Measuring element and measuring device including such measuring element

Abstract

This invention provides a measuring element and a measuring device. The measuring element includes a substrate, a spacer, and an anti-permeability layer, wherein the spacer is fixedly connected to the substrate and defines a sealing cavity between the spacer and the substrate. The anti-permeability layer is disposed on the inner surface of the spacer facing the sealing cavity, and extends on the inner surface of the spacer at least beyond the connection area between the spacer and the substrate. The measuring device includes the measuring element.

Description

Technical Field

[0001] The present invention relates to a measuring element and a measuring device including such a measuring element. Background Technology

[0002] The content in this section only provides background information related to this invention and may not constitute prior art.

[0003] In industrial production processes such as coal chemical, papermaking, and cement industries, it is often necessary to obtain relevant measurement parameters (e.g., pressure, differential pressure, liquid level, etc.) of the process medium (or the medium to be measured) for better production or process control. Due to the limitations of the operating conditions in such production (such as high temperature, strong corrosiveness, high pressure, etc.), remote measuring devices (e.g., remote transmitters) are typically used to acquire the relevant parameters of the medium to be measured. Such remote measuring devices usually include a measuring element located at the end of the medium to be measured. The measuring element may include a substrate and a spacer. A sealed cavity is defined between the spacer and the substrate. The sealed cavity may be filled with a working fluid. Thus, for example, the pressure of the medium to be measured can be measured or monitored by the pressure change of the fluid on both sides of the spacer.

[0004] However, since many of the media to be measured are hydrogen-rich, the hydrogen in the media can pass through the diaphragm into the sealed cavity and accumulate, causing pressure deviation. This results in inaccurate measurement accuracy of the measuring device, and in severe cases, the diaphragm may bulge or even rupture.

[0005] Therefore, there is an urgent need to provide an improved measuring element and measuring device. Summary of the Invention

[0006] The purpose of this invention is to provide an improved measuring element and measuring device to achieve at least one of the following objectives: improved measurement accuracy, improved wear resistance, increased service life, simplified production process, and cost savings.

[0007] According to one aspect of the present invention, a measuring element is provided, comprising a substrate; a spacer fixedly connected to the substrate and defining a sealing cavity between the spacer and the substrate; and an anti-permeability layer disposed on an inner surface of the spacer facing the sealing cavity, and the anti-permeability layer extending continuously on the inner surface of the spacer at least beyond the connection region between the spacer and the substrate.

[0008] According to one embodiment, the spacer is fixedly connected to the substrate by resistance seam welding.

[0009] According to one embodiment, the spacer is connected to the substrate by TIG welding and resistance seam welding, and the welding area of ​​the resistance seam welding is located radially inside the welding area of ​​the TIG welding.

[0010] According to one embodiment, the impermeable layer extends to cover the entire inner surface of the spacer.

[0011] According to one embodiment, the thickness of the anti-permeability layer coated on the separator is less than or equal to 10 micrometers.

[0012] According to one embodiment, one or more annular folds are formed on the spacer.

[0013] According to one embodiment, the substrate has a recessed portion corresponding to the spacer portion.

[0014] According to one embodiment, the substrate is provided with a fluid channel for filling the sealed cavity with fluid.

[0015] According to one embodiment, the anti-permeability layer is a gold-plated layer plated on the inner surface of the separator.

[0016] According to another aspect of the present invention, a measuring device is provided, the measuring device comprising the measuring element described above.

[0017] According to the present invention, an anti-permeability layer (e.g., a gold-plated layer) is provided on the spacer, thus preventing substances in the measured medium (e.g., hydrogen) from permeating into the sealed cavity, thereby greatly improving the measurement accuracy of the measuring element and measuring device. Furthermore, due to the design of the anti-permeability layer facing inwards from the sealed cavity, the anti-permeability layer does not directly contact the measured medium, and is not scratched by particles in the measured medium, improving the product's wear resistance. A zero-hydrogen permeation path design is achieved while ensuring welding strength and quality, thereby extending the product's service life. In addition, since the anti-permeability layer can be applied to the sealing spacer on one side, either entirely or partially, before connecting the spacer to the substrate, safe transportation and low inventory can be achieved, saving significant costs. Moreover, since the anti-permeability layer can cover only the spacer, material costs can be greatly reduced. Attached Figure Description

[0018] The features and advantages of one or more embodiments of this disclosure will become more readily understood from the following description with reference to the accompanying drawings, in which:

[0019] Figure 1 This is a perspective view of a measuring element according to one embodiment of the present disclosure;

[0020] Figure 2 yes Figure 1A cross-sectional view of the measuring element;

[0021] Figure 3 yes Figure 1 A schematic diagram of the cross-section of the measuring element;

[0022] Figure 4 This is a partial cross-sectional view of a measuring element according to one embodiment of the present disclosure;

[0023] Figure 5 This is an EDX microscopic image of a partial cross-section of a measuring element according to one embodiment of the present disclosure; and

[0024] Figure 6 This is a schematic diagram of the structure of a measuring device according to one embodiment of the present disclosure. Detailed Implementation

[0025] The following description of preferred embodiments is merely exemplary and is in no way a limitation of this disclosure or its application or use. In the various figures, the same reference numerals are used to denote the same or corresponding parts, therefore the construction of the same parts will not be described repeatedly.

[0026] In this description, for ease of description, a remote measuring device for measuring the pressure / differential pressure of the medium to be measured is used as an example to describe the measuring element and measuring device according to the present invention. However, it is to be understood that the present invention is not limited to the structure and application described in the preferred embodiments below, and can be applied to any feasible structure or application, for example, for measuring viscosity, liquid level, etc. Similarly, the present invention is not limited to remote measuring devices, and can also be applied to any feasible device or apparatus.

[0027] As previously mentioned, remote measurement devices typically include a measuring element located at the medium to be measured. This measuring element may have a sealed cavity defined by a septum and a substrate. The sealed cavity may be filled with a measuring fluid (or working fluid). Remote measurement devices may also include a sensing element located at a distance from the measuring element. During measurement, the measuring element contacts the medium to be measured and transmits the sensed pressure to the sensing element, thereby converting the physical quantity measured by the measuring element into the required digital quantity. In application, the side of the septum facing away from the sealed cavity (referred to herein as the outer side) and the side facing the sealed cavity (similarly referred to herein as the inner side) are subjected to pressure from the medium to be measured and pressure from the working fluid within the sealed cavity, respectively. The septum transmits the pressure from the measuring medium to the working fluid, which then transmits the sensed pressure to the sensing element for relevant processing. Figure 6 A schematic diagram of a measuring device according to one embodiment of the present disclosure is shown. The measuring device according to the present invention may include measuring elements (such as those described in detail below) Figure 6 (As shown by M).

[0028] The following will combine Figures 1-6 The measuring element according to the invention will be described in further detail. For clarity, not all parts in the drawings are labeled.

[0029] Figure 1 A perspective schematic diagram of a measuring element according to one embodiment of the present disclosure is shown. Figure 1 As shown, the measuring element according to this disclosure may include a substrate 1 and a spacer 2, and both the substrate 1 and the spacer 2 may be made of steel. In this embodiment, the spacer 2 may be a generally circular sheet. The spacer 2 may be fixedly connected to the substrate 1 through its periphery, thereby defining a sealing cavity 3 between the spacer 2 and the substrate 1 (see [link to documentation]). Figure 3 (As shown). The sealed cavity 3 can contain a working fluid. For example, the sealed cavity 3 can be filled with oil. Thus, during application, the outer surface 22 of the diaphragm 2 can be displaced by the pressure of the measuring medium, and this displacement can be transmitted to the sensing element through the working fluid in the sealed cavity, thereby providing the pressure parameters required for process control.

[0030] like Figures 1 to 4 As shown, the spacer 2 may have one or more annular pleats 23, allowing the spacer 2 to be appropriately deformed or partially displaced. Alternatively, if it has sufficient thickness, the spacer 2 may have one or more recesses. Of course, the pleats or recesses on the spacer 2 are not limited to annular.

[0031] A recessed portion 15 may be provided on the portion of the substrate 1 corresponding to the spacer 2, so as to form a sealed cavity 3 between the spacer 2 and the substrate 1.

[0032] The substrate 1 can be further connected to a remote sensing component. For example... Figures 1 to 3 As shown, the base 1 may have a flange 11, on which a through hole 12 for connecting components (such as connecting bolts) to pass through may be provided. A fluid channel 13 may also be provided on the base 1. Before applying the measuring element, working fluid can be injected into the sealed cavity 3 through the fluid channel 13, and the fluid channel 13 can be closed after injection. Thus, when the medium to be measured is guided to the outer surface of the diaphragm 2, the diaphragm 2 can deform or shift appropriately according to the pressure of the measured medium it senses, thereby enabling parameter extraction or measurement.

[0033] However, the inventors have discovered that, since the septum 2 is typically thin, some elements or components in the medium to be measured (such as hydrogen) can easily penetrate through the septum 2 into the sealed cavity 3, and may subsequently dissolve into the working fluid. Moreover, since the sealed cavity 3 is relatively small and enclosed, the penetration of hydrogen can affect the pressure within the sealed cavity 3 and may even cause the septum 2 to bulge or rupture, thereby affecting the accuracy of the measurement or even damaging the measuring element.

[0034] Therefore, this invention proposes a solution involving an anti-permeability structure. An anti-permeability layer can be provided on the separator 2 to block the permeation path through the separator. For hydrogen-rich analyte media, a gold-plated layer can be provided to prevent hydrogen in the analyte media from permeating into the sealed cavity. In this document, for ease of description, only a gold-plated layer is used as an example of an anti-permeability layer. Those skilled in the art will recognize that other anti-permeability materials besides gold can be used to achieve the anti-permeability purpose depending on the specific application.

[0035] However, if the gold plating layer is placed on the outer surface 22 of the spacer 2, considering that some media to be measured may contain a large number of solid particles (such as pulp, gravel, cinders, etc.), these solid particles will scratch the gold plating layer on the spacer. Since the spacer is usually relatively thin and the gold plating layer is soft, the gold plating layer is easily worn away. In this way, the gold plating layer will lose its intended effectiveness, resulting in a reduction in the wear resistance and service life of the measuring element (and even the measuring device), as well as a reduction in measurement accuracy. In addition, this solution requires plating the entire outer surface 22 of the spacer 2 and around the seam area between the spacer 2 and the substrate 1, which not only increases the cost and the manufacturing process, but also makes subsequent transportation and storage difficult.

[0036] In view of the above, the gold plating layer 4 can be disposed on the inner surface 21 of the spacer 2 facing the sealing cavity 3. In this way, the gold plating layer 4 does not come into contact with the medium to be measured, and therefore will not be affected by solid particles in the medium to be measured.

[0037] The gold plating layer 4 may extend continuously beyond the connection area between the inner surface 21 of the separator 2 and the corresponding portion of the substrate 1 (in other words, the outer diameter of the gold plating layer should be at least equal to or greater than the outer diameter of the connection area between the separator 2 and the substrate 1) to prevent hydrogen permeation pathways from forming in the connection area between the separator 2 and the substrate 1. Optionally, the gold plating layer 4 may completely cover the entire inner surface 21 of the separator 2.

[0038] The periphery of the spacer 2 can be fixedly connected to the substrate 1 by resistance seam welding (or other methods that will not damage the gold plating layer in the connection area between the spacer 2 and the substrate 1).

[0039] Figure 5An EDX microscopic image of a partial cross-section of a measuring element according to one embodiment of the present disclosure is shown. From Figure 5 As can be seen, since there is an uninterrupted gold layer in the connection region A between the spacer 2 and the substrate 1, the hydrogen permeation path of the sealed cavity can be completely blocked, thereby improving the accuracy of the measurement.

[0040] Actual tests comparing the application of a gold-plated layer on the outer side of the separator with the application of a gold-plated layer on the inner side of the separator according to the present invention revealed that the hydrogen-blocking effect of the measuring element according to the present invention is almost identical to that of the element with a gold-plated layer on the outer side of the separator.

[0041] Therefore, according to the present invention, since the extended area of ​​the anti-permeability layer at least covers the portion of the inner side 21 of the septum 2 located within the sealing cavity 3 and the connection area between the septum 2 and the substrate 2, components or elements in the medium to be measured outside the septum 2 cannot permeate into the sealing cavity 3 through the septum 2. Thus, the accuracy of the measurement can be improved. Furthermore, since the gold plating layer is located on the inner side 21 of the septum 2, it is not affected by the medium to be measured, thereby improving the wear resistance and service life of the measuring element. In addition, since the sealing septum can be gold-plated directly on one side entirely or partially before assembly, safe transportation and low inventory can be achieved, saving significant transportation and maintenance costs. Moreover, since the anti-permeability layer can only cover the septum, material costs can be greatly reduced compared to the previously mentioned solution of gold plating on the outside of the septum 2.

[0042] Alternatively, it can be achieved through TIG welding (such as...). Figure 4 The periphery of the spacer 2 is fixed to the base 1 by means of (as indicated by B in the diagram) or other fixed connection methods, and then the spacer 2 is further connected to the base 1 by resistance seam welding or other feasible connection methods (such as...). Figure 4 (As shown in region C). This achieves a stable fixed connection between the spacer 2 and the substrate 1, while also blocking any potential hydrogen permeation pathways. In this case, the resistance seam weld area is located radially inside the TIG weld area. Furthermore, the gold plating layer 4 can extend only beyond the resistance seam weld area on the inner surface 21 of the spacer 2.

[0043] A gold plating layer 4 can be applied to the inner surface 21 of the spacer 2 using common processes such as electroplating or vacuum plating. The thickness of the gold plating layer 4 should be such that it does not affect measurement accuracy; for example, the thickness can be less than or equal to 10 micrometers, such as 5 micrometers. Compared to technical solutions that address the problems arising from applying a gold plating layer to the outer surface 22 of the spacer 2 by increasing the plating thickness, the measuring element and measuring device according to the present invention also have advantages in terms of measurement accuracy and cost.

[0044] The spacer 2 can be made of the same or different material as the substrate 1. Optionally, both the spacer 2 and the substrate 1 can be made of stainless steel.

[0045] As can be understood from the above analysis, the measuring element and measuring device according to the present invention improve the accuracy of measurement, increase the service life of components, and reduce manufacturing and maintenance costs.

[0046] Although various embodiments of the invention have been described in detail herein, it should be understood that the invention is not limited to the specific embodiments described and shown herein, and other variations and modifications can be made by those skilled in the art without departing from the essential spirit and scope of the invention. All such variations and modifications fall within the scope of the invention.

Claims

1. A measuring element, characterized in that, The measuring element includes: Matrix (1); A spacer (2) is fixedly connected to the substrate (1) and defines a sealing cavity (3) between the spacer (2) and the substrate (1), wherein the spacer (2) is fixedly connected to the substrate (1) by resistance seam welding; and An anti-permeability layer is disposed on the inner side (21) of the partition (2) facing the sealing cavity (3), and the anti-permeability layer extends continuously on the inner side (21) of the partition (2) beyond the resistance welded connection area between the partition (2) and the substrate (1), wherein the resistance weld does not damage the anti-permeability layer.

2. The measuring element according to claim 1, characterized in that, The spacer (2) is further connected to the substrate (1) by TIG welding, and the welding area of ​​the resistance seam weld is located radially inside the welding area of ​​the TIG weld.

3. The measuring element according to claim 1, characterized in that, The impermeable layer extends to cover the entire inner surface (21) of the diaphragm (2).

4. The measuring element according to claim 1, characterized in that, The thickness of the anti-permeability layer on the separator (2) is less than or equal to 10 micrometers.

5. The measuring element according to claim 1, characterized in that, One or more annular folds (23) are formed on the partition (2).

6. The measuring element according to claim 1, characterized in that, The substrate (1) has a recess (15) corresponding to the spacer (2).

7. The measuring element according to claim 1, characterized in that, The substrate (1) is provided with a fluid channel (13) for filling the sealed cavity (3) with fluid.

8. The measuring element according to any one of claims 1-7, characterized in that, The anti-permeability layer is a gold-plated layer (4) plated on the inner surface (21) of the separator (2).

9. A measuring device, characterized in that, The measuring device includes a measuring element according to any one of claims 1-8.

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