SENSOR-CONTROLLED DIAPHRAGM PUMP

Description

[0001] The invention relates to a method for detecting fault conditions in a defective diaphragm pump. Furthermore, the invention relates to a data processing device with a processor configured to execute the method for detecting fault conditions in a defective diaphragm pump.

[0002] Diaphragm pumps, especially double diaphragm pumps, are used to pump fluids, preferably liquid or gaseous substances. In a double diaphragm pump of this type, the diaphragm is located in a pump housing. The diaphragm divides a pump chamber into two sections: a pressure chamber and a product chamber. Both chambers are equipped with valves that open and close alternately depending on the pressure conditions.

[0003] By periodically pressurizing the pressure chamber, the membrane is forced into the product chamber, thus reducing the volume of this chamber. A decrease in pressure in the pressure chamber causes the membrane to move in the opposite direction, increasing the volume of the product chamber. The volumes of the product chambers and the pressure chamber are complementary. This variation in volume creates alternating periods of overpressure and underpressure in the product chamber, drawing the substance into the chamber and subsequently forcing it out. The membrane thus generates a pump-suction cycle within the chambers.

[0004] A double diaphragm pump has two diaphragms enclosed in a housing. The movements of the two diaphragms are coordinated so that the product chamber volumes increase alternately. In this way, a virtually continuous pumping of the media being conveyed can be achieved.

[0005] Due to the mechanical deformation the diaphragm undergoes during hydraulic or pneumatic operation, it must be made of a flexible material. Elastomers such as acrylonitrile butadiene rubber (NBR) are suitable for this purpose. However, since such diaphragm pumps are also used in the chemical and paint industries, special composite diaphragms consisting of an elastomer layer and another wetted layer, for example made of polytetrafluoroethylene (PTFE), have proven particularly advantageous. Using this hybrid structure significantly extends the diaphragm's service life, as the outer layer is considerably more resistant to the fluid than the elastomer, and only this layer comes into contact with the pumped medium.

[0006] Despite the choice of materials, one of the most frequent causes of diaphragm pump failure is a mechanical defect in the diaphragm, resulting from wear and tear. The extreme stress initially leads to cracking in the layer in contact with the pumped medium. If the pump continues to operate, the crack widens, and the elastomer layer comes into contact with the pumped medium. This then very quickly leads to diaphragm rupture. The ruptured diaphragm allows the medium to come into contact with the pump and potentially with the environment, which can not only destroy the pump but also cause significant environmental pollution. In addition to cracking, especially with composite diaphragms, blistering can occur as an indication of further diaphragm damage.

[0007] To prevent complete rupture or tearing of the membrane, it is replaced at regular maintenance intervals. Since the lifespan of a membrane depends on various factors, such as the quality of the membrane itself and the operating conditions, it is not possible to predict the optimal replacement time in advance. Regular maintenance or prophylactic membrane replacement therefore typically assumes a worst-case scenario. By adhering to the predefined maintenance cycles, membranes that are still intact are often replaced to avoid damage, downtime, and consequential losses.

[0008] From DE 693 02 765 T2, an electronic sensor device for a fluid-driven diaphragm pump is known. The sensor device is capable of detecting the position and magnitude of the diaphragm's movement by measuring the position and magnitude of the movement of a follower element, for example, a rod connected to the diaphragm. Furthermore, the sensor is capable of generating signals corresponding to the movement of the follower element and transmitting them to a control unit. A disadvantage of this is that the installation of sensors for displacement measurement is complex. This is particularly relevant when a diaphragm pump is to be retrofitted with a sensor system for diaphragm rupture monitoring and / or fault detection.

[0009] A method for detecting the operating state of a pump is known from DE 10 2006 049 440 A1. The operating state is determined by measuring the pressure and / or flow profile in the pump system and calculating a characteristic value based on this data, which is then compared to a predefined characteristic value. The pressure is measured using a sensor with a ceramic capacitive pressure measuring cell. Similar to displacement measurement, pressure measurement cannot simply be integrated into an existing pump, as the stroke rate is generally also required for pressure measurement. It is also questionable whether pressure measurements can be transmitted from an EX zone (ATEX zone) with a sufficient bandwidth.

[0010] A pneumatically operated diaphragm pump is known from DE 10 2015 108 963 A1. The diaphragm pump includes a sensor for detecting the displacement of the diaphragms or a rod connected to the diaphragms. Here, too, modifications to the pump mechanism are required.

[0011] From DE 10 2015 108 964 A1, a method for controlling a diaphragm pump is known in which a sensor measures a measurement signal that measures the displacement of a diaphragm in the diaphragm pump. The data regarding the displacement acquired by the sensor are used to control a switching valve. Here, too, an intervention in the pump mechanics is required.

[0012] US Patent 6,036,445 A discloses an electrical switching mechanism for a liquid-operated diaphragm pump. This also requires modification of the pump mechanism.

[0013] From US patent 2014 / 0348667A1, a diaphragm pump with a control system is known that optimizes the flow rate of the compressed air supplied to the pump. This is achieved by reducing the flow rate of the compressed air supplied to the pump while the pump moves between a first and a second diaphragm position. The speed of the diaphragm assemblies is monitored by a sensor that generates position feedback, allowing the pump to adjust itself to determine the optimal or near-optimal throttling point. Minimizing the required amount of compressed air results in a saving of compressed air. This also requires modification of the pump mechanics.

[0014] From WO 2009 / 059 664 A1 a micropump and a method for pumping small and very small quantities of a fluid are known.

[0015] A diaphragm pump with pressure compensation calibration is known from WO 2014 / 133 712 A1. The diaphragm pump comprises a shaft connected to a diaphragm that moves back and forth between a first stroke end position and a second stroke end position. A stroke sensor is provided to detect the stroke end positions. A pressure sensor detects the pressure at the liquid outlet. This also requires modification of the pump mechanism.

[0016] An electrically operated double diaphragm pump is known from WO 2021 001 806 B4. Here too, modifications to the pump mechanics are required.

[0017] From DE 10 2016 001 806 B4, a pump is known in which sensors are arranged on the diaphragms, enabling the measurement of diaphragm damage. However, this requires electrical wiring or electronic components that must be applied to the diaphragm. A further disadvantage is that each diaphragm must be equipped with such sensors, which entails considerable effort and thus a higher price.

[0018] In pumps known from the prior art that rely on position data acquisition, the position data is used to control one or more switching valves. Integrating the sensors required for position data acquisition is complex and difficult to retrofit to existing pumps. Furthermore, the data obtained by the intended sensors primarily serves to control any switching valves on the pump and not for fault detection, particularly early fault detection.

[0019] The invention is therefore based on the objective of proposing a method by which damage to a diaphragm pump, in particular damage to the diaphragm or one of the valves, can be detected simply and at an early stage. Definitions:

[0020] A stroke counter is a device or sensor attached to a diaphragm pump that counts the number of strokes performed by the diaphragm and thus its cycles. Common stroke counters enable the activation of various monitoring functions, such as determining the pump's delivery rate and checking the pump's operation.

[0021] An intelligent stroke counter is a device or sensor that not only counts strokes but is also designed to process the collected data. To this end, the intelligent stroke counter includes a processor that can not only receive and transmit the data from the sensor but also immediately analyze and process it.

[0022] The problem is solved by a method having the features of claim 1.

[0023] The aforementioned method relates to a method for detecting fault conditions of a diaphragm pump, preferably a double diaphragm pump.

[0024] The diaphragm pump includes: a housing with at least one diaphragm enclosed therein, which separates a product chamber and a pressure chamber from each other, wherein the volumes of the product chamber and the pressure chamber can be changed complementarily to each other by a movement of the diaphragm, a preferably mechanical switching valve which is provided to switch the diaphragm pump at a reversal point of the diaphragm from a first operating mode in which the pressure chamber is pressurized with a medium to a second operating mode in which the pressure chamber is depressurized, or back again, a sensor for measuring a measurement signal.

[0025] In addition, a control unit for controlling the switching valve may be provided.

[0026] According to the invention, a first measured value is determined based on data acquired by the sensor, both at the time between switching from the first operating mode to the second operating mode and at the time between switching from the second operating mode to the first operating mode. The first measured value is then compared to the second measured value, and a ratio is calculated from the relationship between the two measured values. Since the sensor and processor are located on the pump, a particular advantage is that the data acquired by the sensor can be processed in real time.

[0027] Due to their generally symmetrical design, diaphragm pumps have nearly identical switching times from one diaphragm cycle to the next. Therefore, the first and second measured values ​​of a functioning diaphragm pump are equal, and the ratio or relationship value derived from these two measurements is one, or nearly one.

[0028] In a further step, the deviation of the ratio resulting from the relationship between the first and second measured values ​​from the ratio of one that would result from identical measured values ​​is determined. This deviation is then compared with a predefined permissible deviation value.

[0029] The invention utilizes the knowledge that changes in the diaphragm in the form of cracks, and in particular the frequently occurring blistering, in which the media-resistant outer layers detach from the elastomer layer through diffusion processes of the medium, lead to uneven pump operation. Since wear phenomena on both sides of the diaphragm never occur simultaneously and symmetrically, and other components of the diaphragm pump, such as valves, also never wear exactly uniformly, impaired operation is observed in a large number of failure cases.

[0030] This impairment is usually barely noticeable because the pumps operate under varying load and flow conditions, resulting in uneven pump operation due to operational factors. However, a suitable sensor can detect this change and generate a warning.

[0031] In simplified terms, the invention enables the early detection of malfunctions and defects in the diaphragm pump by evaluating the switching times of the main valve of a preferably pneumatically driven diaphragm pump. A particular advantage is that fault detection is thus possible even without displacement measurement and without the sensors required for displacement measurement. This greatly simplifies the retrofitting of a diaphragm pump with a fault detection system and the application of the method according to the invention.

[0032] To detect wear, the switching behavior of the diaphragms is first analyzed. For this purpose, the diaphragms themselves, or preferably components of the pneumatic control system, can be equipped with a means of detecting the movement profile. Pumps are typically already equipped with a magnetic stroke counter to monitor the pump's output. In these cases, a magnetic proximity switch is often used as the stroke counter, which outputs a stroke signal when a preset field strength is reached. However, other sensors, such as ultrasonic distance sensors, are also suitable.

[0033] In the present invention, a magnetic field sensor is preferably used which monitors the change in the magnetic field, preferably via the diaphragm stroke or a component of the drive part, such as the piston of the main valve, and determines the switching points exactly based on the changing magnetic field.

[0034] From the data obtained in this way, the measured values—that is, the values ​​required by the two diaphragm chambers for a complete stroke—can be recorded. Depending on the type of sensor used, this information can be binary or trend information. Binary information includes, for example, a temporal and / or spatial start point as well as a temporal and / or spatial end point of a diaphragm stroke or of an element coupled to the diaphragm stroke. Trend information also includes data on additional individual points between the start and end points. The measured values ​​are related, for example by division, so that, in the case of perfectly symmetrical pump operation, the quotient is one. Other mathematical methods that relate the two values ​​are also suitable.

[0035] Diaphragm pumps typically use proximity sensors, preferably with a NAMUR output. NAMUR sensors often operate without physical contact. They represent binary information and are usually implemented as proximity switches. The sensor thus indicates whether a reference object is nearby or not.

[0036] A particular advantage of the aforementioned NAMUR sensors is their low electrical energy level. This significantly reduces, and ideally eliminates, the ignition hazard inherent in electricity. Therefore, the use of such sensors is also permitted in ATEX zones. ATEX zones are areas where explosive atmospheres can occur. Sensor data from an ATEX zone can only be transmitted using signals approved for ATEX zones, such as the 4...20 mA loop or pulse signals according to NAMUR.

[0037] The described method thus enables monitoring of the switching behavior of the diaphragm pump and, consequently, early detection of diaphragm rupture or other damage, such as valve damage. This is because such damage, even in its initial stages, affects the switching from one operating mode to another and thus the synchronization of the operating cycles.

[0038] As previously explained, known methods attempt to avoid system downtime and consequential damage caused by defects in the pump or its components that are not detected in time by replacing certain components, such as the diaphragm of a pump or the entire pump, based on predefined maintenance intervals. This replacement is thus performed prophylactically without considering the actual condition of the components to be replaced. In contrast, the method according to the invention enables targeted predictive maintenance and thus a reduction in costs and downtime. Predictive maintenance is understood as a data-based maintenance method that analyzes the condition of the pump so that maintenance measures can be planned and initiated in a timely manner based on the data obtained.

[0039] In a preferred implementation of the procedure, exceeding the permissible devaluation value triggers a deviation notification. This deviation notification can be used to generate a visual or audible warning signal.

[0040] The aforementioned measured values ​​can be expressed as units of time. Such time units can be calculated by determining the first and second measured values ​​based on the difference between two consecutive switching times. In this case, the first measured value indicates the time interval between switching from the first operating mode to the second operating mode, and the second measured value indicates the time interval between switching from the second operating mode to the first operating mode.

[0041] Due to the high resolution of the magnetic field measurement of a magnetic field sensor, the time until reaching and remaining in the respective end position can also be measured.

[0042] Alternatively or additionally to determining asynchronies based on switching times, an analysis of the switching paths can also be used. For this purpose, the first and second measured values ​​are calculated based on the difference between two switching path points, so that the first measured value indicates the distance traveled between switching from the first operating mode to the second operating mode, and the second measured value indicates the distance traveled between switching from the second operating mode to the first operating mode.

[0043] Magnetic field sensors are also suitable for analyzing switching paths.

[0044] Preferably, a ratio mean value, most preferably a moving ratio mean value, is determined from a predefined number of successive ratio values.

[0045] The invention utilizes the understanding that when a diaphragm changes, for example, by tearing or swelling, its section modulus and thus its resistance to the stroke also change. This change is reflected in the time and / or distance the diaphragm requires for a complete stroke. Increased wear on individual valves also leads to altered stroke behavior and thus altered stroke times. Mathematical methods, such as averaging, can compensate for the influence of one-off or infrequent events.

[0046] In a preferred embodiment of the method, the recorded measured values ​​and / or ratio values ​​are classified and used to determine control signals.

[0047] The underlying principle is that critical and non-critical events have, or can have, the same impact on the pump's synchronization. Unlike fault detection based on exceeding a limit value, non-critical events can be compensated for by classifying the measured values ​​and / or their ratios.

[0048] For example, it is possible to represent the classification of events in a matrix, such as a "confusion matrix". An example matrix classification is described in more detail in connection with the explanations of the figures.

[0049] In a preferred embodiment of the method, the measured values ​​and / or the comparative values ​​are statistically recorded, and a gradient is determined based on these values, characterizing the rate of change. The gradient is defined as the progression of a change. Preferably, exceeding a predefined threshold for the determined gradient is used to generate a deviation notification.

[0050] Changes in stroke times can result not only from actual faults in the diaphragm and other components, but also from altered operating conditions. For example, idling or varying operating pressures can influence the stroke time ratio. Unlike wear-related changes resulting from actual faults, such changes typically do not occur gradually, but rather abruptly when the pump's operating pressure or flow rate changes.

[0051] In other words, changes in measured values ​​due to altered operating parameters occur abruptly, while changes in measured values ​​due to wear occur gradually.

[0052] The reason for these gradually developing failures is that diaphragm tears, bubbles, or valve wear typically develop gradually. Consequently, the stroke times also change gradually. The average stroke times of the two diaphragm chambers, relative to each other, can therefore be observed as a continuous increase or decrease over the period until the diaphragm or valve fails. Such gradual changes in the measured values ​​are thus clearly attributable to component wear and not to operational changes. Mathematically, this gradual change can be represented as a gradient. By comparing a measured gradient determined based on current measurements with other reference gradients, for example, those stored in a data repository, it is possible to determine whether the current measured gradient is due to a failure or changed operating conditions.Furthermore, it is possible to determine characteristic measurement gradients for known error states and to store them in the data memory, so that a direct conclusion about the type of error or at least a probability for a certain type of error can be derived from the current measurement gradient.

[0053] Preferably, calibration is performed before evaluating the measured values ​​in order to compensate for manufacturing-related deviations.

[0054] Since pumps are subject to significant fluctuations during operation, the measured ratio values ​​are stored and averaged over a period of time to compensate for these fluctuations. Such calibration, which is performed particularly on new or serviced pumps, can be carried out by first recording the number of measured values ​​to be averaged in the sensor. Preferably, approximately 8,000 to 10,000 values ​​are recorded and averaged for calibration. The resulting deviation is then stored as a pump-specific offset value. This value results, for example, from component tolerances, variations in the design, and the elasticity of the diaphragm.

[0055] Preferably, not every exceedance of a limit or threshold value is transmitted to the data processing device, but deviations are only transmitted when a predefined ratio of limit exceedances to pump strokes is exceeded.

[0056] Thus, for example, after an interruption of operation, the influence of changed stroke times due to standstill-related changes can be compensated for by not including the sensor data of the first strokes of the diaphragm pump in the evaluation.

[0057] As explained above, the method for detecting fault conditions in a diaphragm pump is based on a change in synchronization. This altered synchronization, in turn, is based on differing stroke times and / or stroke distances of components contained within the diaphragm pump. The determination of measured values ​​relevant to synchronization is preferably based on the following parameters: the movement profile of the diaphragm or, in the case of a double diaphragm pump, the diaphragms and / or the movement profile of a pneumatic control valve and / or the evaluation of the pressure profile of the pumped medium and / or the evaluation of the pressure profile of the compressed air supply.

[0058] The movement profile of a diaphragm or other component, such as a guide rod coupled to the diaphragm or a control valve, can be determined using a suitable sensor. This sensor is preferably a magnetic field sensor capable of detecting the strength of a magnetic field. This allows the movement of a magnet attached to the diverter valve piston of the diaphragm pump to be detected by measuring the changing magnetic field strength. A magnetic field sensor integrated into the sensor detects the position of the magnet on the diverter valve piston at very short intervals, enabling highly precise detection of the valve piston switching. Minimum and maximum values ​​are detected as a double stroke, corresponding to a NAMUR pulse.

[0059] To determine a pressure profile, a pressure sensor, such as a differential pressure sensor, can be connected to the conveying circuit of the conveyed medium or compressed air. The physical quantity of pressure measured by the pressure sensor is converted into an electrical output quantity and transmitted to the data processing device in the form of measured values.

[0060] Preferably, the data acquired by one or more sensors attached to the diaphragm pump is transmitted via a protocol in conjunction with the current stroke rate of the diaphragm pump. This protocol is preferably a type of telegram in which the data to be transmitted is mathematically broken down into signals that can be transmitted sequentially over a common line. In addition to the sensor data, other data from the diaphragm pump, such as its serial number or commissioning date, can also be transmitted using this protocol.

[0061] The protocol can, for example, transmit the hub frequency and the measured values ​​for determining the error status three times per second in the form of a modified telegram.

[0062] In addition, the sensor information can be updated in a loop every minute. This sensor information could include, for example: a serial number provided on the diaphragm pump, further individual parameters of the diaphragm pump such as an installation date number or the installation location of the pump, the total number of strokes, a maintenance counter, a histogram of the diaphragm pump, which, for example, sums the number of strokes per frequency range (0Hz to 8Hz) since the last maintenance.

[0063] The pump's identification within the system can be ensured by its serial number and a writable inventory number. This allows serviced or replaced pumps to automatically register with the system. Manually assigning nameplate data to a specific pump is no longer necessary.

[0064] The number of strokes performed since a pump was commissioned can be analyzed, as can the number of strokes performed since the last maintenance. The histograms make the pump usage profiles transparent and analyzable.

[0065] In another embodiment, in the case of two functionally coupled diaphragm pumps, the stroke times and / or travel distances for each diaphragm pump can be recorded.

[0066] For example, a rotary printing press might be equipped with an ink reservoir (doctor blade chamber) whose fill level is kept constant by two pumps. In this case, two double diaphragm pumps could be used, with one pumping liquid into the reservoir and the other pumping liquid out of the reservoir when a predefined maximum fill level is exceeded. The two pumps are integrated into a control loop in such a way that, firstly, a predefined minimum fill level is not reached, and secondly, a predefined maximum fill level is not exceeded. In such an application, a failure of the drain pump could lead to the ink reservoir overflowing.By applying the described procedure, an overflow of the basin can be prevented by timely fault detection of the drain pump, by sending a fault message and / or deactivating the inlet pump when a fault is detected in the drain pump.

[0067] The invention further relates to a device for data processing, comprising a processor configured to perform a method for detecting fault conditions on a diaphragm of a diaphragm pump according to one of claims 1 to 12.

[0068] The processor enables monitoring of the diaphragm pump. As already mentioned, the information relevant to the diaphragm pump, such as... Pump serial number, day number or installation location of the pump, total number of strokes, maintenance counter, histogram, number of strokes per frequency range (0Hz to 8Hz) since last maintenance (summed), pump synchronization (changes in pump synchronization can indicate, for example, diaphragm breakage, valve malfunction or suction problems) The data can be transmitted by the diaphragm pump via a telegram and are retrieved by the processor during pump operation, in addition to the stroke frequency from the pump.

[0069] The processor detects and evaluates any fluctuations in speed that develop during pump operation. The resulting value can be output as a synchronization indicator. If the synchronization indicator exceeds or falls below a limit predefined by the diaphragm pump manufacturer or user, a control command can be triggered, enabling direct actions such as activating a horn or a safety shutdown.

[0070] The data processing device can be designed as a module box separate from the diaphragm pump and, in addition to the aforementioned processor, may include the following components: a housing for the processor, a data storage device, a first interface for receiving data provided by a diaphragm pump and a sensor coupled to the diaphragm pump, a second interface for forwarding data and / or further data and / or key figures and / or control commands determined in the processor.

[0071] Pumps known from the prior art typically already have a proximity sensor that detects the movement of the diaphragm or a component connected to the diaphragm to determine pump strokes. It is therefore particularly advantageous if the sensor integrated into the module box is mounted at the location on the pump that is standardly intended for a proximity sensor. This allows older pumps to be retrofitted with fault detection, or new pumps can be optionally equipped with the module box.

[0072] In pumps designed for conveying solvent-based paints and varnishes, the module box is located within a work environment where an explosive atmosphere can develop (EX zone). A particular advantage is that communication between the sensor in the EX zone and the evaluation unit in the safe zone is implemented using an intrinsically safe communication protocol. Due to the low bandwidth of the signals, data from the sensor in the EX zone is transmitted to the evaluation unit at different update intervals depending on priority, while the cycle time for critical information always remains constant.

[0073] Advantageously, software is installed on the sensor or on a processor coupled to the sensor. Within the hazardous area (EX zone), pump malfunctions can thus be detected simply by measuring the time from one switching extreme to the other. Differentiation between actual malfunctions and operational events is preferably based on a machine learning algorithm. A machine learning algorithm is an algorithm that enables a computer to learn from data and experience and to continuously improve. Furthermore, the software installed on the sensor or in the module box is designed to recognize when a malfunction has been resolved and to clear a fault message.

[0074] In a preferred embodiment, the data acquired by the sensor and other pump data are transmitted to an evaluation unit located outside the EX zone. This enables the user to utilize this data and information in a machine control system.

[0075] A particular advantage is that the aforementioned module box is independent of the pump and can therefore be installed outside of any ATEX zones. The module box only requires the data provided by the diaphragm pump. If the diaphragm pump is already configured to provide the necessary data, retrofitting the module box within an existing system, such as a paint line, is also straightforward.

[0076] Thus, the module box allows access to pump information and the extended functions of a diaphragm pump, for example from an ATEX zone, during pump operation.

[0077] The module box, in conjunction with the intelligent stroke counter, can report pump malfunctions and also transmit important pump parameters from the ATEX zone via the NAMUR protocol. It is also possible for the module box to process and analyze data from not just one diaphragm pump, but from two or more diaphragm pumps simultaneously.

[0078] For example, in addition to two intelligent stroke counters, two further sensors can be evaluated via a 4...20mA input, e.g. pressure sensors.

[0079] This results in the following standard areas of application for the module box. 1. Use of the module box for fault reporting

[0080] The module box detects pump malfunctions caused by fluctuations in speed. The malfunction is indicated by a standard visual signal, changing from green to red on the electronics housing. Alternatively or additionally, acoustic or other signals can be generated. All necessary components, including the isolation amplifier and power supply, are integrated into or on the module box housing in this application. 2. Monitoring of pump data by integrating the module box into a company network (intranet)

[0081] The module box can be integrated into a company network and enable system monitoring ("cockpit"). In conjunction with a web cockpit, the cockpit allows access to pump data on the company intranet. The components required for such a module box, including the isolation amplifier and power supply, can be mounted together in a single housing. The monitoring software required for connecting to the company internet can be installed on an intranet server. If the data is stored in a cloud, IoT applications can also be implemented. IoT stands for "Internet of Things." Functions implemented with IoT technologies enable interaction between people and any networked electronic systems, as well as between the systems themselves. 3. PLC connection of the module box

[0082] The module box can be integrated into an existing PLC controller at a user's site, such as a paint shop, and used for system control. A wide range of system parameters can be queried via an interface, such as a Modbus interface. This allows for detailed pump status information to be accessed on the operator panel and via remote maintenance. A particular advantage is that the user only needs the module box and, if necessary, a switching amplifier for this application. Therefore, this PLC connection can be easily retrofitted to existing systems.

[0083] The following data is available per channel for monitoring and PLC connection: Information on the module box, pump serial number, TAG number / pump installation location (16 digits for both channels), total number of strokes, number of strokes since last maintenance, histogram, number of strokes per frequency range (0 Hz to 8 Hz) since last maintenance, fault status (which may indicate diaphragm rupture, valve malfunction, or suction problems), measured value of the analog (4...20 mA) sensor (e.g., pressure reading), synchronization value, for external diagnostics, and configuration options for fault handling of the module box.

[0084] For PLC customer applications, the module box provides a Modbus interface for integrating pump information. PC applications can also access the pump data via an interface, such as a UART interface.

[0085] A module box can be designed to accommodate not just one, but two or more diaphragm pumps with intelligent stroke counters. Additional sensors, such as pressure sensors, can also be connected. Any stroke pulses already generated by the diaphragm pump can be accessed by the module box.

[0086] In summary, the use of the inventive method, processor and module box in various diaphragm pump application areas results in industry-specific advantages, some of which are listed below as examples: Flexographic printing industry: Membrane rupture monitoring can be integrated into the printing press PLC. The printing press PLC can access information from the intelligent stroke counter. When a pump is replaced, the pump automatically registers itself with the printing press PLC. Maintenance data can be automatically transferred to the printing press PLC. Employees or external companies contracted for maintenance do not need to manually enter changes into the printing press PLC. When a pump is replaced, the serial number is automatically transferred to the printing press PLC. The monitoring solution allows for pump status visualization to be retrofitted without modifying the printing press PLC. The module box can be retrofitted to existing printing presses. Faults are displayed in a timely manner. The monitored pump can still be flushed, and maintenance is performed before the air side of the pump is flooded with ink.The module box enables the retrofitting of overflow protection to doctor blade chambers with two pumps. Should the outgoing pump stop or malfunction, the air supply to the pumping pump is also shut off. For the chemical / food industry: Pump data can be mirrored to a control room. During maintenance or repairs, the pump data is automatically uploaded to the control room. Active pump fault reporting can increase the overall system safety integrity level (SIL). Backup pumps can be started from the module box in case of a fault. Early fault indication allows the plant operator to clean or decontamination the pump while it is still in the process, significantly simplifying maintenance. An existing pump in a system can also be retrofitted with a module box to protect it against overload, overpressure, and running dry.

[0087] Further measures improving the invention are described in more detail below with reference to the figures and preferred embodiments of the invention.

[0088] The invention further relates to a diaphragm pump with a housing with at least one diaphragm enclosed therein, which separates a product chamber and a pressure chamber from each other, wherein the volumes of the product chamber and the pressure chamber can be changed complementarily to each other by a movement of the diaphragm, a preferably electrical switching valve which is provided to switch the diaphragm pump at a reversal point of the diaphragm from a first operating mode in which the pressure chamber is pressurized with a medium to a second operating mode in which the pressure chamber is depressurized, or back again, and a device for data processing according to claim 13 or a module box according to claim 14.

[0089] Using such a pump, it is possible to detect fault conditions, such as a damaged diaphragm, at an early stage and to carry out predictive maintenance.

[0090] The figures show: Fig. 1 shows a diaphragm pump in the form of a double diaphragm pump in a first embodiment; Fig. 2a shows the diaphragm pump according to Fig. 1in a sectional view; Fig. 2b shows a second embodiment of a diaphragm pump; Fig. 2c shows a third embodiment of a diaphragm pump; Fig. 3 shows a magnetic field-time diagram of an intact diaphragm pump; Fig. 4 shows a displacement-time diagram of an intact diaphragm pump; Fig. 5 shows a visualization matrix of an intact diaphragm pump; Fig. 6 shows a relation diagram of an intact diaphragm pump; Fig. 7 shows a magnetic field-time diagram of a defective diaphragm pump; Fig. 8 shows a displacement-time diagram of a defective diaphragm pump; Fig. 9 shows a visualization matrix of a defective diaphragm pump; Fig. 10 shows a relation diagram of a defective diaphragm pump; Fig. 11 shows a signal flow diagram of a liquid conveying system with one pump and a module box integrated into the system; Fig. 12 shows a signal flow diagram of a liquid conveying system with two pumps and a module box integrated into the system.

[0091] Identical or similar elements in the following figures may be designated with the same or similar reference numerals. Furthermore, the figures of the drawing, their description, and the claims contain numerous features in combination. It is clear to a person skilled in the art that these features can also be considered individually or combined into further combinations not described in detail here. The invention expressly extends to embodiments that are not defined by combinations of features from explicit cross-references in the claims, meaning that the disclosed features of the invention can be combined with one another in any way that is technically feasible. The exemplary embodiments shown in the figures are therefore merely descriptive and are not intended to limit the invention in any way.

[0092] The terms used below: "upper", "top", "lower", "left" or "right" refer to the arrangement of the components shown in the drawing.

[0093] Fig. 1 Figure 1 shows a diaphragm pump 100 designed as a double diaphragm pump in a perspective view. The depicted double diaphragm pump 100 essentially comprises a housing 10 with a pump body 48 arranged between two housing covers 47 and 47' and two diaphragms 11, 11'. An intelligent stroke counter 40 is attached to the housing cover 47. The intelligent stroke counter 40 includes a housing 21 containing a data processing device 17. A processor 18 is an essential component of the data processing device 17. The intelligent stroke counter 40 transmits data to a module box 19 (see Figure 1). Figs. 11 and 12). If necessary, especially if the diaphragm pump 100 operates in an ATEX zone, a isolating switching amplifier (see below) can be installed between the intelligent stroke counter 40 and the module box 19. Figs. 11 and 12 ) be interposed. Within the ATEX zone, the signals are preferably transmitted as a NAMUR telegram from the diaphragm pump 100 to the isolating switching amplifier; outside the ATEX zone, transmission as a 0V to 24V signal is preferably provided.

[0094] The particular advantage of such a system lies in the fact that sensor data is not only acquired at the diaphragm pump itself, but is also processed by the data processing unit 17 directly within the diaphragm pump 100. A large part of the computing work therefore takes place in or on the diaphragm pump 100, so that any necessary reactions and control commands can be generated in real time.

[0095] Fig. 2a The diaphragm pump shows according to Fig. 1in a sectional view. In the pump body 48 there is a Fig. 2a A non-visible switching valve 14 is arranged which controls the switching of two diaphragms 11, 11' also located in the housing 10. Such a diaphragm pump with two diaphragms 11, 11' contained within it forms a double diaphragm pump.

[0096] The membranes 11, 11' each have a peripheral annular ridge which is pressed together and held in a clamping area by the screw connections of the housing covers 47 with the central pump body 48.

[0097] Elastomeric composite materials, such as NBR, are preferably used as materials for the membranes 11, 11'. The NBR material acts as an elastic base material onto which a chemically resistant, thin PTFE film can be laminated on the media side.

[0098] The housing covers 47, 47' together with the pump body 48 form two pump chambers, each of which is divided by the diaphragms 11, 11' into a product chamber 12, 12' and a pressure chamber 13, 13' with alternating volumes. The diaphragms 11, 11' are connected to a piston rod 49 such that the pressure chambers 13, 13' behind the diaphragms 11, 11' can be alternately pressurized with a pressure medium, preferably compressed air, and subsequently vented. The pressurized pressure chambers 13, 13' press the diaphragms 11, 11' alternately towards the housing covers 47, 47' and displace the product or medium to be pumped from the product chambers 12, 12'.

[0099] Simultaneously, the opposing diaphragm 11, 11' is drawn into the center of the pump body 48 by the piston rod 49, causing the product chambers 12, 12' to enlarge and drawing in a further quantity of the medium. Backflow of the medium during chamber switching is prevented by suitable check valves 50.

[0100] The reciprocal control of the pressure chambers 13, 13' is effected by a mechanical switching of the switching valve 14 in each case in the end position of the diaphragms 11, 11'.

[0101] In the Figs. 1 and 2aIn the illustrated embodiment, i.e., in a diaphragm pump 100 with a module box 19 attached to a housing cover 47, a sensor 20 located in or on the housing 21 detects a characteristic of the pump operation, in this case the movement or stroke of a diaphragm 11, 11'. The sensor 20 is a magnetic field sensor which, in conjunction with a magnet coupled to a diaphragm 11, 11', detects a magnetic field with a field strength F. The field strength F of the magnetic field changes depending on the position of the magnet relative to the sensor 20. The sensor 20 can evaluate the movement of the diaphragm 11, 11' from the front, i.e., from the side corresponding to the diaphragm cover 47, 47', or from the rear of the diaphragm.

[0102] As a result, the instantaneous position of the diaphragm 11, 11' can be derived from the strength of the magnetic field detected by the sensor 20. The sensor 20 thus determines both the time information regarding the diaphragm stroke and the travel distance of the diaphragm 11, 11' during this time. This also makes it possible to determine if and when one side of the pump behaves unusually or differently. For example, if a PTFE layer applied to the diaphragm 11, 11' is broken, this causes greater resistance because the broken edges press against each other. Due to the changed resistance of the diaphragm 11, 11', the stroke movement also changes, and thus the time and position data determined by the sensor 20. The data generated by the processor 18 and, if applicable, further data stored in a data memory 22, can be transmitted to downstream components via a data cable 15.If the diaphragm pump 100 is used in an ATEX zone, the data is transmitted in the form of a NAMUR telegram. Outside the ATEX zone, a 0V to 24V signal may be used.

[0103] Fig. 2bFigure 1 shows a second embodiment of a diaphragm pump 200. The design and operation of the diaphragm pump 200 essentially correspond to the design and operation of the diaphragm pump 100. In contrast to the diaphragm pump 100, the criterion for the movement of the diaphragm 11, 11' is not directly the movement of the diaphragm 11, 11' itself, but rather the movement of the piston rod 49 connecting the diaphragms 11, 11'. Accordingly, the intelligent stroke counter 40 is not coupled to a housing cover 47, 47', but is integrated into the pump body 48. The intelligent stroke counter is mounted in the pump body 48 by means of a holder 51 such that its sensor 20, which is also a magnetic field sensor, detects the travel of the piston rod 49. For this purpose, a magnet is attached to the piston rod 49. The same applies to the pump pump 200. Fig. 2b In the illustrated embodiment, the sensor 20 determines, in addition to the time information, analogous to the example according to Fig. 2a the distance traveled in one unit of time.

[0104] Fig. 2c Figure 3 shows a third embodiment of a diaphragm pump 300. The design and operation of the diaphragm pump 300 essentially correspond to the design and operation of the diaphragm pumps 100 and 200. In the diaphragm pump 300, the intelligent stroke counter 40 is mounted such that its sensor 20 is aligned with the changeover valve 14. In the illustrated embodiment according to Fig. 2c In this case, the intelligent stroke counter 40 only determines the switching time. The data determined by the sensor 20 are evaluated in the intelligent stroke counter 40, or rather in the data processing device 17 contained therein, and forwarded in the form of a NAMUR telegram via the data line 15, for example to a switching amplifier (see...). Figs. 11 and 12 ).

[0105] The in Fig 2cThe illustrated embodiment is particularly advantageous when an already installed diaphragm pump is equipped with a stroke counter and is to be retrofitted with a predictive fault detection system. In such a case, only the existing stroke counter and its processor need to be equipped with suitable software for evaluating and processing the data acquired by the sensor. A module box 19 (see figure) can then be installed at a location outside the ATEX zone. Figs. 11 and 12 ) are integrated into the overall system. One advantage is that a system upgraded or retrofitted in this way does not require a new fire safety or safety inspection in the ATEX zone, since the hardware components installed in the ATEX zone do not need to be changed; only the intelligent stroke counter 40 and its processor 18 require a software update.

[0106] Alternatively or possibly also in addition to those in the Figures 2a to 2c In addition to the described application possibilities, it is also possible to monitor the movement of other components with an intelligent stroke counter 40. For example, when using a magnetic field sensor, another component can be equipped with a magnet and monitored by the magnetic field sensor. Furthermore, it is also possible to use other sensors instead of the magnetic field sensor to detect suitable information regarding the diaphragm stroke.

[0107] The Figures 3 to 6 The figures show the behavior of various characteristic values ​​of an intact diaphragm pump 100, 200, or 300 during operation. For the sake of simplicity, the following often refers only to a diaphragm pump 100, but the principles and functions discussed also apply to the diaphragm pumps 200 and 300.

[0108] Fig. 3Figure 1 shows a magnetic field-time diagram of an intact diaphragm pump 100. It depicts the change in a magnetic field with field strength F, measured by sensor 20, over time during operation of the diaphragm pump 100. The diaphragm 11, 11' of the diaphragm pump 100 initially expands from a base position 31 in one direction. Maximum expansion in this direction occurs when a reversing point 26 is reached. Controlled by the switching valve 14, the diaphragm 11, 11' then expands in the opposite direction until the next reversing point 26 is reached. The expansion of the diaphragm 11, 11' in one direction requires a time interval t1, and the expansion in the other direction a time interval t2.

[0109] The magnetic field f abruptly changes its state from a value of 28 to a value of 30 and vice versa upon reaching one of the reversal points 26. Due to the symmetrical design of the diaphragm pump 100, the values ​​28 and 30 oscillate around a value of 29 in a functioning diaphragm pump 100, with equal changes in field strength f1 and f2. Also due to the symmetrical design, the time intervals t1 and t2 are equal. The relationship between such comparative values ​​is subsequently referred to as the ratio V. For a symmetrically designed and fully functional diaphragm pump, the ratio V of the field strength change f1 to the field strength change f2, as well as the ratio V of the time intervals t1 and t2 to each other, is therefore 1 (one).

[0110] In Fig. 4 The change in displacement of a diaphragm 11, 11' of an intact diaphragm pump 100 during operation is shown. Analogous to the representation in Fig. 3During operation, the membrane 11, 11' expands in its two expansion directions and is reversed upon reaching a reversal point 26. Two path lengths s1 and s2 indicate the distance of the membrane 11, 11' from the home position 31 at the reversal point 26. In contrast to the representation in Fig. 3 The representation in Fig 4 It is not a binary system. Rather, the distance is measured continuously by sensor 20. Fig. 4 It can be seen that the change in path from one turning point 26 to the next initially begins rapidly (steep curve) and then slows down as it approaches the next turning point, eventually flattening out. The curve is therefore parabolic and thus typical for the expansion behavior of the diaphragm in a diaphragm pump.

[0111] Analogous to the field strength changes f1 and f2, the changes in Fig. 4The distances s1 and s2 shown and the time intervals t1 and t2 between the turning points are equal and, when compared to each other, each yields the value 1 (one) as the ratio V.

[0112] The field strength changes f1 and f2, the displacements s1 and s2, and the time intervals t1 and t2 represent exemplary parameters that can be used for further considerations regarding the condition assessment of a diaphragm pump 100. For the sake of abstraction, these parameters will also be referred to as measured values, where a first measured value M1 represents a change of state during diaphragm pump operation when the diaphragm 11,11' expands in one direction, and a second measured value M2 represents a change of state during diaphragm pump operation when the diaphragm 11,11' expands in the other direction. The measured value M1 can thus be a field strength change f1, a displacement change s1, or a time interval t1, and the measured value M2 analogously a field strength change f2, a displacement change s2, or a time interval t2.

[0113] In principle, other parameters of a pump 100 can also be used for condition assessment, for example, the pressure profile of a pumped medium or the compressed air supply. The essential point is that the parameters are suitable for characterizing a variable that changes during the operation of a diaphragm pump 100.

[0114] Naturally, to record the respective parameter being observed, a suitable sensor 20 must be installed at a suitable position in or on the diaphragm pump 100 itself or in the environment influenced by the diaphragm pump 100. For example, a sensor can be coupled to the diaphragm 11, 11' to directly record the movement profile of the diaphragm. A sensor 20 can also be coupled to a switching valve 14 or a movable piston rod 49, for example.

[0115] Fig. 5Figure 1 shows a matrix representation of an intact diaphragm pump 100. The matrix is ​​two-dimensional and comprises three columns with consecutive rows. The resulting individual cells are used to perform a block-wise evaluation of the measured values ​​M1 and M2, or the ratio values ​​V, determined based on sensor 20.

[0116] The matrix is ​​based on an evaluation of the True Positive Rate (TPR) and the False Positive Rate (FPR). The TPR indicates the proportion of objects correctly classified as positive out of all truly positive objects. The FPR indicates the proportion of objects incorrectly classified as positive out of all truly negative objects.

[0117] With regard to the diaphragm pump 100 under observation, the measured synchronizations are evaluated block by block and classified into TPR and FPR blocks. Each FPR block raises the alarm trigger, while each TPR block lowers it. Too many consecutive FPR blocks trigger an alarm. This alarm can be transmitted via data transmission, for example, in the form of a NAMUR telegram.

[0118] The completed fields of the in Fig. 5All values ​​in the matrix shown are within a safe range with regard to the defect of the observed diaphragm pump 100. To visualize this result, each filled field is assigned a color F1. Preferably, green is chosen as color F1 for values ​​within a safe range. If the result value shown in the block exceeds a predefined critical deviation 16k, a second color F2, preferably yellow, can be assigned to this block for visualization purposes. If the value exceeds a maximum permissible deviation 16max, a further color, preferably red, can be assigned to this block. In this case, the results are visualized using traffic light colors, where green represents non-critical, yellow represents critical, and red indicates that immediate action is required.

[0119] Fig. 6Figure 1 shows a diagram of the ratios V as a function of time T of an intact diaphragm pump 100. Instead of using specific ratios V, averaged ratios Vm can also be used. The ratios V of a deviation line 16-Actual initially oscillate around a line 16-0. The line 16-0 indicates the synchronicity of pump 100 and is simultaneously the center line of the "green area" marked by the color F1. As in Fig. 6 As can be seen, the deviation is never so large that line 16 is in Fig. 6The dotted boundary line to the yellow area visualized by the color F2 is exceeded. The diaphragm pump is therefore clearly intact. No constant increase in the values ​​in either direction can be observed. Rather, the measured comparative values ​​V merely fluctuate around the center line. The diaphragm pump 100 is therefore not only intact, but no impending damage is detectable.

[0120] While the Figures 3 to 6 The characteristic values ​​and curves of an intact diaphragm pump 100 represent the Figures 7 to 10 The characteristic values ​​and characteristic curves of a defective diaphragm pump 100 are shown.

[0121] The Fig. 7It can be seen that the magnetic field strength F behaves asynchronously. The period t1 for the expansion in one direction is longer than the period t2 for the expansion in the other direction. Similarly, the change in field strength f1 for the movement in one direction is also greater than the change in field strength f2 for the movement in the other direction. The same applies to the distances traveled s1 and s2, which the Figure 8 This can be seen from the data. As a result, there are unequal measured values ​​M1 and M2.

[0122] The ratio values ​​V resulting from unequal measured values ​​M1 and M2 show a large deviation in the illustrated example from the ratio value 1 (one) of an intact diaphragm pump 100. In a Fig. 9Therefore, in the visualization matrix shown, only the blocks in the first row have the color F1, which in this example is green. Subsequent blocks have characteristic values ​​that initially fall within the range of color F2 (yellow) and then within the range of color F3 (red).

[0123] Similarly, the following applies to the Fig. 10The relationship diagram of the ratio values ​​V (or the ratio mean values ​​Vm) versus time T shows that the deviation line 16-actual initially lies in the green area (color F1), then crosses the dotted boundary line to the yellow area (color F2), and finally also crosses the dashed boundary line to the red area (color F3). It is also evident that the line 16-actual does not abruptly switch from one area to another, but rather rises gradually. From this essentially continuous progression, a future development, and thus also the damage prediction intended by the invention, can be derived with a high degree of probability.

[0124] Fig. 11 Figure 1 shows a schematic diagram of the signal flow diagram of a liquid conveying system with a diaphragm pump 100 and a module box 19 integrated into the system. The diaphragm pump 100 is shown here, as well as in Fig. 12, cited as an example. Instead of a diaphragm pump 100, a diaphragm pump 200 or 300 could also be used.

[0125] The diaphragm pump 100 is located in an ATEX Zone 32 and includes an intelligent stroke counter 40 with a sensor 20 and a data processing device 17. The data processing device 17 comprises the processor 18 and other components relevant for the formation of data interfaces and data storage. In ATEX Zone 32, the safety and fire protection requirements for the machines and other components used there are increased. For example, electrical signal transmission must take place at a voltage level that is safe for the ATEX Zone. In this case, the transmission of data stored in the diaphragm pump and data acquired by the sensor 20 takes place in a protocol P via NAMUR telegram 34. The sensor data includes, in particular, the pump strokes and the fault status (ratio value V) determined based on the sensor data.

[0126] The data transmitted via NAMUR telegram 34 is preferably first amplified by an isolating amplifier 33. The isolating amplifier 33 converts the weak NAMUR signal into a 0V to 24V signal. Subsequently, the amplified signal is transmitted – outside the ATEX zone 32 – in telegram form as a message 39 to a module box 19.

[0127] Module box 19 includes a processor 18. Within module box 19, the data telegram transmitted by the iHZ via the isolating amplifier is resolved to include pump strokes, fault status, and pump information, and distributed to data storage locations provided within the module box. Module box 19 includes a data processing device 19, which can also be used to determine and transmit control commands. Furthermore, module box 19 includes outputs for data transmission and forwards a message 36 (pump strokes as 0V to 24V pulses) and a message 37 (fault status as a 0V to 24V level) to a PLC 38 installed at the user's site.

[0128] Fig. 12 shows one Fig. 11 similar signal flow diagram of a liquid conveying system. However, the overall system in the case of the one in Fig. 12 The illustrated embodiment shows two diaphragm pumps 100. Both diaphragm pumps 100 have, analogous to the one in Fig. 11The signal flow diagram shows an intelligent stroke counter 40. The data determined by the intelligent stroke counter are forwarded as protocol P in the form of a NAMUR telegram 34 to isolating amplifier 33.

[0129] An isolation amplifier is a commercially available component for signal transmission. Isolation amplifiers can also transmit DC voltage signals. The term "amplifier" does not necessarily mean that they also perform voltage amplification. If required, an isolation amplifier can be designed to meet the safety requirements relevant in ATEX zones, thus making its use permissible in these zones.

[0130] The data from both diaphragm pumps 100 are amplified by the isolating amplifiers 33, converted into 0V to 24V signals, and transmitted in telegram style as message 39 in the form of a protocol P to the module box 19. There, it is processed by the processor 18 and forwarded via outputs on the module box 19. A message 41 for the pump strokes of the two diaphragm pumps 100 is transmitted as a 0V to 24V pulse, and a message 42 for the fault status of both pumps is transmitted as a 0V to 24V level to a user PLC. Pump stroke, pump status, and other data are transmitted to the user PLC via a MODBUS-RTU interface.

[0131] Alternatively or additionally, the data can also be transmitted to a local server 45 via a UART protocol 44. The data transmitted to the local server 45 can be accessed by external parties, for example, a control system already present at the user's site. Such a control system can also be referred to as a customer cockpit 46.

[0132] The described embodiments are examples of the many possible applications for the diaphragm pumps 100, 200, and 300 with intelligent stroke counter 40 and module box 19. All versions share the common feature that the operating behavior of the diaphragm pumps is monitored during operation, and conclusions about the pump's condition, which can also be described as its "health," are drawn from this behavior.

[0133] As a result, the invention enables early detection of emerging problems and, based on this, predictive maintenance of the diaphragm pumps 100; 200; 300 overall. Reference symbol list

[0134] 10 Housing 11, 11' Membrane 12, 12' Product chamber 13, 13' Pressure chamber 14 Switching valve 15 Data cable 16 Deviation 16-0 Deviation 0 (at synchronization) 16-Actual deviation 16k Critical deviation 16max Maximum permissible deviation 17 Data processing device 18 Processor 19 Module box 20 Sensor 21 Housing 22 Data storage 23 First interface 24 Second interface 25 Center line (of 100) 26 Reversal point 27 Home position 28 Value 1 29 Value 2 (in home position) 30 Value 3 31 Home position (of 11,11') 32 ATEX Zone 33 Isolation Amplifier 34 NAMUR Telegram (Pump strokes and fault status) 35 Message (Pump strokes and fault status as 0V to 24V level) 36 Message (Pump strokes as 0V to 24V pulses) 37 Message (Fault status as 0V to 24V level) 38 User PLC 39 Message (Pump strokes and fault status as 0V to 24V signal) 40 iHZ (intelligent stroke counter) 41 Message (2 x pump strokes as 0V to 24V pulses) 42 Message (2 x fault status as 0V to 24V level) 43 MODBUS RTU 44 UART protocol 45 Local server 46 Customer cockpit (Intranet) 47 Housing cover (of 100; 200; 300) 48 Pump body (of 100; 200; 300) 49 Piston rod 50 Check valve 51 Holder 100 diaphragm pump 200 diaphragm pump 300 diaphragm pump Ffield strength f1 change in field strength 1 f2 change in field strength 2 F1 first color F2 second color F3 third color I - Iintersection M1 first measured value M2 second measured value Pprotocol Spath s1 distance 1 s2 distance 2 Ttime t1 time interval 1 t2 time interval 2 Vratio Vm mean ratio

Claims

1. Method for detecting fault conditions in a diaphragm pump (100; 200; 300), preferably a double diaphragm pump, wherein the diaphragm pump (100; 200; 300) comprises the following components: - a housing (10) with at least one diaphragm (11, 11') enclosed therein, which separates a product chamber (12, 12') and a pressure chamber (13, 13') from each other, wherein the volumes of the product chamber (12, 12') and the pressure chamber (13, 13') can be changed in a complementary manner to each other, - a preferably electric changeover valve (14) which is provided to switch the diaphragm pump (100, 200'; 300) at a reversal point of the diaphragm (11, 11') from a first operating mode, in which the pressure chamber (13, 13') is pressurised with a medium, to a second operating mode, in which the pressure chamber (13, 13') is depressurised, or back, and - a sensor (20) for measuring a measurement signal, characterised in that - based on the data determined by the sensor (20), a first measured value (M1) is determined for the phase between switching from the first operating mode to the second operating mode and a second measured value (M2) is determined for the phase between switching from the second operating mode to the first operating mode, - the measured values (M1, M2) are transmitted to a device for data processing (17), - the first measured value (M1) is set in relation to the second measured value (M2) and a ratio value (V) is formed from the ratio of the two measured values (M1, M2) to each other, - a deviation (16) of the ratio value (V) from a quotient of one resulting from the same measured values (M1, M2) is determined, - the deviation (16) is compared with a predefined permissible deviation value (16max).

2. Method for detecting fault conditions in a diaphragm pump (100; 200; 300) according to claim 1, characterised in that exceeding the permissible deviation value (16max) leads to a deviation message.

3. Method for detecting fault conditions in a diaphragm pump (100; 200; 300) according to claim 1 or 2, characterised in that the measured values (M1, M2) are produced on the basis of the difference between two consecutive switching times, so that the first measured value (M1) indicates the time span between switching from the first operating mode to the second operating mode and the second measured value (M2) indicates the time span between switching from the second operating mode to the first operating mode.

4. Method for detecting fault conditions in a diaphragm pump (100; 200; 300) according to one of claims 1 to 3, characterised in that the measured values (M1, M2) are formed on the basis of the difference between two switching waypoints, so that the first measured value (M1) indicates a distance travelled between switching from the first operating mode to the second operating mode and the second measured value (M2) indicates a distance travelled between switching from the second operating mode to the first operating mode.

5. Method for detecting fault conditions in a diaphragm pump (100; 200; 300) according to one of claims 1 to 4, characterised in that a ratio mean value (Vm), preferably a moving ratio mean value, is determined from a predefined number of consecutive ratio values (V).

6. Method for detecting fault conditions in a diaphragm pump (100; 200; 300) according to one of claims 1 to 5, characterised in that the recorded measured values (M1, M2) and / or ratio values (V; Vm) are classified and control signals based on the classified values are used to assess the fault conditions.

7. Method for detecting fault conditions in a diaphragm pump (100; 200; 300) according to one of claims 1 to 6, characterised in that the measured values (M1, M2) set in relation and / or the ratio values (V; Vm) are recorded statistically and a gradient is determined on the basis of the measured values (M1, M2) and / or comparison values (V; Vm), which characterises a rate of change and preferably leads to a deviation message when a threshold value predefined for the gradient is exceeded.

8. Method for detecting fault conditions in a diaphragm pump (100; 200; 300) according to one of claims 1 to 7, characterised in that calibration is performed before the measured values (M1, M2) are evaluated in order to compensate for manufacturing-related deviations.

9. Method for detecting fault conditions in a diaphragm pump (100; 200; 300) according to one of claims 1 to 8, characterised in that not every exceedance of a maximum permissible deviation (16max) is transmitted to or taken into account by the device for data processing (17), but rather a transmission or consideration of exceedances of the maximum permissible deviations (16max) only takes place, when a predefined ratio of limit value exceedances to pump strokes is exceeded.

10. Method for detecting fault conditions in a diaphragm pump (100; 200; 300) according to one of claims 1 to 9, characterised in that the stroke times and / or stroke distances are detected via - the movement profile of the diaphragms (11, 11') and / or - the movement profile of the changeover valve (14), preferably the pneumatic changeover valve, and / or - the evaluation of the pressure curve of the pumped medium and / or - the evaluation of the pressure curve of the compressed air supply.

11. Method for detecting fault conditions in a diaphragm pump (100; 200; 300) according to one of claims 1 to 10, characterised in that the transmitted data is transmitted via a protocol (P) in conjunction with the current stroke frequency of the diaphragm pump (100; 200; 300).

12. Method for detecting fault conditions in a diaphragm pump (100; 200; 300) according to one of claims 1 to 11, characterised in that, in the case of two diaphragm pumps (100; 200; 300) that are functionally coupled to each other, the measured values (M1, M2) are recorded as stroke times and / or distances per diaphragm (11, 11') for each diaphragm pump (100; 200; 300), the measured values (M1, M2) are recorded as stroke times and / or distances per diaphragm (11, 11').

13. Data processing device (17) comprising a processor (18) configured to perform a method for detecting fault conditions in a diaphragm pump (100; 200; 300) according to one of claims 1 to 12.

14. Module box (19), comprising a data processing device (17) according to claim 13 and - a housing (21) for accommodating the processor (18), - a data memory (22), - a first interface (23) for receiving data provided by a diaphragm pump (100; 200; 300) and a sensor (20) coupled to the diaphragm pump (100; 200; 300), - a second interface (24) for forwarding data and / or further data and / or key figures and / or control commands determined in the processor (18).

15. Diaphragm pump (100; 200; 300) comprising: - a housing (10) with at least one diaphragm (11, 11') enclosed therein, which separates a product chamber (12, 12') and a pressure chamber (13, 13') from each other, wherein the volumes of the product chamber (12, 12') and the pressure chamber (13, 13') can be changed in a complementary manner to each other, - a preferably electric changeover valve (14) which is designed to switch the diaphragm pump (100, 200; 300) at a reversal point of the diaphragm (11, 11') from a first operating mode, in which the pressure chamber (13, 13') is pressurised with a medium, to a second operating mode, in which the pressure chamber (13, 13') is depressurised, or back, characterised in that the diaphragm pump (100; 200; 300) further comprises a device for data processing (17) according to claim 13 or a module box (19) according to claim 14.