DE102019133461A1 - Electromagnetic flow meter - Google Patents

Abstract

The invention relates to a magnetic-inductive flow measuring device, comprising: a measuring tube (1) for guiding a flowable medium in a longitudinal direction, the measuring tube (1) being formed by a measuring tube body (2), the measuring tube body (2) having a receptacle ( 3); - at least two measuring electrodes (4) for forming a galvanic contact with the medium and for detecting a flow velocity-dependent measuring voltage induced in the flowing medium; and- a magnetic field generating device (5), wherein the magnetic field generating device (5) comprises at least one coil core (6) and at least one coil (7), wherein the coil core (7) has a first end face (9) and a second end face (10) which delimit a pole shoe (8) in the longitudinal direction of the measuring tube (1); characterized in that the coil core (6) is arranged in the receptacle (3) and that the measuring tube body (2) extends along the first end face (9) and the second end face (10) and these surfaces each extend in the longitudinal direction of the measuring tube (1 ) in particular completely covered.

Description

The invention relates to a magneto-inductive flow measuring device, a method for producing a magneto-inductive flow measuring device, a measuring point and a use of a magneto-inductive flow measuring device.

Electromagnetic flowmeters are used to determine the flow rate and volume flow of a flowing medium in a process line. An electromagnetic flowmeter has a magnet system that generates a magnetic field perpendicular to the direction of flow of the flowing medium. Individual coils are usually used for this. In order to achieve a predominantly homogeneous magnetic field, pole pieces are additionally shaped and attached in such a way that the magnetic field lines run essentially perpendicular to the transverse axis or parallel to the vertical axis of the measuring tube over the entire pipe cross-section. A pair of measuring electrodes attached to the outer surface of the measuring tube picks up an electrical measuring voltage or potential difference that is applied perpendicular to the direction of flow and to the magnetic field, which occurs when a conductive medium flows in the direction of flow when a magnetic field is applied. Since the measured voltage, according to Faraday's law of induction, depends on the speed of the flowing medium, the flow rate u and, with the addition of a known pipe cross-section, the volume flow V can be determined from the induced measurement voltage U.

So far there are only a few flowmeters that make use of Faraday's law of magnetic induction and at the same time are suitable for so-called single-use applications. Single-use applications require that the parts in contact with the medium can be exchanged. In the case of magnetic-inductive flowmeters, it would therefore be the measuring electrodes and parts of the measuring tube.

The DE 10 2016 118 064 A1 teaches a magnetic-inductive flow measuring device which has a U-shaped measuring tube receptacle for exchangeable measuring tubes. The magnet system is located in the measuring device housing and the mating contacts for the measuring electrodes in the measuring tube are in the measuring tube holder.

The invention is based on the object of providing a magnetic-inductive flow measuring device which, due to its compact design, is suitable for use in single-use applications.

Furthermore, the task is to provide a corresponding method for production, a corresponding measuring point and a corresponding use.

The object is achieved by the magnetic-inductive flow measuring device according to claim 1, the method according to claim 11, the flow measuring point according to claim 13 and the use according to claim 14.

• - ein Messrohr zum Führen eines fließfähigen Mediums in eine Längsrichtung,
  • wobei das Messrohr durch einen Messrohrkörper gebildet ist,
  • wobei der Messrohrkörper eine Aufnahme aufweist,
  • wobei der Messrohrkörper zumindest teilweise elektrisch isolierend ausgebildet ist;
• - mindestens zwei Messelektroden zum Bilden eines galvanischen Kontaktes mit dem Medium und zum Erfassen einer strömungsgeschwindigkeitsabhängigen, im fließenden Medium induzierten Messspannung,
  • wobei die Messelektroden in dem Messrohrkörper auf gegenüberliegenden Seiten angeordnet sind; und
• - eine magnetfelderzeugende Vorrichtung,
  • wobei die magnetfelderzeugende Vorrichtung mindestens einen Spulenkern und mindestens eine Spule umfasst,
  • wobei der Spulenkern aus einem einzelnen Blechteil oder aus einer Vielzahl an insbesondere in Längsrichtung des Messrohres gestapelter und miteinander verbundener Blechteile gebildet ist,
  • wobei der Spulenkern eine erste und eine zweite Stirnseite aufweist, die einen Polschuh in Längsrichtung des Messrohres abgrenzen;

und ist dadurch gekennzeichnet,
dass der Spulenkern in der Aufnahme angeordnet ist und
dass sich der Messrohrkörper entlang der ersten Stirnseite und der zweiten Stirnseite erstreckt und diese Flächen jeweils in Längsrichtung des Messrohres insbesondere vollständig bedeckt.The electromagnetic flowmeter according to the invention comprises

• - a measuring tube for guiding a flowable medium in a longitudinal direction,
  • wherein the measuring tube is formed by a measuring tube body,
  • wherein the measuring tube body has a receptacle,
  • wherein the measuring tube body is designed to be at least partially electrically insulating;
• - At least two measuring electrodes to form a galvanic contact with the medium and to record a flow rate-dependent measuring voltage induced in the flowing medium,
  • wherein the measuring electrodes are arranged in the measuring tube body on opposite sides; and
• - a magnetic field generating device,
  • wherein the magnetic field generating device comprises at least one coil core and at least one coil,
  • wherein the coil core is formed from a single sheet metal part or from a large number of sheet metal parts that are stacked and connected to one another, in particular in the longitudinal direction of the measuring tube,
  • wherein the coil core has a first and a second end face which delimit a pole piece in the longitudinal direction of the measuring tube;

and is characterized by
that the coil core is arranged in the receptacle and
that the measuring tube body extends along the first end face and the second end face and in particular completely covers these surfaces in each case in the longitudinal direction of the measuring tube.

It is particularly advantageous if the measuring tube body has a receptacle in which the coil core is arranged in a form-fitting manner and which is delimited in the longitudinal direction of the measuring tube by the measuring tube body. It is advantageous if the Recording is arranged directly on the measuring tube body, which also forms the channel for guiding the medium. Mounting packages are known in which further assemblies are arranged and attached to the measuring tube body, which are used to attach the magnetic field-generating device to the measuring tube body. According to the invention, a multi-part assembly package can be dispensed with, since the receptacle is integrated in the measuring tube body. The coil core can be inserted into the receptacle or already arranged in the receptacle during manufacture of the measuring tube, so that the coil core can no longer be removed afterwards.

The receptacle is preferably formed in that, during the manufacture of the one-piece measuring tube body, the coil cores are also arranged in the tool and are overmolded. As a result, a subsequent attachment of the coil core to the measuring tube body can be dispensed with, as is the case, for example, in FIG WO 2011/091899 A1 or in the WO 2004/072590 A1 is taught.

Advantageous refinements of the invention are the subject matter of the subclaims.

One embodiment provides that the coil core has at least two side surfaces which each connect the first end face to the second end face,
wherein the measuring tube body extends along the two side surfaces and in particular completely covers them.

The receptacle is preferably also delimited in the direction of the transverse axis by the measuring tube body, the transverse axis intersecting two opposing measuring electrodes. This is advantageously implemented by partially potting the coil core with the potting compound, which is used to form the measuring tube body. The coil core is thus fixed in place and does not require any further fastening elements to be held on the measuring tube body.

One embodiment provides that the pole piece and the coil core are formed in one piece.

On the one hand, this simplifies the respective production and, on the other hand, prevents air inclusions between the coil core and pole piece and thus inferior magnetic coupling between the two components.

One embodiment provides that the receptacle is at least partially designed as a hollow cylinder,
wherein the coil is wound around the measuring tube body in the area of the hollow cylindrical part of the receptacle.

The coils usually have a bobbin around which the coil windings are wound. The coil body and the coil windings are then arranged on the measuring tube of the flow meter. By winding the coil turns onto part of the receptacle, a coil body can be dispensed with. The coil turns are wound directly around the measuring tube body.

One embodiment provides that the measuring tube body is designed in one piece,
wherein the coil core and / or the measuring electrodes are partially encapsulated by means of an original molding process, in particular by means of an injection molding process.

In order to minimize the number of assembly steps, it is advantageous if the measuring tube body is designed in one piece and is manufactured by means of the injection molding process. The injection molding process also enables further measuring components to be integrated into the measuring tube body in one manufacturing step. From the DE 10 2017 115 149 A1 an electromagnetic flowmeter with encapsulated measuring electrodes is already known.

One embodiment provides that the measuring tube body is made of an insulating material, in particular a plastic and preferably polyetheretherketones (PEEK), polyaryletherketones (PAEK), polyphenylsulfones (PPSU), polyethersulfones (PESU), polysulfones (PSU), polyarylamides (PARA), glass and / or ceramic is made.

There is a demand for flowmeters with disposable measuring tubes for biopharmaceutical applications. For this, the materials that come into contact with the medium must be biocompatible and gamma-sterilizable. It is therefore particularly advantageous if the measuring tube is made from one of the above-mentioned materials, since these meet the biopharmaceutical requirements. The plastics mentioned are also suitable for injection molding.

One embodiment provides that the flow measuring device has a housing in which the magnetic field generating device is arranged,
wherein the housing is designed in two parts,
wherein a connector is arranged in the housing,
wherein the measuring electrodes and the coil are electrically connected to the connector, in particular via a ribbon cable.

It is particularly advantageous if the housing has a plug connector which is electrically connected to the measuring electrodes, the coils and possibly other electronic components and is set up to connect these to a measuring circuit, operating circuit and / or evaluation circuit in a separable manner. The connector is arranged in one of the two housing parts. According to the invention, the measuring electrodes and the coils are connected directly to the plug connector, that is to say that no signal evaluating or outputting components are arranged between the respective components and the plug connector.

Measurement circuits in the field of flow measurement technology are well known. The task of the measuring circuit is to detect very small absolute values and changes in the respective measured variable. There are a number of different designs, each with their advantages and disadvantages. A measuring circuit therefore includes an analog / digital converter that converts the incoming signals, in this case the measuring voltage currently applied to a pair of measuring electrodes, into digital data, which are then further processed or stored by an evaluation circuit. However, other measuring converters or measuring transducers of digital measuring technology are also known and are suitable for detecting a measuring voltage or an electrical potential.

One embodiment provides that the magnetic field generating device has at least one field feedback arrangement,
wherein the field return arrangement has a first field return body which is arranged in a first housing part and fixed to an inner wall of the first housing part,
wherein the field return arrangement has a second field return body which is arranged in a second housing part and is fixed to an inner wall of the second housing part.

The fixing of the field return body to the housing parts can preferably be implemented in a non-positive, material and / or positive manner. The housing parts can, for example, each have a receptacle which is arranged on the inner wall of the housing part and into which a field feedback body can be inserted in a form-fitting manner. Preferably, hook-shaped receptacles are arranged on the inner wall of the housing parts, into each of which a field return body is inserted. This enables simplified assembly of the individual components (measuring tube, cabling, housing). When assembling the measuring tube body and the two housing parts, the two coil cores are connected via the field feedback arrangement. The field feedback arrangement does not have to be arranged and / or attached to the measuring tube body beforehand.

One embodiment provides that the field return body has a width
wherein the coil has a coil diameter,
where the width of the field feedback body is greater than or equal to the coil diameter,
wherein the width is a maximum of 25%, in particular 15% and preferably 5% larger than the coil diameter.

The coil diameter is defined by the coil winding on the outside. In order to keep the total mass of the electromagnetic flowmeter low, it is advantageous if the width of the field feedback body is based on the coil diameter. The shielding of the channel from radiation, which is set up to sterilize the parts of the flow measuring device in contact with the medium, is thus reduced by the field return arrangement.

One embodiment provides that the connector is set up to connect the measuring electrodes and the magnetic field generating device to a measuring circuit, an operating circuit and / or an evaluation circuit for processing a measuring signal tapped at the measuring electrodes.

For the sterilization process of the flow measuring device, it is particularly advantageous if the number of electronic components in the flow measuring device is minimized. The measuring, operating and / or evaluation circuit is therefore arranged outside the flow measuring device and connected to the measuring electrodes and coils in a separable manner via plug connectors.

• - Bereitstellen und Positionieren eines Kernes und eines Fo rmnestes sowie mindestens zweier Messelektroden und mindestens zweier Spulenkerne,
  • wobei durch den Kern und das Formnest eine Kavität gebildet wird,
  • wobei das Formnest jeweils Aufnahmen für die Messelektroden und die Spulenkerne aufweist;
• - Ausfüllen der Kavität mit einem Messrohrkörper des Messrohres bildenden Kunststoff durch Spritzgießen;
• - Aufbringen von insbesondere vorgewickelten Spulen auf die die Spulenkerne umschließenden Bereiche des Messrohrkörpers;
• - Verbinden der Spulen und der Messelektroden mit einem in einem Gehäuse angeordneten Steckverbinder, insbesondere mittels eines Flachbandkabels, und
• - Sterilisieren mittels Strahlensterilisation, vorzugsweise Gammastrahlensterilisation oder Elektronenstrahlensterilisation, Heißdampfsterilisation und/oder Gassterilisation.

The method according to the invention for producing a magnetic-inductive flow measuring device, in particular the magnetic-inductive flow measuring device according to the invention, comprises the method step:

• - Provision and positioning of a core and a mold nest as well as at least two measuring electrodes and at least two coil cores,
  • whereby a cavity is formed by the core and the mold cavity,
  • the mold cavity each having receptacles for the measuring electrodes and the coil cores;
• - Filling the cavity with a measuring tube body of the measuring tube forming plastic by injection molding;
• Application of, in particular, pre-wound coils to the areas of the measuring tube body surrounding the coil cores;
• - Connecting the coils and the measuring electrodes to a connector arranged in a housing, in particular by means of a ribbon cable, and
• - Sterilization by means of radiation sterilization, preferably gamma radiation sterilization or electron beam sterilization, hot steam sterilization and / or gas sterilization.

It is particularly advantageous if the mold cavity has receptacles for the measuring electrodes and the coil cores. Preferably, as many components as possible are already fixed on the measuring tube body or integrated in the measuring tube body in and / or by the potting process.

The mold cavity can also have other receptacles. For example for the connection cables of the measuring electrodes. By potting the connection cables, they are fixed in place and protected from mechanical interference. Furthermore, the assembly is also simplified.

Advantageous refinements of the invention are the subject matter of the subclaims.

• - Umhüllen des Messrohrkörpers mit dem Gehäuse,
  • wobei das Umhüllen durch das Verbinden, insbesondere stoffschlüssige Verbinden zweier Gehäuseteile erfolgt,
  • wobei durch das Verbinden der Gehäuseteile ein im ersten Gehäuseteil fixierter erster Feldrückführkörper und ein im zweiten Gehäuseteil fixierter zweiter Feldrückführkörper die zwei Spulenkerne miteinander verbinden.

One configuration includes the process step:

• - Covering the measuring tube body with the housing,
  • where the sheathing takes place by connecting, in particular materially connecting, two housing parts,
  • whereby by connecting the housing parts, a first field feedback body fixed in the first housing part and a second field feedback body fixed in the second housing part connect the two coil cores to one another.

The housing of the electromagnetic flowmeter is formed by connecting the two housing parts. The housing is designed to protect the individual components of the measuring tube from mechanical influences, but also from moisture. According to the invention, a field return body is arranged and fixed on the respective inner sides of the housing parts. Attaching to the measuring tube and connecting both housing parts leads to the field feedback bodies coming into contact with the coil cores and into contact with one another.

• - ein magnetisch-induktives Durchflussmessgerät, insbesondere das erfindungsgemäßes magnetisch-induktives Durchflussmessgeräte; und
• - ein Schlauch- und/oder Kunststoffrohrsystem, vorzugsweise zur Durchflussmessung bei automatisierten industriellen oder labortechnischen Anlagen;

und ist dadurch gekennzeichnet,
dass das magnetisch-induktive Durchflussmessgerät an das Schlauch- und/oder Kunststoffrohrsystem angeschlossen ist und dazu eingerichtet ist die Durchflussgeschwindigkeit und/oder den Volumendurchfluss und/oder den des Mediums zu messen.The flow measuring point according to the invention comprises

• a magneto-inductive flow measuring device, in particular the magneto-inductive flow measuring device according to the invention; and
• - a hose and / or plastic pipe system, preferably for flow measurement in automated industrial or laboratory systems;

and is characterized by
that the electromagnetic flowmeter is connected to the hose and / or plastic pipe system and is set up to measure the flow rate and / or the volume flow and / or that of the medium.

The magnetic-inductive flow measuring device according to the invention is suitable due to its compact design and sterilizability by means of radiation sterilization for applications in hose and / or plastic pipe systems of laboratory equipment.

The inventive use of the magnetic-inductive flowmeter according to the invention, in hose and / or plastic pipe systems, preferably for flow measurement in automated industrial or laboratory systems, preferably medical, biotechnological or food technology systems.

• 1: eine Explosionsdarstellung einer ersten Ausgestaltung des erfindungsgemäßen magnetisch-induktiven Durchflussmessgerätes;
• 2: einen Querschnitt durch die erste Ausgestaltung des magnetisch-induktiven Durchflussmessgerätes;
• 3: zwei perspektivische Ansichten auf die erste Ausgestaltung des erfindungsgemäßen magnetisch-induktiven Durchflussmessgerätes; und
• 4: a) einen Querschnitt durch ein positioniertes Gusswerkzeug gemäß einer ersten Ausgestaltung des erfindungsgemäßen Verfahrens zur Herstellung und b) einen Querschnitt durch ein mittels des erfindungsgemäßen Verfahrens hergestellten magnetisch-induktiven Du rchflussmessgerätes;
• 5: ein Pfaddiagramm einer Ausgestaltung des erfindungsgemäßen Verfahrens zur Herstellung eines magnetisch-induktiven Durchflussmessgerätes.

The invention is explained in more detail with reference to the following figures. It shows:

• 1 : an exploded view of a first embodiment of the magnetic-inductive flow measuring device according to the invention;
• 2 : a cross section through the first embodiment of the magnetic-inductive flow measuring device;
• 3rd : two perspective views of the first embodiment of the magnetic-inductive flow measuring device according to the invention; and
• 4th : a) a cross section through a positioned casting tool according to a first embodiment of the method according to the invention for production and b) a cross section through a magnetic-inductive flow measuring device produced by means of the method according to the invention;
• 5 : a path diagram of an embodiment of the method according to the invention for producing a magneto-inductive flow measuring device.

The 1 shows an exploded view of a first embodiment of the invention electromagnetic flowmeter. The structure and the measuring principle of a magnetic-inductive flow measuring device are known in principle. Through a measuring tube 1 a flowable medium is passed, which has an electrical conductivity. A magnetic field generating device 5 is attached in such a way that the magnetic field lines are oriented perpendicular to a longitudinal direction of the measuring tube defined by the measuring tube axis. As a magnetic field generating device 5 a saddle coil or a pole piece is preferably suitable 8th with attached coil 7th and coil core 6th . When a magnetic field is applied, it arises in the measuring tube 1 a flow-dependent potential distribution, with two on the inner wall of the measuring tube 1 attached measuring electrodes 4th is tapped. As a rule, these are arranged diametrically and form an electrode axis which runs perpendicular to the magnetic field lines and the longitudinal axis of the pipe. On the basis of the measured voltage, taking into account the magnetic flux density, the flow rate and, taking into account the pipe cross-sectional area, the volume flow of the medium can be determined. If the density of the medium is known, the mass flow can be determined. To derive the at the measuring electrodes 4th To prevent the measurement voltage being applied over the pipe, the inner wall is lined with an insulating material, for example a plastic liner.

The pictured measuring tube 1 comprises a measuring tube body 2 , which is formed from an insulating material by means of an injection molding process. The measuring tube body 2 forms the channel for guiding the flowable medium and is used to attach the measuring electrodes 4th and parts of the magnetic field generating device 4th . According to the first embodiment, the measuring tube body 2 also two recordings 3rd on, in each of which a coil core 6th is arranged. The coil cores 6th are made from a single sheet metal part or from a large number of parts in the longitudinal direction of the measuring tube 1 formed stacked and interconnected sheet metal parts, in particular electrical sheet metal parts. The areas of the measuring tube body 2 , which each have a coil core 6th grip around, have a hollow cylindrical basic shape and are each in the radial direction of a coil 7th surround. The sink 7th can around the inclusion 3rd wound or wound on a support body, which on the recording 3rd is postponed. The coil cores 6th each touch a pole piece 8th . According to the first embodiment, the coil core 6th and the pole piece 8th formed in one piece. By expanding the coil core 6th towards the channel is a subsequent insertion of the coil core 6th not possible in the recording. However, it is also possible to use the pole piece 8th and the coil core 8th train in two parts. In this case, it is advantageous if the two areas in contact are designed to be complementary to one another, so that an at least form-fitting connection between the pole piece 4th and coil core 8th is realized. The measuring tube body 2 is designed so that it extends along the two end faces 9 , 10 and parts of the side surfaces of the respective coil cores 6th extends. In injection molding, a potting compound is inserted into the measuring tube body 2 filling the forming cavity, the potting compound is distributed along the front sides 9 , 10 and the side faces 11.1 , 11.2 of the coil core 6th . The potting compound hardens and forms with the coil core 6th a form-fitting connection. The hardened casting compound forms the measuring tube body 2 . The coil core 6th extends from the recording 3rd out and sticks out. The protruding areas of the two coil cores 6th are each in contact with the field feedback arrangement 14th . The field feedback arrangement 14th includes two field feedback bodies 15.1 , 15.2 , which each consist of a single sheet metal parts or of a large number of stacked sheet metal parts and together form the measuring tube body 2 in a cross section of the measuring tube 1 enclose. The field feedback body 15.1 , 15.2 are each bent in a U-shape.

The protruding areas of the coil core are designed to be complementary to the respective ends of the field feedback body. The Indian 1 The field feedback body shown has a slot at each end that serves as a passage for the connection cables of the measuring electrodes. At the same time, the protruding area of the coil core is designed so that when the individual components of the magnetic field generating device are assembled, the side of the coil core facing away from the medium extends between the slots of the field return bodies.

The two field feedback bodies 15.1 , 15.2 are each on a housing part 16.1 , 16.2 positively, non-positively and / or firmly fixed.

Commercially available magnetic-inductive flowmeters have, in addition to the measuring electrodes 4th two more electrodes. A level monitoring electrode (not shown) and a reference electrode 25th . The reference electrode 25th serves to ensure adequate grounding of the medium. The reference electrode shown 25th is offset to the measuring electrode level, which is passed through the measuring electrodes 4th runs, arranged.

The measuring tube body 1 and the coil core 6th each have a guide 27 which is formed by a recess or groove for guiding the connection cables (not shown) of the measuring electrodes 4th along the coil core 6th .

The measuring tube body has two process connections 28 in the form of hose nozzles.

The 2 shows a cross section through the first embodiment of the magnetic-inductive flow measuring device according to the invention. The measuring tube 1 is in a housing 12th arranged, which by two housing parts 16.1 , 16.2 is formed. The field feedback body 15.1 , 15.2 touch at the respective ends together form the field feedback arrangement 14th . This touches the respective the channel 26th of the measuring tube 1 facing away sides of the coil cores 6th . The coil cores 6th are each opposite and form-fitting in recordings 3rd arranged. The coil cores 6th and pole pieces 8th are formed in one piece. The measuring electrodes are used in the manufacture of the measuring tube 4th and the coil cores 6th encapsulated with the casting compound, so that the end faces 9 and the side faces 11.1 , 11.2 of the coil core 6th at least partially the measuring tube body 2 touch. Two coils 7th are on the measuring tube 1 arranged.

There is a connector in the housing 13th arranged with the measuring electrodes 4th and the coils 7th is electrically connected and is set up to connect the flow measuring device to a measuring, operating and / or evaluation circuit in a separable manner. The connector has a connector housing and a plug element. The connector housing can be designed in one piece with one of the two housing parts or it can be formed as a separate component, which is subsequently arranged on the housing part.

The two housing parts 16.1 , 16.2 form the housing 12th . They are positively, non-positively and / or cohesively connected to one another.

The 3rd shows two perspective views of the first embodiment of the magnetic-inductive flow measuring device according to the invention. The magnetic field built up by a magnetic field generating device is generated by means of an operating circuit 18th Generated pulsed direct current of alternating polarity. This ensures a stable zero point and makes the measurement insensitive to influences from electrochemical disturbances. A measuring circuit 17th reads out the voltage applied to the measuring electrodes and outputs a measured flow value, in particular the flow rate and / or by means of an evaluation circuit 19th calculated volume flow or mass flow of the medium. The operating, measuring and / or evaluation circuit 17th , 18th , 19th are arranged according to the invention outside the magnetic-inductive flowmeter and each connected to a connector which is complementary to the one in the housing 12th of the measuring device arranged connector 13th is trained.

The 4th shows a) a cross section through a positioned casting tool according to a first embodiment of the method according to the invention for production and b) a cross section through a magneto-inductive flow meter produced by means of the method according to the invention. The representation is very schematic and serves to explain the manufacturing process. a) The casting tool comprises a core 20th showing the shape of the canal 26th of the measuring tube body and defined a cavity 21 that in combination with the core 20th the shape of the measuring tube body 2 specifies. The mold cavity 21 has two recordings 23 for the measuring electrodes 4th on and at least one recording 24 for the coil core and / or pole piece. The through the core 20th and the mold cavity 21 formed cavity 22nd is filled with a plastic which, after hardening, forms the measuring tube body 2 forms, b) After curing, the core 20th , which can also be designed in several parts, and the mold cavity 21 , which can also be designed in several parts, is detached and the measuring tube body remains 2 which already has the measuring electrodes 4th and a part of the magnetic field generating device.

The 5 shows a path diagram of an embodiment of the method according to the invention for producing a magneto-inductive flow measuring device.

In a first method step, a tool for producing the measuring tube body is provided. To do this, a core and a mold cavity are put together, creating a cavity. The core can be formed in one piece or in several parts. The measuring electrodes and coil cores are arranged in receptacles in the mold cavity.

In a second process step, the cavity is filled with a plastic. The measuring tube body is thereby formed.

In a third process step, the plastic is cured.

In a fourth process step, the core and the mold cavity are removed.

In a fifth process step, coils are arranged on the measuring tube body. These can be pre-wound onto a spool or wound directly onto the measuring tube body.

In a sixth process step, the coils and the measuring electrodes are electrically connected with a connector. The connector is arranged on a housing and set up to connect the electromagnetic flowmeter to a control unit in a separable manner, which has a measuring, operating and / or evaluation circuit.

In a seventh process step, the measuring tube body is provided with the housing. For this purpose, two housing parts are brought together and connected to one another in a form-fitting, force-fitting and / or material fit, the housing having two openings through which the measuring tube body extends. When the two housing parts are connected to the measuring tube body and with one another, the field feedback bodies, which are arranged in the housing parts, are brought into contact with the coil cores and with one another. The two areas of the measuring tube body which are not arranged in the housing have process connections for integrating the magnetic-inductive flow measuring device into a process line.

In an eighth process step, the electromagnetic flowmeter is sterilized by means of radiation sterilization so that the requirements for use in biopharmaceuticals are met.

List of reference symbols

1

Measuring tube

2

Measuring tube body

3

Holder for coil core

4th

Measuring electrode

5

Magnetic field generating device

6th

Coil core

7th

Kitchen sink

8th

Pole piece

9

first face

10

second face

11.1

Side face

11.2

Side face

12th

casing

13th

Connectors

14th

Field feedback arrangement

15th

Field feedback body

15.1

first field feedback body

15.2

second field feedback body

16.1

first housing part

16.2

second housing part

17th

Measuring circuit

18th

Operating circuit

19th

Evaluation circuit

20th

core

21

Mold cavity

22nd

cavity

23

Holder for measuring electrodes

24

Holder for coil core / pole piece

25th

Reference electrode

26th

channel

27

guide

28

Process connection

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102016118064 A1 [0004]
• WO 2011/091899 A1 [0010]
• WO 2004/072590 A1 [0010]
• DE 102017115149 A1 [0019]

Claims (14)

Magnetic-inductive flowmeter, comprising: a measuring tube (1) for guiding a flowable medium in a longitudinal direction, the measuring tube (1) being formed by a measuring tube body (2), the measuring tube body (2) having a receptacle (3), wherein the measuring tube body (2) is designed to be at least partially electrically insulating; - At least two measuring electrodes (4) for forming a galvanic contact with the medium and for detecting a flow rate-dependent measuring voltage induced in the flowing medium, the measuring electrodes (4) being arranged in the measuring tube body (2) on opposite sides; and - a magnetic field generating device (5), wherein the magnetic field generating device (5) comprises at least one coil core (6) and at least one coil (7), wherein the coil core (6) consists of a single sheet metal part or a plurality of, in particular in the longitudinal direction of the Measuring tube (1) of stacked and interconnected sheet metal parts is formed, the coil core (7) having a first end face (9) and a second end face (10) which delimit a pole piece (8) in the longitudinal direction of the measuring tube (1); characterized in that the coil core (6) is arranged in the receptacle (3) and that the measuring tube body (2) extends along the first end face (9) and the second end face (10) and these surfaces each extend in the longitudinal direction of the measuring tube (1 ) in particular completely covered. Flow meter according to Claim 1 , the coil core (6) having at least two side surfaces (11.1, 11.2) which each connect the first end face (9) to the second end face (10), the measuring tube body (2) extending along the two side surfaces (11.1, 11.2) extends and this in particular completely covered. Flow meter according to Claim 1 and / or 2, the pole piece (8) and the coil core (6) being formed in one piece. Flow measuring device according to one of the preceding claims, wherein the receptacle (3) is at least partially hollow-cylindrical, wherein the coil (7) is wound around the measuring tube body (2) in the region of the hollow cylindrical part of the receptacle. Flow measuring device according to one of the preceding claims, wherein the measuring tube body (2) is formed in one piece, wherein the coil core (6) and / or the measuring electrodes (4) are partially encapsulated by means of an original molding process, in particular by means of an injection molding process. Flow measuring device according to one of the preceding claims, wherein the measuring tube body (2) is made of an insulating material, in particular a plastic and preferably polyetheretherketones (PEEK), polyaryletherketones (PAEK), polyphenylsulfones (PPSU), polyethersulfones (PESU), polysulfones (PSU), polyarylamides ( PARA), glass and / or ceramics. Flow measuring device according to one of the preceding claims, wherein the flow meter has a housing (12) in which the magnetic field generating device (5) is arranged, wherein the housing (12) is designed in two parts, a plug connector (13) being arranged in the housing (12), the measuring electrodes (4) and the coil (7) being electrically connected to the plug connector (13), in particular via a ribbon cable. Flow measuring device according to one of the preceding claims, wherein the magnetic field generating device (5) has at least one field feedback arrangement (14), wherein the field return arrangement (14) has a first field return body (15.1) which is arranged in a first housing part (16.1) and is fixed to an inner wall of the first housing part (16.1), wherein the field return arrangement (14) has a second field return body (15.2) which is arranged in a second housing part (16.2) and is fixed to an inner wall of the second housing part (16.2). Flow meter according to Claim 8 , the field return body (15) having a width, the coil (7) having a coil diameter, the width of the field return body (15) being greater than or equal to the coil diameter, the width being a maximum of 25%, in particular 15% and preferably 5% greater is than the coil diameter. Flow meter according to Claim 7 , wherein the connector (13) is set up to connect the measuring electrodes (4) and the magnetic field generating device (5) with a measuring circuit (17), an operating circuit (18) and / or an evaluation circuit (19) for processing a measurement signal tapped at the measurement electrodes (4). Method for producing a magneto-inductive flow measuring device, in particular a magneto-inductive flow measuring device according to one of the preceding claims, comprising the method steps: - Providing and positioning a core (20) and a mold cavity (21) as well as at least two measuring electrodes (4) and at least two coil cores (6), wherein a cavity (22) is formed by the core (20) and the mold cavity (21), the mold cavity (21) each having receptacles (23, 24) for the measuring electrodes (4) and the coil cores (6); - Filling the cavity (22) with a plastic forming a measuring tube body (2) of the measuring tube (1) by injection molding; - Let harden or harden the plastic; - Removing the core (20) and the mold cavity (21); - Application of, in particular, pre-wound coils (7) to the regions of the measuring tube body (2) surrounding the coil cores (6); - Connecting the coils (7) and the measuring electrodes (4) to a plug connector (13) arranged in a housing (12), in particular by means of a ribbon cable, and - Sterilization by means of radiation sterilization, preferably gamma radiation sterilization or electron beam sterilization, superheated steam sterilization and / or gas sterilization. Procedure according to Claim 11 , comprising the process step: enveloping the measuring tube body (2) with the housing (12), the enveloping being carried out by connecting, in particular integrally bonded, two housing parts (16.1, 16.2), whereby by connecting the housing parts (16.1, 16.2) a first field return body (15.1) fixed in the first housing part (16.1) and a second field return body (15.2) fixed in the second housing part (16.2) connect the two coil cores (6) to one another. Flow measuring point, comprising: a magneto-inductive flow measuring device, in particular a magneto-inductive flow measuring device according to one of the Claims 1 to 10 ; and - a hose and / or plastic pipe system, preferably for flow measurement in automated industrial or laboratory systems; characterized in that the electromagnetic flowmeter is connected to the hose and / or plastic pipe system and is set up to measure the flow rate and / or the volume flow and / or the mass flow of the medium. Use of the electromagnetic flowmeter according to one of the Claims 1 to 10 , in hose and / or plastic pipe systems, preferably for flow measurement in automated industrial or laboratory systems; preferably medical, biotechnological or food technology systems.

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