Measuring system, slide with such a measuring system and method for measuring the position of a slide

Abstract

Measuring system for industrial valves, in particular for plants in the chemical, petrochemical, iron or steel production, glass production or energy and environmental technology sectors, for measuring the position of a linearly movable component (10) of the valve, wherein a measuring device (11) for transmitting and receiving radar signals is connected to a probe (12) for guiding the radar signals, wherein a reflection element (13) is guided in the probe (12) and can be coupled to the movable component (10) in such a way that a position of the component (10) corresponds to a position of the reflection element (13) in the probe (12), wherein the probe (12) has an outer tube (14) in which the reflection element (13) is guided. characterized in that the probe (12) has a guide element (16) for the reflection element (13), in particular an inner tube, which is arranged in the outer tube (14).

Description

The invention relates to a measuring system for industrial fittings, in particular for installations in the fields of chemistry, petrochemical, iron or steel production, glass production or energy and environmental technology, for measuring the position of a movable component of the fitting. Measuring systems according to the preamble of claim 1 are known from practice in the form of magnetostrictive measuring systems which are used for the position measurement of moving components in plant construction. The invention further relates to a slide with such a measuring system and to a method for measuring the position of a slide.A position sensor comprising two rod elements with a magnetically coupled bridging contact slide supported by a ceramic guide is known from U.S. Pat. No. 9,250,277 B1.In industrial fittings, it is frequently necessary for the position of linearly moved components, in particular slides, to be known. In this case, it is measured whether the slide is completely closed or completely open or is arranged in an intermediate position. The magnetostrictive measuring systems used hitherto are prone to vibrations and can lead to inaccurate results.The invention is based on the object of specifying a measurement system for industrial fittings which is as robust and simple as possible. The invention is further based on the object of specifying a slide with such a measurement system and a method for measuring the position of a slide.According to the invention, this object is achieved with regard to the measuring system for industrial fittings by the subject matter of claim 1. With regard to the slide, the object is achieved by the subject matter of claim 6 and with regard to the method by the subject matter of claim 8.Specifically, the object is achieved by a measuring system for industrial fittings which are suitable in particular for installations in the fields of chemistry, petrochemicals, iron or steel production, glass production or energy and environmental technology, wherein the measuring system is adapted for measuring the position of a linearly movable component of the fitting. The measurement system has a measurement device for transmitting and receiving radar signals, which is connected to a probe for guiding the radar signals. A reflection element is guided in the probe and can be coupled to the movable component of the fitting in such a way that a position of the component corresponds to a position of the reflection element in the probe.In other words, a change in the position of the component is transmitted to the position of the reflection element in the probe, so that the position of the reflection element in the probe changes accordingly. The position of the reflection element in the probe can be determined by the radar signal which is reflected at the reflection element. This makes it possible to draw conclusions about the respective position of the component. In this case, the distance between the measuring device, which transmits and receives the radar signals, and the reflection element is changed. The propagation time of the reflected radar signals is detected and evaluated. The path change changes the transit time, whereby it is possible to infer the position of the reflection element in the probe and thus the position of the component. The measuring device or the measuring system function according to the principle of time-domain reflectometry, which is also referred to as guided radar or time domain reflectometry, TDR for short. This technology, which is known per se, has the advantage that it is insensitive to vibrations and enables a simple measuring construction.The measuring system is suitable for measuring linear movements on industrial fittings.Time-domain reflectometry is known from electrical technology for measuring cable lengths or fault points in electrical lines. Time-domain reflectometry is also used in fill level measurement transmitters, i.e. for measuring the fill levels of liquid or bulk material containers. Other requirements such as temperature, density or composition of the materials present in connection with the measurement play a role. The known measuring systems cannot be used easily in installation construction.Surprisingly, it has been shown that modified measuring systems from fill level measuring device technology can be used to measure the position of movable components in installation construction and entail advantages in the mechanical loads occurring in installation construction, such as vibrations. Specifically, within the scope of the invention, the probe is equipped with the reflection element guided therein, which can be coupled to the movable component in order to detect the position of the movable component. The measuring device for transmitting and receiving the radar signals can be adopted from the fill level measuring device technology.Preferred embodiments of the invention are set forth in the dependent claims.Thus, the reflection element can be adapted to generate a contact, in particular an electrical contact. The contact is permanent, i.e. continuous, during the measurement. This achieves a strong, in particular complete, reflection of the radar signals. The reflective element changes its position in the probe together with the movable component during operation. The contact region which is generated by the reflection element moves along in the probe, so that the change in the distance between the reflection element and the measuring device for transmitting and receiving the radar signals is detected.According to the invention, the probe has an outer tube in which the reflection element is guided. This embodiment of the probe is simple and robust.The outer tube can have a lateral opening, in particular a longitudinal slot, through which the reflection element can be coupled to the movable component. As a result, linear movements of the component to be measured can be transmitted and easily detected.According to the invention, the probe has a guide element for the reflection element, in particular an inner tube, which is arranged in the outer tube. The reflecting member may move along the guide member.Preferably, the reflecting member electrically connects the guide member and the outer tube to generate the contact. The guide element has the dual function of guiding the reflection element in the outer tube on the one hand and establishing the electrical contact by the reflection element on the other hand. Other embodiments in which a functional separation between the guidance and the contact generation takes place are possible. The present embodiment has the advantage that it is of simple construction and very robust, so that the position of the component can be detected reliably even under difficult conditions.In a further preferred embodiment, the reflection element has an outer diameter which corresponds to the inner diameter of the outer tube. The reflection element has an inner diameter which corresponds to the outer diameter of the guide element. The reflection element is thus arranged flush in the outer tube and also lies against the inner tube, whereby on the one hand a secure guidance and on the other hand the desired electrical contact is made possible.The slide valve according to the invention for industrial plants, in particular in the fields of chemistry, petrochemical, iron or steel production, glass production or energy and environmental technology, has a measurement system with the features of claim 1. In other words, the slide is equipped with such a measurement system. In the slide, the movable component is designed as a slide plate which is coupled to the reflection element of the measurement system in such a way that a movement of the slide plate can be transmitted to the reflection element. The movement can be transmitted directly or indirectly.In a preferred embodiment of the slide, the slide plate has a drive rod which can be designed, for example, as a drive spindle or drive cylinder. The drive rod is connected to the reflection element. When the slide plate is actuated by the drive rod, the latter inevitably changes its position together with the slide plate, so that the position of the slide plate can be deduced by measuring the position of the drive rod. In the case of the drive spindle, the change in position is synonymous with the number of revolutions of the spindle nut.In the method according to the invention for measuring the position of a movable component of an industrial fitting, in particular for installations in the fields of chemistry, petrochemical, iron or steel production, glass production or energy and environmental technology, the position of the component is measured according to the principle of time-domain reflectometry.The invention is explained in more detail on the basis of an exemplary embodiment with reference to the appended schematic drawings.These show FIG. 1 shows a schematic illustration of an exemplary embodiment according to the invention of a measurement system which is coupled to an industrial fitting; FIG. 2 shows a perspective view of the measuring system and the fitting according to FIG. 1, wherein the measuring system is shown in two different measuring positions FIG. 3 shows the lower of the two measurement positions according to FIG. 2 in detail, and FIG. 4 shows the upper of the two measurement positions according to FIG. 2 in detail.The measuring system shown in FIGS. 1 to 4 can be used, for example, for shut-off valves, in particular wedge-in-wedge shut-off valves, for double-plate guide tube valves or single-plate and double-plate control valves. Other application forms in plant construction or in fittings for industrial plants are possible. Generally, such valves can be used in ethylene steam crackers, dehydrogenation plants, fused catalytic cracking (FCC) plants or in delayed cokers.The measuring system is adapted and suitable for measuring the position of a movable component 10 of the fitting. The movable member 10 may be, for example, a slide plate (not shown) connected to a drive rod 17. In the example according to FIG. 1, the drive rod 17 is designed as a spindle which drives the slide plate. The measuring system has a measuring device 11 for transmitting and receiving radar signals. In the example according to FIG. 1, a measuring device 11 known per se is used, which will therefore not be described in more detail. The measuring device 11 is in any case suitable for detecting the position of a reflection element 13, described in more detail below, on the basis of the principle of time-domain reflectometry. For this purpose, the measuring device 11 is connected to a probe 12, which is designed as an outer tube 14 in the example according to FIG. 1. Other forms of probe 12 are possible. As shown in FIG. 1, the radar signals emitted by the measuring device are coupled into the probe 12 and guided along the probe 12. In the example according to FIG. 1, the reflection element 13 is designed as a cylindrical round element which is produced from an electrically conductive material, for example brass or another suitable material. The reflective element 13 may have another shape suitable for being guided in the probe.The reflection element 13 can be moved back and forth in the axial direction of the probe 12, as is illustrated by the double arrow at the height of the reflection element 13 running parallel to the longitudinal axis of the probe. The reflection element 13 can also be referred to as a sliding block or sliding element. A guide element 16 is arranged in the probe 12 or in the outer tube 14. The guide element 16 is designed as an inner tube in the example according to FIG. 1. It is also possible to use an inner rod or another guide element. In the example according to FIG. 1, the outer tube 14 and the guide element 16 are arranged coaxially. Another arrangement is possible. The reflection element 13 has a longitudinal bore in which the guide element 16 is arranged. As a result, the reflection element 13 can be displaced along the guide element 16 in the probe.For coupling the reflection element 13 to the drive rod 17, the probe 12, in particular the outer tube 14, has a lateral opening 15, which is designed as a longitudinal slot in the example according to FIG. 1. The longitudinal slot extends parallel to the longitudinal axis of the probe. As shown in Fig. 1, the probe is arranged parallel to the drive rod 17 with the longitudinal slot facing the drive rod 17.The mechanical connection between the reflecting element 13 and the drive rod 17 is effected by a pin 19 which is connected to a pointer 18. The pin 19 is laterally connected to the reflecting element 13 and extends through the longitudinal slot. The pointer 18 is connected to an adjusting ring 20 which is arranged on the drive rod 17. During a movement of the drive rod 17 in the longitudinal direction, the adjusting ring 20 is positively entrained. This is shown by the double arrow next to the adjusting ring 20 in FIG. 1. As can be further seen in FIG. 1, a compression spring is arranged between the pin 19 and the pointer 18.With this arrangement, the movement, in particular rotational movement of the spindle or generally of the drive rod 17, is transmitted to the reflection element 13. Thereby, the position of the slide plate is correlated with the position of the reflecting member 13 in the probe 12.It can further be seen in FIG. 1 that the reflection element 13 creates a contact between the outer tube 14 and the guide element 16, namely a permanent contact. The contact ensures that the radar signals emitted by the measuring device 11 are well reflected (total reflection). The region in which the contact is generated moves along with the probe during a movement of the reflection element 13, so that the change in the distance which results in this is detected for the radar signals.In Figs. 2 to 4 two different positions of the reflecting element 13 in the probe 12 are shown. The position shown in FIG. 3 is the lower position of the adjusting ring 20 that can be seen in FIG. 2 By longitudinal movement of the drive rod 17, the adjusting ring 20 and thus the reflection element 13 are moved into the upper position. As a result, the distance for the radar signals is shortened. The change in the transit time of the radar signals is detected, so that the position of the reflection element 13 and thus also the position of the slide plate can be measured.List of reference characters10 Component 11 Measuring device 12 Probe 13 Reflection element 14 Outer tube 15 Opening 16 Guide element 17 Drive rod 18 Pointer 19 Pin with spring 20 Adjusting ring

Claims

Measuring system for industrial fittings, in particular for installations in the fields of chemistry, petrochemical, iron or steel production, glass production or energy and environmental technology, for measuring the position of a linearly movable component (10) of the fitting, wherein a measuring device (11) for transmitting and receiving radar signals is connected to a probe (12) for guiding the radar signals, wherein a reflection element (13) is guided in the probe (12) and can be coupled to the movable component (10) in such a way that a position of the component (10) corresponds to a position of the reflection element (13) in the probe (12), wherein the probe (12) has an outer tube (14) in which the reflection element (13) is guided, characterized in that the probe (12) has a guide element (16) for the reflection element (13), in particular an inner tube, which is arranged in the outer tube (14).Measuring system according to claim 1, characterised in that the reflection element (13) is adapted to generate an electrical contact.Measuring system according to claim 1 or 2, characterised in that the outer tube (14) has a lateral opening (15), in particular a longitudinal slot, through which the reflection element (13) can be coupled to the movable component (10).Measuring system according to one of the preceding claims, characterized in that the reflection element (13) electrically connects the guide element (16) and the outer tube (14) in order to produce the contact.Measuring system according to claim 3 or 4, characterised in that the reflection element (13) has an outer diameter which corresponds to the inner diameter of the outer tube (14) and an inner diameter which corresponds to the outer diameter of the guide element (16).Slide for industrial plants, in particular in the fields of chemistry, petrochemical, iron or steel production, glass production or energy and environmental engineering, having a measurement system according to Claim 1, in which the movable component (10) comprises a slide plate which is coupled to the reflection element (13) in such a way that a movement of the slide plate can be transmitted to the reflection element (13).Slide according to claim 6, characterised in that the slide plate has a drive rod (17), in particular a drive spindle or a drive cylinder, which is connected to the reflecting element (13).Method for measuring the position of a movable component (10) of an industrial fitting with a measuring system according to one of Claims 1 to 5, in particular for installations in the fields of chemistry, petrochemical, iron or steel production, glass production or energy and environmental technology, in which the position of the component (10) is measured according to the principle of time-domain reflectometry.

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