Monitoring and testing equipment

Abstract

Monitoring and testing device for a load-bearing structure lined with a lining material (2), which is intended for receiving gaseous or liquid media, wherein the lining material (2) is held at a distance from the structure by a spacer element (5) and is connected to the structure by fastening points (20), wherein the spacer element (5) is at least partially conductive, and wherein a leak test is carried out by applying a voltage to the structure and the lining material (2), and an intermediate space (6) defined by the spacer element (5) is provided for permanent monitoring by sensors (31), wherein - the space (6) can be permanently monitored by a vacuum sensor, overpressure sensor, liquid sensor (32) or a resistance measurement and - the construction has a lower-lying collection trough in the floor area behind the lining material (2), which is equipped with a liquid sensor (32).

Description

[0001] The invention relates to a monitoring and testing device for a supporting structure lined with a lining material, which is intended to accommodate gaseous or liquid media, wherein the lining material is held at a distance from the structure by a spacer element and is connected to the structure by fastening points, wherein the spacer element is at least partially conductive and wherein a leak test is carried out by applying voltage to the structure and the lining material and an intermediate space predetermined by the spacer element is provided for permanent monitoring by sensors, as well as a method for monitoring and leak testing.

[0002] The intended lining material serves as corrosion protection for the supporting structure. For this purpose, plastics made of MFA, PTFE, or FEP are used, for example, in film form. These are welded together due to their finite width and additionally connected to the supporting structure via fastening points. The plastic materials possess sufficient chemical resistance to aggressive media, which can be gases or liquids. To protect the supporting structure or to prevent contamination by gases or liquids, it is completely lined with the lining material, including the floor, walls, and ceiling.

[0003] The supporting structures can be containers, apparatus, channels, housings, or columns, for example, made of metal and coated with a coating that is only partially resistant to aggressive media. Such structures can also be made of plastic or fiberglass, although the materials used are generally not acid-resistant or impure, requiring an additional acid- or alkali-resistant lining of the supporting structure. Such lining protection is almost always required for high-purity containers, such as those used in the semiconductor industry, as well as for highly resistant containers used in the chemical industry.

[0004] The lining materials provide a full-surface lining, which is held in place by numerous attachment points to permanently connect it to the inner wall surface of the supporting structure. Due to pressure fluctuations of the liquid or gaseous media that are introduced into the supporting structure and the resulting mechanical stresses, the attachment points must have sufficient holding force.

[0005] Unfortunately, despite the presence of lining materials, problems can arise with particularly critical chemicals because the required protection against corrosion cannot always be guaranteed with a supporting structure made of metal, as the media contained in the supporting structure can penetrate the lining material. Fluoroplastic materials are generally used for the lining material, but unfortunately these are only slightly permeable to certain substances. For example, particularly strong permeation can occur with halogenated hydrogens such as hydrogen fluoride, which can combine with the permeating water vapor to form the particularly aggressive hydrochloric acid. These substances can penetrate the lining material as permeate in the gas phase and condense behind the lining material, resulting in the formation of hydrochloric acid from hydrogen chloride and water, for example.Hydrogen and helium can also easily penetrate the lining material and, as non-aggressive substances, cause corrosion of the supporting metal structure. The existing temperature of the stored gaseous or, in particular, liquid media supports this process, so providing good insulation is a primary goal. Depending on the type and composition of the permeate, it must be ensured that the permeate cannot condense under any circumstances between the lining material and the supporting structure. Therefore, the temperature may only fall below the dew point of the chemicals in question within the lining materials. Furthermore, care must be taken to prevent cold bridges, as far as possible, to avoid condensation.

[0006] Due to the nature of the chemicals used in the form of gases or liquids, it cannot always be guaranteed with absolute certainty that the media will not diffuse through the lining material and cause damage to the supporting structure due to the aforementioned influences.

[0007] It is therefore necessary to detect any possible leakage of the medium as quickly as possible in order to initiate appropriate measures.

[0008] From DE 10 2020 127 80 A1 a fastening device for a lining and a test method by means of sparkover are known.

[0009] EP 3 896 004 discloses a double-walled container for storing liquids. DE 10 2019 115 540 B3 discloses a container and a method for its production. The focus here is, for example, laminating a sensitive element into the textile reinforcements.

[0010] For the above-mentioned reasons, the object of the present invention is to provide a monitoring and testing unit with which, for example, a leak test can be carried out, but also a permanent control of the space between the lining material and the supporting structure is possible.

[0011] To achieve this objective, the intermediate space is continuously monitored by a vacuum sensor, a pressure sensor, a fluid sensor, or a resistance measurement, and the structure includes a lower collecting trough in the floor area behind the lining material, which is equipped with a fluid sensor. Further advantageous embodiments of the monitoring and testing device are set forth in the subclaims.

[0012] For leak testing and, if necessary, for ongoing monitoring of the space between the lining material and the supporting structure, the invention provides a spacer element which is located in the space and is at least partially conductive. The spacer element fulfills two conditions: firstly, due to its partial conductivity, it can be used for voltage testing, and secondly, the distance between the supporting structure and the lining material is defined so that a distance is always guaranteed. By applying voltage to the structure and the lining material, a potential leak point can be identified very quickly, in this case by a voltage flashover extending from the lining material via the conductive spacer element to the supporting structure.Voltage flashovers occur in the immediate vicinity of the leak, allowing it to be localized. There are various options for repairing the lining material to achieve the required tightness. For example, the lining material can be repaired by welding a layer of the lining material onto the leak. Subsequently, a further test can be performed by applying voltage until it is ensured that the lining material has the required tightness.

[0013] In addition, the spacer element provides a gap for continuous monitoring using sensors, and it also serves as additional insulation between the supporting structure and lining material. The sensors can detect, for example, the leakage of a gaseous or liquid medium, allowing appropriate measures to be initiated immediately to eliminate the leak. Pressure sensors that can detect negative or positive pressure in the gap are also conceivable.

[0014] The particular advantage of the monitoring and testing system is that an initial test can be performed using a voltage application to determine sufficient tightness of the lining material. Continuous monitoring can then be performed using sensors, allowing for long-term monitoring and thus protecting the supporting structure from damage of any kind through early detection of leaks.

[0015] A test is preferably carried out using an alternating voltage applied to the supporting structure and the lining material. In the event of a leak in the lining material, this leads to a lightning discharge, which makes it possible to locate the leak location. However, if the lining material has been welded to be gas- and liquid-tight and there is no leak, a lightning discharge or sparkover will not occur despite the voltage being applied.

[0016] It is also provided that the gap is permanently monitored by a vacuum sensor, overpressure sensor, liquid sensor or a resistance measurement.

[0017] For pressure monitoring, preferably differential pressure monitoring, the gap is equipped with a negative or positive pressure sensor. In the event of a leak, for example, a leak occurs when there is excess pressure, which causes the gaseous or liquid medium to flow from the interior of the supporting structure into the gap, triggering an alarm via the sensors. If a negative pressure is present and a leak is present, the pressure increase can also be monitored by a pressure sensor.

[0018] With the help of the negative pressure or positive pressure sensors, a leak in the lining material can be detected very quickly under given pressure conditions in order to initiate appropriate reactions as quickly as possible.

[0019] Alternatively, it is possible to arrange several liquid sensors at the lowest point of the space within the supporting structure behind the starting material, which immediately detect the leakage of liquid media.

[0020] When monitoring leaks using liquid sensors, these are positioned at a lower level within the gap, allowing leak detection through the escaping medium, particularly liquid or condensed material, in the gap. The sensors can be based on various types of analysis and pinpoint the location of the leak.

[0021] Furthermore, it is possible for the construction to have a deeper collecting trough in the floor area behind the lining material, which is also equipped with a liquid sensor to immediately detect any accumulation of liquid media.

[0022] Monitoring with liquid sensors allows for continuous monitoring of the gap. The sensors are connected to a monitoring station, and their exact location is known, allowing the leak location to be determined. One advantage of liquid or gas sensors is that this detection system can be easily relocated and installed, allowing immediate reuse after a leak and repair.

[0023] It is also possible to implement a resistance measurement. For this purpose, a locating cable is laid at the lowest point of the gap within the supporting structure, which allows the location of the leak to be determined using a resistance measurement.

[0024] In an embodiment of the invention, it is provided that the spacer element used between the structure and the lining material consists at least partially of a PTFE grid structure, which has the particular advantage that it is a grid structure which is, on the one hand, resistant to gas or liquid media and, on the other hand, offers the possibility of capturing accumulations of media in the lower area of ​​the supporting structure more quickly because the liquid media can flow downwards more quickly through the grid structure.

[0025] In a preferred embodiment, the PTFE grid is doped with conductive substances so that a leak can be detected when voltage is applied due to voltage flashovers (lightning discharge).

[0026] The PTFE grid offers another advantage because it has a temperature resistance of more than 400 degrees and is therefore not damaged, for example, by media with higher temperatures. In addition, when the lining material is welded to the inner wall surface of the supporting structure using a laser, it withstands the resulting temperatures and does not melt.

[0027] Furthermore, the present invention is based on the object of demonstrating a method with which the tightness of a lining material can be checked and a permanent monitoring option exists.

[0028] To achieve the procedural task, it is provided that for the monitoring and leak testing of a supporting structure with a lining material, wherein the structure is designed to accommodate gaseous or liquid media and the lining material is kept at a distance from the structure by a spacer element and connected to the structure by fastening points, a leak test is carried out by applying an alternating voltage to the supporting structure and the lining material. In the event of a lack of leakage, a lightning discharge occurs between the lining material and the supporting structure, which can be precisely localized in order to determine the location of the leak. The spacer element used is at least partially conductive, so that a lightning discharge occurs when voltage is applied.The leak can thus be determined by applying voltage and is preferably applied during commissioning of the supporting structure with lining material. Once the leak location has been identified, a repair can be carried out, for example, by welding a foil onto the lining material. The spacer element with appropriate conductive doping enables voltage testing and also keeps the lining material at a distance from the supporting structure. The lattice structure of the spacer element also supports the flow of a liquid or condensed medium.

[0029] In case there is an increased risk of leakage during operation of the supporting structure, the gap will be permanently monitored by a negative pressure sensor, positive pressure sensor, liquid sensor or resistance measurement.

[0030] If a negative or positive pressure sensor is used, the pressure in the gap can be continuously monitored and, in the event of a leak, leads to a pressure change which, after detection, requires further testing to determine the location of the leak.

[0031] Alternatively, a liquid sensor can be used. Typically, several liquid sensors are arranged around the supporting structure, specifically in the gap. These sensors can detect the release of a condensed or liquid medium and indicate a possible leak via a silent alarm. For example, several liquid sensors can be arranged at a low point in the gap within the supporting structure, or alternatively, the structure can have a lower-lying collecting trough in the floor area behind the lining material, which is equipped with a liquid sensor.

[0032] It is also possible to install a locating cable at the lowest point of the gap within the supporting structure, behind the lining material. Using a resistance measurement, a position can be determined distributed over the circumference of the supporting structure.

[0033] Gaseous or liquid media can diffuse through the lining material despite the presence of the lining material, and in the case of aggressive media, this can lead to partial destruction of the supporting structure. Non-aggressive media, such as hydrogen and helium, can also penetrate the lining material and cause corrosion of the supporting structure, if it is made of metal. Continuous monitoring allows such leaks to be identified and subsequently repaired.

[0034] The monitoring and testing device can be used not only for containers with a lining material, but also for pipe connections, manholes, apparatus or ducts.

[0035] The invention is explained in more detail below with reference to the figures.

[0036] It shows Fig. 1 in a perspective view the exemplary arrangement of the lining material relative to a wall construction, Fig. 2 in a sectional side view the structure of the wall construction according to the connecting line AA, Fig. 3 in a sectioned side view according to Fig. 2 a further representation of the wall construction with an enlarged detail and Fig. 4 in a sectional view, for example, the lower corner area of ​​a construction with lining material.

[0037] Fig. Figure 1 shows a perspective view of the construction of a wall cladding 1 using a lining material 2 on an existing wall surface 3 of an exemplary supporting structure. The wall surface 3 is part of a supporting structure consisting of a container, apparatus, duct, housing or

[0038] Column which serves to hold aggressive media in liquid or gaseous form. For the wall surface 3, a stable plastic material, for example PP or PE, is generally used in order to achieve the necessary strength. However, these plastic materials are not resistant to aggressive substances, so that a lining with a lining material 2 is necessary. In the exemplary embodiment shown, the connection point between two lining materials 2 is shown, whereby the lining material can be PTFE in transparent form, for example. A connecting strip 4 is arranged between the lining materials 2, which has a two-layer structure and consists of a PTFE material on the upper side, while the underside can be made of PP or PE. Both the upper and lower layers are laminated and glued together.The lower PE layer is then welded to wall 3, ensuring secure attachment. The lining material 2 is placed on the upper PTFE layer and can also be welded to the upper layer. Alternatively, it can also be bonded using a lamination.

[0039] The lining material 2 thus runs at a distance from the wall surface 3, whereby this distance is additionally supported by a spacer element 5. The spacer element 5 can, for example, consist of an expanded metal mesh which is at least partially conductive, so that a leak test can be carried out by applying voltage to the structure and the lining material 2. The spacer element 5 can be arranged behind the lining material 2 over its entire surface or only partially, so that an intermediate space 6 is created, which is, for example, placed under vacuum. The intermediate space 6 in which the spacer element 5 is located is, on the one hand, as shown in the Fig. 1, the connecting strip 4 and the edge region are sealed, whereby, for example, several of these connecting strips 4 may be present for the lining material 2. Likewise, the edge region of the lining material is sealed so that a vacuum can be drawn in the intermediate space 6.

[0040] Fig. 1 shows the basic structure and the fastening of the lining material 2 relative to the wall surface 3.

[0041] Fig. Figure 2 shows a sectional view along the connecting line AA of the wall surface 3 and the lining material 2. The spacer element 5 is arranged in the intermediate space 6 between the lining material 2 and the wall surface 3. In the illustrated embodiment, the lining material 2 is connected on the one hand to the connecting strips 4 and on the other hand to the wall surface 3 via fastening points 20. The connecting strip 4 consists of a lower plastic layer 7, which is made of PP or PE, for example, and is welded to the wall surface 3 via a weld seam 8. The upper plastic layer 9, in contrast, is made of PTFE and is thus compatible with the material used for the lining material 2.The connection between the lower plastic layer 7 and the upper plastic layer 9 can also be achieved via lamination or adhesive bonding, with the plastic layer 7 being welded to the wall surface 3 and the lining material 2 being connected to the upper plastic layer 9 by a weld seam 10. Additionally, the lining material 2 is connected to the wall surface 3 via fastening points 20, with the fastening points 20 spaced apart and distributed over the surface of the lining material 2. As a rule, a few fastening points 20 per square meter are sufficient to secure the lining material. The fastening points 20 are distributed across both the height and the length or width of the lining material 2.

[0042] Such a fastening point consists of a holding element 21, which is preferably designed as a plastic disc that is in direct contact with the wall surface 3. The holding element 21 is equipped with a recess 22 and elevations 23, which serve as anti-twist protection. Via a further annular elevation, there is contact with the lining material 2 so that welding can take place, with the lining material 2 extending over the further elevations 23. A pressure element 25, which lies in the recess 22 and has corresponding bores to the elevations 23, serves to fasten the holding elements 21. The pressure element 25 is screwed to the wall surface 3, for example using a bolt. It is also possible for the pressure element 25 to be made of a plastic material related to the wall surface 3, so that welding to the wall surface can take place.The pressure element 25 has a different temperature coefficient than the holding element 21, so that when the pressure element 25 is welded to the wall surface 3, no deformation of the holding element 21 occurs. After the individual fastening points 20 are connected to the wall surface 3 in this way, the lining material 2 is then placed over the fastening points 20 and welded to the protruding contact surfaces of the annular elevation, preferably by laser welding.

[0043] In this way, a continuous, closed surface of the lining material 2 is achieved relative to the wall surface 3.

[0044] Fig. 3 shows in a first view again the sectional view AA according to Fig. 2, and in an enlarged view A, a fastening point 20 with holding element 21 and pressure element 25. From this enlarged view it can be seen that the lining material 2 rests on a contact surface 25 of the annular elevation of the holding element 21, so that welding can take place. The holding element 21 consists of a plastic related to the lining material 2, for example PTFE, and is equipped with elevations 23 which engage in corresponding bores in the pressure element 25 and thus offer protection against twisting. The pressure element 25 is either screwed to the wall surface 3 via a bolt or a plastic material related to the wall surface 3 is used for the holding element 21, so that welding can take place via a bore through which the pressure element projects through the holding element 21 to the wall surface 3.

[0045] The spacer elements 5 are arranged laterally to the fastening element 20 in the intermediate space 6. Several of these fastening elements 20 are distributed over the surface of the lining material 2 to ensure a secure hold of the lining material 2.

[0046] Fig. 4 shows a sectional view of the lower area of ​​a construction with lining material 2. This embodiment is to be regarded as exemplary and could be replaced by other corner elements as desired.

[0047] The wall surface 3 is closed in the lower area by a base 27. A wedge-shaped element 28 is provided in the corner transition area to enable the transition of the lining material 2 for both the wall area 3 and the base 27 in a sealed manner. The wedge-shaped element 28 can in turn be made of a PE or PP plastic material and is welded to the wall surface 3 or the base 27. A plastic layer 30, for example glued, is applied to the inward-facing surface 29 of the element 28, which in contrast is made of a PTFE material, so that welding to the lining material 2 is possible.

[0048] The lining material 2 is held at a distance from the wall surface 3 and the floor 27 by a spacer element 5, which lies in the intermediate space 6, and is additionally held in place by fastening points 20 (not shown). A grid or expanded metal, for example, is used as the spacer element 5, which is also at least partially electrically conductive, thus enabling a discharge test of the entire structure for leaks. In this case, the grid is made of PTFE. To monitor a possible vacuum in the intermediate space 6, sensors 31 can also be provided, which are located in the area of ​​the wall surface 3. Likewise, liquid sensors 32 could be arranged on the floor 27 in the intermediate space 6, each of which detects a possible leak separately and transmits the data to a higher-level control unit.With the help of the sensors 31 or liquid sensors 32, the intermediate space 6 in which the spacer element 5 is located is monitored.

[0049] In this way, it is possible to first conduct a leak test before commissioning such a structure by applying a voltage to the wall surface 3 or the structure and the lining material 2. In the event of a leak, a flashover occurs via the spacer element 5 and its conductivity, which can be detected. If the breakdown test is successfully completed, the gap 6 can then be continuously monitored by the sensors 31 or liquid sensors 32. List of reference symbols 1 wall paneling 2 lining material 3 wall surface 4 connecting strips 5 spacer element 6 gap 7 plastic layer 8 Weld seam 9 plastic layer 10 Weld seam 20 attachment point 21 Holding element 22 Deepening 23 Survey 25 Pressure element 27 Floor 28 wedge-shaped element 29 area 30 plastic layer 31 Sensor 32 liquid sensor

Claims

[1] Monitoring and testing device for a supporting structure lined with a lining material (2) which is intended to accommodate gaseous or liquid media, wherein the lining material (2) is kept at a distance from the structure by a spacer element (5) and is connected to the structure by fastening points (20), wherein the spacer element (5) is at least partially conductive and wherein a leak test is carried out by applying voltage to the structure and the lining material (2) and a gap (6) predetermined by the spacer element (5) is provided for permanent monitoring by sensors (31), wherein - the gap (6) can be permanently monitored by a vacuum sensor, overpressure sensor, liquid sensor (32) or a resistance measurement and - the construction has a lower collecting trough in the floor area behind the lining material (2), which is equipped with a liquid sensor (32). [2] Monitoring and testing device according to claim 1, characterized by , that the spacer element (5) between the construction and the lining material (2) consists at least partially of a PTFE grid structure. [3] Monitoring and testing device according to claim 1 or 2, characterized by that the PTFE grid is doped with conductive substances. [4] Monitoring and testing device according to one of claims 1, 2 or 3, characterized by that the PTFE grid has a temperature resistance of more than 400 degrees. [5] Monitoring and testing device according to one of claims 1 to 4, characterized by that a lack of tightness can be detected by a voltage flashover. [6] Monitoring and testing device according to one of claims 1 to 5, characterized by that a locating cable is laid at a lowest point of the intermediate space (6) within the supporting structure, whereby the position of the leakage point can be determined by means of a resistance measurement. [7] Monitoring and testing device according to one of claims 1 to 6, characterized by that a plurality of liquid sensors (32) are arranged at a lowest point of the intermediate space (6) within the supporting structure behind the lining material (2). [8] Monitoring and testing device according to one of claims 1 to 7, characterized by that the intermediate space (6) is under overpressure or underpressure and is monitored via the pressure sensors. [9] Method for monitoring and leak testing of a supporting structure with a lining material (2), wherein the structure is intended to accommodate gaseous or liquid media and the lining material (2) is kept at a distance from the structure by a spacer element (5) and is connected to the structure by fastening points (20), wherein the spacer element (5) is at least partially conductive, comprising - a test of the tightness by applying an alternating voltage to the supporting structure and the lining material (2) - permanent monitoring of the gap (6) formed by the spacer element (5) by a vacuum sensor, overpressure sensor, liquid sensor (32) or a resistance measurement - permanent monitoring of a deeper collecting trough behind the lining material (2) by a liquid sensor (32). [10] Method according to claim 9, characterized by that a lack of tightness is detected by a voltage flashover. [11] Method according to claim 9 or 10, characterized by that a locating cable is laid at a deepest point of the intermediate space (6) within the supporting structure behind the lining material (2), whereby the position of the leakage point is determined by means of a resistance measurement. [12] Method according to one of claims 9 to 11, characterized by that several liquid sensors (32) are arranged at a lowest point of the intermediate space (6) within the supporting structure. [13] Method according to one of claims 9 to 12, characterized by that the intermediate space (6) is under overpressure or underpressure and is monitored via the pressure sensors.

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