DE20005744U1 - Valve monitoring device - Google Patents

Description

Description

The invention relates to a device for monitoring the position of at least one valve, for example in a production plant or in a measuring system, according to the preamble of claim 1.

Process engineering processes in industrial plants are usually controlled by process computer systems. For control purposes, it is necessary to convert physical process data into electrical signals and then feed these to the process computer in the form of changing measured values. Such process data, such as pressure values, differential pressure values, temperature, flow, container level, speed data, etc., are recorded and converted by a wide variety of measuring systems, with analog and binary measurement data acquisition being used.

Figures 8A, 8B and 8C show examples of such pressure and flow measuring points. The pressure, differential pressure, level or flow measuring transducer, designated DU, which converts the physical measured values into electrical signals, consists of mechanical components, such as measuring orifices and diaphragms, and the associated electronic circuit part. The measuring transducer, i.e. the part that contains the measuring diaphragm, can be physically decoupled from the medium to be measured for testing purposes. This is done by regularly manually operating valves V1 and V2 on the respective valve block VB integrated into the measuring system.

The illustrations in Figures 8A to 8C show that such valve blocks are designed differently and that pressure, flow or level-related measuring transducers can be positioned differently with respect to the valve block VB depending on the system.

Before testing such a measuring system, the measuring transducer must be taken out of operation. This is done by closing the corresponding valves Vl and V2 on the valve block VB. To relieve the measuring diaphragm, i.e. to eliminate any residual pressure,

[File:ANM\IC0301 B1.doc] Description, 28*»!00 Device for valve monitoring ICOPS - Industrial & Cyber Operation Services GmbH

In addition, a compensating valve AV is provided, which is also integrated in the valve block VB and is opened to relieve the pressure on the measuring diaphragm. In this operating state, the measuring transducer goes into the so-called 0% state.

After testing according to regulations, the system condition must be

This is done in the last step by returning the associated valves to the operating position. It is particularly important that the AV balancing valve is reliably closed. If this valve is only slightly open, the measurement and thus the measurement result will be falsified, since even a small flow of the medium to be monitored via the AV balancing valve influences the measuring cell, which is particularly the case with flow, level and differential pressure measurements.

Figures 9 and 10 show sections of circuit arrangements in measuring circuit systems, with valve blocks VB1, VB2 and VB3 indicated with dotted lines. The valve block VBI corresponds, for example, to the valve block VB in Figures 8A to 8C. The reference number 1 designates the first measuring line and the reference number 2 the second measuring line for the medium. The reference number 4 designates the shut-off valve V1 and the reference number 6 the shut-off valve V2 in the illustration according to Figures 8A to 8C. The reference number 5 designates the compensating valve AV and the reference numbers 4a and 6a the supply lines to the measuring cell.

Additional valves 7 and 8 are integrated in the valve block VB2, each of which functions as a blow-out or drain valve. The corresponding blow-out or drain lines are designated with the reference symbols Ta and 2a.

The circuit diagram according to Figure 10 shows a further variant of a measuring system in which a cyclical decoupling of a test connection PA on the one hand and a pressure connection 1 on the other hand from a supply line 4a to the measuring cell can take place with the aid of valves 9a and 9b. For example, to check the measuring device, valve 9b is closed and valve 9a is opened towards the test connection. In this position, the measuring device can be checked for measurement tolerance and

[File:ANM\IC0301 B1.doc] Description, 28?(fe*db Device for valve monitoring ICOPS - Industrial & Cyber Operation Services GmbH

Operational reliability must be checked. For the actual measuring process, i.e. for monitoring the pressure in line 1, valve 9a is closed, while valve 9b is opened, remaining constantly open for the measuring process.

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As already mentioned above, such

Systems, especially in such measuring systems, it is important that the associated valves actually take up the intended position in the chronological order of their operation according to the operating position. Otherwise, the measurement and thus the measurement result

more or less distorted.

One difficulty, however, is that certain valves are not designed by the manufacturer to display the exact valve position at any given time. In other words, the valves, such as those shown in Figures 8A to 8C, do not allow the actual position of the valve cone seat inside the valve spindle body to be visually monitored when opening and closing.

In addition, due to technical regulations (TÜV specifications), no invasive changes may be made to the valve blocks and valve inserts. Any change, e.g. any conversion or any change to the valve specifications, would mean that the system would have to be re-certified, which does not make economic sense.

The invention is therefore based on the object of creating a device for monitoring the position of at least one valve, for example in a production plant or in a measuring system according to the preamble of claim 1, which is able to provide meaningful information about the operational readiness on the one hand and the position of the valve on the other hand without invasive interventions in the valve in question and thus to provide safety support to the system parts with predominantly pressure, differential pressure, level and flow measuring points.

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[File:ANM\IC0301 B1.doc] Description, 28<&iacgr;&&agr;&thgr;* Device for valve monitoring ICOPS - Industrial & Cyber Operation Services GmbH

This object is solved by the features of claim 1.

According to the invention, a control module is detachably coupled to the valve housing, with which a movement component proportional to the working movement of the valve body is tapped and converted into a corresponding, preferably electrical signal, which is fed to a display via an evaluation mechanism. According to the invention, the valve positions in the system's operating state on the one hand and service positions on measured value recording systems in industrial plants on the other hand can be visually checked. The device according to the invention can be used to prevent measuring systems installed in the physical system and their components from being impaired in their operating state due to incorrect valve positions, for example due to incorrect handling when restarting after testing the measuring circuit. The invention therefore creates the prerequisite for the correct physical parameters, i.e. the operating states of the valves which are required for the production of perfect measuring signals, to be able to be checked for their target states at any time. The invention is not limited to the monitoring of valves in measuring systems. It is of course also possible to retrofit any valves in process plants with the device according to the invention in order to provide an accurate statement about the valve positions.

Advantageous further training is the subject of the dependent claims.

With the further development of claim 2, it is possible to translate the detected movement component in a suitable manner so that the resolution of the evaluation facial expressions can be optimally adjusted.

The development of claim 3 offers a further possibility of increasing the accuracy of the position monitoring, for example by converting the signal in such a way that it works with a higher resolution in the range of the limit values of the valve positions, i.e. the open position and the closed position.

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Preferably, a visual display of the valve positions is provided so that the components of the measuring systems can be checked particularly quickly for their operating position.

For many measuring systems, it is sufficient to monitor the limit positions of the valves used. This is done, for example, by developing claim 5.

In this case, it is advantageous to work with a pair of LEDs that represent the two limit positions of the valve (open and closed), for example, in the colors green and red, respectively, and intermediate positions in the mixed color orange.

The device according to the invention can be coupled to a process control system using simple means, which makes it possible to centrally monitor and test valves or measuring systems for function and/or position even in very complex systems.

A particularly simple manner of coupling the control module is the subject of claim 9. The geometric adaptation of the clamping device to the valve housing, at least in some areas, ensures a simple and defined positional fixation.

The control module can basically detect any type of outward movement component, for example a linear movement or a swivel movement. However, if a rotary movement proportional to the movement of the valve body is detected, the development of claim 11 is advantageous. However, it should be emphasized that the invention is not limited to the use of a transmitter gear. For example, it is possible to use another incremental encoder instead of a transmitter gear that works together with digital position sensors.

If the valves to be monitored are arranged adjacent to each other, it is advantageous to design the control module in such a way that it has a

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[File:ANM\IC0301 B1 .doc] Description, 28«&Igr;-0&bgr;* Device for valve monitoring ICOPS - Industrial & Cyber Operation Services GmbH

corresponding number of intermediate gears are combined to form a unit, which is the subject of claim 12.

With the further development of claim 15, it is possible to optimally adjust the functional engagement between the intermediate gear and the transmitter gear and at the same time to ensure a secure fixation of the control module on the valve block.

If the evaluation mechanism according to claim 16 is supported by a microprocessor or a microcontroller or a microcomputer, favorable conditions are created for remote monitoring on the one hand and for the connection to a process control system to be made much simpler and clearer. In this way, it is possible to query the status of the valves to be monitored using special software routines. For example, after an overhaul of the system or after testing and recommissioning of the tested measuring systems, an appropriately designed process control system can access the measuring system via a network to check the current valve positions in order to then process these values accordingly.

The monitoring device according to the invention can be combined in a particularly advantageous manner to form a monitoring system according to claim 19. This system makes it possible to integrate the control modules for the visual and/or central computer-supported detection of the valve positions of valve systems of any kind, which are directly connected to an existing measuring arrangement system. In this way, the process control system is given the opportunity to automatically carry out a check of the valve positions via the control modules according to the invention. Any human error during repeated commissioning after a test can be detected in good time in this way and effectively prevented.

Several embodiments of the invention are explained in more detail below using schematic drawings. They show:

[File:ANM\IC0301 B1.doc] Description, 28.03.00 Device for valve monitoring ICOPS - Industrial & Cyber Operation Services GmbH

Fig. 1 is a schematic side view of a control module mounted on the valve block;

Fig. 2 is a perspective schematic view of the control module shown in Fig. 1;

Fig. 3 shows the view "III" in Fig. 1;

Fig. 4 shows a schematic enlarged view of the detail “IV” in Fig. 1;

Fig. 5A and 5B show a circuit diagram for the evaluation, control and display functions of the control unit;

Fig. 6 shows a circuit diagram for the evaluation, control and display mimicry according to a further variant;

Fig. 7 is a block diagram showing the integration of a modified embodiment of the control module for coupling to a process control system;

Fig. 8A to 8C Examples of views of conventional

Arrangements for pressure and flow transducers; and

Fig. 9 and 10 Installation examples of valve blocks,

control modules according to the invention can be used.

To whom the

In Fig. 1, reference numeral 10 designates a valve housing to which a control module designated with reference numeral 13 is coupled. The control module is shown in perspective in Fig. 2 and in front view in Fig. 3. The drive shaft designated with reference numeral 21 of the valve body accommodated in the interior of the valve block 10 carries a transmitter gear 12 in a rotationally fixed manner, which is in meshing engagement with an indication gear 22 of the control module 13.

[File:ANMMC0301 B1.doc] Description, 28.03.00 Device for valve monitoring ICOPS - Industrial & Cyber Operation Services GmbH

The control module 13 is mounted in a fixed position on the valve block 10 in such a way that the meshing between the gears 12 and 22 can be precisely adjusted. For this purpose, the control module 13 has a mounting plate 15 which can be fixed in a precise position and in a way that prevents movement and rotation on the valve block 10 by means of a clamping jaw device 14. Fig. 2 shows in detail that the clamping jaws 14 are designed in the form of a bridge, with the inner contour 14A preferably adapted to the outer diameter of the corresponding part of the valve housing. The clamping bracket 14 has two through holes 14B - the axes 14C of which are aligned with holes 15C in the mounting plate 15. Fastening screws 24 can be inserted through the holes 14B and can be brought into engagement with a thread in a fastening cross member 26 on the underside of the mounting plate 15. By tightening the fastening screws 24, the mounting plate 15 is pulled against the valve housing 10, whereby support is provided via support bodies 17, 18 on both sides of the clamping device 14, 26, which can be seen in detail in Fig. 1.

It can be seen from the illustration in Fig. 1 that the square 21 of the valve is still accessible from the outside, so that the valve in question can still be operated manually.

The reference number 16 designates the front display, which is shown in detail in Figures 2 and 3. The reference number 19 designates the side panel of the control module housing.

The supports 17 and/or 18 are preferably height-adjustable so that the meshing between the gears 12 and 22 can be optimized.
30

It can be seen from Figures 2 and 3 that three indication gears 22 are integrated in the control module shown, so that the control module 13 enables the monitoring of the valve positions of three valves combined in the valve block 10.
35

The rotary movement of the indication gears 22, which are rotatably mounted on a traverse plate 28, is transmitted via a gear 30, which is

[File:ANM\IC0301 B1.doc] Description, 28.03.00 ***" "

Valve monitoring device

ICOPS - Industrial & Cyber Operation Services GmbH

Fig. 4 is shown schematically as a single-stage gear, but can actually be designed as a multi-ratio gear, is transmitted to a potentiometer 32. In this way, the path length (rotational movement) OMEGA is converted into a signal to be processed electrically, whereby a multi-turn precision potentiometer is advantageously used for the theoretical rotation range of 3600°.

The gear unit 30, 22 is selected such that the maximum axial displacement of the valve cone (in the opening and closing mechanism) corresponds to an effectively usable angle of rotation of the potentiometer 32 of approximately 3500°.

Figures 5A and 5B show a circuit diagram for the control module 13, in which the essential functional units are highlighted with dot-dash lines. The potentiometers 32 are fed by a constant voltage source LT 1029, as are the trimming potentiometers 34 required for setting the limit value positions.

The center tap of the potentiometer 32 and thus the voltage drop changing depending on the valve position is evaluated electronically, whereby the evaluation circuit DAS is preferably implemented on a circuit board.

In order to be able to record the minimum limit value and the specified maximum limit value, the voltage from the potentiometer 32 is fed to a comparative circuit arrangement. The switching value adjustment is carried out via the trimming potentiometer 34. The output signal from comparators is processed by a digital circuit, which is designated in Fig. 5A with the reference symbol DAS, according to the required parameters: valve open, valve closed, valve in intermediate position, and displayed via LEDs 36.

The light-emitting diodes 36, for example, are three-coloured (with the primary colours red, green or orange as a mixed colour) and, in the correct operating position, light up either green or red according to the process specifications. In the intermediate position of the valve, they flash orange.

[File:ANM\IC0301 B1.doc] Description, 28.03.00 Device for valve monitoring ICOPS - Industrial & Cyber Operation Services GmbH

In Fig. 5B, MAS designates the sequence control for the measurement. Reference numeral 40 designates an infrared receiver and reference numeral 42 a decoder. Reference numeral 44 designates a connector for supplying the circuit board, which is connected to the battery via the PWR-I connection. Finally, in Fig. 5A, "GEA" designates the limit value detection and evaluation circuit of the circuit.

The measurement process is started by pressing the "TEST" button. The "SERVICE" button has the same function as the "TEST" button, but with a longer measurement time.

The measurement cycle started in this way is followed by a test of the LEDs lasting approximately 2.5 seconds. This is indicated by the mixed color of both LED colors flashing.

The measuring cycle then follows, which takes another 4 to 5

seconds is completed.
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&mdash; The display duration is preferably chosen so that it lasts for a

Recognizing the correct operating state is sufficient.

The detection of the valve positions is converted by the precision potentiometer 32 into an electrical voltage that changes linearly proportional to the position of the valves. This signal is fed to the circuit consisting of two comparators 35 (per channel). The limit values min or max to be set, which correspond to the valve position CLOSED or OPEN, are set via the trim potentiometer 34. The output of the respective comparator circuit takes on the supply voltage Ub(PWRII) if the set limit value is exceeded (max) or undershot.

(min) is.

For the duration of the LED test, the output signal of the comparators is masked by an integrated circuit IC4. The

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[File:ANM\IC0301 B1.doc] Description, 28.03.00 Device for valve monitoring ICOPS - Industrial & Cyber Operation Services GmbH

The output of the individual comparators is fed to the corresponding LEDs via a logic circuit and displayed.

An infrared remote control is provided to simplify the control activities on several devices. To avoid interference, the signal is coded in the IR transmitter. The decoder 42 decodes the incoming data and then activates an output on the decoder after an internal comparison. This output provides a pulse to start the measurement.

The decoder's start signal is functionally equivalent to the "TEST" button.

The power supply is preferably provided by an independent power source such as a 7.2V lithium/tyionyl chloride cell (battery). The entire electronics are preferably powered by an independent operating voltage of 3.6V or less.

A variant of the device according to the invention consists - as shown in Fig. 6 - in implementing all logic functions in an integrated module, i.e. combining a large number of the components shown in the circuit diagram according to Fig. 5 in a PLD (Programmable Logic Device). In Fig. 6, the components combined on the PLD are enclosed in a dashed line. Excluded from this combination on the PLD is the external display EA, which is still implemented in the front panel of the control module.

After any analog processing, the voltages of the potentiometer are fed to an internal analog-digital converter of the microcomputer or microcontroller. The digital implementation of the potentiometer can also be provided when using a microcomputer or a specific integrated circuit solution. The measured signals can then be further processed using software.

If a microcomputer or microcontroller is used, the signal evaluation system can be connected to a process control system particularly easily, which is usually done via an interface. A BUS system is advantageously used here. Such a BUS

[File:ANM\IC0301 B1 .doc] Description, 28.03.00 Device for valve monitoring ICOPS - Industrial & Cyber Operation Services GmbH

The system could be designed as a field bus, professional bus or the like. In other words, the invention makes it possible to connect the valves to a higher-level central computer via a bus system using suitable measures.

Such a concept is shown in Fig. 7:

The individual potentiometers 32 are connected, if necessary, via an analog signal processing unit to a microcomputer, microcontroller or microprocessor 50, which is coupled to a BUS 54 of a process control system via a hardware interface 52. A digital display LCD can be assigned to the control module with processor 50. The processor can be programmable via a serial interface 56.

The measures according to the invention thus make it possible to check all components efficiently, quickly and preferably visually in order to achieve an optimal process flow with a low susceptibility to failure. The invention also makes it possible to check over the course of the valves' service life whether the valves actually assume the end positions aimed for during manual adjustment. For example, it could happen that the valve seat can no longer be fully brought into the end position after prolonged use of the valve due to deposits in the flow medium, even if the manually operated hand lever is brought into the corresponding position with a predetermined force. However, the system according to the invention reliably detects a change in the displacement movement using the measured movement component and displays this visually and thus unmistakably to the operator. If the system according to the invention indicates such misalignments of the valve body, it is time to inspect the valve and, if necessary, replace or rework the valve seat and/or valve body.

Of course, deviations from the embodiments shown are possible without departing from the basic idea of the invention. The valves to be monitored are not limited to the valves of

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[File:ANM\IC0301 B1.doc] Description, 28.03.00 Device for valve monitoring ICOPS - Industrial & Cyber Operation Services GmbH

measuring systems. It is also not necessary to mechanically measure the movement component of the valve body that is directed outwards. It is equally possible to transmit the signal to the control module on the basis of another physical effect, for example inductively 5 or in another contact-free manner. Of course, digital transmission systems can also be used in this area.

The field of application of the invention is therefore wherever the valve specifications - for example at measuring points - do not allow a clear assignment or an insufficient informative value of the valve position.

Claims (19)

1. Device for monitoring the position of at least one valve, for example in a production plant or in a measuring system, in which a working movement of a valve body of the valve to be monitored is guided outwards from a valve housing with a proportional movement component, characterized by a control module ( 13 ) which can be detachably coupled to the valve housing ( 10 ), preferably operating electromechanically, with which the movement component (OMEGA) can be tapped and converted into a corresponding, preferably electrical signal, which is fed to an evaluation device with display ( 36 ) preferably designed as an evaluation circuit (DAS). 2. Device according to claim 1, characterized in that an intermediate gear ( 22 , 30 ) is provided for picking up the movement component, which is integrated in a fixed position in the control module ( 13 ). 3. Device according to claim 1 or 2, characterized in that the movement component can be converted by means of the intermediate gear according to a predetermined rule into an input variable of a signal converter, such as a potentiometer ( 32 ) of the evaluation circuit (DAS). 4. Device according to one of claims 1 to 3, characterized in that the evaluation system (DAS) has a display signal generating device for each valve to be monitored (V1, V2, V3), with which the position of the valve can be visually displayed. 5. Device according to claim 4, characterized in that the evaluation mechanism contains a pair of comparators () with which a separate limit value display signal can be generated when a minimum and a maximum value of an output signal of the signal converter, such as the voltage drop across the potentiometer, is reached. 6. Device according to claim 4 or 5, characterized in that the evaluation system has a pair of light-emitting diodes ( 36 ) for each valve to be monitored, with which the two limit value display signals and the display signals corresponding to the intermediate positions can be displayed in different colors (RED, GREEN, ORANGE). 7. Device according to one of claims 1 to 6, characterized in that the evaluation circuit can be coupled to a process control system via an interface ( 52 ). 8. Device according to one of claims 1 to 7, characterized in that the evaluation circuit is constructed in such a way that it subjects the display ( 36 ) to a TEST routine before the control process. 9. Device according to one of claims 1 to 8, characterized in that the control module ( 13 ) can be coupled to the valve housing ( 10) by means of a detachable clamping device which is geometrically adapted at least in regions to the valve housing (10 ) , such as a clamp arrangement ( 14 , 26 ). 10. Device according to one of claims 1 to 9, characterized in that the control module detects a rotary movement (OMEGA) proportional to the movement of the valve body. 11. Device according to claim 10, characterized in that the rotary movement is picked up by means of a transmitter gear ( 12 ) which can be placed on a drive spindle ( 21 ) of the valve body in a rotationally fixed manner and is accessible from the outside. 12. Device according to one of claims 2 to 11, characterized in that in the control module ( 13 ) for monitoring several valves a corresponding number of intermediate gears ( 22 , 30 ) are combined to form a unit. 13. Device according to one of claims 1 to 12, characterized in that the control module ( 13 ) has a mounting plate ( 15 ) which can be aligned parallel to the at least one valve axis and which carries a housing ( 16 , 19 ) for receiving the evaluation device on the side facing away from the valve housing. 14. Device according to claim 13, characterized in that the mounting plate ( 15 ) laterally covers several valve axes and can be clamped to the valve housing ( 10 ) by means of at least two clamping devices, such as clamps ( 14 ), which are geometrically adapted at least in regions to the valve housing ( 10 ). 15. Device according to claim 13 or 14, characterized in that the alignment of the mounting plate ( 15 ) and thus the functional engagement position of the intermediate gear ( 22 ) is adjustable by means of supports ( 17 , 18 ) which are preferably located on both sides of the clamping device ( 14 , 24 , 26 ). 16. Device according to one of claims 1 to 15, characterized by an evaluation mechanism for the position of the at least one valve supported by a microprocessor ( 50 ), a microcontroller or a microcomputer, wherein the processors used in each case are preferably programmable. 17. Device according to one of claims 1 to 15, characterized in that the logistics functions are combined in an integrated module (PLD). 18. Device according to claim 16 or 17, characterized by a digital display (LCD) for the at least one valve position. 19. System for monitoring the position of a plurality of valves, such as working valves or valves assigned to a measuring system, in industrially operated plants with a process control system, in particular using several devices according to one of claims 1 to 18, wherein preferably retrofittable control modules ( 13 ) for the positions of the valves each have a microprocessor ( 50 ), a microcontroller or a microcomputer which is connected to the BUS of the process control system ( 54 ) for the bidirectional transmission of the control and/or evaluation signals of the control module either directly or via a BUS system.