Sensor controlled diaphragm pump

Abstract

The invention relates to a method for detecting fault conditions in a diaphragm pump (100; 200; 300), preferably a double-diaphragm pump. The diaphragm pump (100; 200; 300) comprises a housing (10), a preferably electrical switching valve (14), and a sensor (20) for detecting a measurement signal.The method according to the invention comprises the following steps: - on the basis of the data determined by the sensor (20), a first measured value (M1) for the phase between switching from the first operating mode to the second operating mode and a second measured value (M2) for the phase between switching from the second operating mode to the first operating mode are determined, - the first measured value (M1) is related to the second measured value (M2) and a ratio value (V) is formed from the ratio of the two measured values (M1, M2) to one another, - the measured values (M1, M2) are transmitted to a data processing device (17), - 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 (16k; 16max).The application of the method according to the invention enables early detection of impending fault conditions, in particular those based on wear, of the diaphragm pump (100; 200; 300) or its components.

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 comprising 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 within a pump housing. The diaphragm separates a pump chamber into two sections: a pressure chamber and a product chamber. Valves are assigned to both sub-chambers, which are alternately opened and closed depending on the pressure conditions.

[0003] By periodically applying pressure to the pressure chamber, the membrane is pushed into the product chamber, reducing its volume. Reducing the 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 complement each other. This variation in volume creates alternating overpressure and underpressure in the product chamber, drawing the aforementioned substance into the product chamber and then expelling it. The membrane thus creates a pump-suction cycle in the subchambers.

[0004] A double diaphragm pump has two diaphragms enclosed in a housing. The movements of the two diaphragms are coordinated in such a way that the product chamber volumes increase alternately. This allows for virtually continuous pumping of the media to be pumped.

[0005] Due to the mechanical deformation of the diaphragm 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, such as polytetrafluoroethylene (PTFE), have proven particularly advantageous. Using this hybrid structure can significantly increase the service life of the diaphragm, as the outer layer is significantly more resistant to the media than the elastomer, and only this layer comes into contact with the pumped medium.

[0006] Despite the choice of material, one of the most common causes of failure in diaphragm pumps is a mechanical defect in the diaphragm due to wear and tear. The extreme stress initially causes cracks to form in the layer that comes into contact with the medium. If the pump continues to operate, the crack grows larger and the elastomer layer comes into contact with the pumped medium. This then very quickly leads to a rupture of the diaphragm. When the diaphragm ruptures, the medium comes into contact with the pump and possibly the environment, which can not only destroy the pump but also cause significant environmental pollution. In addition to cracks, blistering can occur as a sign of further damage to the diaphragm, particularly with composite diaphragms.

[0007] To prevent a complete rupture or tear of the membrane, the membrane is replaced at regular maintenance intervals. Since the service life 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 preventative membrane replacement therefore usually assumes a worst-case scenario. By adhering to the predefined maintenance cycles, intact membranes are often replaced to avoid damage, downtime, and consequential losses.

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

[0009] DE 10 2006 049 440 A1 discloses a method for detecting the operating state of a pump. The operating state is determined by determining the pressure and / or flow profile in the pump system, calculating a characteristic value on this basis and comparing it with a specified characteristic value. The pressure is determined using a sensor with a ceramic-capacitive pressure measuring cell. Similar to a displacement measurement, a pressure measurement cannot simply be integrated into an existing pump, because pressure measurement generally also requires knowledge of the stroke rate. It is also questionable whether pressure measurement values can be transmitted from the EX zone (ATEX zone) within 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, intervention in the pump mechanism is required.

[0011] DE 10 2015 108 964 A1 discloses a method for controlling a diaphragm pump. A sensor measures a signal that reflects the displacement of a diaphragm of the diaphragm pump. The displacement data acquired by the sensor are used to control a switching valve. Here, too, intervention in the pump mechanism is required.

[0012] US 6 036 445 A discloses an electrical switching mechanism for a liquid-operated diaphragm pump. Here, too, intervention in the pump mechanism is necessary. US 2014 / 0 348 667 A1 discloses a diaphragm pump with a control system that optimizes the flow of compressed air supplied to the pump. To do this, the flow of compressed air supplied to the pump is reduced 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 so that the pump adjusts itself to determine the optimal or nearly optimal throttling point. By minimizing the amount of compressed air required, compressed air is saved. Here, too, intervention in the pump mechanism is required.

[0013] From WO 2009 / 059 664 A1 a micropump and a method for conveying small and very small quantities of a fluid are known.

[0014] WO 2014 / 133712 A1 discloses a diaphragm pump with pressure compensation calibration. The diaphragm pump comprises a shaft connected to a diaphragm and reciprocating 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 can be used to detect the pressure at the fluid outlet. Here, too, intervention in the pump mechanism is required.

[0015] An electrically operated double diaphragm pump is known from WO 2021 001 806 B4. Here, too, intervention in the pump mechanism is required.

[0016] DE 10 2016 001 806 B4 discloses a pump with sensors mounted on its diaphragms, allowing the diaphragm to be measured for damage. However, this requires electrical wiring or electronic components that must be applied to the diaphragm. Another disadvantage is that each diaphragm must be equipped with such a sensor, which involves considerable effort and thus additional costs.

[0017] In the prior art pumps based on position data acquisition, the position data is used to control one or more switching valves. Integrating the sensors required to acquire the position data is complex and difficult to retrofit to existing pumps. Furthermore, the data acquired by the sensors is primarily used to control any switching valves provided on a pump and not for fault detection, especially early fault detection.

[0018] The invention is therefore based on the object of proposing a method with which damage to a diaphragm pump, in particular damage to the diaphragm or one of the valves, can be detected easily and at an early stage. Definitions:

[0019] A stroke counter is a device or sensor attached to a diaphragm pump that counts the number of strokes performed by the diaphragm, thus counting its cycles. Stroke counters thus enable various controls to be activated, such as determining the flow rate delivered by the pump and monitoring pump function.

[0020] A smart stroke counter is a device or sensor that not only counts strokes but is also configured to process the collected data. The smart stroke counter includes a processor that can not only record and forward the data collected by the sensor, but also directly evaluate and process it.

[0021] The problem is solved by a method having the features of claim 1.

[0022] The said method relates to a method for detecting fault conditions of a diaphragm pump, preferably a double diaphragm pump.

[0023] The diaphragm pump includes: a housing with at least one diaphragm enclosed therein, which separates a product chamber and a pressure chamber from one another, wherein the volumes of the product chamber and the pressure chamber can be changed complementarily to one another by a movement of the diaphragm, a preferably mechanical switching valve which is provided for switching 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 measuring signal.

[0024] In addition, a control unit can be provided to control the changeover valve.

[0025] According to the invention, based on data acquired by the sensor, a first measured value is initially acquired at the time between switching from the first operating mode to the second operating mode, and a second measured value is acquired at the time between switching from the second operating mode to the first operating mode. The first measured value is then related to the second measured value, and a relative or ratio value is calculated from the relationship between the two measured values. Since the sensor and processor are located on the pump, the particular advantage is that the data acquired by the sensor can be processed in real time.

[0026] Due to their generally symmetrical design, diaphragm pumps have approximately equal switching times from one diaphragm working cycle to the next. For this reason, the first and second measured values of a functioning diaphragm pump are equal, and a relative value resulting from the first and second measured values is equal to or close to one.

[0027] In a further step, the deviation of the ratio value resulting from the relationship between the first and second measured values from the ratio value of one resulting from identical measured values is determined. The deviation is then compared with a predefined permissible deviation value.

[0028] The invention leverages the knowledge that changes in the diaphragm in the form of cracks, especially the frequently occurring blistering, in which the media-resistant cover layers detach from the elastomer layer due to diffusion processes of the medium, lead to uneven running behavior of the pump. Since wear phenomena never occur simultaneously and symmetrically on both sides of the diaphragm, and other components of the diaphragm pump, such as valves, never wear exactly evenly, a deterioration in running behavior can be observed in many cases of damage.

[0029] This impairment is usually difficult to detect, as the pumps assume different load and flow conditions, resulting in uneven pump operation. However, a suitable sensor can detect the change and generate a corresponding message.

[0030] Put simply, 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 particularly advantageous feature 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.

[0031] 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 for detecting the movement profile. Pumps are usually already equipped with a magnetic stroke counter to monitor the pump's flow rate. In these cases, a magnetic proximity switch is often used as the stroke counter, which emits a stroke signal when a certain field strength is reached. However, other sensors, such as ultrasonic distance sensors, are also generally suitable.

[0032] 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 precisely determines the switching points based on the changing magnetic field.

[0033] The measured values, i.e. the values that the two diaphragm chambers need for a complete stroke, can be recorded from the data obtained in this way. Depending on the type of sensor used, this can be binary information or trend information. Binary information contains, for example, a temporal and / or spatial start point and 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 other individual points lying between the start and end points. The measured values are put into relation, e.g. by division, so that when the pump is running completely symmetrically the quotient is one. Other mathematical methods that put the two values in relation are also suitable.

[0034] Diaphragm pumps typically use proximity sensors, preferably with a NAMUR output. NAMUR sensors often operate without contact. They provide binary information and are usually designed as proximity switches. The sensor thus indicates whether a reference object is nearby or not.

[0035] A particular advantage of these NAMUR sensors is that they operate with a low electrical energy level. This greatly reduces the inherent ignition risk associated with electricity and, in the best case, eliminates it altogether. The use of such sensors is therefore also permitted in ATEX zones. An ATEX zone is defined as an area in which potentially explosive atmospheres may occur. Sensor data can only be transmitted from an ATEX zone using signals approved for the ATEX zone, e.g., the 4...20 mA loop or pulses according to NAMUR.

[0036] The described method thus enables monitoring of the switching behavior of the diaphragm pump and, as a result, early detection of diaphragm rupture or other damage, such as valve failure. This is because such damage, even in its early stages, affects the switching from one operating mode to another, thus affecting the synchronization of the working cycles.

[0037] As already explained, known methods attempt to avoid system downtimes and consequential damage caused by defects in the pump or its components that are not detected in a timely manner. This is done by replacing certain components, for example the diaphragm of a pump or the entire pump, based on predefined maintenance intervals. The replacement is therefore carried out prophylactically without taking into account 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 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 acquired data.

[0038] In a preferred embodiment of the method, exceeding the permissible depreciation value triggers a deviation message. This deviation message can be used to generate a visual or acoustic warning signal.

[0039] The measured values mentioned can be in the form of time units. Such time units can be formed 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 period between switching from the first operating mode to the second operating mode, and the second measured value indicates the time period between switching from the second operating mode to the first operating mode.

[0040] 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.

[0041] Alternatively or in addition 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.

[0042] Magnetic field sensors are also suitable for analyzing switching paths.

[0043] Preferably, a ratio mean, most preferably a moving ratio mean, is determined from a predefined number of consecutive ratio values.

[0044] The invention takes advantage of the knowledge that a change in the diaphragm, such as a tear or swelling, also changes the diaphragm's section modulus and thus the resistance to the stroke movement. This change is reflected in the time and / or distance the diaphragm requires to complete a stroke. Increased wear on individual valves also leads to a change in stroke behavior and thus to changes in stroke times. Mathematical methods, such as averaging, can compensate for the influence of one-off or rarely occurring events.

[0045] In a preferred embodiment of the method, the recorded measured values and / or ratio values are classified and used to determine control signals.

[0046] The reason for this is that critical and non-critical events have, or can have, the same impact on the pump's synchronicity. In contrast to error detection based on limit violations, non-critical events can be compensated for by classifying the measured values and / or the ratio values.

[0047] 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 the accompanying explanations of the figures.

[0048] In a preferred embodiment of the method, the related measured values and / or the comparison values are statistically recorded, and a gradient is determined based on the measured values and / or comparison values, which characterizes a rate of change. A gradient is the course of a change. Preferably, the exceedance of a predefined threshold value for the determined gradient is used to generate a deviation report.

[0049] Changes in stroke times can result not only from actual fault conditions of the diaphragm and other components, but also from changes in operating conditions. For example, idle operation or varying operating pressures can influence the relationship between stroke times. However, unlike wear-related changes in actual fault conditions, such changes generally do not occur gradually, but rather abruptly when the pump's operating pressure changes or the discharge volume changes.

[0050] In other words: changes in measured values due to changes in operating parameters occur suddenly, while changes in measured values due to wear occur gradually.

[0051] The reason for the gradual onset of faults is that diaphragm cracks, bubbles, or valve wear generally develop gradually. The stroke times also change gradually accordingly. The mean values of the relative stroke times of the two diaphragm chambers can therefore be observed as a continuous increase or decrease in the values over a period of time until the diaphragm or valve fails. Such gradual changes in the measured values are therefore clearly due to component wear and not to operational changes. Mathematically, the gradual change can be represented as a gradient. By comparing a measured value gradient determined on the basis of current measured values with other comparison gradients, for example those stored in a data memory, it is possible to determine whether the current measured value gradient is due to a fault condition or changed operating conditions.Furthermore, it is possible to determine characteristic measured value 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 measured value gradient.

[0052] Preferably, calibration is carried out before the measured values are evaluated in order to compensate for production-related deviations.

[0053] Since pumps are subject to significant fluctuations due to operation, the determined ratio values are stored to compensate for these fluctuations and averaged over a period of time. Such a calibration, which is particularly useful for new or serviced pumps, can be performed 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 stored as a pump-specific offset value. This value results, for example, from component tolerances, variations in design, and the elasticity of the diaphragm.

[0054] 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 value exceedances to pump strokes is exceeded.

[0055] Thus, for example, after an interruption in operation, the influence of changed stroke times, which are due to downtime-related changes, can be compensated by not including the sensor data of the first strokes of the diaphragm pump in the evaluation.

[0056] As explained above, the method for detecting fault conditions in a diaphragm pump is based on a change in synchronism. The changed synchronism, in turn, is based on different stroke times and / or stroke lengths of components contained in the diaphragm pump. The determination of measured values relevant to synchronism is preferably based on the following variables: 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 curve of the pumped medium and / or the evaluation of the pressure curve of the compressed air supply.

[0057] The movement profile of a diaphragm or another component, such as a guide rod coupled to the diaphragm or a control valve, can be determined using a suitable sensor. The sensor can preferably be a magnetic field sensor that can detect the field strength of a magnetic field. This allows the movement of a magnet attached to the reversing valve piston of the diaphragm pump to be detected by measuring the changing magnetic field strength. A magnetic field sensor built into the sensor detects the position of the magnet on the reversing valve piston at very short time intervals, allowing the switching of the valve piston to be recorded very precisely. Minimum and maximum detection occurs as a double stroke, which corresponds to a NAMUR pulse.

[0058] To determine a pressure profile, a pressure sensor, such as a differential pressure sensor, can be provided, coupled to the conveying circuit of the conveyed medium or compressed air. The physical quantity, pressure, determined by the pressure sensor is converted into an electrical output and transmitted to the data processing device in the form of measured values.

[0059] 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 broken down using mathematical methods into signals that can be transmitted sequentially over a common line. In addition to the sensor data, any other data available about the diaphragm pump, such as its serial number or commissioning, can also be transmitted using the aforementioned protocol.

[0060] For example, the protocol can transmit the hub frequency and the measured values to determine the error status three times per second in the form of a modified telegram.

[0061] In addition, the sensor information can be updated in a loop every minute. The sensor information could, for example, be: 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 up the number of strokes per frequency range (0Hz to 8Hz) since the last maintenance.

[0062] 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 register automatically within the system. Manually assigning nameplate data to a specific pump is no longer necessary.

[0063] The number of strokes performed since a pump was commissioned can be evaluated, as can the number of strokes performed since the last maintenance. Histograms make the pump usage profiles transparent and analyzable.

[0064] In a further embodiment, in the case of two diaphragm pumps that are functionally coupled to one another, the stroke times and / or travel distances for each diaphragm pump can be recorded.

[0065] For example, a rotary printing press may be equipped with an ink reservoir ("doctoring chamber") whose fill level is kept constant using two pumps. In this case, two double-diaphragm pumps may be provided as pumps, with one pump pumping a 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, on the one hand, a predefined minimum fill level is not undercut, and, on the other hand, a predefined maximum fill level is not exceeded. In such an application, a failure of the drain pump can cause the ink reservoir to overflow.By applying the described procedure, overflow of the pool can be prevented by timely detection of faults in the drain pump by generating a fault message and / or deactivating the inlet pump when a fault is detected in the drain pump.

[0066] The invention further relates to a data processing device comprising a processor configured to carry out a method for detecting fault conditions on a diaphragm of a diaphragm pump according to one of claims 1 to 12.

[0067] The processor enables monitoring of the diaphragm pump. As already mentioned, the information relevant to the diaphragm pump, such as Serial number of the pump, tag number or installation location of the pump, total number of strokes, maintenance counter, histogram, number of strokes per frequency range (0Hz to 8Hz) since the last maintenance (summed), synchronization of the pump (changes in the synchronization of the pump can indicate e.g. diaphragm break, valve malfunction or suction problems) can be transmitted by means of a telegram from the diaphragm pump and are retrieved from the pump by the processor along with the stroke frequency during pump operation.

[0068] Any wow and flutter that develops during pump operation is detected and evaluated in the processor. A value generated in this way can be output as a synchronism index. If the synchronism index exceeds or falls below a limit predefined by the diaphragm pump manufacturer or user, a control command can be triggered, which can then be used to execute direct actions, such as activating a horn or activating a safety shutdown.

[0069] The data processing device can be designed as a module box separated from the diaphragm pump and, in addition to the processor mentioned, can comprise the following components: a housing for accommodating the processor, a data memory, 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.

[0070] Usually, pumps known from the state of the art already have a proximity sensor, which detects the movement of the

[0071] The sensor, integrated into the module box, is mounted at the location on the pump that is normally designated for a proximity sensor. This allows even older pumps to be retrofitted with fault detection, and new pumps can be optionally equipped with the module box.

[0072] For pumps designed to pump solvent-based paints and varnishes, the module box is located within a working environment where an explosive atmosphere can arise (EX zone). A particularly advantageous feature 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, the 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] Software is advantageously installed on the sensor or on a processor coupled to the sensor. Within the EX zone, pump malfunctions can thus be detected simply by measuring the time from one switching extreme to the other. The 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 continuously improve. The software installed on the sensor or in the module box is also designed to be able to detect the elimination of a malfunction and delete a malfunction 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 hazardous area. This allows the user to use this data and information in a machine control system.

[0075] A particularly advantageous feature is that the 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 required data, retrofitting the module box within an existing system, such as a paint shop, is also easy.

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

[0077] In conjunction with the intelligent stroke counter, the module box can report pump faults 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 evaluate not only the data from one diaphragm pump, but also the data from two or more diaphragm pumps.

[0078] For example, in addition to two intelligent stroke counters, two additional 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 reports pump faults caused by wow and flutter. The fault is indicated by default as a light signal on the electronics housing, switching from green to red. Alternatively or in addition, acoustic or other signals can also be generated. All required components, including the isolation amplifier and power supply, are integrated in or on the module box housing for 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 enables access to pump data on a company's 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 connection to the company's 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 the "Internet of Things." Functions implemented with IoT technologies enable interaction between people and any electronic systems networked via IoT, as well as between the systems themselves. 3. PLC connection of the module box

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

[0083] For monitoring and PLC connection, the following data is available for each channel: Information about the module box, serial number of the pump, TAG number / installation location of the pumps (16 digits for both channels), total number of strokes, number of strokes since the last maintenance, histogram, number of strokes per frequency range (0Hz to 8Hz) since the last maintenance, error status, can mean diaphragm rupture, valve malfunction or suction problems, measured value of the analog (4...20mA) sensor, e.g. pressure measurement value, synchronization index, for external diagnostics, setting options for error handling of the module box

[0084] For PLC customer applications, the module box provides a Modbus interface for integrating the 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 tapped by the module box.

[0086] In summary, the use of the method, processor and module box according to the invention in various diaphragm pump applications results in industry-specific advantages, some of which are listed below as examples: Flexographic printing industry: Diaphragm rupture monitoring can be integrated into the printing press PLC. The printing press PLC can access the information from the intelligent stroke counter. When a pump is replaced, the pump registers itself with the printing press PLC. Maintenance data can be automatically transferred to the printing press PLC. Employees or external companies commissioned with maintenance do not need to enter changes in the printing press PLC. When a pump is replaced, the serial number is automatically transferred to the printing press PLC. With the monitoring solution, pump status visualization can be retrofitted without interfering with the printing press PLC (retrofit). The module box can be retrofitted to printing presses. Errors are indicated in a timely manner. The monitored pump can still be flushed, and maintenance can be performed before the air side of the pump is flooded with ink.The module box enables the retrofitting of overflow protection in doctor blade chambers with two pumps. If the discharge pump stops or malfunctions, the air supply to the pump being discharged is also shut off. Chemical / Food Industry: Pump data can be mirrored in a control room. During maintenance or repairs, the pump data is automatically uploaded to the control room. An active pump fault report can increase the safety level (SIL) of the entire system. Backup pumps can be started from the module box in the event of a fault. Early notification of a fault allows the plant operator to clean or decontaminate the pump while the process is still running. This significantly simplifies maintenance. A pump in an existing system can also be retrofitted with protection against overload, overpressure, and idle operation by integrating a module box.Further measures which improve the invention are presented in more detail below with the description of preferred exemplary embodiments of the invention with reference to the figures. The invention further relates to a diaphragm pump having a housing with at least one diaphragm enclosed therein which separates a product chamber and a pressure chamber from one another, wherein the volumes of the product chamber and the pressure chamber can be changed complementarily to one another by moving the diaphragm, a preferably electrical switching valve which is provided for switching the diaphragm pump at a reversal point of the diaphragm from a first operating mode in which the pressure chamber is pressurised with a medium, to a second operating mode in which the pressure chamber is depressurised, or back again, and a device for data processing according to claim 13 or a module box according to claim 14.

[0087] Using such a pump, it is possible to detect fault conditions, such as a damaged membrane, at an early stage and to carry out predictive maintenance.

[0088] 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 path-time diagram of an intact diaphragm pump; Fig. 5 shows a visualization matrix of an intact diaphragm pump; Fig. 6 shows a relationship diagram of an intact diaphragm pump; Fig. 7 shows a magnetic field-time diagram of a defective diaphragm pump; Fig. 8 shows a path-time diagram of a defective diaphragm pump; Fig. 9 shows a visualization matrix of a defective diaphragm pump; Fig. 10 shows a relationship 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.

[0089] Identical or similar elements may be provided with identical or similar reference numerals in the following figures. Furthermore, the figures of the drawing, their description and the claims contain numerous features in combination. A person skilled in the art will appreciate that these features can also be considered individually or combined to form further combinations not described in detail here. The invention expressly also extends to embodiments that are not defined by feature combinations from explicit references to the claims, whereby the disclosed features of the invention can be combined with one another in any way, as long as this is technically reasonable. The exemplary embodiments illustrated in the figures are therefore merely descriptive and are not intended to limit the invention in any way.

[0090] The terms "upper", "top", "lower", "left" or "right" used below refer to the arrangement of the components shown in the drawing.

[0091] Fig. 1 shows a diaphragm pump 100 designed as a double diaphragm pump in a perspective view. The illustrated 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 comprises a housing 21 with a data processing device 17 accommodated therein. An essential component of the data processing device 17 is a processor 18. The intelligent stroke counter 40 transmits data to a module box 19 (cf. Figs. 11 and 12). If necessary, especially if the diaphragm pump 100 operates in an ATEX zone, an isolating switching amplifier (cf. Figs. 11 and 12 ) must 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.

[0092] The particular advantage of a system designed in this way is that not only is sensor data recorded at the diaphragm pump itself, but this data is also further processed in the area of the diaphragm pump 100 by the data processing system 17. A large part of the computing work is therefore performed in or on the diaphragm pump 100, so that any reactions and control commands can be generated in real time.

[0093] Fig. 2a shows the diaphragm pump according to Fig. 1in a sectional view. In the pump body 48 there is a Fig. 2a A switching valve 14 (not visible) is arranged, which controls the switching of two diaphragms 11, 11' also mounted in the housing 10. Such a diaphragm pump with two diaphragms 11, 11' contained therein forms a double diaphragm pump.

[0094] The membranes 11, 11' each have a peripheral annular bead, which is compressed and held in a clamping area by the screw connections of the housing cover 47 with the central pump body 48.

[0095] Elastomeric composites, 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.

[0096] The housing covers 47, 47', together with the pump body 48, form two pump chambers, each divided by the diaphragms 11, 11' into a product chamber 12, 12' and a pressure chamber 13, 13' with varying 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 again. The pressurized pressure chambers 13, 13' alternately press the diaphragms 11, 11' toward the housing covers 47, 47' and displace the product or medium to be pumped from the product chambers 12, 12'.

[0097] At the same time, the opposite membrane 11, 11' is pulled into the center of the pump body 48 by the piston rod 49, so that the product chambers 12, 12' enlarge and a further amount of medium is sucked in. The backflow of the medium when switching the chambers is prevented by suitable check valves 50.

[0098] The alternating control of the pressure chambers 13, 13' is achieved by a mechanical switching of the switching valve 14 in the end position of the membranes 11, 11'.

[0099] In the Fig. 1 and 2aIn the exemplary embodiment shown, i.e. in a diaphragm pump 100 with a module box 19 attached to a housing cover 47, a sensor 20 accommodated in or on the housing 21 determines a feature characterizing the pump operation, in the present case the movement or stroke of a diaphragm 11, 11'. A magnetic field sensor is provided as sensor 20 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 assigned to the diaphragm cover 47, 47', or from the back of the diaphragm.

[0100] As a result, the current 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 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. The changed resistance of the diaphragm 11, 11' also changes the stroke movement 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 100 diaphragm pump is used in an ATEX zone, the data is transmitted as a NAMUR telegram. Outside the ATEX zone, a 0V to 24V signal can be provided.

[0101] Fig. 2bshows a second embodiment of a diaphragm pump 200. The structure and functioning of the diaphragm pump 200 essentially correspond to the structure and functioning of the diaphragm pump 100. In contrast to the diaphragm pump 100, the criterion for the movement of the diaphragm 11, 11' is not the direct movement of the diaphragm 11, 11', but rather a 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 again a magnetic field sensor, detects the travel of the piston rod 49. For this purpose, a magnet is attached to the piston rod 49. Also in the Fig. 2b In the illustrated embodiment, the sensor 20 determines, in addition to the time information, analogously to the example according to Fig. 2a the travel distance covered in a unit of time.

[0102] Fig. 2c shows a third embodiment of a diaphragm pump 300. The structure and operation of the diaphragm pump 300 again correspond essentially to the structure 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 switching valve 14. In the illustrated embodiment according to Fig. 2c In this case, the intelligent stroke counter 40 only determines the switching time. In the intelligent stroke counter 40, or in the data processing device 17 contained therein, the data determined by the sensor 20 is evaluated and forwarded in the form of a NAMUR telegram via the data line 15, for example, to an isolating switching amplifier (see Figs. 11 and 12 ).

[0103] The 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 system for predictive fault detection. In such a case, only the existing stroke counter and its processor need to be equipped with appropriate software for evaluating and processing the data determined by the sensor. A module box 19 (see Fig. 1) can then be installed at a location outside the ATEX zone. Figs. 11 and 12 ) into the overall system. One advantage is that a system upgraded or retrofitted in this way does not require a new fire or safety approval in the ATEX zone, since the hardware components installed in the ATEX zone do not need to be modified; only the intelligent stroke counter 40 and its processor 18 require a software update.

[0104] Alternatively or possibly in addition to the Figures 2a to 2c In addition to the possible uses and applications described above, it is also possible to monitor the movement of other components using an intelligent stroke counter 40. When using a magnetic field sensor, for example, another component can be provided 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.

[0105] The Figures 3 to 6 show the development of various parameters of a functioning diaphragm pump 100, 200, or 300 during operation. For simplicity, reference is often made to a diaphragm pump 100 in the following, but the principles and functions discussed also apply to the diaphragm pumps 200 and 300.

[0106] Fig. 3shows a magnetic field-time diagram of an intact diaphragm pump 100. Thus, the change in a magnetic field with field strength F measured by sensor 20 over time during operation of diaphragm pump 100 is shown. The diaphragm 11, 11' of diaphragm pump 100 initially expands from a basic position 31 in one direction of expansion. Maximum expansion in this direction occurs when a reversal point 26 is reached. Controlled by the switching valve 14, the diaphragm 11, 11' then expands in an opposite direction of expansion until the next reversal point 26 is reached. The expansion of the diaphragm 11, 11' in one direction requires a time period t1, and the expansion in the other direction requires a time period t2.

[0107] Upon reaching one of the reversal points 26, the magnetic field f abruptly changes its state from a value of 28 to a value of 30 and vice versa. Due to the symmetrical design of the diaphragm pump 100, the values 28 and 30 in an intact diaphragm pump 100 with equally large field strength changes f1 and f2 oscillate around a value of 29 present in the basic position 31. Also due to the symmetrical design, the time periods t1 and t2 are also equal. The relationship between such comparison values is referred to below as the ratio value V. For a symmetrically designed and completely intact diaphragm pump, the ratio value V of the field strength change f1 to the field strength change f2 as well as the ratio value V of the time periods t1 and t2 to each other is thus 1 (one).

[0108] In Fig. 4 The change in the path of a diaphragm 11, 11' of an intact diaphragm pump 100 during operation is shown. Analogous to the illustration in Fig. 3The membrane 11, 11' expands in its two expansion directions during operation and is reversed when reaching a reversal point 26. Two distances s1 and s2 indicate the distance of the membrane 11, 11' to the base position 31 at the reversal point 26. In contrast to the representation in Fig. 3 The representation in Fig. 4 This is not a binary system. Rather, the distance is measured continuously by sensor 20. In Fig. 4 It can be seen that the change in path from one reversal point 26 to the next initially begins rapidly (steep curve) and slows down as the next reversal point is approached, becoming flatter. The curve is thus parabolic and therefore typical of the expansion curve of the diaphragm of a diaphragm pump.

[0109] Analogous to the field strength changes f1 and f2, the Fig. 4The distances s1 and s2 shown and the time periods t1 and t2 between the reversal points are of equal size and, when put in relation to each other, result in the value 1 (one) as the ratio value V.

[0110] The field strength changes f1 and f2, the distances s1 and s2, and the time periods t1 and t2 represent exemplary parameters that can be used for further considerations with regard to the condition assessment of a diaphragm pump 100. For reasons of abstraction, the parameters mentioned are also referred to below as measured values, whereby a first measured value M1 represents a change in state during diaphragm pump operation upon expansion of the diaphragm 11, 11' in one direction, and a second measured value M2 represents a change in state during diaphragm pump operation upon expansion of the diaphragm 11, 11' in the other direction. The measured value M1 can thus be a field strength change f1, a distance change s1, or a time period t1; the measured value M2 can analogously be a field strength change f2, a distance change s2, or a time period t2.

[0111] In principle, other parameters of a pump 100 can also be used to assess its condition, for example, the pressure curve of a pumped medium or the compressed air supply. It is essential that the parameters are suitable for characterizing a variable that changes during operation of a diaphragm pump 100.

[0112] Of course, to detect the respective observed parameter, 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. However, a sensor 20 can also be coupled, for example, to a switching valve 14 or a movable piston rod 49.

[0113] Fig. 5shows a matrix representation of an intact diaphragm pump 100. The matrix is two-dimensional and comprises three columns with consecutive rows. In the resulting individual fields, a block-by-block evaluation of the measured values M1 and M2 determined based on sensor 20, or the ratio values V, is carried out.

[0114] 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 among the total number of actually positive objects. The FPR indicates the proportion of objects incorrectly classified as positive among the total number of actually negative objects.

[0115] With regard to the diaphragm pump 100 under observation, the measured synchronizations are evaluated block by block and classified into TPR and FPR blocks. With each FPR block, an alarm trigger is raised, and with each TPR block, the alarm trigger is lowered. Too many FPR blocks in a row trigger an alarm. This alarm can be transmitted via data transmission, for example, in the form of a NAMUR telegram.

[0116] The completed fields in Fig. 5The matrix shown all show a value that lies within a safe range with regard to the defect in the observed diaphragm pump 100. To visualize this result, each of the filled fields is assigned a color F1. Preferably, the color F1 is green for values lying 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. If the value exceeds a maximum permissible deviation 16max, a further color, preferably red, can be assigned to this block. In the present case, the results are visualized using traffic light colors, where green stands for non-critical, yellow for critical, and red for immediate action.

[0117] Fig. 6shows a diagram of the ratio values V as a function of time T for an intact diaphragm pump 100. Instead of using specific ratio values V, reference can also be made to averaged ratio values Vm. The ratio values V of a deviation line 16-actual initially oscillate around a line 16-0. 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 shown in Fig. 6 As can be seen, the deviation is never so large that the line 16-1st is a Fig. 6The dotted boundary line crosses the yellow area indicated by the color F2. The diaphragm pump is therefore clearly intact. There is also no discernible increase in the values in either direction. Rather, the determined comparison values V merely oscillate around the center line. The diaphragm pump 100 is therefore not only intact, but also shows no signs of impending damage.

[0118] While the Figures 3 to 6 Characteristic values and characteristic curves of an intact diaphragm pump 100 represent the Figures 7 to 10 the characteristics and curves of a defective diaphragm pump 100.

[0119] The Fig. 7It can be seen that the field strength F of the magnetic field behaves asynchronously. The period t1 for the expansion in one direction is longer than the period t2 for the expansion in the other direction. Analogously, the field strength change f1 for the stroke in one direction is also greater than the field strength change f2 for the stroke in the other direction. The same applies to the distances s1 and s2 traveled by the Figure 8 The result is unequal measured values for M1 and M2.

[0120] The ratio values V resulting from unequal measured values M1 and M2 in the example shown show a large deviation from the relation value 1 (one) of an intact diaphragm pump 100. In a Fig. 9In the visualization matrix shown, only the blocks in the first row have the color F1, which in the example shown is green. This results in characteristic values for the blocks that initially lie in the range of color F2 (yellow) and then in the range of color F3 (red).

[0121] Analogously, the Fig. 10From the relationship diagram of the ratio values V (or the ratio mean values Vm) versus time T shown, it can be seen that the deviation line 16-lst 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 can also be seen that the line 16-lst does not abruptly change from one area to another, but rather rises gradually. From the essentially continuous course, a future development and thus also the damage prognosis intended with the invention can be derived with a high degree of probability.

[0122] Fig. 11 shows a signal flow diagram of a liquid conveying system with a diaphragm pump 100 and a module box 19 integrated into the system in a schematic representation. The diaphragm pump 100 is here, as in Fig. 12, as an example. Instead of a diaphragm pump 100, a diaphragm pump 200 or 300 could also be provided.

[0123] The diaphragm pump 100 is located in an ATEX zone 32 and comprises 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 occur 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 determined 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 error status determined based on the sensor data (ratio value V).

[0124] 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. The amplified signal is then transmitted – outside of ATEX Zone 32 – in telegram form as message 39 to a module box 19.

[0125] The module box 19 contains a processor 18. In the module box 19, the data telegram concerning pump strokes, error status, and pump information transmitted from the iHZ via the isolating amplifier is resolved and distributed to data memories provided in the module box. The module box 19 contains a data processing device 19, which can also be used to determine and transmit control commands. Furthermore, the module box 19 includes outputs for data transmission and forwards a message 36 (pump strokes as 0V to 24V pulses) and a message 37 (error status as 0V to 24V levels) to a PLC 38 installed at the user's site.

[0126] Fig.12 shows one to Fig. 11 similar signal flow diagram of a liquid conveying system. However, the overall system in the Fig. 12 illustrated embodiment two diaphragm pumps 100. Both diaphragm pumps 100 have analogous to the Fig. 11The signal flow diagram shown includes an intelligent stroke counter 40. The data determined by the intelligent stroke counter is forwarded to the isolating amplifier 33 as protocol P in the form of a NAMUR telegram 34.

[0127] An isolating amplifier is a commercially available component for signal transmission. Isolating amplifiers can also transmit DC signals. The term "amplifier" does not necessarily mean that they also provide voltage amplification. If necessary, an isolating amplifier can be designed to meet the safety requirements relevant for ATEX zones, thus permitting its use in these zones as well.

[0128] The isolation amplifiers 33 amplify the data from both diaphragm pumps 100, convert them into 0V to 24V signals, and transmit them in telegram format as message 39 in the form of a protocol P to the module box 19. These messages are processed in the processor 18 located there and forwarded via outputs attached to 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 error status for both pumps is transmitted as a 0V to 24V level to a user PLC. The pump stroke, pump status, and other data are transmitted to the user PLC via a MODBUS-RTU interface.

[0129] 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 from external locations, for example, a control system installed at the user's site. Such a control system can also be referred to as a customer cockpit 46.

[0130] The described embodiments are examples of a wide range of possible applications in which the diaphragm pumps 100; 200; 300 with intelligent stroke counter 40 and module box 19 can be used. What all versions have in common is that the running behavior of the diaphragm pumps is observed during operation, and conclusions about the condition of the pump, which can also be referred to as its "health status," are derived from this running behavior.

[0131] As a result, the invention enables early detection of impending problems and, based thereon, predictive maintenance of the diaphragm pumps 100; 200; 300 as a whole. List of reference symbols

[0132] 10Housing 11, 11'Diaphragm 12, 12'Product chamber 13, 13'Pressure chamber 14Switching valve 15Data cable 16Deviation 16-0Deviation 0 (at synchronicity) 16-actual instantaneous deviation 16kcritical deviation 16maxmaximum permissible deviation 17Data processing device 18Processor 19Module box 20Sensor 21Housing 22Data memory 23First interface 24Second interface 25Center line (of 100) 26Reversal point 27Home position 28Value 1 29Value 2 (in home position) 30Value 3 31Home position (of 11,11') 32ATEX zone 33Isolating switching amplifier 34NAMUR telegram (pump strokes and error status) 35Message (pump strokes and error status as 0V to 24V level) 36Message (pump strokes as 0V to 24V pulses) 37Message (error status as 0V to 24V level) 38User PLC 39Message (pump strokes and error status as 0V to 24V signal) 40iHZ (intelligent stroke counter) 41Message (2 x pump strokes as 0V to 24V pulses) 42Message (2 x error status as 0V to 24V level) 43MODBUS RTU 44UART protocol 45Local server 46Customer cockpit (Intranet) 47Housing cover (from 100; 200; 300) 48Pump body (from 100; 200; 300) 49Piston rod 50Check valve 51Holder , 100 diaphragm pump 200 diaphragm pump 300 diaphragm pump FField strength f1Field strength change 1 f2Field strength change 2 F1First color F2Second color F3Third color I - IIntersection M1First measured value M2Second measured value PProtocol SDistance s1Distance 1 s2Distance 2 TTime t1Time period 1 t2Time period 2 VRatio value VmRatio mean value

Claims

1. A method for detecting fault conditions of 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 one another, wherein the volumes of the product chamber (12, 12') and the pressure chamber (13, 13') can be changed complementarily to one another by a movement of the diaphragm (11, 11'), - a preferably electrical switching valve (14) which is provided for switching 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 pressurized with a medium, to switch to a second operating mode in which the pressure chamber (13, 13') is depressurized, or back, and - a sensor (20) for measuring a measuring signal, characterized in that- on the basis of 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 data processing device (17), - the first measured value (M1) is related to the second measured value (M2) and a ratio value (V) is formed from the ratio of the two measured values (M1, M2) to one another, - 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 of a diaphragm pump (100; 200; 300) according to claim 1, characterized in thatExceeding the permissible deviation value (16max) will result in a deviation message.

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

4. Method for detecting fault conditions of a diaphragm pump (100; 200; 300) according to one of claims 1 to 3, characterized in thatthe 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 traveled between the switching from the first operating mode to the second operating mode and the second measured value (M2) indicates a distance traveled between the switching from the second operating mode to the first operating mode.

5. Method for detecting fault conditions of a diaphragm pump (100; 200; 300) according to one of claims 1 to 4, characterized 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 of a diaphragm pump (100; 200; 300) according to one of claims 1 to 5, characterized in thatthe 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 error conditions.

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

8. Method for detecting fault conditions of a diaphragm pump (100; 200; 300) according to one of claims 1 to 7, characterized in that Before the measured values (M1, M2) are evaluated, calibration is carried out to compensate for production-related deviations.

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

10. Method for detecting fault conditions of a diaphragm pump (100; 200; 300) according to one of claims 1 to 9, characterized in that the recording of the stroke times and / or stroke distances is carried out via - the movement profile of the membranes (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 conveying medium and / or - the evaluation of the pressure curve of the compressed air supply.

11. Method for detecting fault conditions of a diaphragm pump (100; 200; 300) according to one of claims 1 to 10, characterized in that the transmitted data are 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 of a diaphragm pump (100; 200; 300) according to one of claims 1 to 11, characterized in that in the case of two functionally coupled diaphragm pumps (100; 200; 300), the measured values (M1, M2) are recorded as stroke times and / or distances per diaphragm (11, 11') for each diaphragm pump (100; 200; 300).

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

14. Module box (19), comprising a device for data processing (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. A 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 one another, wherein the volumes of the product chamber (12, 12') and the pressure chamber (13, 13') can be changed complementarily to one another by a movement of the diaphragm (11, 11'), - a preferably electrical switching valve (14) which is provided for switching 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 pressurized with a medium, to a second operating mode, in which the pressure chamber (13, 13') is depressurized, or back, characterized in that the diaphragm pump (100; 200; 300) further comprises a data processing device (17) according to claim 13 or a module box (19) according to claim 14.

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