Diagnostic device for a controllable valve and control system for controlling a process plant

Abstract

Diagnostic device (10) for a controllable valve (30), comprising a housing (11) with a membrane (12) arranged therein, at least one photogenerative element (13), at least one photosensitive element (14) and an evaluation unit (20), characterized by that the at least one photogenerative element (13) is arranged in the housing (11) such that light generated by the at least one photogenerative element (13) hits the membrane (12), that the at least one photosensitive element (14) is arranged in the housing (11) in such a way that it detects light emanating from the membrane (12) and that the evaluation unit (20) is designed to evaluate the light detected by the at least one photosensitive element (14) and, according to the evaluation, to generate at least one diagnostic value for the membrane (12).

Description

[0001] The invention relates to a diagnostic device for a controllable valve according to the preamble of claim 1 and a corresponding control system for controlling a process plant.

[0002] Various designs of controllable valves are widespread in the art and generally serve to control the volume flow of a fluid medium. Examples include globe valves, slide valves, or diaphragm valves. These diaphragm valves have a movable diaphragm for controlling the volume flow through the diaphragm valve. Diaphragm-actuated valves, in which the diaphragm is part of a drive unit and is intended to actuate an actuator of the valve, are also known. With both types of valves, aging or wear typically occurs on the diaphragm with continued use. These include degradation or thinning of the material, changes in the geometry of the diaphragm, or cracks in the diaphragm. These can each negatively impact the properties of the diaphragm and, particularly in diaphragm valves, can lead to leakage.These effects can be aggravated by the influences acting on the diaphragm during operation of the diaphragm valve, such as temperature, pressure, and flow rate. When dosing acids or other aggressive chemicals or gases, the diaphragm material can also be attacked by the media used, especially if it is exposed to these media for a longer period of time.

[0003] It is therefore known that the membrane needs to be replaced regularly.

[0004] However, since the diaphragms are usually inaccessible and cannot be inspected without first dismantling the valve, it is difficult to obtain information about the condition of the diaphragms during operation and to reliably predict the remaining service life of the diaphragm.

[0005] It is therefore also known in the prior art to attach sensors directly to the membrane or to embed them in the membrane in order to obtain information about the state of the membrane.

[0006] In this context, US 2008 0202 606 A1 discloses a system for monitoring the condition of diaphragms in industrial control valves and pressure regulators. Sensors integrated into the diaphragm monitor their condition based on parameters such as elasticity, electrical conductivity, or electrical resistance. A control unit analyzes the sensor data and compares it with baseline values ​​to detect wear or material damage at an early stage. Warning messages enable timely maintenance to avoid unexpected failures and reduce maintenance costs.

[0007] DE 10 2015 210 210 A1 relates to a method for diagnosing the condition of diaphragm valves in order to increase operational reliability and reduce costs. According to DE 10 2015 210 210 A1, three data categories are recorded for this purpose: data on the valve diaphragm, data on the diaphragm valve, and operating data. This data, evaluated by algorithms, enables an estimate of the remaining service life and wear of the diaphragm and can be supported by optical surface inspection. During optical surface inspection, an operator can create images, for example, using a smartphone or other imaging device; however, this requires removing the valve diaphragm. These images can be processed using image processing programs, so that additional image analysis algorithms can provide a more precise statement about the condition of the valve diaphragm.This can be done solely based on defined features and thresholds, but more complex methods such as classifying the membrane state based on an existing database can also be used.

[0008] DE 10 2009 023 012 A1 describes a diaphragm for diaphragm valves with integrated sensors for overload and wear monitoring, enabling timely replacement of the diaphragm before it fails. According to DE 10 2009 023 012 A1, the sensors are designed as textile sensors, for example, in the form of nanocomposite materials or silicone strain sensors. These sensors can detect stress caused by stretching or thread breakage, interrupting a signal and triggering a replacement indicator. This minimizes unforeseen downtime.

[0009] However, existing solutions for aging or wear detection affect the properties of the membrane, particularly its flexibility. Furthermore, directly applied or embedded sensors can cause additional stress in the material, thereby accelerating membrane wear.

[0010] It is an object of the present invention to propose an improved diagnostic device for a controllable valve.

[0011] This object is achieved according to the invention by the diagnostic device for a controllable valve according to claim 1. Advantageous embodiments and further developments of the invention emerge from the dependent claims.

[0012] The invention relates to a diagnostic device for a controllable valve, comprising a housing with a membrane arranged therein, at least one photogenerative element, at least one photosensitive element and an evaluation unit.

[0013] The invention therefore relates to a diagnostic device which is advantageously designed to diagnose a state of a controllable valve.

[0014] The controllable valve is preferably a control valve, in particular a globe valve. The globe valve is particularly intended to be integrated into a control loop of a process plant in order to reliably control the volume flow of a transported medium.

[0015] The medium can be a liquid, gaseous, vaporous or multiphase medium.

[0016] According to a preferred embodiment of the invention, the controllable valve is designed as a continuously controllable valve. This means that the valve can be continuously moved between a fully open position and a fully closed position and can assume any intermediate position. In other words, the valve can be adjusted from any initial state to any final state within a finite time.

[0017] Alternatively, the controllable valve can also be designed to move exclusively between discrete switching states. For example, the controllable valve can only have a fully open and a fully closed state.

[0018] The controllable valve can, for example, be controlled via a so-called industrial controller known in the state of the art.

[0019] The valve comprises a housing, which in turn may comprise a valve housing and an actuator housing.

[0020] At least one diaphragm is arranged in the housing, i.e., in the valve housing and / or the actuator housing. If the diaphragm is arranged in the valve housing, it is a diaphragm valve. However, if the diaphragm is arranged in the actuator housing, it is a diaphragm-actuated valve. A combination of both designs is also possible, i.e., a diaphragm is provided in both the valve housing and the actuator housing. In this case, the valve is a diaphragm-actuated diaphragm valve.

[0021] The valve further comprises at least one photogenerative element designed to generate light. This light can be visible, infrared, or ultraviolet light.

[0022] Finally, the valve also comprises at least one photosensitive element which is designed to detect the light generated by the at least one photogenerative element directly or indirectly - for example via reflections.

[0023] The at least one photogenerative element and the at least one photosensitive element are advantageously matched to one another in such a way that light generation by the at least one photogenerative element has a generation maximum at a wavelength at which the at least one photosensitive element has a detection maximum.

[0024] For example, if the at least one photogenerative element has a generation maximum in the visible wavelength range at approximately 550 nm, the at least one photosensitive element also advantageously has a detection maximum at a wavelength of 550 nm. This ensures that the light generated by the at least one photogenerative element can be used effectively.

[0025] The wavelength ranges of greatest possible generativity and sensitivity of the at least one photogenerative element or the at least one photosensitive element are advantageously selected based on the type of medium flowing through the valve—at least in the case of a diaphragm valve. For example, it is advantageous to select a wavelength that is absorbed as little as possible by the medium flowing through the valve.

[0026] The diagnostic device according to the invention is characterized in that the at least one photogenerative element is arranged in the housing in such a way that light generated by the at least one photogenerative element strikes the membrane.

[0027] This means that at least one photogenerative element in the housing is aligned in such a way that light generated by the photogenerative element can hit the membrane directly or at least indirectly via one or more reflections.

[0028] According to the invention, it is further provided that the at least one photosensitive element is arranged in the valve housing in such a way that it detects light emanating from the membrane.

[0029] For this purpose, the at least one photosensitive element is advantageously aligned with its detection area toward the membrane. Alternatively, it is also conceivable for the at least one photosensitive element to be aligned in the housing such that it only detects a reflection of the light emitted by the membrane.

[0030] Finally, according to the invention, it is also provided that the evaluation unit is designed to evaluate the light detected by the at least one photosensitive element and to generate at least one diagnostic value for the membrane in accordance with the evaluation.

[0031] The at least one photosensitive element can supply the detected light to the evaluation unit, for example, in the form of an electrical signal. The electrical signal can, in particular, be an electrical voltage that describes a detected intensity or power of the light. However, the electrical signal can also be a digital signal that, in the form of voltage pulses or current pulses, describes a detected intensity and, if appropriate, a detected wavelength at the photosensitive element in a spatially resolved manner.

[0032] The electrical signal can advantageously be transmitted to the evaluation unit via a proprietary interface, for example via “TROVIS-VIEW”.

[0033] The diagnostic value advantageously describes a state of aging and / or wear of the membrane. The diagnostic value may additionally or alternatively also include a change in the membrane's color and / or porosity.

[0034] The diagnostic device according to the invention thus leads to the advantage that a contactless and thus interference-free detection of the state of the membrane is possible without changing the properties of the membrane, in particular without adversely affecting its flexibility.

[0035] For the purposes of the invention, the term "outgoing light" refers to both light that is reflected by the membrane and light that is transmitted through the membrane. The term "outgoing light" thus describes any light that emanates from the membrane and reaches at least one photosensitive element. The reflected light does not necessarily have to be directed reflected light, such as that reflected from a reflective surface. Rather, it can also be diffusely reflected light, which is fundamentally reflected by any object onto which light falls.

[0036] As already explained, the term "light" in the context of the invention does not necessarily refer to visible light. Rather, it can also refer to light invisible to the human eye, namely infrared or ultraviolet light.

[0037] According to a preferred embodiment of the invention, it is provided that the valve is designed as a diaphragm valve.

[0038] In a diaphragm valve design, the diaphragm is located within the valve housing. One advantage of the diaphragm valve is that mechanical components are largely located outside the wetted area. The medium only contacts the inner surface of the housing and the surface of the diaphragm.

[0039] Diaphragm valves offer a way to effectively control fluid media. Highly viscous and / or highly adhesive media in particular can be efficiently controlled using a diaphragm valve.

[0040] According to an alternative preferred embodiment of the invention, it is provided that the valve is designed as a diaphragm-actuated lift valve.

[0041] In a diaphragm-actuated globe valve design, the diaphragm is located in the actuator housing rather than the valve body. The diaphragm typically acts on a mechanical actuator that can open or close a passage through the valve body.

[0042] The valve itself, or rather its diaphragm, is typically pneumatically actuated. This makes a diaphragm-actuated valve suitable for increased switching cycles.

[0043] According to a further alternative preferred embodiment of the invention, the valve can also be designed as a diaphragm-actuated diaphragm valve, ie the valve comprises a first diaphragm arranged in the valve housing for controlling the flow of the medium and a second diaphragm arranged in the drive housing, which drives or actuates the first diaphragm.

[0044] According to a further preferred embodiment of the invention, it is provided that the at least one diagnostic value comprises information about a general condition of the membrane and / or a roughness of the membrane and / or a discoloration of the membrane and / or a flexibility of the membrane and / or an estimate of the remaining service life of the membrane.

[0045] This allows for reliable assessment of the current condition of the membrane at any time. If increased wear or signs of aging are detected, the membrane can be replaced in time before it fails.

[0046] According to a further preferred embodiment of the invention, it is provided that the at least one photogenerative element and the at least one photosensitive element are arranged in a process medium channel of a valve housing.

[0047] Thus, the at least one photogenerative element is aligned and arranged such that it illuminates the membrane from its position in the process medium channel. Likewise, the at least one photosensitive element is aligned and arranged such that it can detect light emanating from the membrane from its position in the process medium channel. Thus, the photogenerative element and the at least one photosensitive element are arranged such that they detect the side of the membrane exposed to the medium.

[0048] Since the side of the membrane exposed to the medium usually shows the highest wear, particularly due to the aggressiveness of the medium or high temperatures of the medium, an impending failure of the membrane can be detected particularly reliably.

[0049] According to a further preferred embodiment of the invention, it is provided that the at least one photogenerative element and the at least one photosensitive element are arranged on a web of the valve housing between a pre-pressure side and a post-pressure side of the valve housing.

[0050] The web is typically positioned in the process medium channel opposite the diaphragm. Thus, the web and the diaphragm separate the upstream pressure side of the valve housing from the downstream pressure side. By arranging the at least one photogenerative element on the web and the at least one photosensitive element on the web, i.e., opposite the diaphragm, the light from the photogenerative element can be directed directly onto the diaphragm. Likewise, the light emitted by the diaphragm, for example, the light generated by the photogenerative element and reflected by the diaphragm, can be directly detected by the photosensitive element.

[0051] According to an alternative preferred embodiment of the invention, it is provided that the at least one photogenerative element is arranged on a first side of the membrane and the at least one photosensitive element is arranged on a second side of the membrane.

[0052] The terms "first side of the membrane" and "second side of the membrane" are intended, within the meaning of the invention, to indicate that the at least one photogenerative element and the at least one photosensitive element are arranged on opposite sides of the membrane. The first side can be, for example, the top side of the membrane, but can also be the bottom side of the membrane. Analogously, the second side is the other side of the membrane.

[0053] By arranging the at least one photosensitive element and the at least one photogenerative element on different sides of the membrane, only light from the at least one photogenerative element can reach the at least one photosensitive element, which is then transmitted through the membrane. This makes it particularly easy and effective to detect cracks and stretch marks in the membrane, as these transmit a larger proportion of the light generated by the at least one photogenerative element, so that the membrane appears brighter at that location. The light transmitted through the membrane is captured by the at least one photosensitive element.

[0054] In particular, however, at least one photogenerative element can be arranged on both the first side of the membrane and the second side of the membrane.

[0055] According to a further preferred embodiment of the invention, it is provided that the at least one photogenerative element and / or the at least one photosensitive element are protected against a medium in the process medium channel by a transparent cover.

[0056] Depending on the type of medium conveyed in the process medium channel, the transparent cover can be made of glass, particularly a particularly robust glass such as borosilicate glass, or even a plastic. This ensures that neither the at least one photogenerative element nor the at least one photosensitive element are damaged by the medium.

[0057] Alternatively, the at least one photogenerative element and / or the at least one photosensitive element preferably does not have a separate cover for shielding against the medium conveyed in the process medium channel. Instead, the encapsulation material of the at least one photogenerative element and / or the at least one photosensitive element can serve as a shield. In particular, if the at least one photogenerative element is designed as a light-emitting diode and the at least one photosensitive element is designed as a photodiode, these already have an encapsulation material that protects the respective semiconductor structures.

[0058] The potting material can be, for example, a plastic or glass.

[0059] According to a further preferred embodiment of the invention, it is provided that the membrane is opaque.

[0060] Since such membranes in valves are usually opaque, no special additional requirements are placed on the membrane, and the membrane material can be selected solely on the basis of its functional properties to ensure the valve function.

[0061] In addition, an opaque membrane, in particular when the at least one photosensitive element is arranged on a first side of the membrane and the at least one photogenerative element is arranged on a second side of the membrane, promotes the detection of cracks and strain points in the membrane.

[0062] According to a further preferred embodiment of the invention, it is provided that the at least one photogenerative element is designed as a light-emitting diode.

[0063] Light-emitting diodes are comparatively inexpensive, very compact, and have a long service life. They also consume very little energy. Since they are usually made of semiconductor material, they are also relatively robust, even when exposed to aggressive media.

[0064] According to a further preferred embodiment of the invention, it is provided that the at least one photosensitive element is designed as a photodetector.

[0065] The photodetector is preferably also a semiconductor component, constructed like a solar cell. This makes the photodetector comparatively robust, even against aggressive media.

[0066] The photodetector advantageously outputs an electrical voltage or an electrical current, the level of which depends on the light power detected by the photodetector.

[0067] According to an alternative preferred embodiment of the invention, it is provided that the at least one photosensitive element is designed as a camera sensor.

[0068] The camera sensor is advantageously designed as a color camera sensor that can distinguish between different wavelengths of the detected light.

[0069] Alternatively, the camera sensor can also be designed as a black and white camera sensor.

[0070] In addition, a camera sensor typically enables spatially resolved detection of the light emitted from the membrane. This allows different parts of the membrane to be examined individually and independently of one another.

[0071] The camera sensor can, for example, be a CCD sensor.

[0072] According to a further preferred embodiment of the invention, it is provided that the evaluation of the detected light comprises a brightness value of the detected light.

[0073] This is particularly advantageous in an embodiment of the valve in which the at least one photogenerative element is arranged on a first side of the membrane and the at least one photosensitive element is arranged on the second side of the membrane. The more light is transmitted through the membrane from the photogenerative element to the photosensitive element, the more cracks, damage, or stretching characteristics the membrane exhibits.

[0074] Since the brightness or light transmitted through the membrane increases with such damage, the condition of the membrane can be determined based on the brightness value.

[0075] According to a further preferred embodiment of the invention, it is provided that the evaluation of the detected light comprises an optical representation of at least a partial section of the membrane in the detected light.

[0076] An optical representation within the meaning of the invention is understood in particular to mean a spatially resolved camera image. This enables the independent testing or assessment of different sub-areas of the membrane.

[0077] According to a further preferred embodiment of the invention, it is provided that the evaluation unit is designed to generate the at least one diagnostic value for the membrane using analytical pattern recognition methods.

[0078] The analytical pattern recognition methods advantageously enable automated evaluation of the membrane's visual appearance to determine whether it exhibits typical signs of damage, such as cracks, stretching, or other possible surface changes such as discoloration and roughness. This allows for simple and automated conclusions about the membrane's condition.

[0079] According to a particularly preferred embodiment of the invention, it is provided that the evaluation unit is designed to generate the at least one diagnostic value based on a light-dark contrast.

[0080] If different sub-areas of the membrane appear to have different brightness levels, this represents a light-dark contrast within the meaning of the invention. A high light-dark contrast can arise, in particular, from a tear or overstretching of a sub-area of ​​the membrane. Thus, damage or wear of the membrane can be detected based on the light-dark contrast. The at least one diagnostic value can describe these conditions.

[0081] It is advantageous to store a threshold value for the light-dark contrast in the evaluation unit. This threshold value defines the level at which a tear or overstretching is detected. As long as the light-dark contrast does not exceed the threshold value, i.e., the membrane appears relatively uniformly dark, no damage is detected. However, if the light-dark contrast exceeds the threshold value, i.e., if at least one section of the membrane appears noticeably brighter than surrounding areas, damage is detected.

[0082] According to a further particularly preferred embodiment of the invention, it is provided that the evaluation unit is designed to carry out an edge and / or contour detection based on the light-dark contrast and to generate the at least one diagnostic value for the membrane based on the edge and contour detection.

[0083] The invention recognizes that with increasing wear and aging of the membrane, the edges and contours of the membrane, especially the surface of the membrane, also change. Thus, edge and contour detection can also be used to generate a diagnostic value describing the condition of the membrane, such as the surface roughness of the membrane.

[0084] According to a further preferred embodiment of the invention, it is provided that the evaluation unit comprises a learning logic which is trained with data of known states of the membrane.

[0085] Thus, a variety of different signs of wear and a variety of different signs of aging of the membrane can be reliably and automatically detected.

[0086] In an advantageous embodiment of the invention, it is provided that the learning logic is designed as a neural network.

[0087] The neural network is in particular a so-called flat neural network, which is designed to simulate a computational model of the membrane.

[0088] Alternatively or additionally, it can also be a so-called deep neural network, which is designed to determine the general condition of the membrane, the roughness of the membrane, the discoloration of the membrane, the flexibility of the membrane or the estimation of the remaining lifetime of the membrane.

[0089] According to a further preferred embodiment of the invention, it is provided that the diagnosis is carried out as a function of an operating state of the valve.

[0090] The invention has recognized that the diagnosis is particularly reliable if it is always carried out under identical operating conditions of the valve.

[0091] According to a particularly preferred embodiment of the invention, it is provided that the operating state corresponds to a stroke position, a medium temperature, an open valve position or a termination of a cleaning process.

[0092] Other suitable operating conditions may include, for example, commissioning of the valve or a functional test of the valve.

[0093] These operating states can be reliably detected automatically, enabling automated diagnosis under consistently identical conditions, thus producing a particularly reliable diagnostic value.

[0094] In principle, however, any operating state can be used to automatically initiate the execution of the diagnosis.

[0095] The operating states can be detected, for example, via sensors, particularly intelligent sensors, in the valve. Alternatively, information about the operating states can also be provided automatically via the control system or via an industrial controller of the valve.

[0096] Alternatively, it is preferred that the execution of the diagnosis be initiated by means of a manually triggered signal, in particular by means of a signal manually triggered via the control system. The signal can, for example, be a binary electrical signal.

[0097] According to a further preferred embodiment of the invention, it is provided that the at least one photogenerative element and the at least one photosensitive element are wirelessly connected to the evaluation unit at the data level.

[0098] This offers the advantage that no cables need to be routed through the valve housing to the outside. This would require openings in the housing, which would represent a weak point and could lead to leaks.

[0099] The energy required to operate the at least one photogenerative element and the at least one photosensitive element can be provided, for example, via batteries or through so-called energy harvesting. Energy harvesting refers to the extraction of small amounts of electrical energy from sources such as ambient temperature, vibrations, or air currents. The devices used for this purpose are also referred to as nanogenerators. Energy harvesting avoids disadvantages typically associated with the use of batteries, since, for example, regular battery changes are not required.

[0100] Alternatively, it may also be preferred that the at least one photogenerative element and the at least one photosensitive element are connected to the evaluation unit at the data level via one or more cables. In this case, the power supply to the at least one photosensitive element and the at least one photogenerative element can also be provided via the cable connections.

[0101] According to a further preferred embodiment of the invention, it is provided that the evaluation unit comprises a measuring and control unit for controlling the at least one photogenerative element and the at least one photosensitive element.

[0102] The measuring and control unit is designed to control the at least one photogenerative element in such a way that it generates light, which strikes the membrane, in particular in certain operating states of the valve.

[0103] The measuring and control unit is further designed to digitize measured values, for example voltage values, detected by at least one photosensitive element so that they can be fed to further electronic processing.

[0104] According to a further preferred embodiment of the invention, it is provided that the evaluation unit comprises an analysis unit for generating the at least one diagnostic value.

[0105] The analysis unit is preferably a unit downstream of the measuring and control unit, which evaluates and analyzes the measured values ​​recorded by the photosensitive element. The diagnostic value is then generated based on these recorded, evaluated, and analyzed measured values.

[0106] Within the meaning of the invention, the analysis unit is not necessarily physically connected to the evaluation unit. Rather, it can also be a functional integration or connection, with the functionality of the evaluation unit being performed, for example, in a so-called cloud, on a server, or in a data center. In this case, there is only a data connection between the evaluation unit and the analysis unit.

[0107] According to a further preferred embodiment of the invention, it is provided that the evaluation unit comprises a human-machine interface for outputting the at least one diagnostic value.

[0108] The human-machine interface can, for example, be a visual display or an acoustic output. This can advantageously alert an operator of the process plant in a timely manner to an impending membrane failure.

[0109] The invention further relates to a control system for controlling a process plant, comprising a diagnostic device according to the invention.

[0110] In addition to the diagnostic device according to the invention, the control system according to the invention advantageously also comprises a plurality of further control units and regulating units for controlling and regulating the process plant, in particular for controlling or regulating the valve comprising the diagnostic device.

[0111] The diagnostic device is advantageously integrated into the control system in such a way that the status of the membrane can be displayed to an operator of the control system via the human-machine interface.

[0112] However, it should be emphasized again at this point that the diagnostic device according to the invention is also functional independently of a complete control system.

[0113] The invention is explained below by way of example with reference to embodiments shown in the figures.

[0114] They show: Fig. 1 shows, by way of example and schematically, a possible embodiment of a diagnostic device according to the invention for a valve designed as a controllable diaphragm valve and Fig. 2 shows, by way of example and schematically, another possible embodiment of a diagnostic device according to the invention for a valve designed as a controllable diaphragm valve.

[0115] Identical objects, functional units, and comparable components are designated by the same reference symbols throughout the figures. These objects, functional units, and comparable components are identical in terms of their technical features, unless explicitly or implicitly stated otherwise in the description.

[0116] Fig. 1 shows, by way of example and schematically, a possible embodiment of a diagnostic device 10 according to the invention for a valve 30 designed as a controllable diaphragm valve 30.

[0117] The diagnostic device 10 comprises a housing 11, which consists, for example, of a drive housing 11' and a valve housing 11".

[0118] The drive housing 11', in turn, comprises a valve piston 32, which can be actuated via a valve rod 31. Actuation of the piston 32 correspondingly leads to actuation of the diaphragm 12. By moving the diaphragm 12 closer to the web 18 or by completely applying it to it, the valve 30 can be moved from the open state to the closed state.

[0119] The valve housing 11" comprises a process medium channel 17, which connects an upstream pressure side 17' and a downstream pressure side 17". A web 18 is located centrally between the upstream pressure side 17' and the downstream pressure side 17" in the process medium channel 17. The web 18 is arranged opposite the diaphragm 12. The diaphragm 12 separates the valve housing 11" from the actuator housing 11'.

[0120] The diagnostic device 10 further comprises a photogenerative element 13 and a photosensitive element 14 as well as an evaluation unit 20. The evaluation unit in turn comprises, for example, a measuring and control unit 21, an analysis unit 22 and a human-machine interface 23. The photosensitive element 14 is connected to the measuring and control unit 21 via a cable connection 15.

[0121] The photosensitive element 14 is, for example, a photodetector 14. The photogenerative element 13 is, for example, designed as a white light-emitting light-emitting diode 13.

[0122] The light-emitting diode 13 is arranged in the drive housing 11' in such a way that the light generated by the light-emitting diode 13 strikes the membrane 12 directly. In the illustrated embodiment of the Fig. 1, the LED 13 is arranged in the drive housing 11'. The light generated by the LED 13 strikes the second side 12" of the membrane 12. The second side 12" of the membrane 12 points into the drive housing 11'.

[0123] The photodetector 14 is arranged in the valve housing 11" in such a way that it can detect light emanating from the membrane 12. For example, the photodetector 14 is arranged in the web 18, i.e., opposite the membrane 12. The photodetector 14 is protected from the medium in the process medium channel 17 by a transparent cover 18'.

[0124] According to a further embodiment not shown, the diagnostic device 10 of the Fig. 1 is not arranged in a housing 11 of a diaphragm valve 30, but in a drive housing of a diaphragm-actuated valve.

[0125] According to a further embodiment, also not shown, the diagnostic device 10 comprises a camera sensor 14 instead of a photodetector 14. The camera sensor 14 detects both a brightness value of the detected light and an optical representation of the membrane 12. Both the brightness value and the optical representation are then used to generate the diagnostic value.

[0126] Fig. 2 shows, by way of example and schematically, another possible embodiment of a diagnostic device 10 according to the invention for a valve 30 designed as a controllable diaphragm valve 30.

[0127] The diagnostic device 10 of the Fig. 2 differs from the diagnostic device 10 of the Fig. 1 by the arrangement of the photogenerative element 13.

[0128] The photogenerative element 13 is arranged, for example, together with the photosensitive element 14 on the web 18 in the process medium channel 17. A transparent cover 18' protects the photogenerative element 13 and the photodetector 14 from the medium in the process medium channel 17.

[0129] For example, the photogenerative element 13 is a white light-emitting LED 13. The photosensitive element 14, on the other hand, is, for example, a CCD camera sensor 14.

[0130] The CCD camera sensor 14 is connected to the measuring and control unit 21 via a cable connection 15, and the light-emitting diode 13 is connected to the measuring and control unit 21 via another cable connection 16.

[0131] The light-emitting diode 13 is arranged and aligned such that the light it generates strikes the first side 12' of the membrane 12. The CCD camera sensor 14 is arranged and aligned such that it detects light reflected from the first side 12' of the membrane 12, thereby recording an optical representation of the membrane 12. The reflected light is, for example, light diffusely reflected from the membrane 12.

[0132] A special reflective coating of the first side 12' of the membrane 12 is therefore not required.

[0133] The evaluation unit 20 of the diagnostic device 10 of the Fig. 2 also differs from the evaluation unit 20 of the Fig. 1. For example, it contains a learning logic that is trained with data from known states of the membrane 12 and executes analytical pattern recognition methods to generate the diagnostic value.

[0134] The pattern recognition methods include, for example, edge and contour detection based on a light-dark contrast of the captured optical image. Based on the edge and contour detection, the diagnostic value for membrane 12 is generated.

[0135] In addition to the estimate of the remaining service life, the diagnostic value also includes information on the general condition of the membrane 12, the roughness of the membrane 12, the discoloration of the membrane 12 and the flexibility of the membrane 12.

[0136] According to a further embodiment not shown, the diagnostic device 10 of the Fig. 2 is not arranged in a housing 11 of a diaphragm valve 30, but in a drive housing of a diaphragm-actuated valve. List of reference symbols 10 Diagnostic device 11 housings 11' drive housing 11" valve body 12 Membran 12' first side of the membrane 12" second side of the membrane 13 photogenerative element, light-emitting diode, white light-emitting diode 14 photosensitive element, photodetector, camera sensor 15 Cable connection 16 Cable connection 17 Process medium channel 17' preprint page 17" reprint page 18 jetty 18' transparent cover 20 Evaluation unit 21 Measuring and control unit 22 Analysis unit 23 Human-machine interface 30 Valve, diaphragm valve 31 Valve rod 32 valve pistons QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2008 0202 606 A1

[0006] DE 10 2015 210 210 A1

[0007] DE 10 2009 023 012 A1

[0008]

Claims

[1] Diagnostic device (10) for a controllable valve (30), comprising a housing (11) with a membrane (12) arranged therein, at least one photogenerative element (13), at least one photosensitive element (14) and an evaluation unit (20), characterized by , that the at least one photogenerative element (13) is arranged in the housing (11) in such a way that light generated by the at least one photogenerative element (13) strikes the membrane (12), that the at least one photosensitive element (14) is arranged in the housing (11) in such a way that it detects light emanating from the membrane (12) and that the evaluation unit (20) is designed to evaluate the light detected by the at least one photosensitive element (14) and to generate at least one diagnostic value for the membrane (12) in accordance with the evaluation. [2] Diagnostic device (10) according to claim 1, characterized bythat the valve (30) is designed as a diaphragm valve (30). [3] Diagnostic device (10) according to claim 1, characterized by that the valve (30) is designed as a diaphragm-actuated lift valve. [4] Diagnostic device (10) according to at least one of claims 1 to 3, characterized by in that the at least one diagnostic value comprises information about a general condition of the membrane (12) and / or a roughness of the membrane (12) and / or a discoloration of the membrane (12) and / or a flexibility of the membrane (12) and / or an estimate of the remaining service life of the membrane (12). [5] Diagnostic device (10) according to at least one of claims 1 to 4, characterized by that the at least one photogenerative element (13) and the at least one photosensitive element (14) are arranged in a process medium channel (17) of a valve housing (11). [6] Diagnostic device (10) according to claim 5, characterized bythat the at least one photogenerative element (13) and the at least one photosensitive element (14) are arranged on a web (18) of the valve housing (11) between a pre-pressure side (17') and a post-pressure side (17") of the valve housing (11). [7] Diagnostic device (10) according to at least one of claims 1 to 4, characterized by that the at least one photogenerative element (13) is arranged on a first side (12') of the membrane (12) and the at least one photosensitive element (14) is arranged on a second side (12") of the membrane (12). [8] Diagnostic device (10) according to at least one of claims 5 to 7, characterized by that the at least one photogenerative element (13) and / or the at least one photosensitive element (14) are protected against a medium in the process medium channel (17) by a transparent cover (18'). [9] Diagnostic device (10) according to at least one of claims 1 to 8, characterized bythat the membrane (12) is opaque. [10] Diagnostic device (10) according to at least one of claims 1 to 9, characterized by that the at least one photogenerative element (13) is designed as a light-emitting diode (13). [11] Diagnostic device (10) according to at least one of claims 1 to 10, characterized by that the at least one photosensitive element (14) is designed as a photodetector (14). [12] Diagnostic device (10) according to at least one of claims 1 to 10, characterized by that the at least one photosensitive element (14) is designed as a camera sensor (14). [13] Diagnostic device (10) according to at least one of claims 1 to 12, characterized by that the evaluation of the detected light includes a brightness value of the detected light. [14] Diagnostic device (10) according to at least one of claims 1 to 13, characterized bythat the evaluation of the detected light comprises an optical representation of at least a partial section of the membrane (12) in the detected light. [15] Diagnostic device (10) according to at least one of claims 1 to 14 characterized by that the evaluation unit (20) is designed to generate the at least one diagnostic value for the membrane (12) using analytical pattern recognition methods. [16] Diagnostic device (10) according to claim 15, characterized by that the evaluation unit (20) is designed to generate the at least one diagnostic value based on a light-dark contrast. [17] Diagnostic device (10) according to claim 16, characterized by that the evaluation unit (20) is designed to carry out an edge and / or contour detection based on the light-dark contrast and to generate the at least one diagnostic value for the membrane (12) based on the edge and contour detection. [18] Diagnostic device (10) according to at least one of claims 1 to 17, characterized by that the evaluation unit (20) comprises a learning logic which is trained with data of known states of the membrane (12). [19] Diagnostic device (10) according to at least one of claims 1 to 18, characterized by that it is designed to carry out a diagnosis depending on an operating state of the valve (30). [20] Diagnostic device (10) according to claim 19, characterized by that the operating state corresponds to a stroke position and / or a medium temperature and / or an open valve position and / or the completion of a cleaning process. [21] Diagnostic device (10) according to at least one of claims 1 to 20, characterized by that the at least one photogenerative element (13) and the at least one photosensitive element (14) are wirelessly connected to the evaluation unit (20) at the data level. [22] Diagnostic device (10) according to at least one of claims 1 to 21, characterized by that the evaluation unit (20) comprises a measuring and control unit (21) for controlling the at least one photogenerative element (13) and the at least one photosensitive element (14). [23] Diagnostic device (10) according to at least one of claims 1 to 22, characterized by that the evaluation unit (20) comprises an analysis unit (22) for generating the at least one diagnostic value. [24] Diagnostic device (10) according to at least one of claims 1 to 23, characterized by that the evaluation unit (20) comprises a human-machine interface (23) for outputting the at least one diagnostic value. [25] Control system for controlling a process plant, comprising a diagnostic device (10) according to at least one of claims 1 to 24.

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