DE102011079348A1 - Switching armature for analytical measurement, comprises process container, in which medium is accommodated, where process container is disposed on housing with complementary connection unit - Google Patents

Abstract

The switching armature comprises a process container (1), in which a medium (17) is accommodated. The process container is disposed on a housing (2) with a complementary connection unit. A dip tube (3) is axially extended between the housing, where a probe (4) is accommodated in the dip tube. The probe is arranged in a receptacle (5), where a safety device (23) prevents the movement of the dip tube in the receptacle, where the probe is available. The safety device has a lever system (7), which is arranged in a locking recess (8) of the housing.

Description

The invention relates to a retractable fitting.

Retractable fittings are widely used in analytical instrumentation. They are used to remove probes without process interruption even at process pressures of up to 10 bar and more from the process, and thus the medium, and then reintroduce them into the process. Probes for the purposes of this invention include sensors for determining one or more process variables and samplers who remove or add a certain amount of medium from the process.

The probes are moved manually or automatically, for example pneumatically, between a process position (probe has been extended and is in process) and a service position (probe has retracted). In the service position, the probe is sealed against the medium, with typically the probe itself being part of the seal.

In the case of a sensor, the sensor can be checked, calibrated, cleaned and / or replaced in the service position.

In the case of a sampler, the medium taken from the sampler can be examined, forwarded and / or filled in the service position. In addition, the sampler itself can be checked, cleaned and / or replaced. If one or more media are to be added to the process, in the service position the sampler can be filled with medium by means of an appropriate device and be moved through the retractable assembly into the process.

There is a risk that in the case of service (probe in service position) a probe removed and then forgotten to install a replacement probe. If the drive is then actuated in order to shift the dip tube into the process position, medium can escape through the now open tubular receptacle, in which the probe-and thus an important component of the seal-is missing. This medium can have a pressure of 10 bar and a temperature of up to 140 ° C. In addition, the medium can be chemically aggressive. Such incorrect operation can lead to significant accidents.

From the EP 1 540 322 B1 a retractable assembly with a sensor is known in which by means of a safety device, an axial displacement of the dip tube from the service position is prevented when the sensor is removed. For this purpose, the retractable fitting is provided with additional, partially axially acting, components that reduce the space in the dip tube and thus the stroke.

From the DE 20 2007 017 297 U1 is a pneumatic acting safety device for a, acted upon with a pressure medium, changeover fitting for a sensor is known, which ensures that the sensor is not moved when the sensor is missing. This solution is limited to pneumatically driven retractable fittings.

The invention has for its object to provide a purely mechanical-acting safety device for a retractable fitting, which has a simple and space-saving design.

The object is achieved by a retractable fitting, comprising

• - a process container containing a medium,
• A housing,
• A process connection with complementary connection means, which is arranged on the housing and connects the interchangeable fitting with the process container,
• A dip tube which can be moved axially between a process position extended from the housing and a service position inserted into the housing,
• A probe provided in the dip tube, wherein the probe is arranged in a receptacle, wherein the probe has a probe head on its region facing the medium,
• - A safety device that prevents the dip tube is movable when no probe is arranged in the receptacle, wherein the safety device comprises at least one lever system which is designed so that it rests in a locking recess in the housing and prevents axial movement of the dip tube when no probe is disposed in the receptacle and allowing axial movement of the dip tube when a probe is disposed in the receptacle.

In the retractable assembly with safety device according to the invention, the positive aspect shows that the stroke of the dip tube is not reduced. One of the characteristics of retractable fittings is their stroke, d. H. the travel path between service position and process position. The proposed invention does not reduce the stroke, which is considered to be particularly advantageous.

In a preferred embodiment, the lever system comprises a base member, a test page with test element, an active side with active element and a pivot point. The active element is in the locking recess in the housing and an axial movement of the dip tube is prevented when no probe is arranged in the receptacle. By Insertion of the probe in the recording, the test element rotates the lever system to the pivot point and the active element is released from the locking recess. It is considered to be particularly beneficial that the safety device does not require additional space.

In an advantageous development, the lever system is designed in one piece, d. H. the base element, the active element and the test element are made of one piece. This increases the stability of the component and reduces the production costs, since the individual components no longer locked to each other, secured and / or made firm.

In a preferred embodiment, at least one spring element is provided, which is configured such that the active element is present in the locking recess by the force of the spring element when no probe is arranged in the receptacle. If, however, a probe is arranged in the receptacle, the active element comes free against the force of the spring element. By the spring element ensures that the active element is positioned in the locking recess, whereby an axial movement of the dip tube is prevented when no probe is arranged in the receptacle.

In one embodiment, the lever system is a one-sided lever or a two-sided lever, for example also an angle lever. As a result, the safety device can be constructed to save space, without affecting the axial movement of the dip tube with inserted probe.

In a beneficial embodiment, the safety device is arranged in the interior of the piston. As a result, the safety device can be constructed to save space, and the axial movement of the dip tube with inserted probe is not affected. There are no components needed outside the piston and thus the stroke of the retractable fitting is not reduced.

In a further development, the test element engages the shaft of the probe. This increases test safety and ensures that axial movement of the dip tube takes place only when a probe is actually located in the receptacle.

It should be noted that the safety device can be optionally and subsequently attached to the retractable fitting. In order to install the safety device, the housing, the piston and the immersion tube must first be removed and reworked accordingly. Subsequently, the relevant safety device parts, such as the lever system, can be installed. In the next step, the removed and reworked components can be re-installed in the retractable housing.

In a preferred embodiment, the axis of rotation of the lever system extends through the hinge point parallel to the direction of movement of the dip tube. In this embodiment, only radially acting components are used, and the safety device can be constructed in a particularly space-saving manner.

Preferably, the interchangeable fitting is a measuring device for measuring at least one chemical and / or physical measured variable of the medium received in the process container.

The measured variable is, for example, the pH, the redox potential, the absorption of electromagnetic waves in the medium, for example with wavelengths in the UV, IR, and / or visible range, the oxygen, the conductivity, the turbidity Concentration of metallic and / or non-metallic materials or the temperature.

The invention will be explained in more detail with reference to the following figures. It shows

1a an axial cross section in side view of a retractable housing with safety device with probe in the direction of the test elements,

1b an axial cross section in side view of a retractable assembly with safety device with probe in the direction of the active elements,

2 a radial cross section in supervision of a retractable assembly with a safety device with probe,

3a an axial cross section in side view of a retractable assembly with safety device without probe in the direction of the test elements,

3b an axial cross section in side view of a retractable assembly with safety device without a probe in the direction of the active elements, and

4 a radial cross section in supervision of a retractable assembly with a safety device without probe.

In the figures, the same features are identified by the same reference numerals.

The figures 1a and 3a show a cross section through a housing 2 , spanned by the test element plane B, as in 2 and 4 shown. The figures 1b and 3b show a cross section through a housing 2 spanned by the active element level C, as in 2 and 4 shown.

The figures 1a and 1b show a case 2 , which by means of complementary connection means via a process connection with a process container 1 connected is. This can be done for example by a flange o. Ä. In the process container 1 there is a medium 17 , A process container 1 is to be understood in the context of this invention as a container, vessel, pipeline, etc. The housing 2 usually has a cylindrical shape and consists for example of stainless steel or a durable plastic such as polyetheretherketone (PEEK).

Inside the case 2 is a dip tube 3 guided, which axially in the direction of the process container 1 or in from the process container 1 away direction along the central axis A is slidably mounted. The displacement of the dip tube 3 is powered by a manual or automatic, for example pneumatic, drive 20 causes. An automatic drive is not described in detail here. The operation of the automatic drive is for example from the DE 10 2005 051 279 B4 known.

A probe 4 is through a recording 5 with the dip tube 3 , For example, by a screw connection connected. The dip tube 3 can by means of an inside 22 of the housing 2 located piston 21 along the central axis A. The piston 21 is formed cylindrically symmetric with respect to the central axis A and so within the housing 2 slidably arranged. In the case of a pneumatic drive, the piston 21 , and with it the dip tube 3 , by means - not described in detail and not pictured - inlets for a printing medium, for. B. compressed air moves.

One differentiates between two positions of the dip tube 3 : a retracted service position and an extended process position. The extended process position contains the dip tube 3 partially in the process container 1 , At the retracted service position is the dip tube 3 at the inside 22 of the housing 2 ,

In the in the figures 1a - 4 In the embodiment shown, the probe is designed as a sensor with which physical and / or chemical process variables of the medium 17 can be determined. This is located at the medium-side end of the probe 4 a probe head 6 ,

The probe head 6 includes a transducer not described in more detail, which generates a correlated with the process variable to be determined measurement signal. In the probe head 6 If necessary, the measuring signal is converted and further processed by a measuring electronics likewise accommodated there, likewise not further explained. From the probe head 6 the signal is transmitted to a higher-level unit, for example to a transmitter. The parent unit is z. Example by means of a galvanically decoupled interface (inductive, capacitive or optical) with the probe head 6 by an unspecified adapter, z. B. a connector connected. Also, embodiments with a sensor with fixed cable can be realized.

Process variables with the probe 4 can be detected, for example, pH, redox potential, absorption of electromagnetic waves in the medium 17 , For example, with wavelengths in the UV, IR, and / or visible range, oxygen, conductivity, turbidity, concentration of metallic and / or non-metallic materials or temperature.

In an alternative embodiment, it is conceivable that the probe 4 designed as a sampler. This should not be explained in detail. In principle, the sampler removes by means of a corresponding device on the probe head 6 , z. B. a sampling element, medium 17 from the process container 1 by the dip tube 3 with the sampler by the drive 20 is retracted and extended. The removed medium can then be examined, forwarded and / or filled into other containers.

In one variation, the sampler adds one or more media to the probe head by means of an appropriate device 6 , z. B. a Zugebeelement, in the process container 1 by the dip tube 3 with the sampler by a drive 20 is retracted and extended. The added medium can be in the process container 1 located medium 17 undergo a chemical reaction, mix, dissolve, emulsify etc.

As in 1a As can be seen, is a safety device 23 inside the piston 21 arranged and as a symmetrical system with two lever systems 7 realized. Embodiments with only one or more than two lever systems 7 are also possible. The lever system 7 is realized as a two-sided lever. In the embodiment shown, the two lever systems are located 7 inside the piston 21 , A lever system 7 is formed from base element 24 , Test page 9 with inspection element 10 and real page 11 with active element 12 , The test page 9 of the lever system 7 lies with the test element 10 on the shaft 16 the probe 4 at. By the pivot 13 divided, is the impact side 11 with active element 12 opposite the test page 9 with inspection element 10 , In the case 2 you can see a Sperrausnehmung 8th ,

The figures 1a . 1b and 2 show the retractable fitting with in the recording 5 arranged probe 4 ,

In 1a is the view of the inspection element 10 directed. The test element 10 lies on the shaft 16 the probe 4 at. In 1b is the view of the active element 12 directed. As in 1b represented, is the active element 12 not in the locking recess 8th , so that an axial movement of the dip tube 3 is possible.

2 shows a radial cross-section in a perspective view through the housing 2 with safety device 23 with in the recording 5 arranged probe 4 , The test page 9 of the lever system 7 lies with the test element 10 on the shaft 16 the probe 4 at.

In the embodiment shown, the active element 12 with the base element 24 z. B. connected by screwing, locking or gluing. On the real side 11 , on the active element 12 positioned, there is a spring element 14 , Is in the recording 5 a probe 4 arranged, so is the spring element 14 curious; excited.

The basic element 24 and the active element 12 can be made of stainless steel, for example.

The test element 10 is with the base element 24 z. B. connected by screwing, locking or gluing. The test element 10 can be made for example of a plastic.

A probe 10 and active element 12 can be configured as a pin, teeth, pins, bolts, mandrel, etc.

Embodiments are feasible in which the lever system 7 is designed in one piece, ie base element 24 , Test element 10 and active element 12 are made of one piece.

The figures 3a . 3b and 4 show the retractable fitting without a probe 4 in the recording 5 is arranged.

In 3a is the view of the inspection element 10 directed. By not having a probe 4 in the recording 5 is arranged, there is for the inspection element 10 no mechanical resistance. By the force of the spring element 14 becomes the lever system 7 over the pivot 13 rotates, and the inspection element 10 gets inside 15 of the dip tube 3 pressed.

In 3b is the view of the active element 12 directed. As in 3b is shown by the particular embodiment of the safety device 23 the real side 11 of the lever system 7 with the active element 12 into the locking recess 8th of the housing 2 postponed. An axial movement of the dip tube 3 is not possible now.

By replacing a probe 4 in the recording 5 becomes the test element 10 of the lever system 7 in the in the figures 1a - 4 shown embodiment pressed radially outward toward the housing wall. About the pivot 13 the lever system turns 7 with the active element 12 from the lock recess 8th of the housing 2 and gives an axial movement of the dip tube 3 free.

LIST OF REFERENCE NUMBERS

1

process container

2

casing

3

dip tube

4

probe

5

Recording for 4

6

probe head

7

lever system

8th

locking recess

9

verification page

10

A probe

11

action side

12

active element

13

crucial point

14

spring element

15

Inside of 3

16

Shank of 4

17

medium

20

drive

21

piston

22

Inside of 2

23

safety device

24

base element

A

Central axis

B

Prüfelementebene

C

Active element level

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely 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.

Cited patent literature

• EP 1540322 B1 [0007]
• DE 202007017297 U1 [0008]
• DE 102005051279 B4 [0032]

Claims (9)

Retractable fitting, comprising - a process container ( 1 ) into which a medium ( 17 ), - a housing ( 2 ), - a process connection with complementary connection means attached to the housing ( 2 ) is arranged and the retractable assembly with the process container ( 1 ), - a dip tube ( 3 ), which axially between one of the housing ( 2 ) extended process position and one in the housing ( 2 ) retracted service position, - a probe ( 4 ) in the dip tube ( 3 ), the probe ( 4 ) in a recording ( 5 ), wherein the probe ( 4 ) at her the medium ( 17 ) facing a probe head ( 6 ), - a safety device ( 23 ), which prevents the dip tube ( 3 ) is movable, if no probe ( 4 ) in the recording ( 5 ), the safety device ( 23 ) at least one lever system ( 7 ), which is designed such that it is in a locking recess ( 8th ) in the housing ( 2 ) and an axial movement of the dip tube ( 3 ) prevents if no probe ( 4 ) in the recording ( 5 ) is arranged, and an axial movement of the dip tube ( 3 ), if a probe ( 4 ) in the recording ( 5 ) is arranged. Retractable assembly according to claim 1, wherein the lever system ( 7 ) a base element ( 24 ), a test page ( 9 ) with test element ( 10 ), an action page ( 11 ) with active element ( 12 ) and a pivot ( 13 ), wherein the active element ( 12 ) in the locking recess ( 8th ) in the housing ( 2 ) and an axial movement of the dip tube ( 3 ) is prevented when in the recording ( 5 ) no probe ( 4 ), wherein by introducing the probe ( 4 ) into the recording ( 5 ), the test element ( 10 ) the lever system ( 7 ) around the pivot ( 13 ) and the active element ( 12 ) from the locking recess ( 8th ) comes free. Retractable assembly according to claims 1 or 2, wherein the lever system ( 7 ) is designed in one piece. Retractable housing according to at least one of the preceding claims, wherein at least one spring element ( 14 ) is provided, which is designed so that the active element ( 12 ) by the force of the spring element ( 14 ) in the locking recess ( 8th ) is pending when in the recording ( 5 ) no probe ( 4 ) is arranged, and against the force of the spring element ( 14 ) comes free when in the recording ( 5 ) a probe ( 4 ) is arranged. Retractable assembly according to at least one of the preceding claims, wherein it is in the lever system ( 7 ) is a one-sided lever or a two-sided lever, also an angle lever acts. Retractable assembly according to at least one of the preceding claims, wherein the safety device ( 23 ) in the interior of the piston ( 21 ) is arranged. Retractable assembly according to at least one of the preceding claims, wherein the test element ( 10 ) on the shaft ( 16 ) of the probe ( 4 ) attacks. Retractable assembly according to at least one of the preceding claims, wherein the axis of rotation of the lever system ( 7 ) through the pivot ( 13 ) parallel to the direction of movement of the dip tube ( 3 ) runs. Retractable housing according to at least one of the preceding claims, wherein the retractable housing is a measuring device for measuring at least one chemical and / or physical measured variable of the medium received in the process vessel.

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