DE102018129781A1 - Measuring tube for a measuring device and method for its production - Google Patents

Abstract

The invention relates to a measuring tube (7) for guiding a medium (M), comprising a connecting element (1) for a pipeline with at least three openings (2, 3, 4), a first (2) and a second opening (3 ) serve to introduce the connecting element (1) into the pipeline and form a first channel (5) through the connecting element (1), and a second channel (6) is formed through a third opening (4), which is connected to the first channel (5), and an immersion body (9) which is introduced into the third opening (5) of the connecting element (1) and which is closed in a partial area facing the first channel (5). According to the invention, a diameter (d) of a wall (W) of the second channel (6) is variable at least in sections at a predeterminable angle, in particular perpendicular, to the longitudinal axis (L) of the second channel (6), such that the immersion body (9) in the second Channel (6) is attachable. The present invention further relates to a measuring device with a measuring tube according to the invention and a method for producing a measuring tube according to the invention.

Description

The invention relates to a measuring tube for guiding a medium in a pipeline with a connecting element, an immersion body and a fastening means, and to a method for producing a measuring tube according to the invention.

Measuring tubes with immersion bodies are used in connection with a large number of measuring devices and / or field devices for determining at least one process variable, which are manufactured and sold in great variety by the applicant. To determine the respective process variable, a measuring element or a measuring insert with a corresponding sensor element is introduced into the immersion body. The process variable to be determined and / or monitored is, for example, the flow of a flowing fluid through a measuring tube or the fill level of a medium in a container. However, it can also be given by the pressure, the density, the viscosity, the conductivity, the temperature or the pH value. Optical sensors, such as turbidity or absorption sensors, are also known.

For reasons of clarity, however, the following introduction to the description is limited to thermometers. However, it should be pointed out that the considerations made in this context can be transferred directly to other measuring and / or field devices in which a measuring element or measuring insert is to be integrated in a pipeline. In the case of a device for determining the temperature of a medium, the immersion body serves in particular as a protective tube for the respective measuring insert.

Usually, the immersion body is first connected to the connecting element for the pipeline before the respective measuring insert is inserted. The connecting element and the protective tube are often welded and / or glued directly to one another. However, gaps, joints and / or dead spaces can arise.

Particularly in the field of sterile process engineering, the highest demands are placed on the measuring devices used. In particular, the measuring tube must be designed in such a way that sterile production can be guaranteed. For example, in order to prevent deposits or the formation of a biofilm within the pipeline or within the measuring tube, the latter should be designed such that residue-free cleaning is possible. This problem is available, for example, in the article "Dead space-free protective tube" at http://www.prozesstechnik-online.de/fialen/-/article/31534493/37267194/Totraumfreies-Schutzrohr/art_co_INSTANCE_0000/maximized/described.

To ensure this, for example, from the DE102015112424A1 a hygiene-compatible measuring tube and a method for its production have become known, in which the measuring tube is produced by means of a generative method, in particular by means of a 3D printing method. From the DE102016115426A1 It has also become known to manufacture the immersion body and a pipe section from one piece and to produce them by means of a milling process, in particular by means of high-speed machining. However, producing a corresponding measuring tube from one piece is comparatively complex and expensive.

Alternatively, it has become known from the prior art to subsequently edit the walls of the components used in each case at least in sections and to modify them appropriately. So is from the DE102010037994 A1 a hygiene-compatible measuring point has become known, in which the pipe section used has a flattening with an opening through which a flat surface is created, an adapter comprising the measuring insert being insertable through the opening. The adapter is also connected by a material connection to the flattened tube wall in the plane of the opening or in a plane parallel to the flat surface.

Another example of a hygiene-compatible recording device for a measuring insert, in particular for determining the temperature, is shown in FIG DE102012112579A1 known. The receiving device has a first and a second section which are separated from one another by a shoulder, the shoulder having a shape which essentially corresponds to a section of the outer surface of a tubular wall of a process container, for example a pipeline or a tank, in which wall the receiving device can be used.

Based on the prior art mentioned, the present invention is based on the object of a hygienic measuring tube which can be produced in a simple manner and inexpensively.

The object is achieved by a measuring tube according to claim 1, a measuring device with a measuring tube according to the invention as in claim 10, and by a method for producing a measuring tube according to claim 11.

With regard to the measuring tube, the object on which the invention is based is achieved by a A measuring tube for guiding a medium, comprising a connecting element for a pipeline with at least three openings, a first and a second opening serving for introducing the connecting element into the pipeline and forming a first channel through the connecting element, and wherein a second channel through a third opening is formed, which is connected to the first channel, and an immersion body, which is introduced into the third opening of the connecting element, and which is closed in a partial area facing the first channel. According to the invention, a diameter of a wall of the second channel is variable at least in sections at a predeterminable angle, in particular perpendicular, to the longitudinal axis of the second channel, such that the immersion body can be fastened in the second channel.

The connecting element can, for example, be a partial section of a pipeline or a pipeline section. The immersion body in turn serves in particular to hold a measuring element or measuring insert for determining and / or monitoring a process variable of a medium, for example the temperature. The immersion body can, however, also be a pitot tube or another bluff body, which at least partially protrudes into the first channel and, consequently, into the pipeline. The immersion body is preferably designed to be fluid-tight.

The cross-sectional area of the first channel is preferably adapted to the cross-sectional area of the pipeline. The pipeline itself can in turn be, for example, a round pipe, a square pipe, a rectangular pipe or a pipe bend. The connecting element and / or the pipeline can also consist, for example, of a metallic material or a plastic.

The longitudinal axis of the second channel runs at a defined, predeterminable angle, in particular perpendicular, to a longitudinal axis of at least a section of the first channel or a longitudinal axis of at least a section of the pipeline. The angle can be adjusted in relation to a wide variety of requirements for the respective measuring tube, for example in relation to the flow resistance caused in each case. In one embodiment, the immersion body is arranged, for example, perpendicular to the pipeline.

According to the invention, the immersion body is not welded or glued into the connecting element, but is fastened mechanically and in particular releasably. Only the diameter of the wall of the second channel is machined, at least in sections, such that the diameter is variable, at least in sections. This simplifies the manufacturing process and the associated costs. Nevertheless, the measuring tube according to the invention is ideally suited for use in sterile applications.

In one embodiment, the immersion body is introduced into the second channel in such a way that it ends flush with a wall of the first channel. Alternatively, the immersion body can be introduced into the second channel in such a way that it at least partially extends into the first channel or in such a way that the immersion body is located completely within the second channel, that is to say is set back with respect to the wall of the first channel.

A particularly preferred embodiment includes that the diameter of the wall of the second channel is reduced in a partial section along the longitudinal axis, such that a first diameter in the partial section is smaller than a second diameter outside the partial section. The wall of the second channel accordingly has a groove or indentation. It is advantageous if the diameter of the wall of the second channel in the section is reduced by approximately 20%. The immersion body is then fastened in the region of the partial section in the second channel.

In a further particularly preferred embodiment, a diameter of a wall of the immersion body is variable perpendicular to the longitudinal axis of the immersion body. In particular, the diameter of the wall of the immersion body can be adapted to the wall of the second channel.

In this regard, it is advantageous if the wall of the immersion body in a first partial area facing the first channel has a first diameter which is smaller than a second diameter of the wall of the immersion body in a second partial area of the immersion body facing away from the first channel. The immersion body accordingly has a taper along its longitudinal axis.

It is also advantageous if the wall of the immersion body in a transition area between the two partial areas is designed to be complementary to the wall of the second channel in a first transition area facing the second channel. In particular, the said transition regions can be designed in such a way that the immersion body can be fastened in a substantially precisely fitting manner within the second channel.

The wall of the second channel in a second transition area facing away from the first channel towards the partial section can furthermore be analogous to or from the first transition area be designed differently. In particular, the second transition area can be designed such that there is a dead space-free connection to the first channel.

In a further embodiment, the measuring tube comprises fastening means for, in particular releasably fastening the immersion body in the second channel.

In this regard, it is advantageous if the fastening means comprises two mutually complementary threads or a bayonet catch. In the case of a fastener with two mutually complementary threads, it is advantageous if the second channel has a first thread in a partial area facing away from the first channel, and the immersion body has a second thread complementary to the first thread along a longitudinal axis in a partial area.

Likewise or alternatively, it is advantageous if the fastening means comprises a sealing element, in particular an O-ring, a flat ring, or an X-ring. The sealing element can be arranged, for example, in the region of the section of the second channel. An arrangement in the transition area of the immersion body or in the first transition area of the second channel is also possible.

A further embodiment of the measuring tube includes that the immersion body is a protective tube, for example for a device for determining the temperature.

Another embodiment of the measuring tube includes that the connecting element is a T-piece or a corner piece for a pipeline.

The measuring tube according to the invention preferably meets the requirements of at least one hygiene determination, in particular the requirements of at least one of the standards according to the "American Society of Mechanical Engineers" (ASME), in particular the so-called "ASME Bioprocessing Equipment - Standard" (BPE), the " 3-A Sanitary Standards Incorporation "( 3-A ), or the "European Hygienic Design Group" (EHEDG), is sufficient. The ASME, BPE and 3A are particularly relevant for the American area, while the majority of the EHEDG standard applies in Europe. Typical requirements for a component by at least one of the hygiene regulations mentioned relate in particular to the geometry and / or surface of the respective component, which should be such that no deposits can form and the respective component is easy to clean and / or sterilize.

The object on which the invention is based is further achieved by a measuring device comprising a measuring insert for determining a process variable of a medium and a measuring tube according to the invention. The immersion body is designed to receive the measuring insert. The measuring insert is, for example, a measuring insert for determining the temperature of a medium. Such a measuring insert can in turn have, for example, a sensor element comprising a resistance element or a thermocouple.

• - Bearbeiten einer Wandung des zweiten Kanals derart, dass ein Durchmesser der Wandung in einem vorgebbaren Winkel, insbesondere senkrecht, zur Längsachse zumindest abschnittsweise variabel ist, und
• - Einbringen und Befestigen des Eintauchkörpers im zweiten Kanal.

The object on which the invention is based is also achieved by a method for producing a measuring tube according to the invention for guiding a medium, comprising the following method steps:

• - Machining a wall of the second channel in such a way that a diameter of the wall is variable, at least in sections, at a predetermined angle, in particular perpendicular, to the longitudinal axis, and
• - Inserting and fixing the immersion body in the second channel.

In one embodiment of the method, the immersion body is manufactured in such a way that a diameter of a wall of the immersion body is variable along the longitudinal axis of the immersion body.

It is advantageous here if the immersion body is manufactured in such a way that the diameter of the wall of the immersion body is smaller in a first partial area of the immersion body facing the first channel than in a second partial area facing away from the first channel.

A particularly preferred embodiment of the method includes that the diameter of the wall of the second channel is reduced in a partial section along the longitudinal axis.

In this regard, it is advantageous if the diameter of the wall of the second channel is reduced by means of segment presses, cold forming, or rolling.

It should be pointed out that the configurations described in connection with the measuring tube according to the invention can also be applied mutatis mutandis to the measuring device according to the invention and the method according to the invention and vice versa.

The configurations explained in connection with the measuring tube and / or measuring device can also be applied mutatis mutandis to the proposed methods and vice versa.

• 1: ein Verbindungselement für eine Rohrleitung in Form eines T-Stücks gemäß Stand der Technik,
• 2: ein Verbindungselement für eine Rohrleitung in Form eines Eck-Stücks gemäß Stand der Technik,
• 3 eine Ausgestaltung eines erfindungsgemäßen (a) Verbindungselements in Form eines T-Stücks und (b) eines Eintauchkörpers und (c) eines Messrohrs mit einem Eintauchkörper im in das Verbindungselement eingebrachten Zustand,
• 4 eine erste Ausgestaltung eines erfindungsgemäßen Messgeräts mit einem Verbindungselement in Form eines T-Stücks in Verbindungselement für eine Rohrleitung in Form eines T-Stücks, und
• 5 eine zweite Ausgestaltung eines erfindungsgemäßen Messgeräts mit einem Verbindungselement in Form eines T-Stücks.

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

• 1 a connecting element for a pipeline in the form of a T-piece according to the prior art,
• 2nd a connecting element for a pipeline in the form of a corner piece according to the prior art,
• 3rd an embodiment of a (a) connecting element according to the invention in the form of a T-piece and ( b ) an immersion body and ( c ) a measuring tube with an immersion body when inserted into the connecting element,
• 4th a first embodiment of a measuring device according to the invention with a connecting element in the form of a T-piece in connecting element for a pipeline in the form of a T-piece, and
• 5 a second embodiment of a measuring device according to the invention with a connecting element in the form of a T-piece.

In 1 is a first possible embodiment of a connecting element 1 for a pipeline [not shown] with at least three openings 2nd , 3rd , 4th shown. The first 2nd and second 3rd Opening form a first channel 5 , and serve to introduce the connecting element 1 into the pipeline. Through the third opening 4th becomes one in the first channel 5 opening second channel 6 educated. The first 5 and second channel 6 or the first L1 and second longitudinal axis L2 of the first 5 and second channel 6 have a predeterminable angle α to each other. For the example 1 the angle is α = 90 °. It is the connecting element 1 in other words, a T-piece for a pipe.

A second possible embodiment of a connecting element 1 is the subject of 2nd . This is a corner piece for a pipe, the first channel 5 has a bend.

In addition to these two embodiments of a connecting element shown 1 numerous other configurations are also conceivable, which also fall under the present invention. Connectors according to the invention are generally characterized in that three openings 2-4 are provided, two openings 2nd , 3rd the connection of the connecting element 1 serve with a pipeline and a third opening 3rd the inclusion of an immersion body [not in 1 and 2nd shown] serve.

According to the invention, there is now a diameter d _K a wall W _K of the second channel 6 of the connecting element 1 at a predeterminable angle, in particular perpendicular, to the longitudinal axis L ₂ of the second channel 6 variable at least in sections, such that the immersion body 9 in the second channel 6 is attachable, as in 3rd illustrated. 3a shows a schematic drawing of a connecting element 1 in the form of a T-piece, for which the diameter d _K the wall W _K of the second channel 6 in one section 8th along the longitudinal axis L ₂ is reduced such that a first diameter d _{K, 1} in the subsection 8th is less than a second diameter d _{K, 2} outside of the subsection 8th .

Between the areas with the second diameter d _{K, 2} outside of the subsection 8th and the subsection 8th with the first diameter d _{K, 1} there are a first 9a and a second transition area 9b , in which the diameter d _K changes continuously or abruptly.

3b again shows a possible design for an immersion body 9 . Also a diameter d _E a wall W _E of the immersion body 9 perpendicular to the longitudinal axis L ₃ of the immersion body 9 variable. In the example shown here is the wall W _E of the immersion body 9 in a the first channel 5 facing first section 10a a first diameter d _{E, 1} which is less than a second diameter d _{E, 2} the wall W _E of the immersion body 9 in a second the first channel 5 facing away second part 10b of the immersion body 9 . Between the first 10a and the second partial area 10b there is a transition area 10c , in which the diameter d _E changes continuously or abruptly.

A measuring tube 11 with the connecting element 1 according to 3a and the immersion body 9 according to 3b is finally in 3c shown. The immersion body 9 is in the second channel 6 attached and closes in the present example with a wall of the first channel 5 essentially flush.

The first transition area 9a of the second channel 6 of the connecting element 1 and the transition area 10b of the immersion body are designed to be complementary to one another for the embodiment shown here.

In 4th is finally a first embodiment of a measuring device according to the invention 12 with a measuring tube 7 shown which is a connecting element 1 and an immersion body attached therein 9 includes. In the immersion body 9 is also a measuring insert 13 for determining and / or monitoring a process variable of a medium M brought in which medium M from the pipeline and through the first channel 5 of the connecting element 1 flows. For those in 4th The embodiment shown includes the measuring tube 7 also fasteners 13 . On the one hand, the immersion body 9 and the second channel 6 threads complementary to each other 13a on. The other is between the immersion body 9 and the second channel 6 a sealing element 13b arranged in the form of an O-ring. The sealing element 13b is in the area of the subsection 8th of the second channel 6 arranged. The mutually complementary threads are again in the second sub-area 10b of the immersion body 9 or in the first channel 5 part of the second channel facing away 6 .

In an alternative embodiment, as in 5 can be seen, the sealing element 13b but also in the area of the first transition area 9a of the second channel 6 or in the transition area 10b of the immersion body 9 be arranged. These two transition areas 9a and 10b are then particularly designed such that they have a sealing surface a form or for receiving the sealing element 13b designed.

Reference symbol list

1

Fastener

2nd

First opening

3rd

Second opening

4th

Third opening

5

First channel

6

Second channel

7

Measuring tube

8th

Subsection

9a, 9b

First, second transition area of the second channel

10a, 10b

First, second section of the immersion body

10c

Transition area of the immersion body

11

Measuring device

12

Measuring insert

13

Fasteners

13a

Complementary threads

13b

Sealing element

L ₁

Longitudinal axis of the first channel

L ₂

Longitudinal axis of the second channel

L ₃

Longitudinal axis of the immersion body

d _K , d _{K, 1} , d _{K, 2}

Diameter or first and second diameter of the second channel;

d _E , d _{E, 1} , d _{E, 2}

Diameter or first and second diameter of the immersion body;

W _K

Wall of the second channel

W _E

Wall of the immersion body

α

Angle between L ₁ and L ₂

M

medium

a

Sealing surface

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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 102015112424 A1 [0006]
• DE 102016115426 A1 [0006]
• DE 102010037994 A1 [0007]
• DE 102012112579 A1 [0008]

Claims (15)

Measuring tube (7) for guiding a medium (M), comprising a connecting element (1) for a pipeline with at least three openings (2, 3, 4), a first (2) and a second opening (3) for introducing the connecting element (1) serve in the pipeline and form a first channel (5) through the connecting element (1), and wherein a second channel (6) is formed through a third opening (4), which is connected to the first channel (5) , and an immersion body (9) which is introduced into the third opening (5) of the connecting element (1) and which is closed in a partial area facing the first channel (5), characterized in that a diameter (d _K ) of a wall (W _K ) of the second channel (6) is variable at least in sections at a predeterminable angle, in particular perpendicular, to the longitudinal axis (L ₂ ) of the second channel (6), such that the immersion body (9) in the second channel (6) is attachable. Measuring tube (7) after Claim 1 , The immersion body (9) being introduced into the second channel (6) such that it ends flush with a wall of the first channel (5), that it at least partially extends into the first channel (5), or that the immersion body (9) is located entirely within the second channel (6). Measuring tube (7) after Claim 1 or 2nd , wherein the diameter (d _K ) of the wall (W _K ) of the second channel (5) is reduced in a section (8) along the longitudinal axis (L ₂ ), such that a first diameter (d _{K, 1} ) in the section (8) is less than a second diameter (d _{K, 2} ) outside the section (8). Measuring tube (7) according to at least one of the preceding claims, wherein a diameter (d _E ) of a wall (W _E ) of the immersion body (9) perpendicular to the longitudinal axis (L ₃ ) of the immersion body (9) is variable. Measuring tube (7) after Claim 4 , The wall (W _E ) of the immersion body (9) in a first partial area (10a) facing the first channel (5) has a first diameter (d _{E, 1} ) which is smaller than a second diameter (d _{E, 2} ) of the wall (W _E ) of the immersion body (9) in a second partial region (10b) of the immersion body (9) facing away from the first channel (5). Measuring tube (7) according to at least one of the preceding claims, comprising fastening means (13) for, in particular releasably fastening the immersion body (9) in the second channel (6). Measuring tube (7) according to at least one of the preceding claims, wherein the fastening means (13) comprises two mutually complementary threads (13a) or a bayonet catch, and / or wherein the fastening means comprises a sealing element (13b), in particular an O-ring Flat ring, or an X-ring. Measuring tube (7) according to at least one of the preceding claims, wherein the immersion body (9) is a protective tube, for example for a device (11) for determining the temperature. Measuring tube (7) according to at least one of the preceding claims, wherein the connecting element (1) is a T-piece or a corner piece for a pipeline. Measuring device (11) comprising a measuring insert (12) for determining a process variable of a medium (M) and a measuring tube (7) according to at least one of the preceding claims. Method for producing a measuring tube (7) for guiding a medium (M) according to at least one of the preceding claims, comprising the following method steps: - Machining a wall (W _K ) of the second channel (6) such that a diameter (d _K ) of the Wall (W _K ) is variable at least in sections at a predeterminable angle, in particular perpendicular, to the longitudinal axis (L ₂ ), and - introducing and fastening the immersion body (9) in the second channel (6). Procedure according to Claim 11 The immersion body (9) is produced in such a way that a diameter (d _E ) of a wall (W _E ) of the immersion body (9) is variable along the longitudinal axis (L ₃ ) of the immersion body (9). Procedure according to Claim 12 The immersion body (9) is produced in such a way that the diameter (d _E ) of the wall (W _E ) of the immersion body (9) is smaller in a first partial region (10a) of the immersion body (9) facing the first channel (5) than in a second partial area (10b) facing away from the first channel (5). Method according to at least one of the Claims 11 - 13 , The diameter (d _K ) of the wall (W _K ) of the second channel (6) being reduced in a section (8) along the longitudinal axis (L ₁ ). Procedure according to Claim 14 , wherein the diameter (d _K ) of the wall (W _K ) of the second channel (6) is reduced by means of segment presses, cold forming, or rolling.

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