DE102022126137A1 - Rotatable and/or bendable field device - Google Patents

Abstract

The invention relates to a field device with a housing (18), with a sensor element (14) for detecting a process variable, with a process connection (38), with evaluation and/or control electronics (32) and with sensor electronics (36), wherein the housing (18) is rotatable and/or bendable in at least one transition region (24) on a side of the process connection (38) facing away from a process end (28) of the housing (18).

Description

The invention relates to a field device according to the preamble of patent claim 1.

In process automation technology, field devices are often used to record and/or influence process variables. Examples of such field devices are level measuring devices, limit level measuring devices and pressure measuring devices with sensor units that record the corresponding process variables of level, limit level or pressure or process variables derived from them. "Field" refers to the area outside of control rooms. Field devices can therefore be actuators, sensors, data collectors (data loggers) and measuring transducers. Such field devices are often connected to higher-level units, for example control systems or control units. These higher-level units are used for process control, process visualization and/or process monitoring.

The field devices known from the state of the art usually have a housing, a sensor unit and an electronic module arranged in the housing. The measured process variables are usually evaluated and the results can be used, for example, to generate a switching command and/or a proportional analog or digital output variable or to display physical properties or process variables.

Field devices are sometimes used in installation positions that are difficult to access or confined. Field devices are often custom-made to suit the respective conditions in terms of size and geometry so that they can be mounted in the respective installation position.

In addition, the field devices are also used to monitor and control processes with very high process temperatures. Such high temperatures are reached particularly in the area of hygienic applications, e.g. in the food or pharmaceutical industry, when, for example, a CIP (clean in place) or SIP (sterilization in place) process is carried out on the process container and the field device. In these processes, the process containers and the installed measuring technology are cleaned and/or sterilized using different cleaning solutions and steam at elevated temperatures and pressure.

In order to protect the electronics from excessive temperatures, attempts are made to locate the electronics as far away as possible from the part of the field device through which the heat is introduced - usually the process connection and the sensor element. A large part of the heat dissipation takes place via the housing. Accordingly, attempts are made to use housings with large dimensions. This, in turn, is disadvantageous in cramped installation conditions.

The underlying object of the present invention is therefore to provide a field device which can also be used at high temperatures and can be mounted in particular in confined and difficult-to-access installation positions.

The object is achieved according to the invention with the features of the independent claims. Further embodiments and advantages are described in connection with the dependent claims.

The field device according to the invention has a housing. The additional components described below, such as a sensor element and various electronics, are arranged in the housing. The housing serves to protect the components.

The field device has a sensor element for detecting a process variable. The sensor element is in particular an element for detecting a fill level, such as an antenna for transmitting and receiving radar radiation, a limit level sensor, e.g. with a mechanical oscillator, and/or a pressure sensor. The sensor element is in particular arranged at a process end of the housing facing the process.

The field device includes a process connection, by means of which the field device can be attached to a container. The process connection is part of the housing and can be formed integrally with the housing or separately. The process connection forms the mechanical interface between the field device and the process environment, in particular the container.

The field device also has evaluation and/or control electronics. The evaluation and/or control electronics are used to evaluate the process variables recorded by the sensor element and to control the sensor element.

The field device also has sensor electronics. In the case of a radar sensor, the sensor electronics include, for example, the radar chip or a transducer for generating and receiving radar radiation. The sensor electronics are the so-called measuring sensor.

The evaluation and/or control electronics and the sensor electronics are arranged in particular in the housing.

According to the invention, at least one transition region is formed on a side of the process connection facing away from the process end of the housing, in which the housing can be rotated and/or bent. Rotatable and/or bent here means that the housing can be modified so that it extends not only in one spatial direction, but in at least two spatial directions.

The transition area at least is therefore located in an installation position of the field device outside the container and allows - by bending and/or twisting the housing - the geometry and thus the dimensions of the field device to be changed and adapted to the external conditions. If the housing is bent, the direction of extension of the housing outside the container can be varied. This is an advantage in particular for housings with particularly large external dimensions (i.e. very long housings) which are suitable for dissipating heat. This means that field devices can also be used in high-temperature applications and at the same time be flexibly mounted in tight installation conditions.

In particular, the housing is designed in at least two parts and a first housing part is arranged on one side of the transition region and a second housing part on the other side. The transition region can be firmly connected to a housing part or be formed by a separate part.

The division into a first housing part and a second housing part makes it possible for the first housing part and the second housing part to be individually interchangeable, thus increasing the flexibility in the design of the housing with regard to temperature and geometry. The individual housing parts can be easily mounted and detachably connected to the transition area or the other housing part, in particular via a screw connection, a click connection, a bayonet lock or a snap connection.

Alternatively, the housing itself is made of a flexible material, at least in the transition region, or has stretchable structures in the transition region. The transition region can also comprise thermally insulating material, so that temperature transfer from the side facing the process and the first housing part to the second housing part is reduced.

In particular, the housing has a joint in at least one transition area. The joint enables two housing parts to be rotated and/or moved relative to one another. A first housing part extends on the side of the transition area facing away from the end of the process and a second housing part extends on the side of the transition area facing the end of the process. Various types of joints can be used here, but a swivel joint or ball joint is particularly advantageous, by means of which the first and second housing parts can be rotated relative to one another. Such an angled geometry has the advantage that the field device as a whole is easy to grip for assembly.

Preferably, the joint is lockable so that the adjusted bent or twisted geometry of the housing can be fixed.

Alternatively or in addition to this, at least the transition area can be realized by several transition elements. Individual transition elements can be arranged so that they can be rotated relative to one another and/or pushed into one another. Depending on the number and geometry of the transition elements, the bend can be designed as required. The transition elements are in particular cylindrical and/or obliquely cut cylindrical elements, whereby the angle between these transition elements is changed by a relative rotation of these transition elements.

Using a joint or transition elements, the housing can be designed in the shape of a handle and can thus be used as a practical handle for screwing the housing into a container. This allows for tool-free assembly.

The above-mentioned individual transition elements are in particular connected to one another (in a movable manner), e.g. by means of a screw cap, click cap, latch and/or bayonet cap.

In another practical embodiment, the field device has means for detecting the individual components. This can be implemented via NFC, for example. The detection of the individual components makes it possible to determine a maximum permissible temperature at the end of the process of the housing and to issue a warning message if this temperature is exceeded in order to protect the individual electronic components as well as possible. In particular, a first housing part, a second housing part, at least one transition area with a joint or transition elements, an evaluation and/or control electronics, a sensor electronics and/or a process connection can be detected.

In a practical embodiment of the field device according to the invention, the evaluation and/or control electronics and the sensor electronics are arranged at a distance from one another. In particular, such that the evaluation and/or control electronics and the sensor electronics are arranged on different sides of the at least one transition area. The sensor electronics are arranged in particular in the housing part facing the process. This division can be chosen, for example, if the sensor element and the sensor electronics are spatially close to one another or should not be located on different sides of the transition area (such as in the case of a radar sensor with a waveguide). For a high-temperature application, only the sensor electronics would then have to be equipped with heat-resistant and more expensive electronic components, whereby the control and/or evaluation electronics on the remote side of the transition area can only comprise comparatively cheaper electronic components.

If the evaluation and/or control electronics and the sensor electronics are arranged on different sides of the at least one transition area, and the electrical connection between the evaluation and/or control electronics and the sensor electronics can therefore be subject to twisting and/or kinking, the electrical connection is made in particular by means of a sliding contact. A sliding contact can be provided for contacting the evaluation and/or control electronics and/or for contacting the sensor electronics. A sliding contact makes it possible to maintain electrical contact even if individual housing parts are twisted relative to one another.

In particular, the field device is a level sensor that works according to the radar principle, wherein the level sensor has a waveguide. The waveguide is arranged in particular within the housing and extends only on one side of the at least one transition area. In particular, the waveguide extends only on the side of the end of the process. Here, the waveguide extends in particular from the sensor electronics to the sensor element.

It is also conceivable that the waveguide extends over both housing parts and the transition area. This is possible in particular by means of a flexible waveguide that can be bent.

The second housing part with waveguide can, for example, be designed in different lengths, so that the changed length also results in a different length from the sensor element (antenna) to the sensor electronics. This is particularly relevant with regard to high-temperature processes, since the field device can also be used at higher temperatures if the electronics are further away from the heat source.

With a view to reducing the temperature in the area of the control and/or evaluation electronics and/or the sensor electronics, an insulating element can also be arranged on at least one surface facing the process. The insulating element serves in particular to shield heat from the process. The insulating element can thus be arranged in particular on the first housing element, which extends parallel to the container surface. The insulating element can in particular be easily plugged onto the housing.

In a further practical embodiment, a rotatable and/or tiltable display and/or a rotatable and/or tiltable supply unit and/or a rotatable and/or tiltable antenna unit for a radio system such as LoRa, LTE or NB-IoT is arranged on the housing. This also makes it possible to design the outer contour of the housing flexibly in order to adapt the housing to confined spaces.

The invention also relates to an arrangement of a field device as described above on a container, wherein the transition area is located outside the container. This offers the possibility of making even very large or long housings due to temperature conditions compact, so that they can also be used where there is little space.

• 1 ein Feldgerät in einer ersten Ausführungsform mit einem Drehgelenk in einer schematischen Darstellung in einer Seitenansicht,
• 2 ein Feldgerät in einer zweiten Ausführungsform mit einem Drehgelenk in einer schematischen Darstellung in einer Seitenansicht, und
• 3 ein Feldgerät in einer dritten Ausführungsform mit mehreren Elementen in einer schematischen Darstellung in einer Seitenansicht.

Further practical embodiments and advantages are described below in connection with the figures. They show:

• 1 a field device in a first embodiment with a rotary joint in a schematic representation in a side view,
• 2 a field device in a second embodiment with a rotary joint in a schematic representation in a side view, and
• 3 a field device in a third embodiment with several elements in a schematic representation in a side view.

In 1 a field device 10 is shown in a first embodiment. The field device 10 is a level sensor 12 operating according to the radar principle with a sensor sensor element 14, which in this case is designed as an antenna 16.

Furthermore, the field device 10 comprises a housing 18 with a first housing part 20 and a second housing part 22 and a transition region 24. The first housing part 20 is arranged at an end 26 of the housing 18 remote from the process and the second housing part 22 at a process end 28 of the housing 18. The transition region 24 is formed here between the two housing parts 20, 22 and here has a ball joint 30.

Furthermore, an evaluation and control unit 32 (shown here in dashed lines) is arranged in the housing 18, which is arranged in the first housing part 20. The evaluation and control electronics 32 are contacted via a plug connection 34.

In the second housing part 22, a sensor electronics unit 36 (shown in dashed lines) is arranged separately from the evaluation and control electronics unit 32, with a waveguide (not shown) extending from the second housing part 22 from the sensor electronics unit 36 to the sensor element 14. In the embodiment shown, the waveguide extends only in the second housing part 22 and not across the transition region 24.

Furthermore, the housing 18 has a process connection 38, by means of which the housing 18 can be fastened to a container 40. The process connection 38 here has a thread. The process connection 38 is formed in the present case on the second housing part 22.

The transition area 24 is located - as in 1 is clearly visible - outside the container 40.

The housing 18 of the field device 10 is designed to be pivotable or bendable at the transition area 24. The length of the housing 18 outside the container 40 can be reduced by bending the housing 18, so that the field device 10 can also be used in confined situations.

In 1 It is clearly visible that the housing 18 can be bent in such a way that it is designed like a handle - with a 90° angle between the first housing part 20 and the second housing part 22 - and accordingly the field device 10 can be gripped at the housing 18 and screwed into the container 40 with the process connection 38.

A thermally insulating element can also be arranged on a surface 41 of the housing 18 facing the process.

In 2 a field device 10 is shown in a second embodiment. This differs from the first embodiment in that the second housing part 22 is longer and, compared to the first embodiment, the distance between the sensor electronics 36 and the sensor element 14 is increased and the waveguide is correspondingly longer (not visible). This second embodiment of a field device 10 is suitable for high temperatures in that the distance between the sensor element 14 (here antenna 16) and the process connection 38 to the sensor electronics 36 is increased and the sensor electronics 36 is thus better protected against high temperatures.

In the 3 The third embodiment of a field device 10 shown differs from the first two embodiments in the design of the transition region 24. In the present case, the housing 18 further comprises a first housing part 20, a second housing part 22 and a transition region 24 arranged therebetween.

The transition region 24 here comprises three transition elements 42, 44, 46 for producing a bend in the housing 18. The transition elements 42, 44, 46 are each cylindrical elements which can be rotated relative to one another, whereby an angle between the first housing element 20 and the second housing element 22 can effectively be set. The obliquely cut cylindrical transition element 42 borders directly on the first housing part 20 and the obliquely cut cylindrical transition element 46 borders on the second housing part 22. The cylindrical transition element 44 is arranged in between. By rotating the transition elements 42, 44, 46 relative to one another, the direction of extension of the housing 18 is changed and a bend is created accordingly.

List of reference symbols

10

Field device

12

Level sensor

14

Sensor element

16

antenna

18

Housing

20

first housing part

22

second housing part

24

Transition area

26

process-distant end

28

End of process

30

Ball joint

32

Evaluation and control electronics

34

Plug connection

36

Sensor electronics

38

Process connection

40

container

41

Area

42

Transition element

44

Transition element

46

Transition element

Claims (10)

Field device with a housing (18), with a sensor element (14) for detecting a process variable, with a process connection (38), with evaluation and/or control electronics (32) and with sensor electronics (36), characterized in that the housing (18) can be rotated and/or bent in at least one transition region (24) on a side of the process connection (38) facing away from a process end (28) of the housing (18). Field device according to the preceding claim, characterized in that the housing (18) has a joint (30) in at least one transition region (24). Field device according to one of the preceding claims, characterized in that at least one transition region (24) is realized by several transition elements (42, 46, 46). Field device according to the preceding claim, characterized in that the transition elements (42, 44, 46) are connected by means of a screw closure, click closure, latching and/or bayonet closure. Field device according to one of the preceding claims, characterized in that the field device (10) has means for detecting the individual components (20, 22, 24, 32, 36). Field device according to one of the preceding claims, characterized in that the evaluation and/or control electronics (32) are arranged at a distance from the sensor electronics (36). Field device according to one of the preceding claims, characterized in that the electrical connection between the evaluation and/or control electronics (32) and the sensor electronics (36) is made by means of a sliding contact. Field device according to one of the preceding claims, characterized in that the field device (10) is a level sensor (12) operating according to the radar principle, wherein the level sensor (12) has a waveguide. Field device according to one of the preceding claims, characterized in that an insulating element is arranged on the surfaces of the housing (18) facing the process. Field device according to one of the preceding claims, characterized in that a rotatable and/or tiltable display and/or a rotatable and/or tiltable supply unit is arranged on the housing (18).