WO2011128345A1

WO2011128345A1 - Assembly comprising an electropneumatic positioner and a pneumatic drive, and shut-off device for such an assembly

Info

Publication number: WO2011128345A1
Application number: PCT/EP2011/055739
Authority: WO
Inventors: Jochen Gareis
Original assignee: Siemens Aktiengesellschaft
Priority date: 2010-04-12
Filing date: 2011-04-12
Publication date: 2011-10-20
Also published as: DE102010014629A1

Abstract

The invention relates to an assembly comprising an electropneumatic positioner (3), a shut-off device (1) and a pneumatic drive (5, 70). The shut-off device (1) is arranged in a "sandwich" design between the positioner (3) and the drive (5, 70). A shut-off valve (40, 41, 42), by which the air conduit can be shut off in a simple manner before removing the positioner (3), is installed in at least one of the air conduits (21, 22, 23) that are guided in a linear fashion through the shut-off device (1) for connecting the pneumatic connections. A shut-off valve (40, 41, 42) is preferably located in each of the air conduits (21, 22, 23), which also prevents incoming air from escaping and prevents the pneumatic drive (5, 70) from changing the position. A positioner (3) in a process engineering installation can thus be replaced in a simple manner, often without having to interrupt a process for this purpose that is running on the installation with the assembly.

Description

description

Arrangement with an electropneumatic positioner and with a pneumatic drive and shut-off device for such an arrangement

Pneumatic actuators (actuators) are used to control of process valves often used, in which a valve to an actuator, for example, a closing body of a control, acting diaphragm by means of a gaseous Medi ^¬ killed, for in this application, the general term "air "is used, is pressurized and thus directed from ^¬. the application of the membrane with a variable pressure can be carried out on one side, wherein the membrane on the other side is loaded with a spring, or it may be two-sided, with different pressures on both The pressure is controlled by an electropneumatic positioner in which an electrically controllable valve distributes pressurized supply air to the two membrane sides in the actuator via two exhaust ports, depending on the control.

From EP 1632679 Bl is an electro-STEL lung regulator known, which is provided to a pneumatic actuator with a pneumatic interface to the pipe connection without having a supply air connection and two Abluftan ^¬ connections. Such an interface between actuator and positioner is in the directive

VDI / VDE 3847 specified. The attachment of the positioner he ^¬ follows, for example, from the front of a vertical, provided with air ^¬ channels and fastening threads and a coding pin surface on the lantern of a linear actuator. Through the air ducts, both the supply of supply air and the connection with single or double-acting actuators takes place.

As a result, the replacement of the positioner without dismantling existing Zuluft- or control air lines is possible. The interface is thus a tubeless connection of the Positioner suitable for the actuator. Is der Stel ^¬ lung regulator taken to his exchange of the actuator, the air ducts are open at the pneumatic interface of the control device. On the one hand, supply air can escape from the supply air duct, on the other hand, the pressure in the working chambers of the drive changes to ambient pressure. This can disadvantageously lead to an adjustment of the actuator. The escape of air supply could be verhin ^¬ changed, for example, by a toy in the supply air supply air valve is closed. Such supply valves are usually arranged remotely in process equipment, since they also serve for the shutdown of a whole group of actuators. If a displacement of the drive during disassembly of the positioner would lead to an inadmissible disturbance of the process, the drive can in some cases be ^blocked with additional aids, for example blocks, while the positioner is being changed. Replacement of the positioner, however, would often involve stopping the process that takes place in the process plant.

The invention has for its object to provide an arrangement with an electropneumatic positioner and with a pneumatic drive, in which the replacement of the electropneumatic positioner can be performed comparatively one ^¬ fold.

To solve this problem, the new arrangement with an electropneumatic positioner and with a pneumatic drive drive of the type described above, a shut-off device with the features stated in the characterizing part of claim 1. In the dependent claims advantageous developments, in claim 7 a shut-off device for such an arrangement are described.

The invention has the advantage that air ducts between the electro-pneumatic drive and positioner when needed, that is, for example, to replace the positioner, can be locked directly on site. Must be ^¬ example, only the supply air to avoid a Entwei ^¬ Chen of supply air during the disassembly of the positioner, Ge ^¬ blocks, so the shut-off devices in a check valve is provided in the supply air processing. This is advantageously no longer necessary to operate a possibly remote, provided for a whole group of actuators supply air valve. Advantageously, the drive maintains disassembly of the positioner in its last position when shut-off valves are arranged in all the air passages of the shut-off device, so that all Luftka ^¬ ducts may be blocked prior to disassembly of the positioner. An exchange of positioner is then no longer associated with a costly interruption of a process that runs on a process engineering system in which the assembly is installed. Advantageously, moreover, no blocking of the drive with additional aids is more necessary.

A particularly simple operation of the shut-off device is achieved when the shut-off valves are adjustable together by a single actuator. In a further advantageous embodiment, the shut-off valves are designed as ball valves with a common axis of rotation. Such shut-off valves are characterized by ei ^¬ NEN particularly low flow resistance when open to stand ^¬ because the air flow is straight through the air duct and at most small turbulences occur.

The ball valves can be advantageously provided in each case with a seal which is pressed by a spring against the switching ball, which is a spherical closing body. Occurs on the sealing surface wear, so the seal is pushed by the spring and it is thus reliably prevented that over the Betriebsdau ^¬ he the shut-off device in the sealing area creates a gap, which could lead to leakage currents. In addition, such an embodiment leads to lower requirements with respect to the manufacturing tolerances and thus to lower manufacturing costs of the shut-off device.

If the third and fourth interface, which are arranged on the shut- ^¬ device, compliant with the directive

VDI / VDE 3847 executed and are arranged parallel to each other, the shut-off can advantageously be screwed on one hand to a corresponding interface of a drive and on the other hand on its gegenü ^¬ opposite side exactly this interface again to Ver ^¬ addition, so that the positioner can be mounted on this. Thus, a "sandwich" - construction of the arrangement is advantageously obtained, in which the shut-off device between the pneumatic actuator and the electropneumatic positioner, each having to VDI / VDE 3847 compliant interfaces, is located.

Reference to the drawings, in which embodiments of the invention are illustrated, the invention and refinements and advantages are explained in more detail below. It shows: an arrangement with an electropneumatic

Positioner, a shut-off device and a pneumatic drive, a perspective view of a Absperreinrich ^¬ tung, a further perspective view of a shut-off ^¬ device,

FIG. 4 is a sectional view of a shut-off device, FIG. 5 shows an attachment of an adapter for linear actuators,

Figure 6 is a perspective view of an adapter for

Linear actuators,

Figure 7 shows an attachment with adapter for quarter-turn actuators and

Figure 8 is a perspective view of an adapter for

Part-turn actuators.

In the drawings, the same parts are provided with the same Bezugszei ^¬ chen.

As shown in Figure 1, a new shut-off device 1 in "sandwich" construction between a first pneumatic interface 2 of an electropneumatic positioner 3 and a second pneumatic interface 4 of a pneumatic ^¬ tischen drive 5 is arranged. For this purpose, the shut-off ^{device is provided} with a third interface which corresponds to the first interface 2 and is connected thereto, and with a fourth interface which corresponds to the second interface 4 and is connected thereto. The first, second, third and fourth interface have to ^¬ circuit pattern on according to the VDI / VDE 3847th It would thus be possible alternatively waiving the shut-off and associated with this advantages, the electropneumatic positioner 3 with its pneumatic interface 2 directly on the pneumatic

4 interface of the pneumatic drive 5 to mount. The shut-off device 1, which is located in the "sandwich"

Construction is located between the positioner 3 and the drive 5, however, has the advantage that an exchange of Stel ^¬ tion controller 3 can be easily done in case of a defect. For closing the air ducts, which lead to the pneumatic interface 2 of the electropneumatic positioner ^¬ controller 3, namely only a single Be ^¬ actuating device 6 of the shut-off device 1 must be rotated from a position "on" in a position "off". In order to are both a supply air duct, via which the positioner 3 is supplied with, for example, compressed air, as well as each of the two control air ducts which connect the positioner 3 with the two working chambers of the pneumatic drive in the case of a double-acting drive locked. When dismantling the positioner 2 therefore can escape neither to ^¬ air or air from the two working chambers. In an advantageous manner thus an actuator, which is actuated by the pneumatic drive 5, remains in its last position. Thus, it is often also no interruption of a process presented on a not further Darge ^¬ in Figure 1 runs process control system, for the exchange of the positioner 3 is required. Notwithstanding only the air duct for supply air by means of the shut-off device 1 is locked by the DAR ^¬ identified embodiment, as otherwise a required locking may already account by a possibly arranged at a remote location Zuluftven ^¬ til, so that even this represents a significant Vereinfa ^¬ chung ,

FIG. 2 shows a perspective view of the shut-off ^device 1, in which the fourth interface 20, which serves for connection to the second interface (4 in FIG. 1) of the pneumatic drive, is clearly visible. At the fourth interface 20, a supply air duct 21 ends as well as ^¬ two control air ducts 22 and 23, which are in the open state of ^¬ in the shut-off device 1 shut-off valves are passed straight through the shut-off device 1. A bore 24 serves to receive a coding pin according to the guideline VDI / VDE 3847. To fasten ^¬ tion of the shut-off device 1 on the second interface (4 in Figure 1) of the pneumatic drive (5 in Figure 1) serve two mounting screws 25 and 26th In the perspective view of the shut-off device 1 according to FIG. 3, the third interface 30 to which the electropneumatic positioner (3 in FIG. 1) is connected to the first interface (2 in FIG can, well visible. A coding pin 31 is used for the exact positioning of the positioner, which has a corres ^¬ dierende bore. In threaded bores 32 and 33 can be screwed for mounting the positioner fixing screws that correspond to the mounting screws 25 and 26 in Figure 2. The third interface 30 comprises a fourth interface (20 in Figure 2) spiegelbildli ^¬ ches connection pattern. Due to the configuration of the third and fourth interface of the shut-off device 1, a rotation of the shut-off device 1 by 180 ° is advantageously possible if required, for example if the actuating device 6 would otherwise be difficult to access. The sectional view of Figure 4 shows the internal structure of

Shut-off device 1. Three ball valves 40, 41 and 42, the switching balls are rotatable upon actuation of the actuator 6 about a common axis of rotation 48, serve for Absper ^¬ tion of the air channels 21, 22 and 23 through the course of the air ducts 21 to 23 is in advantageously allows a straight flow of air, which at most low vortex he testifies ^¬ . As a result, the air channels 21 to 23 have a comparatively low flow resistance. The structure of the seals of the shut-off valves 40 to 42 are identical, so that it suffices to explain in the following only the seal structure of the shut-off valve 42 in more detail. A sealing insert 43, which is displaceable perpendicular to the axis of rotation 48 of the actuating device 6, is provided on its side facing the switching ball 44 with a metallic sealing surface 45 corresponding to the shape of the switching ball 44, which is pressed against the switching ball 44 by a spring 46. When Ver ^¬ wear of the sealing surfaces of the sealing insert 43 is thus nachgeschoben, so that a gap formation and thus a due to wear resulting leakage can be largely avoided. In addition, the seal is provided with a circumferential O-ring seal 47. Thus, a good long-term stability of the shut-off device 1 can be ensured. In addition, due to the construction of the shut-off device 1 requirements for their compressive strength very well met, as could be demonstrated by an overpressure test.

As already explained above, the shut-off device is in a "sandwich" design between the electropneumatic

Positioner 3 and the pneumatic drive 5 arranged. Compared to an assembly of the positioner on the drive without intervening shut-off device so that the interface for mounting a displacement sensor on the electro-pneumatic positioner 3 is shifted by a distance corresponding to the thickness of the shut-off device. This distance can be bridged in a simple manner in a linear actuator by an adapter 50 shown in Figures 5 and 6. The height of the adapter 50 corresponds to the thickness of the shut-off device in "sandwich" design

Screws 51 and 52, the adapter 50 is fixed at the same point at which the transducer of the electropneumatic ^¬ rule positioner 3 would be attached without the use of a shut-off device. On a rear side 53 of the adapter 50 of the position transducer 54 of the positioner 3 is attached. Thus in a particularly simple manner A possible ^¬ friendliness is created to compensate the damage caused by the interposition of the adapter device distance when connecting the transducer 54th

Reference to the figures 7 and 8 is still the height compensation in an arrangement with a pneumatic rotary actuator 70 are illustrated. The position of the pivot drive is output by means of the angular position of a rotatable shaft 71. To bridge the gap here is an adapter 72, which has on its side facing the pivot drive 70 side a threaded shaft 73 and on the opposite side ent speaking threaded ^¬ 74. Even with the adapter 72 can be bridged in a very simple manner, the distance between the positioner 3 and drive 70, which is caused by the interposition of the shut-off device 1. On the basis of the examples shown in ^FIGS. 5 to 8, it will be particularly clear that the shut-off device 1 is in one "Sandwich" design with very little effort between a positioner 3 and a drive 5 or 70 conventional design can be inserted.

Claims

claims

1. An arrangement with an electro-pneumatic positioner (3) and with a pneumatic drive (5, 70), wherein the electro-pneumatic positioner, a first pneumatic interface (2) and the pneumatic drive has a thereto kor ^¬ respondierende second pneumatic interface (4) aufwei ^¬ sen , which is suitable for the tube-less connection of the electropneumatic positioner to the pneumatic drive, characterized in that

the arrangement comprises a shut-off device (1) which

a third interface (30) corresponding to the first interface and connected thereto

- Has a corresponding to the second interface and connected to this fourth interface (20), wherein pneumatic ports of the third interface with corresponding pneumatic ports of the fourth interface in each case by an air duct (21, 22, 23) ver ^¬ prevented and

wherein in at least one of the air channels, a shut-off valve (40, 41, 42) is arranged.

2. Arrangement according to claim 1, characterized in that in all air channels (21, 22, 23) of the shut-off device (1) off- shutoff valves (40, 41, 42) are arranged.

3. Arrangement according to claim 2, characterized in that the shut-off valves (40, 41, 42) together by a Actuate ^¬ generating device (6) are adjustable.

4. Arrangement according to claim 3, characterized in that the shut-off valves (40, 41, 42) are designed as ball valves with a common axis of rotation (48).

5. Arrangement according to claim 4, characterized in that the ball valves (40, 41, 42) are each provided with a seal (43, 45, 47) by a spring (46) against the respective switching ball (44) of the ball valves (40, 41, 42) is pressed ^¬ .

6. Arrangement according to one of the preceding claims, characterized in that the third interface (30) and the fourth interface (20) conform to the directive

VDI / VDE 3847 executed and arranged parallel to each other.

7. shut-off device for an arrangement with an electro-pneumatic positioner (3) and a pneumatic drive (5, 70), wherein the electropneumatic positioner a first pneumatic interface (2) and the pneumatic drive ^¬ a corresponding thereto second pneumatic interface (4 ), which is suitable for the tube-less connection of the electropneumatic positioner to the pneumatic drive,

characterized in that

- The shut-off device (1) to the first interface (2) corresponding and connectable with this third

Interface (30) and

a fourth interface (20) corresponding to and connectable to the second interface (4), wherein pneumatic connections of the third interface (30) to corresponding pneumatic connections of the fourth interface (20) are respectively through an air duct (21, 22, 23 ) are connected and