Probe device with a measuring probe received in a dip tube, wherein the dip tube is axially displaceable between a measuring position and a treatment position.

Abstract

Probe device (1, 100) for measuring a quantity of a process medium contained in a process vessel (101), comprising: - a connection device that can be connected to complementary connection means of the process vessel, - a treatment chamber part (4, 104) forming a treatment chamber (13, 113) with at least one supply line (14, 15) leading into the treatment chamber (13, 113) for a treatment medium, - a measuring probe (8, 108) with a measuring head (11, 111) designed for acquiring measured values, which is received in a dip tube (7, 107) mounted axially displaceably between a measuring position in which the measuring head (11, 111) is arranged outside the treatment chamber (13, 113) and a treatment position in which the measuring head (11, 111) is retracted into the treatment chamber (13, 113), the dip tube having a protective cylinder closed at its end face at its connection-side front end, wherein the measuring head (11, 111) is arranged in a section of the dip tube (7, 107) located behind the protective cylinder, wherein this section of the dip tube (7, 107) has openings (10, 110), wherein the measuring head (11, 111) extends through the openings in the measuring position of the dip tube (7, 107). (10, 110) can be supplied with the process medium and in the treatment position of the immersion tube (7, 107) with the treatment medium, - a drive device arranged at the end region of the probe device facing away from the connection device for axially displacing the immersion tube (7, 107), wherein the treatment chamber part (4, 104) is surrounded by a support structure (5, 105) connected to the connection device and the drive device, wherein the support structure (5, 105) is designed as a bushing having at least a tubular wall in sections, which receives the treatment chamber part (4, 104) and has at least one through-opening (26, 27) extending through the wall, and wherein the treatment chamber part (4, 104) and the support structure (5, 105) are arranged in an orientation relative to each other in such a way as to prevent rotation, in which the through-opening (26, 27) is aligned with the supply line (14, 15) for the treatment medium opening into the treatment chamber (13, 113).

Description

[0001] The invention relates to a probe device for measuring a quantity of a process medium contained in a process vessel, in particular for use in chemical, food technology, biotechnological or pharmaceutical processes.

[0002] The application range of probe devices for measuring physical or chemical parameters of a medium in process measurement technology is diverse. For example, chemical, food processing, biotechnological, or pharmaceutical processes require the use of probes to monitor the process or a product manufactured within that process. These probes can include, for example, pH probes, ion-selective electrodes, conductivity probes, turbidity probes, or optical or electrochemical probes for determining the concentration of a substance contained in the process medium being monitored, such as O2, CO2, certain types of ions, or organic compounds.

[0003] It is known from the prior art to perform inline measurements on process media using probe devices with an axially movable immersion tube that holds a measuring probe. Such probe devices are also referred to as interchangeable fittings. These interchangeable fittings are attached to a process vessel, for example, a pipe carrying the process medium. They have a treatment chamber into which the measuring probe can be temporarily moved during operation using the immersion tube. Various treatment media can be introduced into the treatment chamber. For example, a rinsing fluid can be passed through the treatment chamber to clean the measuring probe. It is also possible to expose the measuring probe to a sterilizing medium, such as hot steam, in the treatment chamber. Finally, a calibration fluid can also be introduced into the treatment chamber to calibrate the measuring probe.After the treatment is complete, the measuring probe is returned to the process vessel or the process medium to continue the inline measurement. Contamination of the process medium being monitored, or conversely, contamination of the calibration fluid with the process medium, is prevented by means of seals that seal the treatment chamber and the process vessel against each other.

[0004] For many processes, particularly in food processing, pharmaceuticals, and biotechnology, even minor contamination from the leaching of substances from the process vessel or the medium-contacting parts of the probe assembly is unacceptable. Other processes, especially for cleaning the process vessel, use aggressive media that can attack the medium-contacting parts of the probe assembly and lead to undesirable corrosion. Chemically resistant materials that can avoid these problems include titanium or highly corrosion-resistant nickel-chromium-molybdenum-tungsten alloys. However, these materials are very expensive. Chemically largely inert plastic materials, such as PTFE, PFA, or PVDF, often exhibit significantly lower mechanical strength compared to metals and metal alloys.

[0005] DE 10 2009 033 558 A1 describes a probe device for measuring process variables, in particular in the form of a pushrod fitting, which is inserted into a process vessel via an Ingold nozzle.

[0006] US 2007 / 0034028A1 discloses a holder fitting for replaceable measuring probes, which is used in chemical or biological processes and places particular emphasis on safety and ease of maintenance.

[0007] German patent application DE 10 2009 033 558 A1 describes a probe device of the type mentioned above, designed for connection to an Ingold fitting of a process vessel. The probe device has a spigot section that, when connected, is inserted into the Ingold fitting. This spigot section consists of an outer metal retaining ring, which can be fastened to the Ingold fitting with a union nut, and a plastic spigot anchored therein, which can be inserted into the Ingold fitting. The plastic material of the spigot is intended to be suitable for use in aggressive process media, while the metal retaining ring is intended to ensure sufficient strength for a robust and stable mounting of the fitting by means of the union nut.

[0008] For cleaning and / or calibrating the measuring probe, the probe assembly includes a flushing chamber section containing a flushing chamber sealed against the process medium by gaskets. When the immersion tube with the measuring probe is retracted into the flushing chamber, process medium is inevitably carried into the chamber. Therefore, the flushing chamber must also be considered as a medium-contacting component of the probe assembly. However, DE 10 2009 033 558 A1 does not provide for the flushing chamber to be made of an inert material. In the probe assembly described therein, the flushing chamber is formed within a base section of the probe fitting, which is attached to a pneumatic actuator for the immersion tube by means of a further union nut. For this reason, the base section must be relatively robust and mechanically stable.Constructing the base from titanium or highly corrosion-resistant materials would be disadvantageous for cost reasons. A plastic construction would not guarantee the required mechanical stability.

[0009] It is therefore an object of the invention to provide a probe device that overcomes the disadvantages of the prior art. In particular, the probe device should, with a simple design, allow the components that come into contact with the process medium during operation to be made of a material with sufficient chemical resistance, while ensuring the robustness and mechanical stability required for use in process measurement technology.

[0010] This problem is solved by a probe device according to claim 1.

[0011] This probe device for measuring a parameter of a process medium contained in a process vessel includes: - a connection device that can be connected to complementary connection means of the process vessel, - a treatment chamber component forming a treatment chamber with at least one supply line for a treatment medium leading into the treatment chamber, - a measuring probe with a measuring head designed for recording measured values, which is received in a dip tube axially displaceable between a measuring position in which the measuring head is arranged outside the treatment chamber and a treatment position in which the measuring head is inserted into the treatment chamber, the dip tube having a protective cylinder closed at its end face at its connection-side front end, wherein the measuring head is arranged in a section of the dip tube located behind the protective cylinder, wherein this section of the dip tube has openings, wherein the measuring head can be exposed to the process medium via the openings in the measuring position of the dip tube and to the treatment medium in the treatment position of the dip tube, - a drive device arranged at the end region of the probe device facing away from the connection device for axially displacing the immersion tube, wherein the treatment chamber part is surrounded by a support structure connected to the connection device and the drive device, wherein the support structure is designed as a bushing having at least a tubular wall in sections, which receives the treatment chamber part and has at least one through-opening extending through the wall, and wherein the treatment chamber part and the support structure are arranged in an orientation relative to each other in such a way as to prevent rotation, in which the through-opening is aligned with the supply line for the treatment medium opening into the treatment chamber.

[0012] By surrounding the treatment chamber component with a support structure connected to the connection device and the drive unit, the support structure provides stabilization for the treatment chamber component located between these two components. This means the treatment chamber component does not have to bear the weight of the drive unit alone and can therefore be made of a softer material or have thinner walls than it would without the additional support structure. Consequently, the treatment chamber component itself can be made of a largely chemically inert plastic or, alternatively, of one of the high-priced, highly corrosion-resistant metallic materials, particularly a highly corrosion-resistant alloy such as Hastelloy. In the latter case, the wall of the treatment chamber component can be made very thin to save material and thus costs.

[0013] Suitable chemically inert materials include PVDF (polyvinylidene fluoride), PEEK (polyetheretherketone), PFA (perfluoroalkoxyl alkane), and PTFE (polytetrafluoroethylene). Suitable metallic corrosion-resistant materials include highly corrosion-resistant nickel-chromium-molybdenum-tungsten alloys such as 2.4602 or Hastelloy, or titanium.

[0014] A chemically inert material, in this context, refers specifically to a material that is chemically resistant to the process medium contained in the process vessel and / or to the treatment media supplied to the treatment chamber during operation of the probe device. In particular, the chemically inert material should be such that it neither undergoes chemical reactions with these media nor that substances from the material dissolve into these media. Furthermore, the absorption of process or rinsing medium or its components into the material should be prevented; that is, the material must not be porous or develop pores over time due to corrosion.

[0015] All components of the probe assembly that come into contact with the process medium—that is, all components that contact the process medium in any position of the dip tube, particularly in the measuring position, the treatment position, or when moving the dip tube between the measuring and treatment positions—can, in an advantageous embodiment, be made of such a chemically inert material. The various components in contact with the medium can be made of different inert materials, for example, depending on the specific mechanical requirements that must be placed on the individual components. However, it is also possible for all components of the probe assembly that come into contact with the medium to be made of the same material as the treatment chamber section.

[0016] The drive unit is preferably designed as a linear drive and comprises a moving part, which may, for example, include a push rod, and a stationary part in which a bearing for the moving part is formed. In this configuration, the support structure is fixedly and / or detachably connected to the stationary part.

[0017] The immersion tube, as a component also in contact with the medium, can be made entirely of a chemically inert material. Advantageously, the immersion tube can be composed of several components made of different materials. For example, the medium-contacting, connection-side front end, which includes the protective cylinder and the section of the immersion tube with openings located behind the protective cylinder, can be made of a chemically inert material as the first component and connected to a second, drive-side component made of a mechanically stable, not necessarily chemically inert, material. This design allows, on the one hand, a mechanically stable and robust connection of the immersion tube to the drive unit, and on the other hand, ensures sufficient chemical stability of the medium-contacting front end with respect to the process medium or the treatment medium.

[0018] The support structure is designed as a bushing, at least partially comprising a tubular wall, which receives the treatment chamber part and has at least one through-opening extending through the wall. The treatment chamber part and the support structure are arranged relative to each other in an orientation such that the through-opening is aligned with the supply line for the treatment medium leading into the treatment chamber. The through-opening preferably extends radially so that the treatment medium can be introduced into the treatment chamber via a supply line connection arranged laterally on the support structure.As a rotation protection device between the support structure and the treatment chamber part, for example at least one radially movable locking element arranged in the support structure, in particular a pin connection for example by means of a dowel pin, which engages in a recess of the treatment chamber part, can serve.

[0019] The support structure can have an annular surface, formed by a ring step in its inner wall and pointing towards the connection device, which abuts an annular shoulder formed by a reduction in the outer diameter of the treatment chamber part at an end region of the treatment chamber part facing away from the connection device. In this way, the treatment chamber part is positively locked to the connection device of the probe assembly by means of the support structure.

[0020] In one embodiment, the connection device can comprise a flange connected to the support structure, which can be connected to a complementary flange of the process vessel via an annular sealing strip.

[0021] The connection-side end of the treatment chamber part can have an annular shoulder which sits in a receptacle formed by an axially extending nozzle of the sealing strip, wherein the gap formed between the receptacle and the treatment chamber part is sealed against the process vessel by means of at least one ring seal.

[0022] The treatment chamber part can have at least one internal seal in its connection-side end area, which rests against the immersion tube and seals the treatment chamber against the process vessel in both the measuring position and the treatment position of the immersion tube.

[0023] The receptacle formed in the axially extending nozzle of the sealing strip, or the connection-side end of the treatment chamber part, may have a recess, for example an annular shoulder or an annular groove, in which a wiper ring bearing against the immersion tube is received. The wiper ring may also be held between an end face of the treatment chamber part facing the process vessel and a surface opposite this end face of an annular step formed in the inner wall of the axial nozzle of the sealing strip.

[0024] The sealing strip, as a component in contact with the medium, can be made of a chemically inert material. In particular, it can be made of the same material as the treatment chamber part.

[0025] In an embodiment adapted for connecting the probe device to a complementary nozzle of a process vessel, the treatment chamber part has a pin-like extension at its connection-side end, which is designed to engage in the nozzle of the process vessel, wherein the connection device comprises a retaining ring which can be fastened to the complementary nozzle by means of a union nut, and which has an annular surface facing away from the process vessel, against which an annular step formed in the outer wall of the treatment chamber part rests.

[0026] In this embodiment, the support structure is connected to the side of the retaining ring facing the drive device, wherein the support structure has a shoulder facing the connection device which rests against a ring shoulder of the treatment chamber facing away from the connection device in order to further stabilize the treatment chamber part.

[0027] Further features, details and advantages of the invention are explained in more detail below with reference to the exemplary embodiments shown in the figures. The figures show: Fig. 1 a probe device according to a first embodiment for connection to a flange of a process vessel; Fig. 2 the in Fig. 1 Probe device shown in a longitudinal section view; Fig. 3 the in Fig. 1 Probe device shown in a longitudinal section view in a longitudinal section view of the Fig. 2 perpendicular cutting planes; Fig. 4 a probe device according to a second embodiment for connection to a nozzle of a process vessel in measuring position; Fig. 5 the in Fig. 4 Probe devices shown in treatment position.

[0028] Fig. Figure 1 shows a probe device 1 connected to a flange 2 of a process vessel (not shown in detail). For connection to the flange 2 of the process vessel, the probe device 1 has a connection device with a complementary flange 3. A support structure 5 is connected to the flange 3, which supports a (in Fig. The support structure 5 surrounds and stabilizes the treatment chamber part 4 (not visible). At its end facing away from the connection device, the support structure 5 is connected to a drive unit of the probe assembly 1. In the example shown here, the drive unit comprises a pneumatic drive with a cylinder 6 in which a piston (not shown) is axially movably mounted, dividing the cylinder 6 into two pressure chambers. By pressurizing one of the pressure chambers, the piston can be moved axially within the cylinder towards the other pressure chamber. The piston is operatively connected to a dip tube 7, so that the dip tube can also be moved axially by means of the axial movement of the piston and can be inserted into or removed from the treatment chamber part 4.A detailed description of such a pneumatic drive for a probe device of the type mentioned above can be found, for example, in DE 20 2007 017 297 U1. The drive device can alternatively be designed for manual operation or in another manner. In this case, the support structure can be connected directly or via several intermediate pieces to a stationary component of the drive device.

[0029] Fig. 2 and Fig. Figure 3 shows longitudinal sections through the in Fig. 1 Probe device 1 shown along two mutually perpendicular cutting planes AA and BB.

[0030] The probe assembly 1 comprises an axially movable immersion tube 7 in which a measuring probe 8, for example a pH glass electrode, is arranged. The immersion tube 7 is guided axially displaceably in the treatment chamber part 4, which is designed as an essentially tubular bushing. At two opposing end sections of the treatment chamber part 4, the annular gap formed between the treatment chamber part 4 and the immersion tube 7 is sealed liquid-tight against the process vessel and the drive unit, respectively, by sealing rings 12 which are received in an annular groove in the inner surface of the treatment chamber part and bear against the immersion tube 7 in the measuring position and in the treatment position.In a section of the treatment chamber part 4 arranged between the sealing rings 12, its inner diameter is widened, so that in this section between the immersion tube 7 and the treatment chamber part 4 an annular chamber is formed which is sealed against the process vessel by the process-side sealing ring 12 and serves as the treatment chamber 13.

[0031] In this example, the immersion tube 7 is constructed in multiple parts. The front end of the immersion tube 7, which comes into contact with the process medium in the measuring position, is formed from a first immersion tube section 16 made of a chemically inert material, for example, a plastic such as PFA, PTFE, or PEEK, or a metal such as titanium, or a highly corrosion-resistant alloy such as Hastelloy. It can be connected to a further immersion tube section 17 at the rear, which does not come into contact with the process or treatment medium, for example, via a threaded connection or a bayonet fitting. The further immersion tube section 17 does not have to be made of a particularly inert material. It can, for example, be made of stainless steel. This further immersion tube section 17 is connected directly or via additional intermediate pieces to the drive unit 6.If the drive unit includes, for example, a pneumatic drive as described above, the further immersion tube section 17 is in operative communication with the piston moving within the pneumatic cylinder. This ensures, on the one hand, that the medium-contacting part of the immersion tube does not interact with the process and / or treatment medium in an undesirable way, and on the other hand, a sufficiently robust and stable mechanical connection between the immersion tube and the drive is guaranteed. At the same time, the material costs of the potentially expensive, highly corrosion-resistant material used for the medium-contacting area of ​​the immersion tube are also minimized.

[0032] Fig. Figure 2 shows the immersion tube 7 in a measuring position extended from the treatment chamber part 4, Fig. 3 in a treatment position inserted into the treatment chamber section. At its connection-side front end, the immersion tube 7 has a protective cylinder 9 that is closed at the end. The measuring head 11 of the measuring probe 8 is arranged in a section of the immersion tube adjoining the protective cylinder 9, which has openings 10 through which the measuring head 11 can be exposed to a liquid or gaseous medium. In the measuring position ( Fig. 2) The section of the immersion tube 7 having the openings 10 is located inside the process vessel, so that the measuring head 11 can be exposed to the process medium contained in the process vessel. In the treatment position ( Fig. 3) the measuring head is located inside the treatment chamber 13, which is also sealed to the process vessel in this position of the immersion tube 7 by the process-side sealing ring 12 which abuts the protective cylinder 9 of the immersion tube 7.

[0033] For the purpose of supplying a treatment medium, for example a cleaning or calibration fluid or a sterilization medium, into the treatment chamber 13, the treatment chamber part 4 has a radially extending through-opening 14 ( Fig. 3), which opens into the treatment chamber 13. The measuring head 11 can be supplied with the treatment medium via the openings 10 in the treatment position. For draining the treatment medium, the treatment chamber part 4 has a further through-opening 15, also extending radially and preferably opposite the first through-opening 14, which opens into the treatment chamber 13. In other embodiments, the through-openings 14 and 15 can also be inclined at an angle to the radial direction. For cleaning the seals 12 or a section of the immersion tube 7 arranged behind the process-side seal 12, one or more further supply lines 29 can be provided in an end region of the treatment chamber part 4 facing away from the connection.

[0034] When the front end of the immersion tube 7 with the measuring head 11 is retracted into the treatment chamber 5, process medium can be carried from the process vessel into the treatment chamber 13. Therefore, to protect against the attack of aggressive process media, the treatment chamber section 4 is made of a chemically inert material, in particular a plastic material such as PFA, PVDF, PTFE, or PEEK. Alternatively, it can also be made of a highly corrosion-resistant metal such as titanium or a highly corrosion-resistant alloy, e.g., Hastelloy, whereby the costly metallic material can be minimized by using the thinnest possible wall thickness. To ensure sufficient stability of the probe assembly 1 despite the lower mechanical stability of the plastic materials or due to the thin wall thickness of the treatment chamber section 4, the treatment chamber section 4 is surrounded by the support structure 5.The support structure 5 is connected at its connection end to the flange 3, which is intended for connection to the process vessel, and is designed to positively lock and thus fix the treatment chamber part 4 on its side facing away from the connection device. On its side facing away from the process vessel, the support structure 4 is connected to the cylinder 6 of the drive unit. In this example, the support structure 5 is designed as a one-piece, tubular bushing surrounding the treatment chamber part 4. It can, for example, be made of stainless steel. At its connection end, the support structure 5 is detachably but securely connected to the flange 3 via a screw connection. At its opposite end, facing away from the connection, the support structure 5 can also be fastened to the drive unit, in this case to the pneumatic cylinder, by means of one or more screws or a union nut.In the end region of the treatment chamber part 4 facing away from the connection device, its outer diameter tapers abruptly, forming an annular shoulder 18 against which a stop surface 19, formed in the inner wall of the support structure 5 and facing the process connection, rests. On its side facing the process connection, the treatment chamber part 4 is held by a sealing strip 20 fixed between the flange 3 of the connection device of the probe assembly 1 and the flange 2 of the process vessel.

[0035] In the example shown here, the sealing strip 20 is made of the same material as the treatment chamber part 4, in particular a plastic material such as PFA, PTFE, PVDF, or PEEK. It has an annular, disc-shaped section extending between the flange 2 of the process vessel and the flange 3 of the probe assembly 1, which serves as a sealing element for the flange connection with the process vessel. Furthermore, the sealing strip 20 has an axially extending nozzle 21 that projects into the central opening of the flange 3. The nozzle 21 forms an annular receptacle 22 in which an annular shoulder 23, formed by a reduction in its outer diameter at the connection-side end of the treatment chamber part 4, is seated. The annular gap formed between the treatment chamber part 4 and the nozzle 21 is sealed against the ingress of process medium by a sealing element 24.Between the sealing strip 20 and the end face of the treatment chamber part 4 facing the process vessel, a further ring seal 25, which also serves as a scraper ring, is pressed in.

[0036] The support structure 5 has a first radial through-opening 26, which is aligned with the radial through-opening 14 of the treatment chamber part 4, so that treatment medium can be supplied to the treatment chamber 13 through the aligned through-openings 26 and 14. Correspondingly, the support structure 5 has a further radial through-opening 27, aligned with the through-opening 15 of the treatment chamber part 4, to discharge treatment medium from the treatment chamber 13. To ensure the alignment of the through-openings 14 and 15 of the treatment chamber part 4 with those of the support structure 5, a locking mechanism prevents the treatment chamber part 4 from rotating relative to the support structure 5. In the example shown here, the locking mechanism comprises a dowel pin 28, which is resiliently held in the inner wall of the support structure 5 on the connection side and engages in a recess of the treatment chamber part 4.

[0037] Fig. 4 and Fig. Figure 5 shows a second example of a probe device 100, which is designed to be connected to a process vessel 101 which has a connection nozzle 102. Fig. Figure 4 shows the probe device 101 with the immersion tube 107 in measuring position, while Fig. Figure 5 shows the probe device 101 with the dip tube 107 in treatment position.

[0038] The probe device 100, like the one based on the Fig. 2 and Fig. 3 described probe device 1 one, in Fig. 4 and Fig. 5. A drive device (not shown) for the axial movement of the immersion tube 107, which can be actuated, for example, pneumatically or manually. The immersion tube 107 is designed in the same way as the immersion tube 7 of the [reference to be added]. Fig. 2 and Fig. The device shown in Figure 3 has a front-facing protective cylinder and a section behind the protective cylinder with openings 110 through which the measuring head 111 of the measuring probe 108, which is housed in the immersion tube, can be exposed to the process medium or, in the treatment position, to a treatment medium. The immersion tube 107 is formed from a front, medium-contacting first immersion tube section 116 and a second immersion tube section 117 connected to it via a threaded or bayonet connection. The second immersion tube section 117 is in operative connection with the movable part of the drive unit, either directly or via one or more intermediate pieces. The medium-contacting first immersion tube section 116 is made of a material that is chemically inert with respect to both the process medium and the treatment medium, for example, a plastic such as PFA, PTFE, or PEEK, while the second immersion tube section 117 need not be made of an inert material.

[0039] The immersion tube 107 is guided in a treatment chamber part 104, which is designed as an essentially tubular bushing surrounding the treatment chamber 113 and has a series of internal grooves in which ring seals 112 are held. The ring seals 112 bear against the immersion tube 107. An annular gap, which serves as the treatment chamber 113, is formed between the immersion tube 107 and the treatment chamber part 104 by means of an expansion of the inner diameter of the treatment chamber part 104 between two ring seals 112. The treatment chamber 113 is sealed off from the process vessel 101 and from the (in) Fig. 4 and Fig. 5 (not shown) drive unit sealed in a liquid-tight manner.

[0040] The treatment chamber part 104 is surrounded by a support structure 105, which in the example shown here is a one-piece, essentially tubular bushing surrounding the treatment chamber part 104. The treatment chamber part 104 has several (in Fig. 4 and Fig. The treatment chamber 113 has five (non-visible) radially extending through-openings that open into it to supply a treatment fluid and / or discharge it from it. The support structure 105 has the same number of radial through-openings aligned with the radial through-openings of the treatment chamber part 104, so that treatment media can be supplied to and discharged from the treatment chamber 113 through the support structure 105. The through-openings of the treatment chamber part 104 and the support structure 105 can, for example, be designed in the same way as shown in the figure. Fig. 2 and Fig. 3 shown in the exemplary embodiment. As illustrated in the example below. Fig. 2 and Fig. In the embodiment described in section 3, a rotational movement can occur between the treatment chamber part 104 and the support structure 105 of the Fig. 4 and Fig. The probe device 100 shown in Figure 5 is locked by means of an anti-rotation device. The anti-rotation device can, for example, comprise a locking bolt 128 which is held resiliently in the support structure 105 and engages in a radial recess in the opposite side wall of the treatment chamber part 104.

[0041] On the connection side, the treatment chamber part 104 has a pin-like, tubular extension 130, which is designed to engage in the connection nozzle 102 of the process vessel 101. An annular groove is formed in an outer wall of the extension 130, in which an external ring seal 131 is received, which bears against the inner wall of the connection nozzle 102.

[0042] To form a stable mechanical connection between the probe assembly 100 and the connection nozzle 102 of the process vessel 101, the probe assembly 100 has a retaining ring 132, which can be secured to the connection nozzle 102 by means of a union nut 133. The retaining ring 132 has a bearing and fastening surface 134 facing away from the connection device for the support structure 105, to which the latter is attached, for example, by a screw connection. The retaining ring 132, together with the end region of the connection nozzle 102 adjoining the retaining ring 132 in the process-side direction, forms an abutment on which the treatment chamber part 104 is supported by an annular step 135 formed by a stepped reduction in its outer diameter.The retaining ring 132 and the support structure 105 can be formed as non-medium-contacting parts from a stable, chemically not necessarily inert material, such as stainless steel, so that a stable mounting of the probe device 100 and sufficient stability of the probe device 100 in itself is ensured.

[0043] In the end region of the treatment chamber part 104 facing away from the connection device, its outer diameter tapers in a step-like manner, thus forming an annular shoulder 118, against which a stop surface 119, formed in the inner wall of the support structure 105 and facing the connection device, rests.

[0044] The treatment chamber part 104, which comes into contact with the medium, can be made of a chemically inert, and potentially less mechanically stable, material, for example, a plastic material such as PEEK, PTFE, PFA, or PVDF. Since it is held in a form-fitting manner by the retaining ring 132 and the support structure 105 at its opposite end, the treatment chamber part 104 does not require any particular mechanical stability.

[0045] What is particularly advantageous about the ones in the Fig. In the embodiments shown in Figures 2 to 5, it is further shown that the sealing elements, which seal the process vessel against the environment or against the treatment chamber, are held in grooves in the treatment chamber section. All sealing elements are thus easily accessible for replacement by removing the treatment chamber section from the probe assembly, which significantly simplifies maintenance of the probe assembly.

Claims

[1] Probe device (1, 100) for measuring a quantity of a process medium contained in a process vessel (101), comprising: - a connection device that can be connected to complementary connection means of the process vessel, - a treatment chamber part (4, 104) forming a treatment chamber (13, 113) with at least one supply line (14, 15) leading into the treatment chamber (13, 113) for a treatment medium, - a measuring probe (8, 108) with a measuring head (11, 111) designed for acquiring measured values, which is received in a dip tube (7, 107) mounted axially displaceably between a measuring position in which the measuring head (11, 111) is arranged outside the treatment chamber (13, 113) and a treatment position in which the measuring head (11, 111) is retracted into the treatment chamber (13, 113), the dip tube having a protective cylinder closed at its end face at its connection-side front end, wherein the measuring head (11, 111) is arranged in a section of the dip tube (7, 107) located behind the protective cylinder, wherein this section of the dip tube (7, 107) has openings (10, 110), wherein the measuring head (11, 111) extends through the openings in the measuring position of the dip tube (7, 107). (10, 110) can be supplied with the process medium and in the treatment position of the immersion tube (7, 107) with the treatment medium, - a drive device arranged at the end region of the probe device facing away from the connection device for axially displacing the immersion tube (7, 107), wherein the treatment chamber part (4, 104) is surrounded by a support structure (5, 105) connected to the connection device and the drive device, wherein the support structure (5, 105) is designed as a bushing having at least a tubular wall in sections, which receives the treatment chamber part (4, 104) and has at least one through-opening (26, 27) extending through the wall, and wherein the treatment chamber part (4, 104) and the support structure (5, 105) are arranged in an orientation relative to each other in such a way as to prevent rotation, in which the through-opening (26, 27) is aligned with the supply line (14, 15) for the treatment medium opening into the treatment chamber (13, 113). [2] Probe device (1, 100) according to claim 1, wherein the treatment chamber part (4, 104) is made of a chemically inert material with respect to the process medium and the treatment medium, in particular a plastic material. [3] Probe device (1, 100) according to claim 2, wherein the plastic material comprises PVDF (polyvinylidene fluoride), PEEK, PFA (perfluoroalkoxyl alkane), PTFE (polytetrafluoroethylene). [4] Probe device (1, 100) according to one of claims 1 to 3, wherein all components of the probe device which come into contact with the process medium in a position of the immersion tube (7, 107) are made of a chemically inert material, in particular of the same material as the treatment chamber part (4, 104). [5] Probe device (1, 100) according to one of claims 1 to 4, wherein the treatment chamber part (4, 104) is positively attached to the connection device by means of the support structure (5, 105). [6] Probe device (1) according to one of claims 1 to 5, wherein the connection device comprises a flange (3) connected to the support structure (5), which can be connected to a complementary flange (2) of the process vessel via an annular sealing strip (20). [7] Probe device (1) according to claim 6, wherein a connection-side end of the treatment chamber part (4) has an annular shoulder (23) which sits in a receptacle (22) formed by an axially extending nozzle (21) of the sealing strip (20) and wherein the gap formed between the receptacle (22) and the treatment chamber part (4) is sealed against the process vessel by means of at least one annular seal (24). [8] Probe device (1) according to claim 7, wherein the receptacle (22) formed in the axially extending nozzle (21) of the sealing strip (20) has an annular groove in which a wiper ring (25) bearing against the immersion tube (7) is received. [9] Probe device (1) according to one of claims 6 to 8, wherein the sealing strip (20) is made of the same material as the treatment chamber part (4, 104). [10] Probe device (100) according to one of claims 1 to 5, wherein the treatment chamber part (4, 104) has a pin-like extension (130) at its connection-side end, which is designed to engage in a complementary nozzle (102) of the process vessel (101), wherein the connection device comprises a retaining ring (132) which can be attached to the complementary nozzle (102) by means of a union nut (133), and which has an annular surface (135) facing away from the process vessel (101), against which an annular step formed in the outer wall of the treatment chamber part (4, 104) rests.

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