CLAMP-ON ULTRASONIC FLOW METER

Abstract

The invention relates to a clamp-on ultrasonic flowmeter (1) comprising: - at least one pair of ultrasonic transducers (10) which are attached to the pipe (11) having an in particular round cross-section or to a measuring tube (12) of the flowmeter, which measuring tube is integrated in the pipe and has an in particular round cross-section, - an electronic measuring / operating circuit (20) for operating the ultrasonic transducers, analyzing measurement signals from the ultrasonic transducers, and providing measured values, wherein: the ultrasonic transducers of each pair are each attached separately to the measuring tube or the pipe; the pipe or the measuring tube has, in cross-section, a vertical diameter (13.1); in an associated cross-section, the ultrasonic transducers are mutually spaced peripherally in relation to the vertical diameter, characterized in that a counterweight (14), in particular precisely one counterweight (14), is assigned to each ultrasonic transducer and is at a distance from the ultrasonic transducer and opposite thereto in relation to the vertical diameter, wherein the ultrasonic transducer and the associated counterweight (14) are connected by a flexible, in particular resilient, connecting element (15), such as a belt, a cable, a chain or a spring, which connecting element (15) extends above, in particular exclusively above, the measuring tube or the pipe.

Description

[0001] Clamp-on ultrasonic flow meter

[0002] The invention relates to a clamp-on ultrasonic flowmeter for measuring a flow velocity or a volume flow of a medium flowing through a pipeline.

[0003] Such devices are known, for example, from DE102020116181A1. Ultrasonic transducers are attached to the measuring tube or pipeline using tensioning straps or magnets, for example. Attaching the individual ultrasonic transducers to a measuring tube or pipeline is problematic, especially when the ultrasonic transducers are located away from the vertical line of a cross-section of the measuring tube or pipeline. In this case, loosening or slipping of the tensioning strap due to temperature fluctuations, or vibration-induced slipping of the magnets, for example, can lead to a displacement of the ultrasonic transducers in the direction of gravity.

[0004] The object of the invention is to propose a robust and secure fastening for clamp-on ultrasonic transducers.

[0005] The object is achieved by a clamp-on ultrasonic flowmeter according to independent claim 1.

[0006] A clamp-on ultrasonic flowmeter according to the invention for measuring a flow velocity or a volume flow of a medium flowing through a pipeline comprises

[0007] - at least one ultrasonic transducer, in particular at least one pair of ultrasonic transducers, wherein the at least one ultrasonic transducer is attached to the pipeline with a particularly round cross-section or to a measuring tube of the flowmeter with a particularly round cross-section integrated into the pipeline,

[0008] - an electronic measuring / operating circuit for operating the at least one ultrasonic transducer and for evaluating measuring signals from the at least one ultrasonic transducer and providing measured values, wherein the pipeline or the measuring tube in cross sections each has a diameter in a longitudinal section containing a pipeline axis or measuring tube axis, wherein the at least one ultrasonic transducer is arranged circumferentially spaced apart in an associated cross section with respect to the diameter, and is characterized in that each ultrasonic transducer is assigned a counterweight, in particular exactly one counterweight (14), which with respect toof the vertical diameter is spaced opposite to the ultrasonic transducer, wherein the ultrasonic transducer and the associated counterweight are connected by a flexible, and in particular resilient, connecting element, such as a belt or a rope or a chain or a spring, which connecting element runs above, in particular exclusively above, the measuring tube or the pipeline, wherein the flexible connecting element is in a state tensioned by the ultrasonic transducer and the counterweight when the clamp-on flowmeter is arranged on the pipeline or on the measuring tube.

[0009] In this way, influences such as temperature fluctuations or vibrations on the positions of the ultrasonic transducers are reduced.

[0010] The flexible connecting element has a spring constant in the longitudinal direction of greater than 50 Newton per millimeter, and in particular greater than 80 Newton per millimeter and preferably greater than 100 Newton per millimeter.

[0011] In one embodiment, one ultrasonic transducer of a pair has a first circumferential distance from a starting point to a center of gravity of the respective ultrasonic transducer, wherein the associated counterweight has a second circumferential distance from the vertical diameter, wherein the amounts of the first circumferential distance and the second circumferential distance deviate by less than 20% from an average value of the amounts. In this way, a displacement-causing influence on the ultrasonic transducer can be mitigated.

[0012] In one embodiment, the ultrasonic transducer of a pair each has a first mass, wherein the counterweight each has a second mass, wherein the first mass and the second mass deviate less than 20% from an average value of the masses.

[0013] In this way, a displacement-causing influence on the ultrasonic transducer can be mitigated.

[0014] In one embodiment, the ultrasonic transducers are fastened to the measuring tube or pipeline, for example, by means of a magnet or a tensioning belt encircling the measuring tube or pipeline.

[0015] In one embodiment, the counterweight has an anti-slip surface, which surface is in contact with the measuring tube or the pipeline.

[0016] In this way, displacement of the ultrasonic transducer can be better inhibited.

[0017] In one embodiment, the slip resistance is achieved by a surface structuring such as a pyramid or needle structure, or by an elastomer such as acrylonitrile butadiene rubber or silicone, or by a self-adhesive coating.

[0018] In one embodiment, the ultrasonic transducer and counterweight are each attached to the tensioning belt, for example by crimping or screwing.

[0019] In one embodiment, the tensioning belt forms the flexible connecting element.

[0020] In one embodiment, the flexible connecting element is made of at least one of the following materials: a metallic material such as steel or in particular stainless steel or a glass, carbon, polymer or a natural material such as hemp.

[0021] In one embodiment, in the absence of a tensioning belt or a chain, the flexible connecting element has a spring constant of greater than 50 Newton per millimeter, and in particular greater than 80 Newton per millimeter and preferably greater than 100 Newton per millimeter in a longitudinal direction of the connecting element.

[0022] In the case of a belt or rope as a flexible connecting element, the materials can be processed in the form of fibers, for example.

[0023] In one embodiment, in the presence of a tensioning belt or a chain, the flexible connecting element has a spring constant in a longitudinal direction of the connecting element of greater than 500 Newtons per millimeter, and in particular greater than 800 Newtons per millimeter and preferably greater than 1000 Newtons per millimeter and / or wherein the flexible connecting element has a spring constant in a longitudinal direction of the connecting element which is at least a factor of 2 and in particular at least a factor of 4 greater than a spring constant of the tensioning belt or the chain along a corresponding longitudinal direction.

[0024] In one embodiment, the clamp-on ultrasonic flowmeter comprises at least two pairs of ultrasonic transducers, wherein one ultrasonic transducer of each of two pairs of ultrasonic transducers forms the counterweight of the other ultrasonic transducer of the two pairs of ultrasonic transducers.

[0025] In one embodiment, the counterweight is neither designed and / or suitable to generate nor receive ultrasonic waves.

[0026] In one embodiment, the counterweight does not have an ultrasonic transducer or no ultrasonic transducer is arranged on the counterweight.

[0027] In one embodiment, the ultrasonic transducer, the counterweight and the connecting element are designed such that the ultrasonic transducer remains in its mounting position in the event of a mechanical deformation of the pipeline or the measuring tube, in particular due to temperature.

[0028] In the following, the invention is described using exemplary embodiments.

[0029] Fig. 1 outlines an exemplary schematic clamp-on ultrasonic flowmeter according to the prior art in a side view;

[0030] Fig. 2 outlines an exemplary schematic implementation of the invention in a front view.

[0031] Fig. 1 shows an exemplary clamp-on ultrasonic flowmeter with two ultrasonic transducers, which are arranged on a measuring tube 12 integrated into a pipeline or on a pipeline 11 and are configured to mutually transmit and receive ultrasonic signals. An electronic measuring / operating circuit 20 is configured to operate the ultrasonic transducers and to evaluate measurement signals from the ultrasonic transducers and to provide measured values. For example, a flow velocity or a speed of sound of the medium can be deduced from transit time differences of ultrasonic signals in and against a flow direction of a medium in the pipeline. Clamp-on ultrasonic flowmeters are known in which the ultrasonic signals pass through the measuring tube or pipeline once or multiple times. Such measuring devices can have one or more pairs of ultrasonic transducers.Doppler measuring devices are also known which only require an ultrasonic transducer for flow measurements.

[0032] Fig. 2 shows a front view of an exemplary clamp-on ultrasonic flowmeter according to the invention with a pair of ultrasonic transducers arranged one behind the other and transmitting ultrasonic signals through the medium with an even number of measuring tubes or pipe crosspieces. Regarding the basic technical functionality, the same applies to Fig. 1.

[0033] The pipeline 11 or the measuring tube 12 each has a diameter 13.1 in cross sections in a longitudinal section containing a pipeline axis or measuring tube axis, wherein the ultrasonic transducers have a circumferential distance 13.2 in an associated cross section with respect to the diameter, wherein each ultrasonic transducer is assigned a counterweight according to the invention, which is spaced opposite to the ultrasonic transducer with respect to the vertical diameter.

[0034] Further according to the invention, an ultrasonic transducer and an associated counterweight are connected by a flexible connecting element 15, such as a belt or a rope, which extends above the measuring tube or pipeline, wherein the flexible connecting element is in a tensioned state by the ultrasonic transducer and the counterweight. In this way, a circumferential component of a weight force of the ultrasonic transducer 10 is reduced in magnitude, thus preventing any risk of displacement of the sensor.

[0035] In one embodiment, the counterweight 14 has an anti-slip surface 14.1, which surface is in contact with the measuring tube 12 or the pipeline 11. This allows the ultrasonic transducer to be further stabilized, since the counterweight has a secure positioning. The anti-slip feature can be provided by a surface structure such as a pyramid or needle structure, or by an elastomer such as acrylonitrile butadiene rubber or silicone, or by a self-adhesive coating.

[0036] In one embodiment, the ultrasonic transducer of a pair each has a first circumferential distance 13.2 from the vertical diameter, while the counterweight each has a second circumferential distance from the vertical diameter, wherein the amounts of the first circumferential distance and the second circumferential distance deviate by less than 20% from an average value. This contributes to a better compensability of the circumferential component of the weight force of the ultrasonic transducer.

[0037] In one embodiment, each ultrasonic transducer in a pair has a first mass, while the counterweight has a second mass, wherein the first mass and the second mass deviate by less than 20% from a mean value of the masses. This contributes to a better compensation of the circumferential component of the weight force of the ultrasonic transducer. The attachment of the ultrasonic transducers 10 to the measuring tube 12 or to the pipeline 11 can be achieved, as shown here, by means of a magnet 16 and / or a tensioning belt 17.1 or a chain 17.2 spanning the measuring tube or pipeline.

[0038] The ultrasonic transducer and counterweight can each be attached to the tensioning belt by crimping or screwing.

[0039] In one embodiment, the tensioning belt 17.1 or the chain 17.2 forms the flexible connecting element 15.

[0040] In one embodiment, the flexible connecting element has a spring constant in a longitudinal direction of the connecting element of greater than 50 Newtons per millimeter, and in particular greater than 80 Newtons per millimeter and preferably greater than 100 Newtons per millimeter.

[0041] In one embodiment, the flexible connecting element has a spring constant in a longitudinal direction of the connecting element of greater than 500 Newtons per millimeter, and in particular greater than 800 Newtons per millimeter and preferably greater than 1000 Newtons per millimeter, and / or the flexible connecting element has a spring constant in a longitudinal direction of the connecting element which is at least a factor of 2 and in particular at least a factor of 4 greater than a spring constant of the tensioning belt or the chain along a corresponding longitudinal direction.

[0042] The ultrasonic signals generated by the ultrasonic transducers can pass through the measuring tube or pipeline once or multiple times, i.e. they can be single- or multi-crossbeam systems. The number and arrangement of ultrasonic transducers shown in Fig. 2 is purely exemplary. The invention is applicable to all ultrasonic transducer arrangements. For example, the clamp-on ultrasonic flowmeter can have several pairs of ultrasonic transducers, with one ultrasonic transducer from each of two different pairs forming the counterweight of the other ultrasonic transducer in the two different pairs. In one embodiment, the counterweight is neither designed nor suitable to generate nor receive ultrasonic waves. Accordingly, the counterweight itself is not an ultrasonic transducer as in the above embodiment, but a simple inactive, i.e. acoustically inactive, body.

[0043] In one embodiment, the counterweight does not have an ultrasonic transducer or no ultrasonic transducer is arranged on the counterweight. Thus, the counterweight is also not an adapter, sensor adapter for receiving an ultrasonic transducer or the like. In one embodiment, the ultrasonic transducer, the counterweight and the connecting element are designed such that the ultrasonic transducer remains in its mounted position during mechanical deformation of the pipeline or measuring tube, in particular due to temperature. When the arrangement is mounted on the pipeline or measuring tube, the ultrasonic transducer is in its mounted position. If the diameter of the pipeline or measuring tube changes due to temperature- or pressure-related influences, the ultrasonic transducer does not slip according to the invention, but remains fixed in its original mounted position.The position of the ultrasonic transducer can change radially towards the center, but not in the circumferential direction.

[0044] List of reference symbols

[0045] 1 clamp-on ultrasonic flow meter

[0046] 10 ultrasonic transducers

[0047] 11 Pipeline 12 Measuring tube

[0048] 13.1 Diameter

[0049] 13.2 circumferential distance

[0050] 14 Counterweight

[0051] 14.1 anti-slip surface

[0052] 15 flexible connecting element

[0053] 16 Magnet

[0054] 17.1 Tension strap

[0055] 17.2 Chain

[0056] 20 Electronic measuring / operating circuit

Claims

Patent claims 1. Clamp-on ultrasonic flowmeter (1) for measuring a flow velocity or a volume flow of a medium flowing through a pipeline (11), comprising: - at least one ultrasonic transducer, in particular at least one pair of ultrasonic transducers (10), wherein the at least one ultrasonic transducer is attached to the pipeline (11) with a particularly round cross-section or to a measuring tube (12) of the flow measuring device with a particularly round cross-section, which is integrated into the pipeline, - an electronic measuring / operating circuit (20) for operating the at least one ultrasonic transducer and for evaluating measuring signals from the at least one ultrasonic transducer and providing measured values, wherein the pipeline or the measuring tube in cross sections each has a diameter (13.1) in a longitudinal section containing a pipeline axis or measuring tube axis, wherein the at least one ultrasonic transducer is arranged circumferentially spaced apart in an associated cross section with respect to the diameter, characterized in that each ultrasonic transducer is assigned a counterweight (14), in particular exactly one counterweight (14), which with respect toof the vertical diameter is spaced opposite to the ultrasonic transducer, wherein the ultrasonic transducer and the associated counterweight (14) are connected by a flexible, and in particular resilient, connecting element (15), such as a belt or a rope or a chain or a spring, which connecting element runs above, in particular exclusively above, the measuring tube or the pipeline, wherein the flexible connecting element (15) when the clamp-on ultrasonic flow meter (1) is arranged on the pipeline or on the measuring tube in. in a state tensioned by the ultrasonic transducer and the counterweight.

2. Clamp-on ultrasonic flowmeter according to claim 1, wherein each ultrasonic transducer, starting from a starting point up to a center of gravity of the respective ultrasonic transducer, has a first circumferential distance (13.2) to the vertical diameter, wherein the counterweight (14) has a second circumferential distance (13.2) to the vertical diameter, wherein amounts of the first circumferential distance and the second circumferential distance deviate by less than 20% from an average value of the amounts.

3. Clamp-on ultrasonic flowmeter according to claim 1 or 2, wherein each ultrasonic transducer (10) has a first mass, wherein the counterweight (14) has a second mass, wherein the first mass and the second mass deviate less than 20% from a mean value of the masses.

4. Clamp-on ultrasonic flowmeter according to one of the preceding claims, wherein the fastening of the at least one ultrasonic transducer to the measuring tube or to the pipeline is effected by means of a magnet (16) or a tensioning belt (17.1) or chain (17.2) spanning the measuring tube or the pipeline.

5. Clamp-on ultrasonic flowmeter according to one of the preceding claims, wherein the counterweight (14) has an anti-slip surface (14.1), which surface is in contact with the measuring tube (12) or the pipeline (11).

6. Clamp-on ultrasonic flowmeter according to claim 5, wherein the anti-slip feature is provided by a surface structuring such as a pyramid or needle structure, or by an elastomer such as acrylonitrile butadiene rubber or silicone, or by a self-adhesive coating.

7. Clamp-on ultrasonic flowmeter according to one of claims 4 to 6, wherein the ultrasonic transducer (10) and counterweight (14) are each attached to the tensioning belt by a fastening such as crimping, screwing, gluing, welding, riveting.

8. Clamp-on ultrasonic flowmeter according to one of claims 4 to 7, wherein the tensioning belt (17) forms the flexible connecting element (15).

9. Clamp-on ultrasonic flowmeter according to one of the preceding claims, wherein the flexible connecting element (15) is made of at least one of the following materials: a metallic material such as steel or in particular stainless steel or a glass, carbon, polymer.

10. Clamp-on ultrasonic flowmeter according to one of the preceding claims, unless directly or indirectly dependent on claim 4, wherein the flexible connecting element (15) has a spring constant in a longitudinal direction of the connecting element (15) greater than 50 Newtons per millimeter, and in particular greater than 80 Newtons per millimeter and preferably greater than 100 Newtons per millimeter.

11. Clamp-on ultrasonic flowmeter according to one of claims 4 to 9 without 7, wherein the flexible connecting element (15) in a longitudinal direction of the connecting element (15) has a spring constant greater than 500 Newton per millimeter, and in particular greater than 800 Newton per millimeter and preferably greater than 1000 Newton per millimeter, and / or wherein the flexible connecting element (15) has a spring constant in a longitudinal direction of the connecting element (15) that is at least a factor of 2 and in particular at least a factor of 4 greater than a spring constant of the tensioning belt or chain along a corresponding longitudinal direction.

12. Clamp-on ultrasonic flowmeter according to one of the preceding claims, comprising at least two pairs of ultrasonic transducers, wherein one ultrasonic transducer (10) of each of two pairs of ultrasonic transducers forms the counterweight (14) of the other ultrasonic transducer of the two pairs of ultrasonic transducers.

13. Clamp-on ultrasonic flowmeter according to one of claims 1 to 11, wherein the counterweight (14) is neither designed and / or suitable to generate nor receive ultrasonic waves.

14. The clamp-on ultrasonic flowmeter according to claim 13, wherein the counterweight (14) does not have an ultrasonic transducer or no ultrasonic transducer is arranged on the counterweight (14).

15. The clamp-on ultrasonic flowmeter according to any one of the preceding claims, wherein the ultrasonic transducer, the counterweight (14), and the connecting element (15) are configured such that the ultrasonic transducer remains in its mounted position during mechanical deformation of the pipeline or the measuring tube, in particular due to temperature.