise for instance the outer end part 3 of the measuring unit 1 or a separate, dedicated plugging equipment, for instance a cap, a cover, or a plug. According to an embodiment, the plugging equipment may also be designed to limit the movement of the frame part 2 of the measuring unit 1, or a part of the frame part 2, in relation to the cavity 31 and / or the filter plate 30. Figure 7 illustrates schematically a measuring arrangement according to an embodiment.

[0060] According to an aspect, a measuring arrangement 40 may comprise a plurality of measuring units 1 according to an embodiment disclosed in this description and / or accompanying claims and / or drawings, or a combination of such embodiments.

[0061] According to an embodiment, the measuring arrangement 40 may further comprise the second data collecting unit 51. According to an embodiment, the measuring arrangement 40 may further comprise third connecting equipment 42 for transferring data in a wired or wireless manner from the second data collecting unit 51 to a remote control system 52. The third connecting equipment 42 may be similar or different from the first data connecting equipment 20 and / or the second connecting equipment 41. For instance, according to an embodiment, the first data connecting equipment 20 may provide a wired connection, and second connecting equipment 41 and / or third connecting equipment may provide a wireless connection.

[0062] According to an embodiment, the remote control system 52 may comprise the control system of the filter press 50 and / or the filtering process. According to an embodiment, the remote control system 52 may be configured to monitor condition of the filter press 50 and the filter plates 30, for instance to detect wear of the filter plates to predict end of life cycle and / or need to replace the filter plate 30 or a part of the filter plate 30, such as the filter cloth 39 and / or the membrane 38. According to an embodiment, the remote control system 52 may be configured to control the filtering process on the basis of the data received from the detectors.

[0063] According to an aspect, a filter press 50 comprises at least one of a plurality of measuring units 1 according to an embodiment disclosed in this description and / or accompanying claims and / or drawings, or a combination of such embodiments; a plurality of filter plates 30 according to an embodiment disclosed in this description and / or accompanying claims and / or drawings, or a combination of such embodiments; or a measuring arrangement 40 according to an embodiment disclosed in this description and / or accompanying claims and / or drawings, or a combination of such embodiments.

[0064] Figure 8 illustrates schematically a method for monitoring condition of a filter plate.

[0065] According to an aspect, a method for monitoring condition of a filter plate 30 comprises detecting 100 one or more characteristics of a filtering process by at least one measuring unit according to an embodiment disclosed in this description and / or accompanying claims and / or drawings, or a combination of such embodiments. According to an embodiment, the method also comprises determining 120 condition of the filter plate 30 on the basis of a value or a trend of one or more of the detected characteristics.

[0066] According to an embodiment, the method further comprises determining 140 wear of the filter plate 30 on the basis of the determined condition. According to an embodiment, the method also comprises determining 160 expected remaining lifespan of the filter plate 30. According to an embodiment, the method further comprises generating 180 an indication of a need to replace the filter plate 30 before the end of the expected remaining lifespan of the filter plate 30.

[0067] According to an embodiment, the method further comprises controlling the filter press 50, for instance controlling the actuator(s) 55 and / or pumping of slurry to filtration chamber(s), on the basis of the one or more detected characteristics of the filtering process by the at least one measuring unit and / or on the basis of the condition of the filter plate 30 determined on the basis of the value or the trend of one or more of the detected characteristics to provide optimal operating conditions for the filter plate 30. Optimal operating conditions for the filter plate 30 refer, in this case, to operating conditions which optimize the process efficiency and the life span of the filter plate 30 and / or part(s) of the filter plate 30 or the filter press 50 in a manner predetermined for the filter press 50 and the process in question. In other words, the solutions disclosed in this disclosure including the accompanying claims and figures may be used for instance for extending the life span for the equipment, such as the filter press 50, the filter plate 30 or a part of the filter press 50 or filter plate 30, for optimizing energy use in the filtering process and / or for optimizing results of the filtering process. These purposes may in each case be balanced considering different factors, such as cost and availability of filter press components in question, logistics, cost of unplanned and planned maintenance breaks and so on.

[0068] It is clear for a person skilled in the art that in the accompanying figures, the types and positions of the detectors may be illustrative of some embodiments only, where no other information regarding the type and / or the position is disclosed. In other words, the types of detectors and the positions thereof may vary depending on the embodiment within the scope of the claims.

[0069] According to an embodiment, the method according to any embodiment disclosed in this description may be implemented using a measuring unit 1, filter plate 30, measuring arrangement 40, or filter press 50 according to any one embodiment or a combination of embodiments described in this description and / or accompanying claims or drawings. According to an embodiment, any measuring unit 1 described in this description and / or accompanying claims or drawings may be provided in any filter plate 30, measuring arrangement 40, filter press 50, or for a method according to any one embodiment or a combination of embodiments described in this description and / or accompanying claims or drawings.

[0070] A measuring unit 1, filter plate 30, measuring arrangement 40, or method according to any one embodiment or a combination of embodiments disclosed in this description and / or accompanying claims or drawings may be used, where applicable, in connection with a filter press 50, which may comprise a horizontal filter press or a vertical filter press.

[0071] It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims, and embodiments disclosed may be combined.

Claims

CLAIMS1. A measuring unit for a filter press, characterized in that the measuring unit comprises an elongated frame part comprising an outer end part at a first end and an inner end part at a second end, and a middle part extending between the outer end part and the inner end part, wherein the outer end part and the inner end part are coupled to the middle part, a temperature detector provided in connection with the frame part,, and a strain detector provided in connection with the frame part in the area of the middle part such that the strain detector is arranged to detect deformation of the middle part, wherein the cross-sectional area of the middle part is smaller than the cross-sectional area of the outer end part and the inner end part, whereby the measuring unit or a part of the measuring unit is designed to be removably mounted in a cavity, especially a cavity in a form of an elongated hole, provided in a filter plate, where the measuring unit and the detectors provided in the measuring unit are isolated and protected from the surrounding operating conditions.

2. A measuring unit according to claim 1, wherein the measuring unit further comprises at least one identification detector provided in connection with to the frame part.

3. A measuring unit according to claim 1 or 2, wherein the measuring unit further comprises at least one of the following: a pressure detector, a leakage detector, a sound detector, a position detector, an acceleration detector, a gyroscope, or an inertial measurement unit.

4. A measuring unit according to claim 2 or 3, wherein the measuring unit further comprises first connecting equipment for transferring data from the detectors in a wired or wireless manner to a first data collecting unit.

5. A measuring unit according to claim 4, wherein the first data collecting unit is provided in connection with the measuring unit.

6. A measuring unit according to any one of claims 1 - 5, wherein the inner end part of the measuring unit comprises a threaded portion.

7. A measuring unit according to any one of claims 1 - 6, wherein the difference between the largest dimension of the outer end part in a transverse direction of the measuring unit and the largest dimension of the inner end part in the transverse direction of the measuring unit is less than or equal to 20 percent of the largest of the largest dimension of the outer end part and largest dimension of the inner end part.

8. A measuring unit according to any one of claims 1 - 7, wherein the largest dimension of the outer end part is provided at the outer edge of the outer end part, whereby the outer edge of the outer end part can be used for plugging an outer edge of a cavity, when the measuring unit is received in said cavity.

9. A measuring unit according to any one of claims 1 - 8, wherein the measuring unit further comprises at least one mounting member in the area of the middle part or the inner end part for receiving at least one detector or other device mounted in the transverse direction of the measuring unit.

10. A filter plate, characterized in that the filter plate comprises at least one measuring unit according to any one of claims 1 - 9.

11. A filter plate according to claim 10, wherein the filter plate comprises a cavity, which cavity is a blind hole, and wherein the measuring unit is provided in the cavity such that the inner end part is directed towards the bottom of the cavity and the outer end part is directed towards an edge of the filter plate12. A filter plate according to claim 11, wherein the filter plate comprises a recess at least on one side of the filter plate, and wherein the cavity, a length of the frame part, and positioning of the detectors in relation to the frame part is designed such that at least the inner end part and at least one detector are arranged within the filter plate in the area of the recess.

13. A filter plate according to any one of claims 10 - 12, wherein the at least one measuring unit comprises the first data collecting unit and wherein the filter plate is provided with second data connecting equipment for transferring data from the first data collecting unit in a wired or wireless manner to a second data collecting unit provided in connection with the filter press.

14. A filter plate according to any one of claims 11 - 13, wherein the filter plate further comprises plugging equipment for plugging the cavity at the outer edge of the cavity.

15. A measuring arrangement, characterized in that the measuring arrangement comprises a plurality of measuring units according to any one of claims 1-9 and / or a plurality of filter plates according to any one of claims 10-14.

16. A measuring arrangement according to claim 15, wherein the measuring arrangement further comprises the second data collecting unit and wherein the measuring arrangement further comprises third connecting equipment for transferring data in a wired or wireless manner from the second data collecting unit to a remote control system.

17. A filter press, characterized in that the filter press comprises at least one of a plurality of measuring units according to any one of claims 1-9, a plurality of filter plates according to any one of claims 10-14, or a measuring arrangement according to claim 15 or 16.

18. A method for monitoring condition of a filter plate, wherein the method comprises detecting one or more characteristics of a filtering process by at least one measuring unit according to any one of claims 1 - 9, and determining condition of the filter plate on the basis of a value or a trend of one or more of the detected characteristics.

19. A method according to claim 18, wherein the method further comprises determining wear of the filter plate on the basis of the determinedcondition, determining expected remaining lifespan of the filter plate, and generating an indication of a need to replace the filter plate before the end of the expected remaining lifespan of the filter plate.

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