Ultrasonic flow measuring device and measuring assembly

Abstract

The invention relates to an ultrasonic flow measuring device for insertion into a first tube of a tube system at the point of a flange connection of the tube system, comprising a measuring tube having a longitudinal axis for conducting a flowable medium and a flange for at least indirectly fixing the measuring tube in the tube system, wherein the measuring tube has at least one first transducer recess for receiving a first ultrasonic transducer and at least one second transducer recess for receiving a second ultrasonic transducer, the first ultrasonic transducer being arranged in the first transducer recess and being configured as an ultrasonic transmitter and / or an ultrasonic receiver, a second ultrasonic transducer is arranged in the second transducer recess, which is designed as an ultrasonic transmitter and / or an ultrasonic receiver, and wherein the measuring tube is designed as a thin-walled tube such that the wall thickness of the measuring tube is smaller than the extent of the transducer recess perpendicular to the longitudinal axis of the measuring tube, and wherein a second ultrasonic transducer is arranged in the second transducer recess, which second ultrasonic transducer is designed as an ultrasonic transmitter and / or an ultrasonic receiver. The transducer recess extends into the outer space of the measuring tube.

Description

Technical Field

[0001] The invention relates to an ultrasonic flow measuring device for insertion into a first pipe of a pipe system at the location of a flange connection of the pipe system, the device having a measuring tube with a longitudinal axis for guiding a flowable medium and having a flange for at least indirectly fixing the measuring tube in the pipe system, wherein the measuring tube has at least one first transducer recess for accommodating a first ultrasonic transducer and at least one second transducer recess for accommodating a second ultrasonic transducer, wherein a first ultrasonic transducer is arranged in the first transducer recess and is configured as an ultrasonic transmitter and / or an ultrasonic receiver, and wherein a second ultrasonic transducer is arranged in the second transducer recess and is configured as an ultrasonic transmitter and / or an ultrasonic receiver.

[0002] Furthermore, the invention relates to a measuring arrangement comprising an ultrasonic flow measuring device according to the invention and at least one first tube of a tube system, wherein a measuring tube is inserted into the first tube. Background Art

[0003] The ultrasonic flow measuring devices in question are known from the prior art and are used to determine the flow velocity and thus the flow rate of a flowable medium.

[0004] It is known from the prior art that ultrasonic flow measuring devices form part of a pipe system. This ultrasonic flow measuring device, also called an in-line flow measuring device, is usually inserted into the pipe system with the aid of two flanges and thus forms an independent part of the flow section of the medium. The measuring tube must therefore meet all sealing and strength requirements that the pipe system must also meet, in particular in view of the pressure and temperature strength. Since the ultrasonic transducer is inserted into the measuring tube, the transducer recess (Wandlertasche) provided for this purpose and the connection between the transducer recess and the ultrasonic transducer must also correspond to the strength requirements. Since the ultrasonic transducer protrudes from the measuring tube, it also requires at least mechanical shielding of the transducer in the form of a housing.

[0005] The situation is different in the case of the ultrasonic flow measuring device mentioned at the beginning, whose measuring tube is inserted into the tube of the tube system, that is, into the inner space of the tube. The ultrasonic flow measuring device therefore does not form an independent part of the flow section of the medium. Usually, at the assembly site of such an ultrasonic flow measuring device, a first tube with a first tube flange and a second tube with a second tube flange of the tube system are brought together, wherein the first tube flange and the second tube flange then realize a flange connection between the first tube and the second tube. In order to fix the measuring tube in the tube system, the measuring tube is inserted into the first tube or the second tube of the tube system, and the flange of the measuring tube is clamped between the first tube flange and the second tube flange. Often, the measuring tube can be surrounded by the medium as much as possible, so that the problem of pressure strength does not actually arise, and the sealing aspect is also not critical. Known ultrasonic flow measuring devices are often complex in construction and inflexible in their use. Summary of the invention

[0006] The invention is based on the object of developing the ultrasonic flow measuring device mentioned at the outset in such a way that it has a simple structure and is flexible in terms of application. In addition, the invention is based on the object of specifying a measuring arrangement comprising the ultrasonic flow measuring device according to the invention.

[0007] This object is firstly and essentially achieved in the ultrasonic flow measuring device according to the invention by the following features with the characterizing part of patent claim 1: the measuring tube is designed as a thin-walled tube, such that the wall thickness of the measuring tube is smaller than the extension of the transducer recess perpendicular to the longitudinal axis of the measuring tube. In addition, in the ultrasonic flow measuring device according to the invention, the transducer recess extends into the exterior space of the measuring tube.

[0008] According to the invention, it is known that the physical boundary conditions in the case of using a measuring tube in the first tube of a tube system (no pressure difference between the interior and the exterior of the measuring tube) enable very extensive structural measures. The thin-walled structural form of the measuring tube is not only advantageous, because this results in a significant reduction in the material required for production, it is also advantageous because the thin-walled measuring tube enables the use of generative manufacturing processes (e.g. 3D printing), which would not normally seem to make sense. In addition, the thin-walled measuring tube structure also leads to only a minimal reduction in the internal cross-section of the tube of the tube system into which the measuring tube is inserted.

[0009] Thin-walled in the sense of this patent application means that the wall thickness of the measuring tube is smaller than the extension of the transducer recess perpendicular to the longitudinal axis of the measuring tube. The absolute wall thickness depends on the diameter of the measuring tube and is selected accordingly by a person skilled in the art.

[0010] The embodiment according to the invention makes it possible to achieve a significant saving of material and thus reduce material costs.

[0011] According to the invention, the transducer recess is also designed in the measuring tube in such a way that it extends into the exterior of the measuring tube. This has the advantage that the transducer recess does not protrude into the interior of the measuring tube and therefore does not protrude into the flow cross section of the medium and thus does not cause disturbances in the flow of the medium through the transducer recess, which could, for example, lead to eddy current formation.

[0012] In order to insert the measuring tube into the tube of the tube system and to fix it on the tube, a flange is provided. The particularly preferred design of the ultrasonic flow measuring device according to the invention is distinguished by the fact that the measuring tube and the flange are constructed in one piece. One-piece means that the measuring tube and the flange are not composed of two workpieces connected to each other, but are made of a single workpiece or generated as a single workpiece. This has the advantage that the flange and the measuring tube do not have to be connected to each other. As a result, connecting devices can be omitted and the manufacturing process is also simplified. Because the measuring tube and the flange are in one piece, leaks in non-existent connection areas will also not occur. In addition, there is no need to coordinate different material properties with each other, as is the case when the flange and the measuring tube are made of different materials. Preferably, the transducer recess is also designed in one piece with the measuring tube.

[0013] In a particularly preferred variant, the measuring tube and the flange are made of plastic. In particular, the use of polyethylene terephthalate modified with ethylene glycol (PETG for short), acrylonitrile butadiene styrene (ABS for short), polypropylene (PP for short), acrylonitrile styrene acrylate (ASA for short) or nylon is provided. It is also advantageous to use polyetheretherketone (PEEK for short) as the material for producing the measuring tube and the flange.

[0014] The use of plastics also has the advantage that the measuring tube and the flange have a lower weight. When using non-conductive plastics, the advantage also results that the ultrasonic transducers arranged in the transducer recesses are automatically electrically insulated from one another. Furthermore, the sound propagation in plastics is generally poorer than in metals, so that the problem of parasitic ultrasound being transmitted through the measuring tube is reduced.

[0015] Particularly preferably, the measuring tube and the flange are produced by means of a generative manufacturing process, thereby further minimizing the manufacturing effort.

[0016] According to a further particularly preferred embodiment, the measuring tube and the measuring tube flange are produced from epoxy resin.

[0017] According to another design of the ultrasonic flow measuring device, the measuring tube and the flange are made of different materials. For example, the flange is made of a pressure-resistant material, such as epoxy resin, and the measuring tube is made of the above-mentioned plastic. According to this design, the measuring tube and the flange are subsequently connected to each other.

[0018] As described at the beginning, the measuring tube has at least two transducer recesses for accommodating two ultrasonic transducers. One of the ultrasonic transducers is at least configured as an ultrasonic transmitter, and the other ultrasonic transducer is at least configured as an ultrasonic receiver. Preferably, the two ultrasonic transducers are configured as ultrasonic transmitters and ultrasonic receivers. The two ultrasonic transducers jointly span the measuring path. In order to improve the measurement accuracy, it is meaningful to realize more than one measuring path, wherein the measuring path preferably extends through different areas of the measuring tube. In a preferred design of the ultrasonic flow measurement device according to the present invention, the measuring tube has at least one additional transducer recess for accommodating another ultrasonic transducer, a reflector or a closure body in order to realize another measuring path. Particularly preferably, the measuring tube has not only another transducer recess, but also a plurality of additional transducer recesses for accommodating another ultrasonic transducer, a reflector or a closure body in order to realize another measuring path. In the transducer recess, it is not necessary to arrange an ultrasonic transducer compulsorily, but a reflector can also be arranged in the transducer recess, at which the ultrasonic signal is reflected. The design according to the invention has the advantage, in addition to the possibility of realizing additional measuring paths, that the measuring tube can be prefabricated independently of its specific use. Depending on the measurement situation, the measuring tube can be equipped with an ultrasonic transducer or a reflector individually. In addition, according to the invention, it is provided that the closure can also be arranged in the transducer cavity. The closure then only forms part of the inner wall of the measuring tube and is inserted into the transducer cavity at a position where neither an ultrasonic transducer nor a reflector is provided. The described measuring tube can also be inserted very flexibly, because it can be configured completely differently with low cost. In this way, with the same number of ultrasonic transducers, completely different measuring paths can be realized, which can be implemented with completely different numbers of ultrasonic transducers but with very different degrees of complexity of the measuring path arrangement. If a corresponding number of transducer cavities are provided, all this is possible with a single type of prefabricated measuring tube.

[0019] In one variant, the longitudinal axis of the transducer recess is perpendicular to the longitudinal axis of the measuring tube. In an alternative variant, the longitudinal axis of the transducer recess is at an angle not equal to 90° on the longitudinal axis of the measuring tube. In another variant, the longitudinal axes of different transducer recesses are at different angles on the longitudinal axis of the measuring tube. For example, the angle between the longitudinal axis of the measuring tube and the longitudinal axis of at least a portion of the transducer recess is between 30° and 50°, in particular about 45°. The orientation of the transducer recess depends on the measurement path to be achieved. According to one design, the transducer recess has different angles at least partially relative to the longitudinal axis of the measuring tube, wherein preferably the corresponding two ultrasonic transducers that achieve a common measurement path have the same angle relative to the longitudinal axis of the measuring tube.

[0020] According to a design of the ultrasonic flow measurement device according to the present invention, at least one other sensor, in particular a pressure sensor and / or a temperature sensor, is arranged in one of the transducer recesses. This results in the following advantage, namely, the pressure sensor and / or the temperature sensor can be arranged in the ultrasonic flow measurement device close to the medium, in particular touching the medium, but without affecting the flow of the medium. Preferably, a plurality of pressure sensors and / or temperature sensors can be arranged in a plurality of transducer recesses, thereby, on the one hand, being able to measure temperature or pressure at a plurality of locations, and on the other hand, when one of the sensors fails, another sensor can be used to perform the measurement.

[0021] In order to be able to fix the ultrasonic transducer, the reflector, the sealing body and / or the sensor (such as a temperature sensor and / or a pressure sensor) in the transducer cavity, various embodiments are provided according to the invention.

[0022] In a first variant, the ultrasonic transducer, the reflector, the enclosure and / or the sensor and the transducer cavity have corresponding retaining projections and retaining recesses. The retaining projection engages in the retaining recess, thereby establishing a form-fitting connection. In a variant, the retaining projection is configured at an element that can be inserted into the transducer cavity and the retaining recess is configured in the transducer cavity. In another variant, the retaining projection is configured in the transducer cavity and the retaining recess is configured at the element to be inserted. It is also configured that the retaining recess and the retaining projection are configured at the element to be inserted and correspondingly in the transducer cavity. In other embodiments, the retaining projection is formed by an O-ring, which is retained in a surrounding recess in the transducer cavity, in the ultrasonic transducer, in the reflector, in the enclosure and / or in the sensor.

[0023] Particularly preferably, the holding projections and the holding recesses are configured to be interrupted in the peripheral direction of the transducer cavity and the element to be inserted. This allows accurate positioning of the element to be inserted.

[0024] In another variant, at least one elastic latching element or a plurality of elastic latching elements are provided at the element to be inserted and / or at the transducer recess. Additionally or alternatively, at least one elastic latching element or a plurality of elastic latching elements are provided. The elastic and / or resilient latching element is arranged at the element to be inserted and / or in the transducer recess. Correspondingly, a retaining projection is provided. When the element to be inserted is introduced into the transducer recess, the elastic and / or resilient element is then preloaded by the retaining projection so that after being guided through the retaining projection, it returns to an at least partially unloaded state and thereby forms a projection that retains the retaining projection.

[0025] Preferably, the ultrasonic flow measuring device in question has a control and evaluation unit. The control and evaluation unit is arranged outside the pipe system, into which the measuring pipe is inserted. In order to guide the electrical line from the ultrasonic transducer to the control and evaluation unit, according to one embodiment of the invention, the electrical line is preferably guided from the ultrasonic transducer to the control and evaluation unit via a flange.

[0026] Particularly preferably, the flange is formed at least partially by a printed circuit board, which forms a partial section of the electrically conductive connection between the ultrasonic transducer and the control and evaluation unit.

[0027] According to this embodiment, the flange enables an electrical feed-through. For this purpose, according to one embodiment, the flange has, on the one hand, contact elements for contacting at least the ultrasonic transducer and, on the other hand, at least one contact element for contacting the control and evaluation unit. Particularly preferably, the flange has a contact element for each ultrasonic transducer. In this case, the contact elements for the ultrasonic transducer are arranged in the interior of the tube system in the assembled state and the contact elements for connection to the control and evaluation unit are arranged in the exterior of the tube system.

[0028] This refinement has the advantage that no additional components must be provided for conducting the electrical feedthrough into the exterior of the tube system.

[0029] According to another design solution, the ultrasonic flow measuring device has a control and evaluation unit, which is arranged outside the pipe system in the assembled state, wherein the control and evaluation unit is connected to at least the ultrasonic transducer via an electrical line, and wherein the ultrasonic flow measuring device has a circuit board, wherein the circuit board is arranged between a first pipe flange of the first pipe and a second pipe flange of the second pipe in the assembled state such that it realizes an electrical connection of at least the ultrasonic transducer from the interior space of the pipe system to the exterior space of the pipe system.

[0030] The printed circuit board has at least contact elements for the ultrasonic transducer, which are arranged in the interior of the tube system in the assembled state, and preferably for at least one further sensor (if present), and preferably has contact elements for contacting a control and evaluation unit, which are arranged outside the tube system in the assembled state. The control and evaluation unit can be connected to the contact elements of the printed circuit board via a cable connection.

[0031] Furthermore, the control and evaluation unit can also be arranged directly on the printed circuit board. For example, the control and evaluation unit can be connected to the printed circuit board by means of a plug connection or a clamping connection or a soldering connection. The control and evaluation unit can be designed in particular as a further printed circuit board or have another printed circuit board.

[0032] Furthermore, the printed circuit board can also be equipped directly with the control and evaluation unit.

[0033] In the last-mentioned embodiment, no additional cable connection of the control and evaluation unit and the printed circuit board is required.

[0034] In the case in which the flange of the measuring tube is designed as a printed circuit board, the control and evaluation unit can also be arranged on the printed circuit board in accordance with one of the connections described above.

[0035] For assembly, the printed circuit board is clamped between a first tube flange of a first tube and a second tube flange of a second tube of the tube system.

[0036] Particularly preferably, the flange of the measuring tube is fixed to the printed circuit board, for example the flange and the printed circuit board are screwed to each other. According to this design, the outer diameter of the flange can also be smaller than the inner diameter of the first tube into which the measuring tube is inserted, so that the measuring tube can be completely inserted into the first tube and is only fixed by the connection to the printed circuit board. According to this design, the flange is not clamped between the first tube flange and the second tube flange in the assembled state.

[0037] In another variant of the ultrasonic flow measuring device according to the invention, the measuring tube is coated on its outer side with an electrically insulating layer. Particularly preferably, the electrically insulating layer is implemented after the transducer cavity is equipped with the ultrasonic transducer, so that the electrical conductors of the ultrasonic transducer are electrically shielded by the electrically insulating layer on the one hand and fixed to the measuring tube on the other hand.

[0038] In order to avoid crosstalk of the ultrasound to the tube system, the measuring tube has a sound-insulating layer on its outer side in a preferred embodiment. Thus, crosstalk of the ultrasound as interfering housing waves is minimized.

[0039] A particularly preferred embodiment of the ultrasonic flow measuring device according to the invention is characterized by the fact that the measuring tube has a constant internal cross section. In an alternative preferred variant, the measuring tube has a variable internal cross section along its longitudinal axis. By selecting the internal cross section, the flow profile of the medium can be advantageously influenced.

[0040] Furthermore, a preferred embodiment of the ultrasonic flow measuring device according to the invention is distinguished by the fact that the inner diameter of the measuring tube at the transition to the pipeline corresponds to the inner pipeline diameter. The continuous transition between pipeline and measuring tube minimizes disturbances in the flow profile. Alternatively, the inner diameter of the measuring tube at the transition to the pipeline is smaller than the inner pipeline diameter.

[0041] According to a second teaching of the invention, the task set out at the outset is solved by a measuring assembly comprising the ultrasonic flow measuring device described above and at least a first tube of a tube system, wherein the measuring tube is inserted into the first tube, in such a way that the first tube and the measuring tube are coordinated with one another in such a way that the transducer recess does not touch the first tube.

[0042] For example, the diameter of the first tube can be increased at least in the region in which the measuring tube is inserted. Particularly preferably, the inner diameter of the measuring tube corresponds substantially to the inner diameter of the second tube of the tube system and to the inner diameter of the first tube in the region in which the diameter is not increased, if the first tube has only a local increase in the inner diameter.

[0043] Alternatively or additionally, the measuring tube can have a tapered measuring tube cross section at least in the region of the transducer recess.

[0044] It is likewise conceivable that the inner cross-sectional area of ​​the measuring tube is so small as to be smaller than the inner cross-sectional area of ​​the first tube that the transducer recess does not touch the first tube in the inserted state.

[0045] With regard to further advantageous embodiments of the measuring arrangement, reference is made to the above description insofar as it relates to the special embodiment of the measuring arrangement.

[0046] In particular, the measuring component preferably has a second tube, wherein the first tube has a first tube flange, and wherein the second tube has a second tube flange, and wherein the measuring tube is arranged with the measuring tube flange between the first tube flange and the second tube flange, or wherein the measuring tube is arranged with the measuring tube flange on a circuit board which is clamped between the first tube flange and the second tube flange. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In detail, there are different possibilities for designing and improving the ultrasonic flow measurement device according to the invention and the measuring assembly according to the invention. For this, reference is made to the patent claims following the independent patent claims and to the description of the preferred embodiments in conjunction with the drawings. In the drawings:

[0048] Figure 1 shows a schematic diagram of a first embodiment of an ultrasonic flow measuring device,

[0049] Figure 2 shows a first measuring tube of an ultrasonic flow measuring device,

[0050] Figure 3 shows the second measuring tube of the ultrasonic flow measuring device,

[0051] Figure 4 shows an ultrasonic transducer,

[0052] Figure 5 shows an ultrasonic transducer inserted into a transducer pocket,

[0053] Figure 6 The transducer pocket is shown,

[0054] Figure 7 Another view of the measuring tube is shown,

[0055] Figure 8A view showing an additional circuit board and a measuring tube for the electrical connection of the ultrasonic transducer and the control and evaluation unit,

[0056] Fig. 9 A measuring assembly comprising an ultrasonic flow measuring device and a pipe system is shown, and

[0057] Fig.10 A further measuring arrangement comprising an ultrasonic flow measuring device and a pipe system is shown. DETAILED DESCRIPTION

[0058] Figure 1 The schematic diagram of an ultrasonic flow measuring device 1 is shown, which is designed to be inserted into a pipe system 2, wherein the pipe system 2 has at least one first pipe 3 with a first pipe flange 3a and a second pipe 4 with a second pipe flange 4a. The ultrasonic flow measuring device 1 has a longitudinal axis l M The measuring tube 5 is provided with a flange 6 for guiding the flowable medium and for fixing the measuring tube 5 in the tube system 2. In the embodiment shown, the flange 6 of the measuring tube 5 is clamped between the first tube flange 3a and the second tube flange 4a. To ensure better clarity, the second tube flange 4 has a spacing from the flange 6. In the assembled state, the flange 6 is naturally clamped tightly (dicht, sometimes also called sealingly) between the tube flanges 3a and 4a.

[0059] The measuring tube 5 has a first transducer cavity 7 in which a first ultrasonic transducer 8 is arranged, and the measuring tube 5 has a second transducer cavity 9 in which a second ultrasonic transducer 10 is arranged. The two ultrasonic transducers 8, 10 are configured as an ultrasonic transmitter and an ultrasonic receiver and transmit and receive ultrasonic signals propagating along a measuring path 11. The measuring tube 5 is configured as a thin-walled tube 12 and is distinguished by the fact that the wall thickness w of the measuring tube 11 is smaller than the wall thickness w of the transducer cavities 7, 9 perpendicular to the longitudinal axis l of the measuring tube 5. M The transducer recesses 7, 9 also extend into the outer space 13 of the measuring tube 5. As can be seen from the figure, the transducer recesses 7, 9 extend only into the outer space 13 of the measuring tube 5, and therefore they do not protrude into the inner space of the measuring tube 5. Here, the transducer recesses do not touch the first tube 3, so that crosstalk to the first tube can be avoided or at least reduced during operation. For this purpose, the diameter of the first tube 3 is increased in the region of the measuring tube 5, in particular in the region of the transducer recess 7.

[0060] The control and evaluation unit 15 serves to control the ultrasonic transducers 8, 10 and to evaluate the ultrasonic signals. The supply lines to the ultrasonic transducers 8, 10 are connected at Figure 1 The control and evaluation unit 15 is located outside the tube system 2 and thus also outside the measuring tube 5 .

[0061] As from Figure 1As can be seen in FIG. 5 , the measuring tube 5 and the flange 6 are constructed in one piece. Currently, the measuring tube 5 and the flange 6 are made of plastic by means of a generative manufacturing process, that is, by means of 3D printing. Alternatively, the complete component (Einsatz) including the measuring tube 5 and the measuring tube flange 6 can also be made of epoxy resin.

[0062] Figure 2 Another embodiment of a measuring tube 5 with a flange 6 for an ultrasonic flow measuring device 1 is shown. The measuring tube 5 has a plurality of transducer pockets 14 in which ultrasonic transducers, reflectors, sensors, such as temperature sensors and pressure sensors, and closures can be accommodated. The closures close the transducer pockets, thereby creating a continuous measuring tube interior surface. Depending on the equipment of the measuring tube 5, a plurality of additional measuring paths can be realized.

[0063] Figure 3 The cross section of the measuring tube 5 is shown. In addition to the first transducer cavity 7 in which the first ultrasonic transducer 8 is arranged and the second transducer cavity 9 in which the second ultrasonic transducer 10 is arranged, the measuring tube 5 has a plurality of further transducer cavities 14.1, 14.2, 14.3, 14.4, 14.5, 14.6, 14.7, 14.8 and 14.9. Two ultrasonic transducers are also arranged in the transducer cavities 14.1 and 14.2, which are however not visible in the view. By means of these two ultrasonic transducers, a second measuring path 16 is realized. In the transducer cavities 14.3 and 14.4, only closures are arranged, which end flush with the inner wall of the measuring tube 5. The closures can be replaced by further ultrasonic transducers if another measuring path is desired. Two ultrasonic transducers are also arranged in the transducer cavities 14.5 and 14.7. A reflector is arranged in the transducer cavities 14.6. In this way, a further measuring path 16 ′ is realized. A temperature sensor for measuring the temperature of the medium is arranged in the transducer cavity 14 . 8 . The transducer cavity 14 . 9 accommodates a pressure sensor for determining the pressure.

[0064] Figure 4 Schematically, an ultrasonic transducer 8 is shown, which can be inserted into the transducer cavity 7. The ultrasonic transducer 8 has a retaining projection 17, which engages in a corresponding retaining recess 18 of the transducer cavity 7 in the inserted state of the ultrasonic transducer 8, so that the ultrasonic transducer can be retained in the transducer cavity in a form-fitting manner. The ultrasonic transducer presented can thus be arranged in a simple, replaceable manner in the transducer cavity.

[0065] Figure 5Schematic diagram of an ultrasonic transducer 8 inserted into the transducer pocket 7 is shown. Thus, the ultrasonic transducer 8 can be introduced through the transducer pocket 7 until the retaining recess 18, and the retaining projection 17 has elasticity, which enables deformation of the retaining projection 17. Alternatively, the transducer pocket 7 can also be elastically constructed and enable easy insertion of the ultrasonic transducer 8 into the transducer pocket.

[0066] Figure 6 is a schematic diagram of a cross section of a transducer cavity 9, where an elastic retaining element 19 is constructed. If an ultrasonic transducer 10 with a retaining projection is inserted into the transducer cavity 9, the elastic retaining element 19 is elastically deflected in the direction of the arrow by the retaining projection. Once the retaining projection is guided past the elastic retaining element 19, it returns to its initial position and retains the ultrasonic transducer in a form-fitting and / or force-fitting manner according to the specific design. With the generative manufacturing process, very delicate structures can be manufactured at the same time, so that a plurality of practical retaining structures can be realized.

[0067] Figure 7 2 is a schematic diagram of another measuring tube 5. The measuring tube 5 is coated with a sound insulating layer 21 on its outer side. In addition, the measuring tube 5 has a longitudinal axis l M Variable internal cross section. By reducing the internal cross section, it is ensured that in the installed state the transducer recesses 7 and 9 do not touch the first tube 3 of the tube system, so that at least crosstalk to the first tube 3 can be reduced.

[0068] Figure 8 An exemplary embodiment of a measuring tube 5 with a collar 6 and a printed circuit board 22 is shown. The printed circuit board 22 and the measuring tube collar 6 have bores 23 which are matched to one another in such a way that the collar 6 can be screwed to the printed circuit board 22 .

[0069] In addition, the circuit board 22 has contact elements 24, which can be connected to the electrical conductors of the ultrasonic transducer or other sensors, for example by means of plug connections. In the embodiment shown, the contact elements 24 are arranged circularly around the cutouts of the circuit board 22. Each ultrasonic transducer and, if present, each sensor can be connected to the contact elements. For this purpose, the flange 6 has further bores, through which the electrical conductors of the ultrasonic transducer can be guided.

[0070] The printed circuit board 22 also has a further contact element 24 for connection to the control and evaluation unit. The contact element 24 for connection to the control and evaluation unit 15 is arranged in such a way that it is arranged outside the tube system in the installed state. The printed circuit board 22 is designed overall in such a way that it can be clamped between the first tube flange 3a of the first tube 3 and the second tube flange 4a of the second tube 4, so that the printed circuit board 22 and the measuring tube 5 are fixed in the tube system.

[0071] Fig. 9An embodiment of a measuring assembly 25 with an ultrasonic flow measuring device 1 is shown, which comprises a measuring tube 5 with a measuring tube flange 6, wherein the measuring tube 5 has a transducer recess 14, in which ultrasonic transducers 8, 10 (not explicitly shown here) are arranged. The flange 6 is clamped between a first tube flange 3a and a second tube flange 4a. In addition, there is a circuit board 22, which is also clamped between the first tube flange 3a and the second tube flange 4a.

[0072] The printed circuit board 22 is screwed to the measuring tube flange 6. In addition, the printed circuit board 22 has contact elements 24, which are connected to the electrical conductors of the ultrasonic transducer. For this purpose, there are bores in the flange 6, through which electrical conductors are guided.

[0073] Furthermore, the printed circuit board in the exterior of the tube system has a further contact element 24 which is connected to a control and evaluation unit 15 which is likewise arranged in the exterior of the tube system.

[0074] In order to ensure good clarity, there are gaps between the individual components in the illustration. It is clear that in operation, the measuring tube flange 6 and the circuit board 22 are tightly clamped between the flanges 3a and 4a.

[0075] Overall, the presented measuring arrangement 25 has the advantage that the ultrasonic flow measuring device 1 can be used in different measuring environments due to the design of the measuring tube 5 .

[0076] Fig.10 Another embodiment of the measuring assembly 25 is shown. Fig. 9 In the measuring assembly presented in FIG. 3 , the measuring tube 5 and the flange 6 are arranged completely inside the first tube 3. The measuring tube 5 is screwed to the circuit board 22 via the boreholes in the flange 6. The circuit board 22 is clamped between the tube flanges 3 a and 4 a and thus forms a through-guide for the signal transmission. At the same time, the connection between the circuit board 22 and the tube flange is a tight connection.

[0077] Furthermore, the control and evaluation unit 15 is arranged directly on the printed circuit board 22 and connected thereto by means of a clamping connection. This arrangement saves an additional cable connection between the control and evaluation unit and the printed circuit board, which in turn has a cost-saving effect.

[0078] Reference Symbols List

[0079] 1 Ultrasonic flow measurement device

[0080] 2-pipe system

[0081] 3 First tube

[0082] 3a First pipe flange

[0083] 4 Second tube

[0084] 4a Second pipe flange

[0085] 5 Measuring tube

[0086] 6 Flange

[0087] 7 First transducer cavity

[0088] 8. First Ultrasonic Transducer

[0089] 9 Second transducer cavity

[0090] 10. Second ultrasonic transducer

[0091] 11 Measurement path

[0092] 12 Thin wall tube

[0093] 13 External space of the measuring tube

[0094] 14 Additional transducer recesses

[0095] 15 Control and evaluation unit

[0096] 16 Additional signal paths

[0097] 17. Keep the protrusion

[0098] 18 Keep notch

[0099] 19 Elastic locking element

[0100] 20 Electrical insulation layer

[0101] 21 Sound insulation layer

[0102] 22 Circuit Board

[0103] 23 Drilling

[0104] 24 Contact elements

[0105] w Measuring tube wall thickness

[0106] a Extension of the transducer cavity

[0107] l M The longitudinal axis of the measuring tube.

Claims

1. An ultrasonic flow measuring device (1) for insertion into a first pipe (3) of a pipe system (2) at the location of a flange connection of the pipe system (2), with a longitudinal axis (1) for guiding a flowable medium. M ) and having a flange (6) for at least indirectly fixing the measuring tube (4) in the pipe system (2), wherein the measuring tube (5) has at least one first transducer recess (7) for accommodating a first ultrasonic transducer (8) and at least one second transducer recess (9) for accommodating a second ultrasonic transducer (10), wherein a first ultrasonic transducer (8) is arranged in the first transducer recess (7), which is configured as an ultrasonic transmitter and / or an ultrasonic receiver, and wherein a second ultrasonic transducer (10) is arranged in the second transducer recess (9), which is configured as an ultrasonic transmitter and / or an ultrasonic receiver, It is characterized in that The measuring tube (5) is constructed as a thin-walled tube (12), such that the wall thickness (w) of the measuring tube (5) is smaller than the transducer recess (7, 9) perpendicular to the longitudinal axis (l M ) and the transducer recess (7, 9) extends into the outer space (13) of the measuring tube (5).

2. The ultrasonic flow measurement device (1) according to claim 1, characterized in that: The measuring tube (5) and the flange (6) are designed as one piece, in particular wherein the measuring tube (5) and the flange (6) are designed from plastic and / or wherein the measuring tube (5) and the flange (6) are manufactured by means of a generative manufacturing process.

3. The ultrasonic flow measurement device (1) according to claim 1 or 2, characterized in that: The measuring tube (5) has at least one further transducer recess (14) for accommodating a further ultrasonic transducer, a reflector or a closing body in order to realize a further measuring path (16, 16'), in particular the measuring tube (5) has a plurality of further transducer recesses (14) for accommodating further ultrasonic transducers, reflectors or closing bodies in order to realize a further measuring path (16, 16').

4. The ultrasonic flow measurement device (1) according to claim 3, characterized in that: At least one pressure sensor and / or temperature sensor is arranged in the transducer cavity (14.8, 14.9).

5. The ultrasonic flow measurement device (1) according to any one of claims 1 to 4, characterized in that: The ultrasonic transducer (8, 10) and, if present, the reflector, the closure body or the sensor and the transducer recess (7, 9) have corresponding retaining projections (17) and retaining recesses (18) for fixing the ultrasonic transducer and, if present, the reflector, the closure body or the sensor in the transducer recess (7, 9).

6. The ultrasonic flow measurement device (1) according to any one of claims 1 to 5, characterized in that: The ultrasonic transducer (8, 10) and, if present, the reflector, the closure body or the sensor and / or the transducer recess (7, 9) have a resilient and / or elastic latching element (19) for fixing the ultrasonic transducer and, if present, the reflector, the closure body or the sensor in the transducer recess (7, 9).

7. The ultrasonic flow measurement device (1) according to any one of claims 1 to 6, characterized in that: A control and evaluation unit (15) is provided which is arranged outside the pipe system (2) and electrical lines are led from the ultrasonic transducers (8, 10) and, if present, from the reflector, the closure body or the sensor, preferably via the flange (6) to the control and evaluation unit (15).

8. The ultrasonic flow measurement device (1) according to claim 7, characterized in that: The flange (6) is formed at least partially by a printed circuit board, which forms part of an electrically conductive connection between the ultrasonic transducer (8, 10) and the control and evaluation unit (15).

9. The ultrasonic flow measurement device (1) according to any one of claims 1 to 6, characterized in that: The ultrasonic flow measuring device comprises a control and evaluation unit (15) which is arranged outside the pipe system (2) in the assembled state, wherein the control and evaluation unit is connected to the ultrasonic transducers (8, 10) at least via electrical conductors, and the ultrasonic flow measuring device comprises a circuit board, wherein the circuit board can be arranged between a first pipe flange of the first pipe and a second pipe flange of the second pipe in the assembled state such that an electrical connection is achieved from the interior space of the pipe system to the exterior space of the pipe system.

10. The ultrasonic flow measurement device (1) according to any one of claims 1 to 9, characterized in that: The measuring tube (5) is coated on its outer side with an electrically insulating layer (20), in particular wherein the flange is also at least partially coated with the electrically insulating layer (20).

11. The ultrasonic flow measurement device (1) according to any one of claims 1 to 10, characterized in that: The measuring tube (5) is coated on its outer side with a sound-insulating layer (21).

12. The ultrasonic flow measurement device (1) according to any one of claims 1 to 11, characterized in that: The measuring tube (5) has a constant internal cross section or the measuring tube (5) has a constant internal cross section along its longitudinal axis (1 M ) has a variable internal cross-section.

13. The ultrasonic flow measurement device (1) according to any one of claims 1 to 12, characterized in that: The inner diameter of the measuring tube (5) at the transition to the pipe system (1) corresponds to the inner pipe diameter of the pipe system, or the inner diameter of the measuring tube (5) at the transition to the pipe system (2) is smaller than the inner pipe diameter of the pipe system.

14. A measuring assembly comprising an ultrasonic flow measuring device according to any one of claims 1 to 13 and at least one first tube of a tube system, wherein the measuring tube (5) is inserted into the first tube (3), characterized in that The first tube (3) and the measuring tube (5) are coordinated with one another in such a way that the transducer recess (7) does not touch the first tube (3).

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