Pressure sensor

Abstract

The utility model discloses a pressure sensor, which is characterized in that a flexible film clings to the inner side of a groove of a pressure sensor main part, so that corrosion damage caused by direct contact of leacheate with the pressure sensor main part is avoided; a gasket is placed above the flexible membrane, a balance membrane with the same outer diameter is stacked above the gasket, a small hole is formed in the circle center position of the balance membrane, and a relatively closed cavity is formed between the groove and the balance membrane and used for balancing the pressure of leacheate and the cavity and reducing the dead volume of the cavity; the flexible film is not easy to damage, high in corrosion resistance, better in sealing performance, higher in sensitivity and less in interference; the balance membrane has the advantages of being not prone to damage, high in durability, smooth in pressure transmission and the like. The pressure sensor has the advantages of low dead volume, corrosion resistance, high sensitivity and the like.

Description

Technical Field

[0001] The invention relates to the technical field of liquid phase / ion chromatography, and in particular to a pressure sensor. Background Art

[0002] Pressure sensor is the most commonly used sensor in industrial practice. It is widely used in various industrial automatic control environments, designing water conservancy and hydropower, railway transportation, intelligent buildings, production automatic control, aerospace, military industry, petrochemical, oil wells, electricity, ships, machine tools, pipelines and many other industries.

[0003] Liquid / ion chromatography technology is widely used in the field of chemical analysis to detect compounds and ion components in samples such as water and food. As a key component, pressure sensors usually need to work in harsh chemical environments, so they need to be corrosion-resistant. In addition, in order to ensure detection accuracy, pressure sensors also need to have high sensitivity and low dead volume characteristics to reduce sample retention and signal distortion.

[0004] CN202222060663.5 reports a pressure sensor adapter for non-contact determination of the pressure in a target fluid, comprising a disposable flow path assembly including a main body having a chamber and a conduit, which defines the flow path of the fluid; a flexible membrane in contact with the fluid pressure, and a reusable flexible membrane fixing assembly; the flexible membrane and its reusable fixing assembly are pressed and fixed together to the disposable flow path assembly so that the flexible membrane is in direct contact with the target fluid; a locking assembly creates pressure contact between the pressure sensor and the flexible membrane.

[0005] Although this solution can meet the requirements of improving versatility by adapting to pressure sensors of various brands, and can be used for application requirements of different specifications by replacing disposable flow path modules of different diameters, improving convenience and reducing the requirements of use cost, its disadvantages are also quite obvious. The flexible membrane is fixed by the annular end face of its reusable fixing component and the recessed annular step surface inside the disposable flow path through compression to form a docking sealing flange surface, thereby sealing the flow path and making the flexible membrane contact with the fluid. However, the measuring cavity formed by this method is small, and the corresponding measuring range will be relatively narrow. In addition, the flexible membrane is easily leaked or ruptured due to the support force of the everted edge and the partial pressure given by the liquid, and the measuring cavity will cause a large dead volume.

[0006] The pressure sensors in the prior art often have some deficiencies in performance and are difficult to simultaneously meet the requirements of the chromatography system for high sensitivity, low dead volume and corrosion resistance. Therefore, a new type of pressure sensor is urgently needed to meet these requirements. Summary of the invention

[0007] In order to solve the problem raised in the background technology, the utility model provides a pressure sensor, including an exhaust valve, a pressure module and a sensor pressure plate, wherein:

[0008] The pressure module and the sensor pressure plate are provided with a pressure sensor main part;

[0009] A first groove is provided at the signal sensing end of the pressure sensor main component;

[0010] A flexible film is provided in the first groove of the pressure sensor main part, and is closely attached to the inner side of the first groove. The first groove and the flexible film form a closed chamber.

[0011] A gasket having the same outer diameter as the main component of the pressure sensor is stacked above the flexible membrane;

[0012] A balance membrane with the same outer diameter is stacked on the gasket, and a small hole is provided on the balance membrane for solution circulation, and the position of the small hole is the center position of the gasket;

[0013] The pressure module is provided with a second groove, and the second groove is gap-assembled with the pressure sensor main component.

[0014] Preferably, the drain valve has threads matching the threads of the pressure module, and the drain valve and the pressure module are connected by a spiral connection.

[0015] Preferably, two parallel ends of the pressure module are provided with eluent through holes, and the eluent through holes at the two parallel ends form an eluent channel inside the pressure module.

[0016] Preferably, the surface of the pressure module is provided with four holes, which correspond to four holes of the sensor pressure plate, and the pressure module and the sensor pressure plate are connected by bolts.

[0017] Preferably, the sensor pressure plate is provided with six holes, four of which correspond to the four holes of the pressure module, and the remaining two holes serve for locking.

[0018] Preferably, the interior of the sensor pressure plate is a hollow structure for placing a main component of the pressure sensor.

[0019] Preferably, the flexible film is made of polytetrafluoroethylene.

[0020] Preferably, the balancing membrane is made of polytetrafluoroethylene.

[0021] Preferably, the gasket is made of polytetrafluoroethylene.

[0022] The utility model has the following beneficial effects: the utility model uses hot air to tightly attach the flexible membrane to the inner side of the groove of the pressure sensor main part, so as to prevent the eluent from directly contacting the pressure sensor main part and causing corrosion damage; a gasket is placed above the flexible membrane, and a balancing membrane with the same outer diameter is stacked above the gasket, and a small hole is provided at the center of the balancing membrane, so that a relatively closed chamber is formed between the groove and the balancing membrane, which is used to balance the eluent and the cavity pressure and reduce the dead volume of the cavity; this pressure sensor has the following advantages:

[0023] 1. The flexible membrane is not easy to be damaged, has strong durability, good sealing, and will not easily leak;

[0024] 2. The flexible membrane is direct and the measurement cavity formed in this way is larger and more sensitive;

[0025] 3. Both the flexible membrane and the balance membrane are made of polytetrafluoroethylene, which will not melt out impurities when in contact with the solution, thus affecting the chromatographic column;

[0026] 4. The flexible film is evenly attached to the bottom of the groove, and there will be no problem of uneven distribution;

[0027] 5. The balance membrane is not easy to be damaged, has strong durability and smooth pressure transmission;

[0028] 6. The small hole design at the center of the balance membrane makes it easy to balance the pressure of the eluent and the cavity and reduce the dead volume of the cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the implementation of the present invention, and together with the specification are used to explain the principles of the embodiments of the present invention. Obviously, the accompanying drawings described below are only some embodiments of the implementation of the present invention, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0030] Figure 1 It is a schematic diagram of the structure of the pressure sensor provided by the embodiment of the utility model;

[0031] Figure 2 It is a partial enlarged diagram of the schematic diagram of the structure of the pressure sensor provided by the embodiment of the utility model;

[0032] Figure 3 It is a partial cross-sectional view of a pressure sensor provided by an embodiment of the utility model;

[0033] Figure 4 It is a partial enlarged view of a partial cross-sectional view of a pressure sensor provided by an embodiment of the utility model;

[0034] In the figure: 1-pressure sensor main part; 2-pressure sensor sealing ring; 3-pressure module; 4-sensor pressure plate; 5-drain valve; 6-drain valve sealing ring; 7-flexible membrane; 8-gasket; 9-balance membrane. DETAILED DESCRIPTION

[0035] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0036] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0037] like Figure 1 , Figure 2 As shown, the pressure sensor includes an exhaust valve 5, a pressure module 3 and a sensor pressure plate 4, wherein:

[0038] The pressure module 3 and the sensor pressure plate 4 are provided with a pressure sensor main component 1;

[0039] The signal sensing end of the pressure sensor main component 1 is provided with a first groove;

[0040] A flexible membrane 7 is provided in the first groove of the pressure sensor main component 1 and is closely attached to the inner side of the first groove. The first groove and the flexible membrane 7 form a closed chamber.

[0041] A gasket having the same outer diameter as the pressure sensor main component 1 is stacked on the flexible membrane 7;

[0042] A balancing membrane 9 with the same outer diameter is stacked on the gasket 8. The balancing membrane 9 is provided with a small hole for solution circulation. The position of the small hole is the center of the gasket 8.

[0043] The pressure module 3 is provided with a second groove, and the second groove is assembled with a gap with the pressure sensor main component 1 .

[0044] Preferably, the drain valve 5 has threads which match the threads of the pressure module 3 , and the drain valve 5 and the pressure module 3 are connected by a spiral connection.

[0045] Preferably, two parallel ends of the pressure module 3 are provided with eluent through holes, and the eluent through holes at the two parallel ends form an eluent channel inside the pressure module 3 .

[0046] Preferably, the surface of the pressure module 3 is provided with four holes, which correspond to four holes of the sensor pressure plate 4 , and the pressure module 3 and the sensor pressure plate 4 are connected by bolts.

[0047] Preferably, the sensor pressing plate 4 is provided with six holes, four of which correspond to the four holes of the pressure module 3, and the remaining two holes serve for locking.

[0048] Preferably, the interior of the sensor pressing plate 4 is a hollow structure for placing the pressure sensor main component 1 .

[0049] Preferably, the flexible membrane 7 is made of polytetrafluoroethylene.

[0050] Preferably, the balancing membrane 9 is made of polytetrafluoroethylene.

[0051] Preferably, the gasket 8 is made of polytetrafluoroethylene.

[0052] like Figure 3 , Figure 4 As shown, the sensor main part 1 has a groove, and the flexible membrane 7 is attached tightly to the groove of the pressure sensor main part 1 by hot air, so that a closed chamber is formed between the groove and the flexible membrane 7. The solution is input into the through hole of the pressure module 3 and enters the pressure sensor through the eluent channel. At this time, the flexible membrane 7 in the groove is subjected to pressure, and the flexible membrane 7 is deformed, thereby changing the output voltage of the piezoelectric element. This voltage change is proportional to the applied pressure, and the pressure value can be measured by measuring the output voltage. A gasket 8 with the same outer diameter as the pressure sensor main part 1 is stacked on the flexible membrane 7; a balancing membrane 9 with the same outer diameter is stacked on the gasket 8, and a small hole is provided at the center of the balancing membrane 9. A relatively closed chamber is formed between the groove and the balancing membrane 9, which is used to balance the eluent and cavity pressures and reduce the dead volume of the cavity.

[0053] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A pressure sensor, characterized in that: It comprises an exhaust valve (5), a pressure module (3) and a sensor pressure plate (4), wherein: The pressure module (3) and the sensor pressure plate (4) are provided with a pressure sensor main component (1) inside; The signal sensing end of the pressure sensor main component (1) is provided with a first groove; A flexible membrane (7) is provided in the first groove of the pressure sensor main component (1) and is closely attached to the inner side of the first groove, and the first groove and the flexible membrane (7) form a closed chamber; A gasket (8) having the same outer diameter as the pressure sensor main component (1) is stacked above the flexible membrane (7); A balancing membrane (9) having the same outer diameter is stacked on the gasket (8), and a small hole is provided on the balancing membrane (9) for solution circulation, and the position of the small hole is the center position of the gasket (8); The pressure module (3) is provided with a second groove, and the second groove is gap-assembled with the pressure sensor main component (1).

2. The pressure sensor according to claim 1, characterized in that: The drain valve (5) has threads which match the threads of the pressure module (3); the drain valve (5) and the pressure module (3) are connected by means of a screw connection.

3. The pressure sensor according to claim 1, characterized in that: The pressure module (3) is provided with eluent through holes at two parallel ends, and the eluent through holes at the two parallel ends form an eluent channel inside the pressure module (3).

4. The pressure sensor according to claim 1, characterized in that: The surface of the pressure module (3) is provided with four holes, the four holes corresponding to four holes of the sensor pressure plate (4), and the pressure module (3) and the sensor pressure plate (4) are connected by bolt connection.

5. The pressure sensor according to claim 1, characterized in that: The sensor pressure plate (4) is provided with six holes, four of which correspond to the four holes of the pressure module (3), and the remaining two holes serve a locking function.

6. The pressure sensor according to claim 1, characterized in that: The interior of the sensor pressure plate (4) is a hollow structure and is used for accommodating the pressure sensor main component (1).

7. The pressure sensor according to claim 1, characterized in that: The material of the flexible membrane (7) is polytetrafluoroethylene.

8. The pressure sensor according to claim 1, characterized in that: The material of the balancing membrane (9) is polytetrafluoroethylene.

9. The pressure sensor according to claim 1, characterized in that: The material of the gasket (8) is polytetrafluoroethylene.

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