Remote transmission component with double isolation diaphragms and remote transmission pressure transmitter

Abstract

The present invention provides a remote transmission component with a double isolation diaphragm for a pressure transmitter (1), the remote transmission component comprising a base (10) having three through holes and isolation diaphragms (7, 8) arranged on both end surfaces of the base (10). The present invention also provides a remote pressure transmitter, the remote pressure transmitter comprising the remote transmission component and a pressure transmitter (1) connected to the remote transmission component. Under the same flange caliber, compared with a conventional single diaphragm remote pressure transmitter with a small-caliber flange, the remote pressure transmitter of the present invention increases the effective area of ​​the isolation diaphragm to be measured, thereby reducing the diaphragm stiffness, and can effectively solve the quality problem of large temperature drift and instability of the remote pressure transmitter.

Description

Technical Field

[0001] The invention relates to the field of measurement technology, in particular to a remote transmission component with a double isolation diaphragm and a remote transmission pressure transmitter comprising the remote transmission component. Background Art

[0002] Pressure transmitter is a device that converts pressure into pneumatic or electric signals for control and remote transmission. It can convert physical pressure parameters such as gas and liquid sensed by the pressure measuring element sensor into standard electrical signals to supply secondary instruments such as indicator alarms, recorders, and regulators for measurement, indication, and process regulation. Pressure transmitter is the most commonly used sensor in industrial practice. It is widely used in various industrial automatic control environments, involving many industries such as water conservancy and hydropower, railway transportation, intelligent buildings, production automatic control, aerospace, military industry, petrochemical, oil wells, electricity, ships, machine tools, pipelines, etc.

[0003] At present, pressure transmitters can be divided into basic pressure transmitters and remote pressure transmitters according to the type of working conditions. Among them, the remote pressure transmitter is mainly designed to measure special media such as high temperature and corrosion. It is mainly composed of the pressure transmitter body, mounting flange, isolation diaphragm, capillary and silicone oil. The isolation diaphragm is welded on the sealing surface of the mounting flange, connecting the capillary and the pressure transmitter body to form a sealed cavity. The cavity is filled with silicone oil, and the pressure of the medium is transmitted to the transmitter body through the isolation diaphragm and the silicone oil, and the electrical signal is transmitted and output. The mounting flange and diaphragm components can be selected from different materials and specifications according to the process requirements to adapt to special media and protect the pressure transmitter body.

[0004] The measuring diaphragm of the remote pressure transmitter is a metal elastic element, and its area size and stiffness have a certain influence on the performance of the transmitter. In field applications, the size of the mounting flange diameter is basically the same as the effective diameter of the measuring diaphragm. The smaller the flange diameter, the smaller the effective measuring area of ​​the isolation diaphragm. Due to the small area, large stiffness, and poor elastic deformation of the diaphragm, the silicone oil in the instrument expands due to the influence of temperature, and the expansion pressure generated, the elastic variable of the diaphragm is not enough to offset the expansion pressure, which will lead to unstable performance of the pressure transmitter, temperature drift, and extremely high damage rate. For example, the existing conventional standard flange specifications are DN25, DN32, DN40, and DN50, and the effective diameter (or measuring area S) of the measuring diaphragm is relatively small. The instrument generally has quality problems such as large temperature drift and instability, and the rework rate is very high. Summary of the invention

[0005] In order to solve or alleviate the above problems, the present invention provides a remote transmission component with double isolation diaphragms for a pressure transmitter and a remote pressure transmitter including the remote transmission component and a pressure transmitter connected to the remote transmission component. The remote transmission component includes a base with three through holes and isolation diaphragms respectively arranged on both end surfaces of the base.

[0006] In an improved embodiment of the present invention, the remote transmission component also includes a connecting rod, a flange and a capillary. The center hole at one end of the connecting rod is aligned with and fixed to the peripheral hole of the base, and the other end of the connecting rod is inserted into the center hole of the sealing surface end of the flange and fixed to the flange. One end of the capillary is fixed to the center hole position of the other side of the flange opposite to the sealing surface, and the other end of the capillary is fixedly connected to the pressure transmitter, and the inner hole of the capillary is connected to the center hole of the flange. A sealed pressure-conducting cavity is formed between the base, the connecting rod, the flange, the capillary and the pressure transmitter.

[0007] In an improved embodiment of the present invention, the capillary is a metal capillary.

[0008] In an improved embodiment of the present invention, the center of the connecting rod has an oil guide hole.

[0009] In an improved embodiment of the present invention, the remote transmission component further includes a catheter, a flange and a capillary tube. One end of the catheter is fixed on the outer peripheral surface of the base, and the other end of the catheter is inserted into the center position of the sealing surface of the flange and fixed to the flange. One end of the capillary tube is inserted into the outer peripheral hole of the base and fixedly connected to the base, and the other end of the capillary tube passes through the catheter and the center hole of the flange and is fixedly connected to the pressure transmitter. A sealed pressure-conducting cavity is formed between the base, the capillary tube and the pressure transmitter.

[0010] In an improved embodiment of the present invention, the capillary is a stainless steel soft capillary.

[0011] In an improved embodiment of the present invention, the base is a cylindrical pressure measuring base.

[0012] In an improved embodiment of the present invention, all of the above-mentioned fixings are fixed by welding.

[0013] In an improved implementation manner of the present invention, the sealed pressure-conducting cavity is filled with silicone oil.

[0014] According to the remote pressure transmitter with double isolation diaphragms in the present invention, the beneficial effects that can be obtained are at least:

[0015] The remote pressure transmitter uses a remote transmission component including a base with three through holes and an isolation diaphragm arranged on the two end faces of the base, wherein two holes in the three through holes lead to one of the isolation diaphragms arranged on the two end faces of the base respectively, and the other hole in the three through holes leads to the capillary, that is, the three through holes are connected to the two end faces of the base and the peripheral hole of the base respectively. The medium pressure is transmitted to the pressure transmitter through the measuring diaphragm and the silicone oil in the cavity, and the signal is output. When the conventional remote pressure transmitter uses a single isolation diaphragm when measuring with a small-diameter flange, the performance of the pressure transmitter is unstable and the temperature drift is large due to the small area and high rigidity of the diaphragm. When a double isolation diaphragm is used, under the same caliber size, the area of ​​the isolation diaphragm is increased, the rigidity of the diaphragm is reduced, and the measurement stability and temperature drift of the instrument can be guaranteed. Therefore, compared with the single diaphragm remote pressure transmitter of the conventional small-diameter flange, the present invention has great technical and application advantages, improves the stability of the instrument, and solves quality problems such as temperature drift.

[0016] It should be understood that the foregoing general description and the following detailed description are exemplary illustrations and explanations and should not be used as limitations on the content of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] With reference to the accompanying drawings, further objects, functions and advantages of the present invention will be clarified through the following description of embodiments of the present invention, in which:

[0018] Figure 1A is a schematic structural diagram of a remote pressure transmitter according to a first exemplary embodiment of the present invention, wherein: Figure 1B It is the right view;

[0019] Figure 2A is a schematic structural diagram of a remote pressure transmitter according to a second exemplary embodiment of the present invention, wherein: Figure 2B It is the right view;

[0020] Figure 3A This is a structural installation diagram of the remote pressure transmitter of the present invention, taking a DN40 flange as an example, wherein: Figure 3B This is a partial installation top view of the base part. Figure 3C is the right view, and Figure 3D Taking DN40 flange as an example, it shows the structural installation diagram of the existing remote pressure transmitter and the bottom view of the isolation diaphragm part. DETAILED DESCRIPTION

[0021] By referring to the exemplary embodiments, the objects and functions of the present invention and the methods for achieving these objects and functions will be explained. However, the present invention is not limited to the exemplary embodiments disclosed below; it can be implemented in different forms. The essence of the description is only to help those skilled in the relevant art to comprehensively understand the specific details of the present invention.

[0022] The present invention aims at the shortcomings of the existing remote pressure transmitter when measuring with a small-diameter flange, and proposes a remote pressure transmitter with a double isolation diaphragm. The remote pressure transmitter welds a pressure measuring base with a double isolation diaphragm to the sealing surface of the remote flange of the transmitter through a connecting rod or a conduit, and connects the pressure transmitter body and the flange component through a stainless steel capillary. The medium pressure is transmitted to the pressure transmitter body through the measuring diaphragm and the silicone oil in the cavity, and the signal is output. When measuring with a small-diameter flange, when a conventional remote pressure transmitter uses a single isolation diaphragm, the performance of the pressure transmitter is unstable and the temperature drift is large due to the small area and high rigidity of the diaphragm. When a double isolation diaphragm is used, under the same caliber size, the area of ​​the isolation diaphragm is increased and the rigidity of the diaphragm is reduced, so the measurement stability and temperature drift of the instrument can be guaranteed. Therefore, under the same flange diameter, compared with the single diaphragm remote pressure transmitter with a conventional small-diameter flange, the remote pressure transmitter of the present invention increases the effective area of ​​the measured isolation diaphragm, thereby reducing the diaphragm stiffness, and can effectively solve the remote pressure transmitter's large temperature drift and unstable quality problems.

[0023] In order to make the technical solution of the present invention clearer and more understandable, the remote pressure transmitter of the present invention will be described in detail below with reference to the accompanying drawings and in combination with specific embodiments.

[0024] Figure 1A FIG. 2 shows a schematic diagram of the structure of a remote pressure transmitter according to a first exemplary embodiment of the present invention. Figure 1A As shown, the remote pressure transmitter includes a remote component and a pressure transmitter 1 connected to the remote component, wherein the remote component includes a pressure measuring base 10, a first isolation diaphragm 7 and a second isolation diaphragm 8 opposite to each other, a connecting rod 4, a flange 3 and a capillary 2.

[0025] Preferably, the pressure measuring base 10 is a cylindrical pressure measuring base with a three-way pressure conducting hole. The first isolation diaphragm 7 and the second isolation diaphragm 8 are welded to the two end surfaces of the pressure measuring base 10 respectively. The center hole at one end of the connecting rod 4 is aligned with the outer circumferential hole of the pressure measuring base 10 and welded to the middle position of the waist of the pressure measuring base 10. The other end of the connecting rod 4 is inserted into the center hole of the sealing surface end of the flange 3 and welded and fixed. In addition, the center of the connecting rod 4 has an oil guide hole for filling silicone oil 9 into the sealed pressure conducting cavity (described later).

[0026] The capillary 2 is preferably a metal capillary, more preferably a soft stainless steel capillary. One end of the capillary 2 is welded to the center hole of the other side of the flange 3, and the other end is welded to the pressure transmitter 1. At the same time, the inner hole of the capillary 2 is connected to the center hole of the flange 3.

[0027] A sealed pressure-conducting cavity is formed between the pressure measuring base 10, the connecting rod 4, the flange 3, the capillary tube 2 and the pressure transmitter 1, and pressure transmission can be achieved through the silicone oil 9 filled in the cavity. Specifically, the pressure detected by the isolation diaphragms at both ends of the pressure measuring base 10 is transmitted to the pressure transmitter 1 through the silicone oil 9 in the cavity.

[0028] Similarly, in the remote pressure transmitter of this exemplary embodiment, the measuring isolation diaphragm at the remote end is changed from a conventional single diaphragm to two diaphragms. Under the same flange diameter, the area of ​​the measuring diaphragm of the remote pressure transmitter is increased, which is beneficial to improving the performance of the instrument.

[0029] Figure 2A FIG. 2 shows a schematic diagram of the structure of a remote pressure transmitter according to a second exemplary embodiment of the present invention. Figure 2A As shown, the remote pressure transmitter includes a remote component and a pressure transmitter 1 connected to the remote component, wherein the remote component includes a pressure measuring base 10, a first isolation diaphragm 7 and a second isolation diaphragm 8 opposite to each other, a conduit 5, a flange 3 and a capillary 6.

[0030] Preferably, the pressure measuring base 10 is a cylindrical pressure measuring base with a three-way pressure-conducting hole. The first isolation diaphragm 7 and the second isolation diaphragm 8 are respectively welded to the two end surfaces of the cylindrical pressure measuring base 10. One end of the conduit 5 is welded to the outer circumferential surface of the pressure measuring base 10, and the other end is inserted into the center of the sealing surface of the flange 3 and welded to play a supporting role.

[0031] The capillary 6 is preferably a soft stainless steel capillary. The conduit 5 and the flange 3 are sequentially inserted into the outside of the capillary 6. One end of the capillary 6 is inserted into the outer circumferential hole of the base 10 and fixedly connected to the base 10, and the other end of the capillary 6 is extended through the center hole of the flange 3 and connected to the pressure transmitter 1, preferably sealed and fixed by welding. A sealed pressure-conducting cavity is formed between the pressure measuring base 10, the capillary 6 and the pressure transmitter 1, and pressure transmission can be achieved through the silicone oil 9 filled in the cavity. Specifically, the pressure detected by the isolation diaphragms at both ends of the pressure measuring base 10 is transmitted to the pressure transmitter 1 through the silicone oil 9 in the cavity.

[0032] It can be seen from this that in the remote pressure transmitter of this exemplary embodiment, the measuring isolation diaphragm at the remote end is changed from a conventional one diaphragm to two diaphragms. Under the same flange diameter size, the area of ​​the measuring diaphragm of the remote pressure transmitter is increased, which is beneficial to improving the performance of the instrument.

[0033] In the technical solutions of the above two exemplary embodiments, the connection method and pressure transmission path between the pressure measuring base and the flange are different, but the isolation diaphragm can transmit the pressure to the pressure transmitter body through the silicone oil filled in the cavity. The measuring isolation diaphragm at the remote end of the instrument is changed from the conventional one to two, and under the same flange diameter size, the area of ​​the measuring diaphragm of the remote pressure transmitter is increased, which is conducive to improving the performance of the instrument.

[0034] Figure 3A and Figure 3D This is a structural installation comparison diagram of the remote pressure transmitter of the present invention and the existing remote pressure transmitter, taking the DN40 flange as an example. Figure 3A As shown, taking the DN40 paired flange installation as an example, the present invention and the conventional instrument are compared. The paired flange diameter is about 45mm. Under the same flange diameter size, the instrument of the present invention uses the first isolation diaphragm 7 and the second isolation diaphragm 8 at both ends of the pressure measuring base 10 for measurement, and the effective diameters of the two isolation diaphragms can reach 35mm, while the conventional instrument uses an isolation diaphragm 11 welded on the flange sealing surface end for measurement, and the effective diameter is 38mm. From this comparison, it can be seen that the total area of ​​the isolation diaphragms at both ends of the pressure measuring base 10 is much larger than the area of ​​one diaphragm. In this way, the effective area of ​​the isolation diaphragm is increased, the stiffness of the diaphragm can be reduced, and the elastic deformation of the diaphragm can be increased, which is sufficient to offset the pressure caused by the expansion of silicone oil due to temperature, thereby ensuring the performance of the pressure transmitter.

[0035] In summary, the design of the remote pressure transmitter with double isolation diaphragms of the present invention can increase the number of isolation diaphragms in the same installation space, thereby increasing the effective measurement area of ​​the isolation diaphragms in disguise, thereby reducing or eliminating the disadvantages of small diaphragms and high rigidity, and solving the quality problems of unstable measurement and large temperature drift of small-diameter flange remote pressure transmitters.

[0036] Other embodiments of the present invention will be readily apparent to those skilled in the art from the description and practice of the invention disclosed herein. The description and embodiments are intended to be exemplary only, and the true scope and spirit of the present invention are defined by the claims.

Claims

1. A remote transmission component with a double isolation diaphragm for a pressure transmitter (1), characterized in that: The remote transmission component comprises a base (10) having three through holes, isolation diaphragms (7, 8) respectively arranged on both end surfaces of the base (10), a connecting rod (4) and a flange (3); The isolation diaphragms (7, 8) include a first isolation diaphragm (7) and a second isolation diaphragm (8), the first isolation diaphragm (7) and the second isolation diaphragm (8) are respectively welded to the end faces of two holes of the three-way hole of the base (10), the center hole of one end of the connecting rod (4) is aligned with the outer circumferential hole of the base (10) and is welded to the middle position of the waist of the base (10), and the other end of the connecting rod (4) is inserted into the center hole of the sealing surface end of the flange (3) and is welded and fixed; The remote transmission component further comprises a first capillary tube (2), wherein: One end of the first capillary tube (2) is fixed to the center hole position of the other surface of the flange (3) opposite to the sealing surface, the other end of the first capillary tube (2) is fixedly connected to the pressure transmitter (1), and the inner hole of the first capillary tube (2) is connected to the center hole of the flange (3); A sealed pressure-conducting cavity is formed between the base (10), the connecting rod (4), the flange (3), the first capillary tube (2) and the pressure transmitter (1).

2. The remote transmission component according to claim 1, characterized in that: The first capillary (2) is a metal capillary.

3. The remote transmission component according to claim 1, characterized in that: The center of the connecting rod (4) is provided with an oil guide hole.

4. The remote transmission component according to claim 1, characterized in that: The remote transmission component further comprises a catheter (5) and a second capillary tube (6), wherein: One end of the conduit (5) is fixed to the outer peripheral surface of the base (10), and the other end of the conduit (5) is inserted into the center position of the sealing surface of the flange (3) and fixed to the flange (3); One end of the second capillary tube (6) is inserted into the peripheral hole of the base (10) and is fixedly connected to the base (10), and the other end of the second capillary tube (6) passes through the conduit (5) and the central hole of the flange (3) and is fixedly connected to the pressure transmitter (1); A sealed pressure-conducting cavity is formed between the base (10), the second capillary tube (6) and the pressure transmitter (1).

5. The remote transmission component according to claim 4, characterized in that: The second capillary (6) is a stainless steel soft capillary.

6. The remote transmission component according to any one of claims 1 to 5, characterized in that: The base (10) is a cylindrical pressure measuring base.

7. The remote transmission component according to claim 6, characterized in that: All fixation is done by welding.

8. The remote transmission component according to claim 1 or 6, characterized in that: The sealed pressure-conducting cavity is filled with silicone oil.

9. A remote pressure transmitter, characterized in that: The remote pressure transmitter comprises a remote transmission component according to any one of claims 1 to 8 and a pressure transmitter (1) connected to the remote transmission component.

Images