Apparatus for determining or monitoring a process variable of a medium in a pipeline

Abstract

An apparatus for determining or monitoring a process variable of a medium in a pipeline, which has a predetermined inner cross section, comprising a sensor and a T-shaped adapter. The adapter has a first portion and a second portion arranged essentially perpendicular to the first portion. The first portion has essentially the same inner cross section as the pipeline and the sensor is so arranged in the second portion that the end face of the sensor facing the medium is flush with the inner surface of the first portion of the adapter.

Claims

1. An apparatus for determining or monitoring a process variable of a medium in a pipeline, which has a predetermined inner cross section, comprising: a sensor; and a T-shaped adapter, wherein: said adapter has a first portion and a second portion arranged essentially perpendicular to said first portion; said first portion has essentially the same inner cross section as the pipeline; and said sensor is so arranged in said second portion that the end face of said sensor facing the medium is flush with the inner surface of said first portion of said T-shaped adapter; said pipeline has an essentially circularly shaped, inner cross section; and said end face of said sensor facing the medium has essentially the same curvature as the inner surface of the pipeline.

2. The apparatus as claimed in claim 1, wherein: the end face of said sensor facing the medium is arranged gap-freely in said T-shaped adapter.

3. The apparatus as claimed in claim 1, wherein: said sensor is one of: a conductive and capacitive sensor.

4. The apparatus as claimed in claim 3, wherein: said capacitive or conductive sensor is composed of a first electrode, an electrode insulation, a second electrode, a guard and a guard insulation.

5. The apparatus as claimed in claim 3, wherein: said capacitive or conductive sensor is composed of a first electrode, an electrode insulation, a guard and a guard insulation; and a second electrode is formed by said T-shaped adapter.

6. The apparatus as claimed in claim 3, wherein: said electrode/the electrodes is/are composed preferably of the same material as the pipeline and/or said T-shaped adapter.

7. The apparatus as claimed in claim 1, wherein: said T-shaped adapter is a cast part.

8. A method for manufacture of an apparatus, comprising: a sensor; and a T-shaped adapter, wherein: said adapter has a first portion and a second portion arranged essentially perpendicular to said first portion; said first portion has essentially the same inner cross section as the pipeline; and said sensor is so arranged in said second portion that the end face of said sensor facing the medium is flush with the inner surface of said first portion of said T-shaped adapter, the method comprising the steps of: pressing the sensor into the second portion of the adapter in such a manner that the sensor has an excess protruding into the adapter relative to the inner cross section of the first portion; then by a machining method the excess protruding into the adapter and/or the inner surface of the first portion of the adapter are/is so machined over that the inner cross section of the first portion of the adapter and the inner cross section of the pipeline are essentially equal; and after mounting the sensor, the adapter is integrated into the pipeline.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be explained in greater detail based on the appended drawing, the figures of which show as follows:

(2) FIG. 1a is a first perspective view of a first embodiment of the adapter of the invention;

(3) FIG. 1b is a second perspective view of the embodiment of the adapter of the invention shown in FIG. 1a;

(4) FIG. 2a is a perspective view of the apparatus of the invention illustrating the first manufacturing step;

(5) FIG. 2b is a perspective view of the apparatus of the invention illustrating the second manufacturing step;

(6) FIG. 3a is a perspective view of the embodiment of the apparatus of the invention shown in FIG. 2b plus electronics housing;

(7) FIG. 3b is a first perspective view of a form of embodiment of the apparatus of the invention with electronics housing and clamp connections;

(8) FIG. 3c is the form of embodiment shown in FIG. 3b in a second perspective view; and

(9) FIG. 4 is a cross section through the embodiment of the apparatus of the invention shown in FIG. 2b.

DETAILED DISCUSSION IN CONJUNCTION WITH THE DRAWINGS

(10) FIG. 1a shows a first perspective view of a first embodiment of the adapter 1 of the invention. FIG. 1b shows a second perspective view of the embodiment of the adapter 1 of the invention shown in FIG. 1a.

(11) Adapter 1 is composed of a first tubular portion 3 and a second tubular portion 4 arranged essentially perpendicular thereto. Via the first portion 3, the adapter 1 is securable in a pipeline 7. Adapter 1 in the illustrated case is a T-piece. Adapter 1 is a cast part, a turned part or a milled part and serves, moreover, also as a process connection.

(12) In the mounted state, a medium (not shown) is located in the pipeline 7 and in the first portion 3 of the adapter 1. The inner diameter D1 of the first portion 3 of the adapter 1 and the inner diameter D2 of the pipeline 7 are essentially equal, so that the medium can flow unimpeded. FIGS. 1a and 1b show the traversing opening 8 in the second portion 4 of the adapter 1. Opening 8 serves for accommodating the sensor 2.

(13) FIGS. 2a and 2b are perspective views of the apparatus of the invention and illustrate the two manufacturing steps for manufacturing the apparatus of the invention. The sensor 2 is, as shown in FIG. 2a, so mounted in the traversing opening 2 in the second portion 4 of the adapter 1 that a defined excess 15 protrudes beyond the inner surface 6 of the first portion 3 of the adapter 1. The mounting of the sensor 2 in the second portion 4 occurs preferably via a press fit. In the illustrated case, the sensor 2 is a capacitive sensor.

(14) In a second method step, the excess 15 of the sensor 2 protruding into the interior of the adapter 1 is removed by a machining method. Preferably, the first portion 3 of the adapter is internally completely machined over, respectively bored out, including the excess of sensor 2. Especially, the sensor 2 and/or the inner surface 6 of the first portion 3 of the adapter 1 are/is so machined over that the inner cross section A1 of the first portion 3 of the adapter 1 and the inner cross section A2 of the pipeline 7 are essentially equal. Therefore, the inner diameter of the first portion 3 before the second manufacturing step must, in given cases, be correspondingly less than the inner diameter D2 of the pipeline.

(15) In the finally mounted state, the end face 5 of the sensor 2 is virtually an integral part of the inner surface 6 of the first portion 3 of the adapter 1. The solution of the invention has the advantage that the sensor 2 is arranged non-intrusively in the medium and is, thus, mounted flushly and gap-freely in the first portion 3 of the adapter 1. The mounted flush installation means that medium flowing in the pipeline 7 is not hindered. Since the installation is gap-free, so that there are no hollow spaces or dead spaces present, the solution is ideally suitable for hygienic applications.

(16) FIG. 3a shows the apparatus of the invention provided supplementally with an electronics housing 9. While the apparatus of the invention shown in FIG. 3a is welded into the pipeline 7, in the case of the embodiment shown in FIG. 3b, two clamp-adapters 10 are welded on the two ends of the adapter 1. The clamp-adapters 10 facilitate assembly of the apparatus of the invention into the pipeline 7, wherein corresponding clamp-adapters are provided on the pipeline 7. FIG. 3c shows the form of embodiment shown in FIG. 3b in a second perspective view.

(17) FIGS. 3a and 4 show an embodiment of the apparatus of the invention, in the case of which a capacitive sensor 2 is integrated in the adapter 1. As a result of the mutually matching inner-dimensions of the first portion 3 of the adapter 1 and the pipeline 7, adapter 1 represents virtually a portion of the pipeline 7. The capacitive sensor mounted flushly in the first portion 3 of the adapter 1 measures, especially, whether medium is located in the pipeline 7 or whether the pipeline 7 is empty.

(18) The capacitive sensor 2 is composed of a centrally arranged, first electrode 11, which is insulated from a guard electrode 13 via an insulator 12. The insulator 12 and the guard electrode 13 surround the first electrode 11 concentrically. Preferably, the first electrode 11 is manufactured of the same material as the adapter, e.g. both are stainless steel. Via an additional insulator 14 arranged concentrically to the first electrode 11, the guard electrode 13 is insulated from the second electrode 15. The second electrode is in the illustrated case the adapter 1. Of course, in connection with the invention, all known embodiments of capacitive or conductive sensors can be applied.