Flow meter and reflector

Abstract

The invention relates to a flow meter comprising at least two measuring sensors, preferably ultrasonic sensors, which are spaced apart from each other, wherein the measuring signals of the measuring sensors are reflected by an anti-deposition reflector.

Description

[0001] This application is a divisional application of patent application No. 201880050993.X entitled "Flowmeter and Reflector", filed on August 7, 2018. Technical Field

[0002] The present invention relates to a flow meter according to the preamble of claim 1, the flow meter being used to measure the flow rate of fluid in a pipe or similar container, and the present invention relates to a reflector suitable for such a flow meter. Background Technology

[0003] EP 2 306 160 A1 discloses a flow meter / flow counter in which a measuring insert both houses an ultrasonic transducer and forms the actual measuring channel. Thus, the profile body forming the measuring channel is immersed through a recess in a pipe section surrounded by a flange, which affects the flow rate within the measuring range, and an additional reflector for measuring the signal is provided thereon.

[0004] A similar solution is shown in EP 2 386 836 B1. The flow path inside the measurement channel is defined by a housing insert adapted to be inserted from the end face of the housing, which also supports a reflector for the ultrasonic signal, so that the ultrasonic wave is output by one of the ultrasonic transducers and, for example, reflected via the reflector to another ultrasonic transducer located downstream. Of course, the signal can also be directed in the opposite direction.

[0005] A flow meter is described in document EP 0 890 826 B1, in which a measuring insert is equivalently attached to a tangentially extending flange in the region of a pipe section of the housing. Ultrasonic energy is helically deflected by multiple reflective surfaces fastened to the bottom, sidewalls, and cover of the insert. Multiple inserts made of plastic are configured to accommodate reflectors and to position these reflectors with high precision.

[0006] The drawback of these solutions is that deposits can form on the reflector due to particles, sediments, and similar components in the fluid, which can lead to signal quality degradation. Summary of the Invention

[0007] Conversely, the purpose of this invention is to provide a flow meter / flow counter and a reflector that achieves measurement with improved measurement accuracy and improved signal quality.

[0008] This objective is achieved with respect to the flow meter having the features of claim 1 and the reflector having the features of independent claim 9.

[0009] Advantageous developments of the invention are the subject of the dependent claims.

[0010] Preferably, the flush-inserted reflector has a reflective surface whose surface structure is configured to eliminate potential contact surfaces for dirt deposits, which, despite reduced turbulence and stall, can still occur. At extremely low flow rates and with very slow velocities, if the transverse walls on the reflector side are aligned with gravity, dirt deposits in the form of sediments and / or other suspended particles will be deposited in the fluid at the reflector-side transverse walls of the measurement channel due to gravity. Due to the nature of the reflector surface, deposition on the reflector surface becomes virtually impossible even at low flow rates, thus permanently ensuring the reflection of the measurement signal and the associated high signal quality. To further counteract deposition, the entire measurement channel may be rotated along the axis of the flow direction, so that the transverse walls on the reflector side are not aligned with gravity.

[0011] According to a preferred embodiment of the invention, the reflector is positioned away from the ultrasonic transducer at the transverse wall, preferably inserted flush with a recess in the transverse wall. Because the reflector / mirror and / or sensor / connector is inserted flush into the measurement channel, turbulence and stall in the area of ​​these components, as well as the associated dirt buildup and resulting signal distortion, are prevented. It is also conceivable to arrange more than one reflector in the measurement channel. In a three-reflector arrangement, two reflectors are positioned at the transverse wall opposite the sensor, and one reflector is positioned between the sensors, thus forming a W-shaped signal path. This three-reflector arrangement is suitable for lengthening the signal path, thereby improving measurement accuracy.

[0012] To improve resistance to deposition, the surface structure is preferably formed in a biomimetic manner. This form offers advantages in areas such as friction, wear, lubrication, wetting, self-cleaning, and antifouling. Surprisingly, it has been shown that a specifically structured surface based on a biological model (biomimetic) achieves the desired function (e.g., resistance to deposition) while still ensuring adequate reflection, compared to a smooth surface. This surface structure can also be formed at the coating of a reflector.

[0013] An example embodiment of a biomimetic surface constitutes a surface with a sharkskin effect (rib effect). This design continuously reduces resistance in fluids and prevents the deposition and growth of any type of organism (fouling). The sharkskin effect is caused, in particular, by longitudinal microgrooves on the surface. Ideally, these longitudinal microgrooves are in the form of blades and perpendicular to the surface. However, a wave-like profile (fan-shaped) shape, made conveniently, also achieves the desired effect. The ratio between the height of the longitudinal grooves and the distance between them depends on the flow velocity of the surrounding fluid, and when the velocity reaches 5 m / s, this ratio should fall within the range of 0.4 to 0.9, ideally within the range of 0.7. In this embodiment, the rib height (h) is 50 µm, and the rib spacing (s) is 70 µm.

[0014] Another example of a biomimetic surface is a surface exhibiting the lotus leaf effect, where a superhydrophobic layer is provided, on which the contact surface with the fluid occupies only a few percent of the fluid surface. This effect is caused by structural protrusions in the biomimetic surface, which do not impair the reflection of ultrasonic waves.

[0015] Another suitable variation of the biomimetic surface is a surface with a rice leaf effect, that is, protrusions of varying heights arranged along the direction of fluid flow on the surface. The protrusions are arranged transversely to the flow direction, wherein, when viewed from the center of one protrusion to the center of the next, some protrusions appear to be half the height of the others and have equal diameters, spaced twice the diameter apart from each other.

[0016] In the flowmeter according to the invention, the sidewalls of the measuring channel, extending in the direction of the vertical axis (generally in the direction of transmitting and receiving ultrasonic signals), are raised and form an elliptical shape, wherein the generally flat or slightly raised transverse walls extend generally in the direction of the transverse axis. Surprisingly, this elliptical geometry has proven to ensure optimal flow and the accompanying highest signal quality.

[0017] The aforementioned biomimetic surface has been optimized for its function as an ultrasonic reflector. Attached Figure Description

[0018] Preferred exemplary embodiments of the present invention will be described in detail below with the aid of the accompanying drawings, in which:

[0019] Figure 1 An example embodiment of a flow meter including a reflector is shown;

[0020] Figure 2 A schematic diagram showing the reflector;

[0021] Figure 3 The surface structure exhibiting the sharkskin effect is schematically illustrated.

[0022] Figure 4 A schematic diagram of the surface layer that produces the rice leaf effect is shown;

[0023] Figure 5 A schematic diagram of a reflector surface layer exhibiting a combination of sharkskin and rice leaf effects is shown. Detailed Implementation

[0024] Figure 1 The diagram illustrates a longitudinal section of the flow meter 1. Two connectors 2 and 4 are shown in this view, each comprising two sensors 6 and 8. These sensors are inserted into two corresponding recesses 10a and 10b. The connecting surface 12 extends flush with the circumferential walls of the measuring channel 18 (adjacent areas of the transverse wall 14 and sidewall 16), which in this exemplary embodiment is formed by a pipe segment 20. Therefore, a portion of the flange 22 forms the transverse wall 14. In this exemplary embodiment, the opposing transverse wall 24 is formed as a recess 26 with an outward opening into which a reflector 28 is inserted.

[0025] Figure 2 The diagram illustrates the process based on... Figure 1 A possible example embodiment of the reflector 28 in the measurement channel 18. In this configuration, the reflector 28 is pressed into a recess. Therefore, the reflector 28 is required to have a base region 30. This shape can be configured in different ways in different types of inserts. Of particular importance is that the base material of the reflector 28 is a material suitable for reflecting ultrasound. Here, for example, a structure containing steel or a polymer structure can be used, where any other material suitable for reflecting ultrasound is also conceivable. A surface layer 32 is applied to the base material. The surface layer 32 is formed to have anti-deposition properties, which will be further discussed in the following figures.

[0026] Figure 3 The diagram schematically illustrates a method for designing a sharkskin effect on a surface. Longitudinal microgrooves 36 are provided on the base region 34. These longitudinal grooves protrude with a uniform height h and width t. The distances s between them are equal throughout the entire region. The longitudinal microgrooves 36 can be applied to the base material 34, for example, by machining the base material 34 or by a very fine casting or injection molding process. Due to the filigree structure, wave structures 38 of equal size can be produced at a reduced cost in terms of manufacturing. In the case of grooves in the wave structure 38, reflection and anti-deposition properties are not limited.

[0027] Figure 4The microscopic design of the rice leaf structure is schematically illustrated. The anti-deposition effect occurring in this way is attributed to the structure. Thus, individual protrusions 40, 42 are applied to the surface. For example, the smaller protrusion 42 has a height half that of the larger protrusion. When viewed in the flow direction, the protrusions 40, 42 are arranged side-by-side, whereby a row of large protrusions 40 alternates with a row of small protrusions 42. Except for the different heights, the protrusions are designed to be identical, such that the diameter D and the distance P between them are the same.

[0028] Figure 5 Formed Figure 3 and Figure 4 The two figures are combined. In this illustration, the waveform structure 38 with the sharkskin effect, along with the protrusions 40 and 42 that cause the rice leaf effect, are visible. It is important to observe that, in this case, the illustration has protrusions of uniform height. Variations with protrusions of varying heights as described above are not shown.

[0029] It has been found that the aforementioned coating or structure of reflector 28 is suitable for preventing deposition during use, or at least for preventing the formation of deposits.

[0030] The present invention discloses a flow meter comprising at least two measuring sensors (preferably ultrasonic sensors) spaced apart from each other, the measuring signals of which are reflected by an anti-deposition reflector.

[0031] List of reference numerals

[0032] 1. Flow meter

[0033] 2 Connecting parts

[0034] 4 Connecting parts

[0035] 6 sensors

[0036] 8 sensors

[0037] 10 concavity

[0038] 12 Connecting surfaces

[0039] 14. Transverse wall

[0040] 16 Sidewalls

[0041] 18 Measurement Channels

[0042] 20 pipe sections

[0043] 22 Flange

[0044] 24. Transverse wall

[0045] 26. Depression

[0046] 28 Reflectors

[0047] 30 Base Area

[0048] 32 Surface layer

[0049] 34. Base Area

[0050] 36 longitudinal micro-grooves

[0051] 38 Waveform Structure

[0052] 40 large bumps

[0053] 42 small bumps

Claims

1. A flow meter comprising a measuring channel (18) adapted to be inserted into a pipe section through which fluid flows, wherein at least two ultrasonic sensors (6, 8) are arranged in the measuring channel, wherein a reflector (28) is arranged away from the ultrasonic sensors (6, 8) at a transverse wall (24) of the measuring channel (18), the reflector (28) having an anti-deposition surface structure, characterized in that, The anti-deposition property of the reflector (28) is achieved through a biomimetic structure.

2. The flow meter according to claim 1, wherein, The biomimetic structure exhibits a sharkskin effect.

3. The flow meter according to claim 1, wherein, The biomimetic structure exhibits a lotus flower effect.

4. The flow meter according to claim 1, wherein, The biomimetic structure exhibits the rice leaf effect.

5. The flow meter according to claim 1, wherein, The biomimetic structure has a combination of sharkskin effect and / or lotus effect and / or rice leaf effect.

6. The flow meter according to any one of the preceding claims, wherein, The measurement channel (18) has an elliptical shape.

7. The flow meter according to any one of the preceding claims, wherein, The reflector (28) is inserted flush with the measuring channel (18) and / or inserted into the recess (26) of the measuring channel.

8. A reflector, specifically used for the flow meter (1) according to claim 1, characterized in that, The reflector (28) has an anti-deposition surface.

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