CLAMP-ON ULTRASONIC FLOW METER

Description

[0001] The invention relates to a clamp-on ultrasonic flow meter for measuring the flow velocity or volumetric flow rate of a medium flowing through a pipeline.

[0002] Such devices are known, for example, from DE102020116181A1. The attachment of ultrasonic transducers to the measuring tube or pipeline is achieved, for example, using tension straps or magnets. A problematic aspect of such devices is the attachment of the individual ultrasonic transducers to a measuring tube or pipeline, particularly when the transducers are located away from the vertical of the cross-section of the measuring tube or pipeline. In this case, for example, loosening or slippage of the tension strap caused by temperature fluctuations, or vibration-induced displacement of the magnets, leads to a shift of the ultrasonic transducers in the direction of gravity.

[0003] CN 212363316 U describes an ultrasonic flow meter with a sliding ring in conjunction with counterweight blocks, allowing the ultrasonic transducer to be easily rotated on the outside of the pipe wall to find an optimal mounting position. A disadvantage of this solution is that it is unsuitable for existing pipelines that cannot be opened, and therefore also unsuitable for clamp-on ultrasonic flow meters.

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

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

[0006] A clamp-on ultrasonic flow meter according to the invention for measuring a flow velocity or volumetric flow rate of a medium flowing through a pipeline comprises 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 flow meter integrated into the pipeline with a particularly round cross-section, an electronic measuring / operating circuit for operating the at least one ultrasonic transducer and for evaluating measurement signals from the at least one ultrasonic transducer and providing measured values, wherein the pipeline or measuring tube has in cross-sections each 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 with respect to the diameter in an associated cross-section, wherein each ultrasonic transducer is assigned a counterweight, in particular exactly one counterweight (14), which is spaced apart with respect to the vertical diameter opposite to the ultrasonic transducer, and is characterized in that the ultrasonic transducer and the associated counterweight are connected by a flexible, and in particular resilient, connecting element, such as a strap or a rope or a chain or a spring, which connecting element is located above, in particular exclusively above, the measuring tube or measuring tube.the pipeline, whereby the flexible connecting element, when the clamp-on flow meter is arranged on the pipeline or on the measuring tube, is in a tensioned state due to the ultrasonic transducer and the counterweight.

[0007] In this way, the effects of, for example, temperature fluctuations or vibrations on the position of the ultrasound transducers are reduced.

[0008] The flexible connecting element has a spring constant greater than 50 Newtons per millimeter in the longitudinal direction, and in particular greater than 80 Newtons per millimeter and preferably greater than 100 Newtons per millimeter.

[0009] In one embodiment, an ultrasound transducer of a pair has a first circumferential distance extending from a starting point to a center of gravity of the respective ultrasound transducer, wherein the associated counterweight has a second circumferential distance to the vertical diameter, wherein the magnitudes of the first circumferential distance and the second circumferential distance deviate by less than 20% from a mean value of the magnitudes.

[0010] In this way, a displacement-causing influence on the ultrasound transducer can be weakened.

[0011] In one embodiment, the ultrasound transducer of a pair has a first mass, and the counterweight has a second mass, wherein the first mass and the second mass deviate less than 20% from an average of the masses.

[0012] In this way, a displacement-causing influence on the ultrasound transducer can be weakened.

[0013] In one embodiment, the attachment of the ultrasonic transducers to the measuring tube or to the pipeline is accomplished, for example, by means of a magnet or a tension strap spanning the measuring tube or the pipeline.

[0014] In one embodiment, the counterweight has a non-slip surface, which surface is in contact with the measuring tube or the pipeline.

[0015] In this way, displacement of the ultrasound transducer can be better inhibited.

[0016] In one design, the slip resistance produced 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.

[0017] In one embodiment, the ultrasonic transducer and counterweight are each attached to the tensioning strap, for example by crimping or screwing.

[0018] In one embodiment, the tension strap forms the flexible connecting element.

[0019] 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 glass, carbon, polymer, or a natural material such as hemp.

[0020] In one embodiment, the flexible connecting element has a spring constant greater than 50 Newtons per millimeter, and in particular greater than 80 Newtons per millimeter and preferably greater than 100 Newtons per millimeter, in the absence of a tensioning strap or chain in a longitudinal direction of the connecting element.

[0021] In the case of a strap or rope as a flexible connecting element, the materials can, for example, be processed in the form of fibers.

[0022] In one embodiment, when a tensioning strap or chain is present, the flexible connecting element has a spring constant greater than 500 Newtons per millimeter, and in particular greater than 800 Newtons per millimeter and preferably greater than 1000 Newtons per millimeter, in a longitudinal direction of the connecting element and / or wherein the flexible connecting element has a spring constant in a longitudinal direction of the connecting element which is at least by a factor of 2 and in particular at least by a factor of 4 greater than a spring constant of the tensioning strap or chain along a corresponding longitudinal direction.

[0023] In one embodiment, the clamp-on ultrasonic flowmeter comprises at least two pairs of ultrasonic transducers, wherein one ultrasonic transducer of each pair of ultrasonic transducers forms the counterweight of the other ultrasonic transducer of the two pairs of ultrasonic transducers.

[0024] In one embodiment, the counterweight is neither designed and / or suitable to generate nor receive ultrasound waves.

[0025] In one embodiment, the counterweight does not have an ultrasonic transducer or no ultrasonic transducer is arranged on the counterweight.

[0026] 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 mechanical deformation of the pipeline or measuring tube, particularly due to temperature.

[0027] The invention will be described below using exemplary embodiments. Fig. 1 sketches an exemplary schematic clamp-on ultrasonic flowmeter according to the state of the art in a side view; Fig. 2 outlines an exemplary schematic implementation of the invention in a front view.

[0028] Fig. 1 Figure 1 shows an exemplary clamp-on ultrasonic flowmeter with two ultrasonic transducers arranged on a measuring tube 12 integrated into a pipeline or on a pipeline 11. These transducers are configured to transmit and receive ultrasonic signals reciprocally. An electronic measuring / operating circuit 20 is used to operate the ultrasonic transducers, evaluate their measurement signals, and provide measured values. For example, the flow velocity or the speed of sound of the medium can be determined from the transit-time differences of ultrasonic signals traveling in and against the 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 that only require an ultrasonic transducer for flow measurements.

[0029] Fig. 2 Figure 1 shows a front view of an exemplary clamp-on ultrasonic flowmeter according to the invention, comprising a pair of ultrasonic transducers arranged in series and transmitting ultrasonic signals through the medium with an even number of measuring tubes or pipe crossheads. Regarding the basic technical operation, the following applies: Fig. 1 Said.

[0030] 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 with respect to the diameter in an associated cross-section, wherein, according to the invention, each ultrasonic transducer is assigned a counterweight which is spaced apart with respect to the vertical diameter opposite to the ultrasonic transducer.

[0031] According to the invention, an ultrasonic transducer and an associated counterweight are connected by a flexible connecting element 15, such as a strap or a rope, which connecting element runs above the measuring tube or pipeline, wherein the flexible connecting element is in a state of tension exerted by the ultrasonic transducer and the counterweight. In this way, the circumferential component of the weight force of the ultrasonic transducer 10 is reduced in magnitude, thus preventing the sensor from shifting.

[0032] In one embodiment, the counterweight 14 has a non-slip surface 14.1, which is in contact with the measuring tube 12 or the pipe 11. This further stabilizes the ultrasonic transducer, as the counterweight is securely positioned. The non-slip effect can be achieved through a surface texture such as a pyramid or needle structure, or through an elastomer such as acrylonitrile butadiene rubber or silicone, or through a self-adhesive coating.

[0033] In one embodiment, the ultrasound transducer of each pair has a first circumferential distance 13.2 from the vertical diameter, and the counterweight has a second circumferential distance from the vertical diameter, wherein the magnitudes of the first circumferential distance and the second circumferential distance deviate by less than 20% from a mean value of the magnitudes. This contributes to better compensation of the circumferential component of the weight force of the ultrasound transducer.

[0034] In one embodiment, each pair of ultrasonic transducers has a first mass, and each counterweight has a second mass, wherein the first and second masses deviate by less than 20% from an average value of the masses. This contributes to better compensation of the circumferential component of the weight force of the ultrasonic transducer.

[0035] The attachment of the ultrasonic transducers 10 to the measuring tube 12 or to the pipeline 11 can be accomplished, as shown here for example, by means of a magnet 16 and / or a tension strap 17.1 or a chain 17.2 spanning the measuring tube or the pipeline.

[0036] The ultrasonic transducer and counterweight can each be attached to the tensioning strap by crimping or screwing.

[0037] In one embodiment, the tensioning strap 17.1 or the chain 17.2 forms the flexible connecting element 15.

[0038] In one embodiment, the flexible connecting element has a spring constant greater than 50 Newtons per millimeter in a longitudinal direction of the connecting element, and in particular greater than 80 Newtons per millimeter and preferably greater than 100 Newtons per millimeter.

[0039] In one embodiment, the flexible connecting element has a spring constant greater than 500 Newtons per millimeter, and in particular greater than 800 Newtons per millimeter and preferably greater than 1000 Newtons per millimeter, in a longitudinal direction of the connecting element, and / or the flexible connecting element has a spring constant which is at least by a factor of 2 and in particular at least by a factor of 4 greater than a spring constant of the tensioning strap or chain along a corresponding longitudinal direction.

[0040] The ultrasonic signals generated by the ultrasonic transducers can pass through the measuring tube or pipeline once or multiple times, i.e., single or multi-traverse systems. The in Fig. 2The number and arrangement of ultrasonic transducers shown 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, wherein one ultrasonic transducer from each of two different pairs forms the counterweight of the other ultrasonic transducer of the two different pairs.

[0041] In one embodiment, the counterweight is neither designed nor suitable for generating nor receiving ultrasound waves. Therefore, the counterweight itself is not an ultrasound transducer as described in the embodiment above, but rather a simple inactive, i.e., acoustically inactive, body.

[0042] In one embodiment, the counterweight does not have an ultrasonic transducer, or rather, no ultrasonic transducer is arranged on the counterweight. Therefore, the counterweight is also not an adapter, sensor adapter for receiving an ultrasonic transducer, or similar device.

[0043] In one embodiment, the ultrasonic transducer, the counterweight, and the connecting element are designed such that the ultrasonic transducer remains in its mounting position even when the pipeline or measuring tube undergoes mechanical deformation, particularly due to temperature. When the assembly is mounted to the pipeline or measuring tube, the ultrasonic transducer is already in its mounting position. If the diameter of the pipeline or measuring tube changes due to temperature or pressure-related influences, the ultrasonic transducer, according to the invention, does not slip but remains fixed in its original mounting position. While the position of the ultrasonic transducer can change radially from the center, it cannot change circumferentially. Reference symbol list

[0044] 1 Clamp-on ultrasonic flowmeter 10 Ultrasonic transducer 11 Piping 12 Measuring tube 13.1 Diameter 13.2 Circumference 14 Counterweight 14.1 Anti-slip surface 15 Flexible connecting element 16 Magnet 17.1 Tension strap 17.2 Chain 20 Electronic measuring / operating circuit

Claims

1. Clamp-on ultrasonic flow meter (1) for measuring a flow velocity or a volume flow of a medium flowing through a pipe (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 pipe (11) with a particularly round cross-section or to a measuring tube (12) of the flow meter integrated into the pipe with a particularly round cross-section, - an electronic measuring / operating circuit (20) for operating the at least one ultrasonic transducer and for evaluating measurement signals from the at least one ultrasonic transducer and providing measured values, wherein the pipeline or measuring tube has a diameter (13.1) in cross-sections in a longitudinal section containing a pipeline axis or measuring tube axis , wherein the at least one ultrasonic transducer is arranged in an associated cross-section with respect to the diameter at a circumferential distance, wherein each ultrasonic transducer is assigned a counterweight (14), in particular exactly one counterweight (14), which is spaced apart with respect to the vertical diameter opposite to the ultrasonic transducer, characterized in that 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) is in a tensioned state by the ultrasonic transducer and the counterweight when the clamp-on ultrasonic flow meter (1) is arranged on the pipeline or on the measuring pipe.

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

3. Clamp-on ultrasonic flow meter according to claim 1 or 2, wherein each ultrasonic transducer (10) has a first mass, wherein the counterweight (14) having 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 flow meter according to any of the preceding claims, wherein the attachment of the at least one ultrasonic transducer to the measuring tube or the pipe is effected by means of a magnet (16) or a tension belt (17.1) or chain (17.2) spanning the measuring tube or pipe.

5. Clamp-on ultrasonic flow meter 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 flow meter according to claim 5, wherein the slip resistance by means of 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 flow meter according to any of claims 4 to 6, wherein the ultrasonic transducer (10) and counterweight (14) are each attached to the tension strap by a fastening such as crimping, screwing, gluing, welding, or riveting.

8. Clamp-on ultrasonic flow meter according to any one of claims 4 to 7, wherein the tension strap (17) forms the flexible connecting element (15).

9. Clamp-on ultrasonic flow meter 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 glass, carbon, polymer.

10. Clamp-on ultrasonic flow meter 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 greater than 50 newtons per millimeter in a longitudinal direction of the connecting element (15), and in particular greater than 80 Newtons per millimeter and preferably greater than 100 Newtons per millimeter.

11. Clamp-on ultrasonic flow meter according to any of claims 4 to 9 except 7, wherein the flexible connecting element (15) has a spring constant greater than 50 Newtons per millimeter in a longitudinal direction of the connecting element (15), and element (15), has a spring constant 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 (15) is arranged in a longitudinal direction of the connecting element (14) and is connected to the connecting element (14) in a manner such that the connecting element (14) can be moved in a direction parallel to the longitudinal direction of the connecting element (14) when the connecting element (14) is moved in a direction perpendicular to the longitudinal element (15) has a spring constant 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 strap or chain along a corresponding longitudinal direction.

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

13. Clamp-on ultrasonic flow meter according to one of claims 1 to 11, wherein the counterweight (14) is neither designed and / or suitable for generating ultrasonic waves nor for receiving ultrasonic waves.

14. Clamp-on ultrasonic flow meter 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. Clamp-on ultrasonic flow meter according to one of the preceding claims, wherein the ultrasonic transducer, the counterweight (14), and the connecting element (15) are designed such that the ultrasonic transducer remains in its mounting position in the event of mechanical deformation of the pipeline or measuring tube, in particular due to temperature.