CORIOLIS SENSOR AND CORIOLIS MEASURING DEVICE HAVING A CORIOLIS SENSOR

Abstract

A Coriolis sensor includes: a measurement tube having an inlet and an outlet; an exciter; and two sensor elements, wherein the exciter and/or the sensor element respectively have a coil arrangement and a magnet arrangement, wherein the magnet arrangement has a retainer for magnets, at least one first magnet group and at least one second magnet group, wherein the retainer is U-shaped with a first arm, a second arm and a base connecting the arms, wherein the retainer engages around the coil arrangement, wherein the first magnet group is retained on the first side of the coil arrangement by the retainer, and wherein the second magnet group is retained on the second side of the coil arrangement by the retainer, wherein the retainer has a cavity in a region of each of the arms for receiving a magnet group, wherein the retainer is manufactured using a 3D printing process.

Claims

1-13. (canceled)

14. A Coriolis measuring sensor of a Coriolis measuring instrument for detecting a mass flow rate or a density of a medium flowing through the Coriolis measuring instrument, the sensor comprising: at least one measurement tube having an inlet and an outlet and configured to convey the medium between the inlet and outlet; a supporting element configured to retain the at least one measurement tube; at least one exciter configured to excite the at least one measurement tube to vibrate; and at least two sensor elements, each configured to detect vibrations of the at least one measurement tube, wherein the at least one exciter and/or at least one sensor element of the at least two sensor elements each respectively have a coil arrangement with at least one coil, respectively, and each have a magnet arrangement, wherein each magnet arrangement and each corresponding coil arrangement are movable relative to each other, wherein each magnet arrangement includes a retainer for magnets, at least one first magnet group including at least one magnet, and at least one second magnet group including at least one magnet, wherein the retainer is U-shaped, including a first arm, a second arm and a base connecting the arms, wherein the retainer engages around the corresponding coil arrangement such that the first arm is arranged on a first side of the corresponding coil arrangement with respect to a coil cross-section, and wherein the second arm is arranged on a second side of the corresponding coil arrangement, wherein the first magnet group is retained on the first side of the corresponding coil arrangement by the retainer, and wherein the second magnet group is retained on the second side of the corresponding coil arrangement by the retainer, wherein the retainer includes a cavity in a region of each of the first and second arms, wherein each cavity is configured to receive one of the magnet groups, wherein the cavities are each defined by a corresponding cavity wall, wherein the corresponding cavity wall includes at least one first opening adapted to receive the magnet group, and wherein the retainer is manufactured using a three-dimensional (3D) printing process.

15. The sensor of claim 14, wherein the at least one first and second magnet groups are each retained in the respective cavity using an adhesive.

16. The sensor of claim 15, wherein the adhesive is especially a ceramic adhesive.

17. The sensor of claim 15, wherein each respective cavity wall includes at least one undercut in a region of the at least one first opening on an inner side adjacent the respective cavity, which at least one undercut is configured to receive a portion of the adhesive.

18. The sensor of claim 14, wherein a wall of the cavity on a side of the cavity facing toward a respective opposing arm has, at least in portions, a first wall thickness that is smaller than a wall thickness of the cavity wall of other cavity sides, or wherein a wall of the cavity has a second opening, at least in portions, on a side of the cavity facing toward the respective opposing cavity.

19. The sensor of claim 14, wherein the at least one first opening can be closed by a closure mechanism, including a folding mechanism or a bracket mechanism, wherein a flap or a bracket is a component of the retainer.

20. The sensor of claim 14, wherein each magnet group includes two magnets and at least one magnetically conductive closure device, wherein magnetic fields of the two magnets are oriented opposite each other, and wherein the closure device is configured to conduct and merge field lines of the magnetic fields of the two magnets, wherein the magnets are mechanically contacted with the closure device, and wherein magnetic fields of opposing magnets of different magnet groups are rectified.

21. The sensor of claim 14, wherein the at least one coil has a central region, and a winding region comprising the central region, wherein, in an idle state of the at least one measurement tube, a boundary between magnets of each magnet group, as projected onto the cross-sectional plane, is disposed at least in portions in the central region.

22. The sensor of claim 14, wherein the cavity wall, at least in portions, includes a first structure on a side opposite the first opening, and wherein an associated magnet group of the at least one first and second magnet groups includes a second structure which is complementary to the first structure at least in portions, wherein the associated magnet group, in the installed state, is configured to terminate, in a fitting manner, with the first structure via the second geometric structure.

23. The sensor of claim 14, further comprising two collectors, including: a first collector on an upstream side of the sensor configured to receive the medium flowing from a source flow into the sensor and to guide the medium to the inlet of the at least one measurement tube; and a second collector configured to receive the medium exiting the outlet of the at least one measurement tube and to guide the medium into the source flow.

24. The sensor of claim 14, wherein the at least one measurement tube of the sensor includes a single measurement tube, wherein the retainer and corresponding coil arrangement of the at least one exciter or the at least one sensor element are respectively fastened to the measurement tube, and wherein the coil arrangement and the retainer of the at least one exciter or the at least one sensor element are respectively fastened to the supporting element, or wherein the at least one measurement tube of the sensor includes a measurement tube pair, wherein the retainer and corresponding coil arrangement of the at least one exciter or the at least one sensor element are respectively fastened to a first measurement tube of the measurement tube pair, and wherein the coil arrangement and the retainer of the at least one exciter or the at least one sensor element are respectively fastened to a second measurement tube of the measurement tube pair.

25. The sensor of claim 24, wherein the at least one measurement tube of the sensor includes two measurement tube pairs.

26. The sensor of claim 14, wherein the retainer of each magnet arrangement is made of at least one 3D-printable metal or at least one metal alloy.

27. A Coriolis measuring device, comprising: a Coriolis sensor according to claim 14; an electronic circuit configured to operate the at least two sensor element and the at least one exciter, wherein the at least two sensor element and the at least one exciter are connected to the electronic circuit via electrical connections; and an electronics housing adapted to contain the electronic circuit, wherein the electronic circuit is further configured to determine and output mass flow rate values and/or density values of the medium.

Description

[0025] The invention will now be described with reference to exemplary embodiments.

[0026] FIG. 1 shows a Coriolis measuring device 1 with an example of a Coriolis sensor according to the invention.

[0027] FIG. 2 shows a section through a sensor element or exciter.

[0028] FIG. 3 shows a detail of a section through a retainer according to the invention for magnets with a magnet group.

[0029] FIG. 4 schematically illustrates an arrangement of a magnet group with respect to a coil in the idle state of a measurement tube.

[0030] FIG. 1 shows an example of a Coriolis measuring device 1 with an exemplary Coriolis sensor 10. The sensor comprises a supporting element 20, a first measurement tube 11.1, and a second measurement tube 11.2. The sensor furthermore comprises an exciter 12 for exciting measurement tube vibrations, and two sensor elements 13 for detecting measurement tube vibrations. The Coriolis measuring device comprises an electronics housing 80, in which is arranged an electronic measuring/operating circuit 77 which is configured to operate the exciter and the sensor elements and to provide measured values with respect to a medium flowing through the measurement tubes. The exciter and the sensor elements are connected to the electronic measuring/operating circuit 77 by means of electrical connections 24.

[0031] The embodiment shown here is by way of example; the sensor can thus also have only one measurement tube or more than two measurement tubes.

[0032] FIG. 2 shows a section through an exciter 12 or sensor element 13, with a retainer 15.3 according to the invention for magnets with magnet groups, as well as a coil arrangement 14.

[0033] The retainer 15.3 has a U-shape with a first arm 15.31, a second arm 15.32, and a base 15.33 connecting the arms. The retainer engages around the coil arrangement so that the first arm is arranged on a first side of the coil arrangement 14.01 with respect to a coil cross section, and the second arm is arranged on a second side of the coil arrangement 14.02, wherein a first magnet group 15.1 is retained on the first side of the coil arrangement by the retainer, and wherein a second magnet group 15.2 is retained on the second side of the coil arrangement by the retainer. As shown here, each magnet group may have two magnets 15.6, wherein the magnets of one magnet group advantageously have differently oriented magnetic fields. Opposing magnets of different magnet groups advantageously have magnetic fields of the same orientation. In this way, an overall magnetic field generated by the individual magnetic fields has strong inhomogeneity. Relative movements between coil arrangement 14 and retainer 15.3 lead to a strong induction of electric fields in a coil of the coil arrangement 14.01 insofar as the inhomogeneity decreases in a central region of the coil 14.1; see also FIG. 4 in this respect. In order to strengthen the magnetic flux of the magnetic fields, the magnet group has, in addition to two magnets, a magnetically conductive closure device which is configured to close field lines of magnetic fields of adjacent magnets of a magnet group. The closure device is thereby made of a ferromagnetic material, for example.

[0034] The retainer is preferably formed from a magnetically non-conductive or only weakly conductive material, such as stainless steel or aluminum.

[0035] The retainer has a cavity 15.4 in the region of each of the arms, wherein the cavities are configured to receive the magnet groups. The cavities are respectively formed by a cavity wall 15.5, wherein the cavity wall respectively has at least one first opening 15.51 for receiving a magnet group. As shown in the first arm 15.31, each arm can have a second opening 15.52 on a side of the associated cavity facing toward the coil arrangement, in order to reduce a magnetic resistance of the retainer. Alternatively, a wall thickness can be reduced for the same purpose as shown in the second arm 15.32.

[0036] The magnet groups 15.1, 15.2 are advantageously each retained in the respective cavity by means of an adhesive, wherein the adhesive is especially a ceramic adhesive. As shown here, an undercut in the cavity wall in the region of the corresponding first opening can be configured to receive a portion of an adhesive compound upon inserting the magnet groups into the respective cavity. After the adhesive compound cures, the adhesive compound is anchored in the undercut and secures the magnet group so that it is immovably located in the cavity.

[0037] Furthermore, the first opening 15.51 can, for example, be closable by means of a closure mechanism 15.54 as shown here. The closure mechanism can be a folding mechanism or a bracket mechanism, for example.

[0038] The retainer is produced especially by means of a 3D printing process. It can thereby be manufactured in a compact and lightweight form so that, when fastened to a measurement tube, measurement tube vibrations are influenced only slightly and in a non-disruptive manner.

[0039] The retainer can, for example, have a bore for fastening to a fastening device. A person skilled in the art will select a manner of fastening in accordance with their requirements.

[0040] Typical dimensions of a convex envelope of the retainer are 15 mm * 10 mm * 5 mm, wherein each dimensional specification can deviate by less than 40% from said value.

[0041] Typical dimensions of a magnet are 5 mm * 3.5 mm * 2 mm, wherein each dimensional specification can deviate by less than 40% from said value. The magnets may also have a round or oval cross section.

[0042] Typical dimensions of the magnetically conductive closure device are 5 mm * 3.5 mm * 1 mm, wherein each dimensional specification can deviate by less than 30% from said value.

[0043] FIG. 3 illustrates a section through a cavity with a magnet group located therein. As shown here, the cavity wall can at least in portions have a first geometric structure 15.55 on a side facing away from the first opening, wherein an associated magnetic group can have a second geometric structure 15.56 which is complementary to the first geometric structure at least in portions, wherein the magnet group in the installed state is configured to terminate, in a fitting manner, with the first geometric structure by means of the second geometric structure. As shown here, the geometric structures may have a rectangular shape. Any other shape, such as a triangular shape, can be used just as well. Among other things, a triangular shape is advantageous since no precisely targeted insertion of the magnet group is necessary during assembly; rather, the end position occurs automatically.

[0044] FIG. 4 illustrates a relative positioning of a magnet group with two magnets 15.6 with respect to a coil arrangement 14 with a coil 14.1. The coil has a central region 14.11 and a winding region surrounding the central region. In an idle state of the at least one measurement tube, a boundary between the magnets of a magnet group, projected onto the cross-sectional plane, is preferably located at least approximately in a center of the central region.

[0045] In the direction of the relative movements caused by measurement tube vibrations, the central region of the coil preferably has an extent that is larger than vibration amplitudes typical of the measurement tube and that is smaller than two times a typical vibration amplitude.

[0046] The boundary between the magnets thereby preferably travels perpendicular to the direction of the relative movement. Relative movements between the coil and the magnet arrangement thereby cause a strong induction of electrical voltages in the coil.

[0047] Given a single-tube Coriolis sensor, the retainer 15.3 of a sensor element or exciter is preferably arranged on the measurement tube, and the coil arrangement of a sensor element or exciter is preferably arranged on the supporting element 20 by means of a retaining device.

[0048] Given a double-tube Coriolis sensor, the retainer of a sensor element or exciter is preferably fastened to a first measurement tube, and the coil arrangement of a sensor element or exciter is preferably fastened to a second measurement tube.

LIST OF REFERENCE SIGNS

[0049] 1 Coriolis measuring device

[0050] 10 Coriolis sensor

[0051] 11 Measurement tube

[0052] 11.1 First measurement tube

[0053] 11.2 Second measurement tube

[0054] 12 Exciter

[0055] 13 Sensor element

[0056] 14 Coil arrangement

[0057] 14.01 First side of the coil arrangement

[0058] 14.02 Second side of the coil arrangement

[0059] 14.1 Coil

[0060] 14.11 Central region

[0061] 14.12 Winding region

[0062] 15 Magnet arrangement

[0063] 15.1 First magnet group

[0064] 15.2 Second magnet group

[0065] 15.3 Retainer for magnets

[0066] 15.31 First arm

[0067] 15.32 Second arm

[0068] 15.33 Connecting base

[0069] 15.4 Cavity

[0070] 15.5 Cavity wall

[0071] 15.51 First opening

[0072] 15.52 Second opening

[0073] 15.53 Undercut

[0074] 15.54 Closing mechanism

[0075] 15.55 First geometric structure

[0076] 15.56 Second geometric structure

[0077] 15.6 Magnet

[0078] 15.7 Magnetically conductive closure device

[0079] 20 Supporting element

[0080] 77 Electronic measuring/operating circuit

[0081] 80 Electronics housing