Accessories

Abstract

The present invention discloses an accessory for accommodating a sensor designed to measure at least one measured variable of a medium in a container, the accessory comprising: a basically hollow cylindrical housing designed to connect the accessory to the container and at least partially arranged in the container, wherein the housing comprises a first opening and a second opening, through which the medium flows in or out; an inspection chamber formed inside the housing in a region between the first and second openings; a rotatably movable closing element in the housing, which in a first position releases the flow through the inspection chamber from the first opening to the second opening and in a second position blocks the flow through the inspection chamber; a sensor bracket; and the sensor having a sensitive element and arranged on or in the sensor bracket, wherein the sensor bracket is designed so that the sensitive element is arranged in the inspection chamber in the measuring / inspection position.

Description

Technical Field

[0001] The invention relates to a fitting for receiving a sensor which is designed to measure at least one measured variable of a medium in a container. Background Art

[0002] Accessories, such as retractable accessories, are widely used in analytical measurement technology and process automation. Accessories are used to remove the sensor from the process and thus from the medium without interrupting the process, and to reintroduce the sensor into the process afterwards. The sensor is fastened in a level probe and is moved axially by hand or automatically (e.g. pneumatically) by a drive between a process position (measurement) and an inspection position (maintenance, calibration, flushing, probe replacement, etc.). Such processes take place over a certain period of time, which depends on the drift of the measured values ​​and the contamination of the measuring element. Sensors are used to measure one or more physical or chemical process variables.

[0003] A large number of different types of retractable fittings are offered and commercialized by the Endress+Hauser group of companies, for example under the name "Cleanfit CPA 871". Information about these fittings can be found on the applicant's website, for example as of the filing date at http: / / www.endress.com / cpa871.

[0004] In such a retractable fitting, the sensor holder with the sensor is moved linearly along the main axis of the fitting into the process, i.e. into the medium. The movement results from a service position (sensor isolated from the process, e.g. for cleaning or calibration) into a measuring position (sensor in the process). In the service position, sealing to the environment or to the process is performed, for example, by pins with polymer seals. This area is traversed by the above-mentioned linear movement from the service position into the measuring position (or vice versa), resulting in high stresses and signs of wear. Long travel paths require long sensor holders. In this case, there is a risk of sticking to the pipe, which puts great stress on the sealing system, especially in the case of polymers. Therefore, the seals must be replaced frequently. Due to the process, the movement additionally puts stress on the sensor. Moreover, when using pH glass sensors, the adhesion caused by agglomeration and / or crystallization of the medium increases the risk of glass breakage during installation and removal of the sensor. Summary of the invention

[0005] The invention is based on the object of minimizing the mechanical loads on the sensor and the fittings which occur as a result of the above-described method and at the same time achieving a large immersion depth.

[0006] This object is achieved by an accessory for accommodating a sensor, which is designed to measure at least one measured variable of a medium in a container, the accessory comprising: a basically hollow cylindrical housing, which is designed to connect the accessory to the container and is at least partially arranged in the container, wherein the housing comprises a first opening and a second opening, through which the medium flows in or out; an inspection chamber, which is formed inside the housing in a region between the first opening and the second opening; a rotatably movable closing element located in the housing, which in a first position releases the flow through the inspection chamber from the first opening to the second opening and in a second position blocks the flow through the inspection chamber; a sensor bracket; and the sensor, which has a sensitive element and is arranged on or in the sensor bracket, wherein the sensor bracket is designed so that the sensitive element is arranged in the inspection chamber in the measuring / inspection position.

[0007] One embodiment provides that the closing element is designed as a ball or a plug.

[0008] One embodiment provides that the sensor holder comprises a thread, in particular an internal thread, and that the sensor, in particular, has an external thread, which is screwed into the sensor holder.

[0009] One embodiment provides that the sensor holder is movable in the housing in the axial direction at least between a measuring / servicing position and an external position.

[0010] One embodiment provides that the sensor holder can be moved into the measuring / servicing position or out of the measuring / servicing position manually, pneumatically or by means of a motor.

[0011] An embodiment provides that the sensor holder is connected to the housing via a quick-release connector, in particular a bayonet connector.

[0012] One embodiment provides that the sensor holder is designed corresponding to the immersion depth in the inspection chamber.

[0013] One embodiment provides that, at the end region on the service compartment side, the sensor holder comprises a protective basket for the sensitive element of the sensor.

[0014] One embodiment provides that the housing comprises one or more seals, which seal the inspection compartment from the environment.

[0015] One embodiment provides that the housing comprises a scraper seal, by means of which the medium is scraped off the sensor during the movement of the sensor holder out of the measuring / servicing position.

[0016] One embodiment provides that the housing comprises at least two flushing connections to the service chamber, wherein the closing element in the first position blocks access to the flushing connections to the service chamber and in the second position releases access to the flushing connections to the service chamber.

[0017] One embodiment provides that the flushing connections are each arranged offset by 90° from the first opening or the second opening.

[0018] One embodiment provides that a handle for moving the closing element is arranged on the closing element. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is explained in more detail with reference to the following figures.

[0020] Figure 1 A three-dimensional view of the claimed accessory in said second position is shown.

[0021] Figure 2 A side view of the claimed fitting is shown in said first position.

[0022] Figure 3 A cross-sectional side view of the claimed fitting is shown in said first position.

[0023] Figure 4 Shows Figure 3 A diagram of the claimed accessory in the second position.

[0024] Figure 5 Shows Figure 2 A diagram of a cross section of the claimed accessory.

[0025] In the figures, the same features are identified by the same reference numerals. Within the meaning of the present invention, "top", "above" and related terms mean facing away from the measuring medium 14. Within the meaning of the present invention, "bottom", "below" and related terms mean facing the medium 14. DETAILED DESCRIPTION

[0026] The accessory to be protected is given the reference numeral 1 as a whole and is shown in Figure 1 middle.

[0027] In the following, the fitting 1 is explained in the form of a ball element (see below) with reference to the design of the closing element 3. This fitting corresponds to a type of spherical fitting. With few modifications, the concept can also be used when the closing element 3 is designed as a plug element, that is, the fitting 1 is a type of plug valve.

[0028] When the fitting 1 has a ball element, the ball element comprises a drilled ball to serve as a shut-off body 3 and is also referred to as a ball valve. The shut-off body 3 is also referred to as a closing element. The characteristic of such a fitting is that it is completely closed by a 90° rotation of the closing element 3. Thus, a rotational movement occurs. These fittings can be equipped with an actuator for automatic opening and closing. By rotating the ball (i.e. the closing element 3) by 90°, a flow of the medium through the fitting 1 can be achieved or a flow of the medium through the fitting 1 can be prevented. The closing element can also be designed in the form of a drilled roller or round rod.

[0029] The fitting 1 comprises a substantially cylindrical housing 2, which is designed to be connected to a container. For this purpose, the housing comprises a connection device. The connection device can be designed, for example, as a welded or flanged connection (e.g. made of stainless steel). However, other embodiments are possible. The measured medium 14 to be measured is located in the container. The container can be, for example, a tank, a boiler, a pipe, a pipeline, etc.

[0030] The housing comprises a first opening 9a and a second opening 9b through which the medium can flow in or out. The area of ​​the fitting 1 formed by the housing between the openings 9a, 9b is referred to as the inspection chamber 10. The cross section through the fitting 1 is Figure 3 By rotating the closing element 3 , the flow through the inspection chamber 10 is released (first position of the closing element) or blocked (second position of the closing element).

[0031] Figure 1 and Figure 2 The fitting 1 is shown in an open position and in a closed position, respectively. Figure 3 and Figure 4 A section through the fitting 1 is shown in the open position and in the closed position respectively.

[0032] The fitting 1 comprises a movable closing element 3 in a housing 2, which in a first position releases the flow of the medium through the housing 2 and in a second position blocks the flow of the medium through the housing. In the embodiment as a ball valve, the closing element is designed as a drilled ball; in the embodiment as a plug valve, the closing element is a so-called (flat) conical plug. The first position is also referred to as the open position, and the second position is correspondingly referred to as the closed position.

[0033] The accessory 1 further comprises a sensor holder 4. The sensor 5 is arranged on or in the sensor holder 4. The sensor holder 4 is designed, for example, as a carriage; the sensor 5 then rests "against" the sensor holder 4. The sensor holder 4 can also be designed as a hollow cylindrical component; the sensor 5 then lies "in" the sensor holder 4. In both cases, the opening for the sensitive element 5a of the sensor 5 is located at the bottom end.

[0034] The sensor holder 4 has, for example, an internal thread into which a sensor 5 having an external thread is screwed. Typically, the sensor is connected to the sensor holder at a first end, typically at the top. A portion of the sensor holder 4 is located in the housing 2 and a portion is located outside the housing 2.

[0035] In one embodiment, the sensor holder 4 is movable in the housing between a measuring / servicing position and an external position. If the sensor holder 4 is in the measuring / servicing position, the sensor 1 is arranged such that the sensor 1 is positioned with its sensitive element 5a in the service chamber 10 .

[0036] The sensor 5 itself is thus not displaced, but is mounted in the fitting 1 by means of the sensor holder 4. In addition to the simple assembly (disassembly) of the sensor 5, the purpose of the sensor holder 4 is in particular to make it easier to service the process seal 6 (see below) of the sensor 5. Thanks to the sensor holder 4, the sensor can be used even at greater immersion depths. The sensor is, for example, 120 mm long. Thus, short, relatively cheap sensors that are usually common in stock can be installed, but large immersion depths are still possible. In addition, the extension of the holder allows scaling the immersion depth. The sensor holder 4 (including the already preassembled sensor 5) can be mounted in the fitting 1 by means of a quick-release connector, such as a bayonet connector. The holder 4 can be inserted into the fitting 1 manually. The movement may also occur by means of pneumatics or a motor.

[0037] The guide body 12 is arranged on the housing 2, the guide body 12 at least partially protruding into the housing; see for example Figure 4 The guide body is fixed to the housing by screwing, gluing, welding or other means. The guide body can also be an integral part of the housing 2.

[0038] The sensor holder 4 is arranged in the housing via the guide body 12 so that the sensor 5 projects through the bottom end into the inspection chamber 10; therefore, in a first position of the closing element 3, the medium 14 flows around the sensor 5, and in a second position of the closing element 3, the sensor 5 is separated from the medium 14. The sensor holder 4 is adapted to the length of the sensor so that the sensor 5 with its sensitive area 5a always projects into the inspection chamber 10. The sensor holder 4 is designed corresponding to the immersion depth of the sensor 5 in the inspection chamber 10. In the bottom end region, the sensor holder 4 comprises a protective basket for the sensitive element 5a of the sensor 5; see, for example, Figure 5 .

[0039] The sensor bracket 4 is connected to the housing 2 or the guide body 12 via a quick-release connector, in particular a bayonet connector.

[0040] One or more seals 6 are arranged on the sensor support 4 and seal the flow region from the environment; see for example Figure 5 The term "environment" refers to everything outside the container and outside the fitting. The closing element 3 also includes a seal 6a (see Figure 5 ), the seal 6a also plays a role of sealing to the environment. The seal 6a is designed as a sealing seat and, for example, has a (hollow) spherical shape or is composed of two half shells.

[0041] A scraper seal is introduced into the housing 2 , by means of which the medium 14 is scraped off the sensor 5 during the movement of the sensor holder 4 out of the measuring / servicing position.

[0042] A handle 8 is attached to the closing element 3. As a result, the closing element 3 can be easily rotated. The closing element 3 can also be operated pneumatically or electrically, for example using a rotary drive.

[0043] In order to flush the sensor 5 in the closed position, at least two flushing connections 7 are attached to the housing 2, which have holes leading to the inspection chamber 10. In the open position, the fitting leads to the medium 14, which flows around the sensor 5; this is the first position. In the closed position, the fitting 1 leads to the flushing connections 7. Therefore, the medium cannot flow through the fitting, i.e. through the openings 9a and 9b; instead, the medium 14 is blocked. The flushing connections 7 are correspondingly released and the inspection chamber 10 can be flushed therethrough. The sensor 5 can also be flushed, calibrated, adjusted, etc. A flushing / cleaning / calibration and / or disinfection medium can be introduced into the inspection chamber 10 via one connection 7. The flushing / cleaning / calibration and / or disinfection medium can be a liquid or a gas. The liquid can then flow out via the corresponding other flushing connection 7. The flushing connection 7 also allows the residual medium to be conveniently removed from the fitting 1, more precisely from the inspection chamber 10.

[0044] The sensor 5 within the meaning of the present invention comprises a sensor for measuring one or more physical or chemical process variables. The sensor 5 comprises a sensitive area 5a, for example for measuring pH value, oxygen, conductivity, turbidity, concentration of metal and / or non-metallic materials, or temperature, the pH value also being measured via an ISFET, redox potential, absorption of electromagnetic waves (e.g. with a wavelength in the ultraviolet, infrared and / or visible range) in the medium 14. The sensor 5 is connected to a cable 16 (symbolically at Figure 5 ). The cable 16 is then connected to a transmitter not shown. The sensor 5 is designed, for example, as a digital sensor with a microcontroller and a memory; in particular, the sensor 5 is an inductive sensor, in particular, the sensor 5 supports plug-and-play with a transmitter connected to the sensor. The applicant sells this sensor under the name "Memosens". For example, the sensor 5 has a diameter of 12 mm.

[0045] The sensor holder 4 can be made of different materials, for example steel or stainless steel. Very corrosion-resistant materials are also possible, for example in the chemical industry. Therefore, the sensor holder 4 can also be made of a plastic, such as polyetherketone (PEEK), polytetrafluoroethylene (PTFA), perfluoroalkoxy polymer (PFA), another plastic, or a corrosion-resistant metal, such as Hastelloy. Ceramics can also be used. In particular, the closing element is made of ceramic. Another option is to use a coating of one or more of the above-mentioned polymers. The same applies to the housing 2 or the guide body 12.

[0046] Reference numerals list

[0047] 1 Accessories

[0048] 2 Housing

[0049] 3 Close the element

[0050] 4 Sensor bracket

[0051] 5 Sensors

[0052] 5a Sensitive area

[0053] 6 Seals

[0054] 6a Ball seal

[0055] 7 Flush the connection

[0056] 8. Handle

[0057] 9a, 9b Open

[0058] 10 Maintenance Room

[0059] 11 Scraper

[0060] 12 Guide body for 4

[0061] 13 Driver

[0062] 14 Medium

[0063] 15 Protection basket

[0064] 16 Cables

Claims

1. An accessory (1) for receiving a sensor (5), the sensor (5) being designed to measure at least one measured variable of a medium (14) in a container, the accessory (1) comprising: a hollow cylindrical housing (2) designed to connect the fitting (1) to the container and to be arranged at least partially in the container, The housing comprises a first opening (9a) and a second opening (9b), and a medium (14) flows in or out through the first opening (9a) and the second opening (9b); - an inspection chamber (10) formed inside the housing (2) in a region between the first opening (9a) and the second opening (9b); - a rotatably movable closing element (3) in the housing (2), which in a first position releases the flow through the inspection chamber (10) from the first opening (9a) to the second opening (9b) and in a second position blocks the flow through the inspection chamber (10); - a sensor support (4); and - the sensor (5), which has a sensitive element (5a) and is arranged on or in the sensor support (4), wherein the sensor support (4) is designed such that the sensitive element (5a) is arranged in the servicing chamber (10) in a measuring / servicing position, The housing (2) comprises a scraper (11), and during the movement of the sensor support (4) away from the measuring / maintenance position, the medium (14) is scraped off from the sensor (5) by the scraper (11). wherein the housing (2) comprises at least two flushing connections (7) leading to the inspection chamber (10), Therein, the closing element (3) blocks access of the flushing connection (7) to the inspection chamber (10) in the first position and releases access of the flushing connection (7) to the inspection chamber (10) in the second position.

2. The accessory (1) according to claim 1, in, The closing element (3) is designed as a ball or a plug.

3. Accessory (1) according to one of the preceding claims, in, The sensor bracket (4) comprises a thread, and the sensor is screwed into the sensor bracket (4).

4. The accessory (1) according to claim 3, in, The sensor bracket (4) comprises an internal thread, and the sensor has an external thread.

5. The accessory (1) according to claim 1 or 2, in, The sensor support is movable in the housing (2) in the axial direction at least between a measuring / maintenance position and an external position.

6. Accessory (1) according to claim 5, in, The sensor bracket (4) can be moved into the measuring / maintenance position or out of the measuring / maintenance position manually, pneumatically or by means of a motor.

7. Accessory (1) according to claim 1 or 2, in, The sensor bracket (4) is connected to the housing via a quick-release connector.

8. Accessory (1) according to claim 7, in, The sensor bracket (4) is connected to the housing via a bayonet connector.

9. Accessory (1) according to claim 1 or 2, in, The sensor holder (4) is designed to correspond to the immersion depth in the inspection chamber (10).

10. Accessory (1) according to claim 1 or 2, in, At the end region on the inspection compartment side, the sensor support (4) comprises a protective basket (15) for the sensitive element (5a) of the sensor (5).

11. Accessory (1) according to claim 1 or 2, in, The housing (2) comprises one or more seals (6, 6a) which seal the inspection room (10) from the environment.

12. The accessory (1) according to claim 1, in, The flushing connections (7) are each arranged offset by 90° from the first opening (9a) or the second opening (9b).

13. Accessory (1) according to claim 1 or 2, in, A handle (8) for moving the closing element (3) is arranged on the closing element (3).

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