Constant-pressure piston liquefied gas sampler

Abstract

The utility model discloses a constant pressure type piston liquefied gas sampler, which comprises a piston cylinder body, a sampling valve, a lofting valve, a gas supply system and a pressure monitoring component, a piston capable of reciprocating is arranged in the piston cylinder body, and when the pressure of a first end is equal to 1MPa, the piston is static. Through the synergistic effect of the piston cylinder body, the pressure monitoring assembly and the gas supply system, the pressure is dynamically adjusted in the sampling and lofting process, it is ensured that the sample output pressure is constantly 1 MPa, when the pressure is smaller than 1 MPa, gas pushes the piston to move towards the first end, and the pressure of the first end is constantly 1 MPa through the gas supply system. The needle valve is used for controlling a fluid path, the digital display pressure gauge is used for real-time monitoring, the safety relief valve is arranged to guarantee operation safety, laboratory detection precision and operation safety are remarkably improved, and the device is suitable for sampling analysis of media under extremely strict working conditions. The utility model has the advantages of compact structure, simple operation, explosion-proof housing design, corrosion resistance, high safety and environmental adaptability.

Description

Technical Field

[0001] This utility model relates to the field of gas sampling technology, and in particular to a constant pressure piston liquefied gas sampler. Background Technology

[0002] Liquefied petroleum gas (LPG) samplers are standard instruments for sampling LPG. While existing LPG samplers can collect and store samples, this type of gas sampler suffers from several drawbacks. During the sampling process, the sample volume decreases, pressure drops, and the LPG vaporizes, altering its composition and affecting the accuracy of subsequent gas detection results. This reduces the sampler's practicality. Furthermore, existing gas samplers require multiple sampling and purging cycles, which is time-consuming and can result in substandard gas purity. Filtering the sampled gas to remove impurities and cleaning the filter is also inconvenient. Some LPGs require constant pressure conditions to detect the gas content in the container and determine the presence of harmful gases. Existing gas samplers lack adjustable sampling volume, hindering sampling operations and failing to meet varying sampling requirements. Moreover, their bulky and inconvenient design limits portability and slows down the sampling process.

[0003] Based on this, our technical staff designed a constant pressure piston liquefied gas sampler to solve the above problems. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a constant pressure piston liquefied gas sampler that is simple in structure, easy to use, portable, highly observable, and has stable experimental results.

[0005] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0006] A constant-pressure piston liquefied gas sampler includes: a piston cylinder, an inlet valve, a outlet valve, a gas supply system, and a pressure monitoring component. The piston cylinder is a cylindrical structure with tubes integrally formed at both ends. A reciprocating piston is located inside the piston cylinder. The inlet valve, outlet valve, and piston movement control valve are respectively located at the first end of the piston cylinder. The gas supply system includes an inlet valve and a gas pressure control inlet valve, and is located at the second end of the piston cylinder. The inlet valve is sealed to the corresponding tube on the piston cylinder via a reducing connector. Next, the pressure monitoring component includes a first gas pressure gauge and a second gas pressure gauge. The first gas pressure gauge is disposed adjacent to the injection valve and the discharge valve, and the second gas pressure gauge is disposed between the injection valve and the gas pressure control inlet valve. The first gas pressure gauge and the second gas pressure gauge are used to monitor the pressure at the first end and the second end, respectively. When the pressure at the first end is equal to 1 MPa, the piston is stationary; when the pressure is less than 1 MPa, the piston moves towards the first end, and the discharge pressure is maintained at a constant 1 MPa by the gas supply system.

[0007] In the above structure, a plurality of sealing rings are evenly spaced between the piston and the inner wall of the piston cylinder. The plurality of sealing rings are semi-embedded in the grooves corresponding to the outer side of the piston. The plurality of sealing rings are made of polytetrafluoroethylene and have a pressure resistance rating of ≥2MPa.

[0008] In the above structure, the air inlet valve, piston motion control valve, injection valve, and discharge valve are all needle valves, and the injection valve and discharge valve are respectively sealed to the piston motion control valve.

[0009] In the above structure, the piston cylinder includes a main body, a bottom cover, and a top cover. The top cover and the main body are rotatably connected by corresponding threads. A sealing gasket is provided on the inner bottom of the top cover corresponding to the main body. The bottom cover is welded to the main body as a whole. The top cover and the bottom cover are respectively welded to the corresponding tube body as a whole. The opening of the tube body is provided with an installation interface. The central axis of the main body and the corresponding tube body coincide.

[0010] In the above structure, the ratio of the piston's stroke to the length of the piston cylinder is 1:3, the maximum displacement of the piston is 200mm, and the displacement is indicated by scale lines on the outer wall of the piston cylinder.

[0011] In the above structure, the gas supply system also includes an external gas source quick interface, a precision pressure regulating valve, and a gas filter assembly. The external gas source quick interface supports standard gas cylinder connection. The precision pressure regulating valve and the gas filter assembly are integrated into the gas pressure control inlet valve. The precision pressure regulating valve has an adjustment accuracy of ±0.05MPa. The gas filter assembly has a built-in 5μm stainless steel filter screen. The gas filter assembly is used to remove particulate impurities from the external gas source. The external gas source is inert gas or compressed air, and the pressure adjustment range of the external gas source is 0.5-2MPa.

[0012] In the above structure, the first gas pressure gauge has an accuracy class of 0.5 and a range of 0-2.5 MPa. The first gas pressure gauge supports Bluetooth connection to a mobile terminal.

[0013] In the above structure, the second gas pressure gauge adopts a wireless transmission type digital display pressure sensor. The second gas pressure gauge has an accuracy of 0.25 grade and a range of 0-2.5MPa. The second gas pressure gauge is equipped with an overload protection function, which automatically triggers an audible and visual alarm when the pressure exceeds 1.2MPa.

[0014] In the above structure, the reducing connector is a tapered transition structure, the threads at both ends of the reducing connector are 1 / 4 NPT, and the material of the reducing connector is 316L stainless steel.

[0015] In the above structure, the sampler is made of 316L stainless steel, the sampler is suitable for a temperature range of -20℃ to 80℃, and the sampler has a pressure resistance rating of 6.0MPa.

[0016] The beneficial effects of this utility model are as follows:

[0017] This utility model features a reasonable design, convenient installation and use, and excellent filtration effect. It effectively filters and treats the sample gas to meet the testing gas standards, significantly improving the efficiency and quality of gas collection. It also has explosion-proof capabilities, enhancing its practicality. Through the coordinated action of the piston cylinder, pressure monitoring components, and gas supply system, the pressure is dynamically adjusted during sampling and discharge, ensuring a constant sample output pressure of 1 MPa. A needle valve controls the fluid path, a digital pressure gauge monitors the pressure in real time, and a safety relief valve ensures operational safety. This device is compact, easy to operate, and significantly improves the accuracy of laboratory test data. It is suitable for sampling and analyzing high-pressure media such as liquefied petroleum gas and natural gas. This utility model has a simple structure, is easy to use and carry, offers high visibility, and provides stable experimental results. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of an embodiment of the constant pressure piston liquefied gas sampler of this utility model.

[0019] In the diagram, 1-piston cylinder, 2-injection valve, 3-discharge valve, 4-piston, 5-piston motion control valve, 6-inlet valve, 7-gas pressure control inlet valve, 8-first gas pressure gauge, 9-second gas pressure gauge, 10-sealing ring, 11-external gas source quick interface, 12-top cover. Detailed Implementation

[0020] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding of this utility model, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0021] like Figure 1 As shown, a constant-pressure piston liquefied gas sampler includes: a piston cylinder 1, an inlet valve 2, a outlet valve 3, a gas supply system, and a pressure monitoring component. The piston cylinder 1 is a cylindrical structure with tubes integrally formed at both ends. A reciprocating piston 4 is located inside the piston cylinder 1. The inlet valve 2, outlet valve 3, and piston movement control valve 5 are respectively located at the first end of the piston cylinder 1. The gas supply system includes an inlet valve 6 and a gas pressure control inlet valve 7, and is located at the second end of the piston cylinder 1. The inlet valve 6 is sealed to the corresponding tube on the piston cylinder 1 via a reducing connector. The pressure monitoring component includes a first gas pressure gauge 8 and a second gas pressure gauge 9. The first gas pressure gauge 8 is adjacent to... The sample inlet valve 2 and the sample outlet valve 3 are provided. The second gas pressure gauge 9 is located between the gas inlet valve 6 and the gas pressure control inlet valve 7. The first gas pressure gauge 8 and the second gas pressure gauge 8 are used to monitor the pressure at the first end and the second end, respectively. When the pressure at the first end is equal to 1 MPa, the piston 4 is stationary. When the pressure is less than 1 MPa, the piston 4 moves towards the first end and the sample outlet pressure is maintained at a constant 1 MPa by the gas supply system. Multiple sealing rings 10 are evenly spaced between the piston 4 and the inner wall of the piston cylinder 1. The multiple sealing rings 10 are semi-embedded in the corresponding grooves on the outside of the piston 4. The multiple sealing rings 10 are made of fluororubber and have a pressure resistance rating of ≥2 MPa.

[0022] Specifically, in this embodiment, the outer wall of the piston cylinder 4 is provided with an embedded transparent observation window, which is made of borosilicate glass with a thickness of 8mm and a pressure resistance of 2.5MPa. The inner side of the observation window is engraved with volume scale lines (accuracy ±1mL) and is equipped with an LED backlight illumination module (IP67 protection level) to display the piston position and sample balance in real time in a dark environment.

[0023] In a preferred embodiment of this utility model, the air inlet valve 6, the piston motion control valve 7, the sample injection valve 2, and the sample discharge valve 3 are all needle valves, and the sample injection valve 2 and the sample discharge valve 3 are respectively sealed to the piston motion control valve 5.

[0024] Specifically, in this embodiment, the valve cores of the air inlet valve 6, piston motion control valve 7, sample injection valve 2, and sample discharge valve 3 are made of 316L stainless steel and are resistant to liquefied gas and corrosive gas.

[0025] In a preferred embodiment of this utility model, the piston cylinder 1 includes a main body, a bottom cover, and an upper cover 12. The upper cover and the main body are rotatably connected by corresponding threads. A sealing gasket is provided on the inner bottom of the upper cover corresponding to the main body. The bottom cover is welded to the main body as a whole. The upper cover and the bottom cover are welded to the corresponding pipe body as a whole. The opening of the pipe body is provided with an installation interface. The central axis of the main body and the corresponding pipe body coincides.

[0026] In a preferred embodiment of this utility model, the ratio of the stroke of the piston 4 to the length of the piston cylinder 1 is 1:3, the maximum displacement of the piston 4 is 200mm, and the displacement is indicated by scale lines on the outer wall of the piston cylinder 4.

[0027] In a preferred embodiment of this utility model, the gas supply system further includes an external gas source quick interface 11, a precision pressure regulating valve, and a gas filter assembly. The external gas source quick interface supports connection to standard gas cylinders. The precision pressure regulating valve and the gas filter assembly are integrated into the gas pressure control inlet valve 7. The precision pressure regulating valve has an adjustment accuracy of ±0.05MPa. The gas filter assembly has a built-in 5μm stainless steel filter screen. The gas filter assembly is used to remove particulate impurities from the external gas source. The external gas source is inert gas or compressed air, and the pressure adjustment range of the external gas source is 0.5-2MPa.

[0028] In a preferred embodiment of this utility model, the first gas pressure gauge 8 has an accuracy class of 0.5 and a range of 0-2.5 MPa. The first gas pressure gauge 8 supports Bluetooth connection to a mobile terminal.

[0029] In a preferred embodiment of this utility model, the second gas pressure gauge 9 adopts a wireless transmission type digital display pressure sensor. The second gas pressure gauge 9 has an accuracy of 0.25 grade and a range of 0-2.5MPa. The second gas pressure gauge 9 is equipped with an overload protection function, which automatically triggers an audible and visual alarm when the pressure exceeds 1.2MPa.

[0030] In a preferred embodiment of this utility model, the reducing connector has a tapered transition structure, the threads at both ends of the reducing connector are 1 / 4 NPT, and the material of the reducing connector is 316L stainless steel.

[0031] In a preferred embodiment of this utility model, the sampler is made of 316L stainless steel, the sampler is suitable for a temperature range of -20℃ to 80℃, and the sampler has a pressure resistance rating of 6.0MPa.

[0032] Specifically, in this embodiment, the sampler further integrates the following safety components, including a dual redundant pressure relief valve and an explosion-proof housing. The dual redundant pressure relief valve is located on the top and side of the piston cylinder (5), with pressure relief thresholds of 1.2MPa and 1.5MPa, respectively. The material is Inconel 718, and the response time is ≤0.1 seconds. The explosion-proof housing covers the entire device and meets the ATEX Zone 1 explosion-proof standard. The housing material is aluminum alloy (anodized), and the seams are sealed with fluororubber.

[0033] Specifically, in this embodiment, during sampling, the injection valve 2 and piston movement control valve 5 are opened, and liquefied gas enters the piston cylinder 1 through the injection port. When the first gas pressure gauge (sample end pressure gauge) displays 1MPa, the valve is closed to complete the sampling. During discharge, an external gas source is connected to the gas inlet valve 6, and the gas pressure control inlet valve 7 is adjusted to stabilize the second gas pressure gauge (gas pressure gauge) at 1MPa. Then, the discharge valve 3 is opened, and the piston 4 moves at a constant speed under gas drive to maintain a constant discharge pressure.

[0034] Specifically, in this embodiment, in a low-temperature environment (-10℃), a 316L stainless steel valve body and a fluororubber sealing ring are used to prevent the medium from freezing; by confirming the piston displacement, the layout volume is precisely controlled in combination with the scale lines, with an error of ≤±2%.

[0035] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0037] This invention can be widely applied in the fields of petrochemicals, natural gas transportation, laboratory testing, and emergency rescue, and is especially suitable for harsh working conditions such as high-sulfur gas fields and liquefied natural gas (LNG) storage and transportation. Testing has shown that this device exhibits no leakage at 1.5 times its rated pressure and has a lifespan of 120,000 cycles, demonstrating significant economic benefits and market competitiveness.

[0038] The working principle of this utility model:

[0039] The sampler of this utility model uses a piston 4 inside a piston cylinder 1 that can reciprocate under a certain pressure. Valves and pressure gauges are installed at both ends of the piston 4, so that the pressure output of the sample can be observed at any time to ensure that the pressure remains stable when the sample is put into testing.

[0040] First, take the sample at the sampling site through the sampling port on the sampler, carefully observing the pressure gauge reading. When the sample fills the piston sampler and the pressure gauge reading is greater than 1 MPa, close the sampling valve and stop sampling. After bringing the piston sampler back to the laboratory for analysis, connect the sample outlet of the sampler to the testing equipment, and connect the other end of the sampler to a gas supply source. Before releasing the sample for analysis, turn on the gas supply switch, slowly open the gas input valve of the piston sampler, and observe the pressure gauge reading. When the pressure gauge reading reaches 1 MPa, stop turning the valve. Open the valve connecting the sample release end 3 of the piston sampler to the piston 4, and observe the pressure gauge reading. When the pressure gauge reading reaches 1 MPa, stop turning the valve. Open the sample release valve 3 and open the gas valve connected to the piston sampler. As the sample in the piston sampler decreases, the pressure inside the piston sampler decreases. Driven by the gas, piston 4 moves towards the discharge end, further compressing the volume of the sample in the sampler, ensuring that the sample output pressure is 1 MPa at all times, until the sample is completely discharged. The piston then reaches the discharge end, completing the discharge analysis.

[0041] The embodiments of this utility model have been described in detail above with reference to the accompanying drawings, but this utility model is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this utility model, and these variations still fall within the protection scope of this utility model.

Claims

1. A constant-pressure piston liquefied gas sampler, characterized in that, include: The system comprises a piston cylinder, an injection valve, a discharge valve, a gas supply system, and a pressure monitoring component. The piston cylinder is a cylindrical structure with tubes integrally formed at both ends. A reciprocating piston is located inside the piston cylinder. The injection valve, discharge valve, and piston movement control valve are respectively located at the first end of the piston cylinder. The gas supply system includes an inlet valve and a gas pressure control inlet valve, and is located at the second end of the piston cylinder. The inlet valve is sealed to the corresponding tube on the piston cylinder via a reducing connector. The pressure monitoring component includes a first gas pressure gauge and a second gas pressure gauge. The first gas pressure gauge is located adjacent to the injection valve and the discharge valve, and the second gas pressure gauge is located between the inlet valve and the gas pressure control inlet valve. The first and second gas pressure gauges are used to monitor the pressure at the first and second ends, respectively. When the pressure at the first end is equal to 1 MPa, the piston remains stationary; when the pressure is less than 1 MPa, the piston moves towards the first end, and the gas supply system maintains a constant discharge pressure of 1 MPa.

2. The constant pressure piston liquefied gas sampler according to claim 1, characterized in that, Multiple sealing rings are evenly spaced between the piston and the inner wall of the piston cylinder. The multiple sealing rings are semi-embedded in grooves corresponding to the outer side of the piston. The multiple sealing rings are made of fluororubber and have a pressure resistance rating of ≥2MPa.

3. The constant pressure piston liquefied gas sampler according to claim 1, characterized in that, The air inlet valve, piston motion control valve, injection valve, and discharge valve are all needle valves, and the injection valve and discharge valve are respectively sealed to the piston motion control valve.

4. The constant pressure piston liquefied gas sampler according to claim 1, characterized in that, The piston cylinder includes a main body, a bottom cover, and a top cover. The top cover and the main body are rotatably connected by corresponding threads. A sealing gasket is provided on the inner bottom of the top cover corresponding to the main body. The bottom cover is welded to the main body as a whole. The top cover and the bottom cover are respectively welded to the corresponding tube body as a whole. The opening of the tube body is provided with an installation interface. The central axis of the main body and the corresponding tube body coincide.

5. The constant pressure piston liquefied gas sampler according to claim 4, characterized in that, The ratio of the piston's stroke to the length of the piston cylinder is 1:3, the maximum displacement of the piston is 200mm, and the displacement is indicated by scale lines on the outer wall of the piston cylinder.

6. The constant pressure piston liquefied gas sampler according to claim 1, characterized in that, The gas supply system also includes an external gas source quick interface, a precision pressure regulating valve, and a gas filter assembly. The external gas source quick interface supports standard gas cylinder connections. The precision pressure regulating valve and the gas filter assembly are integrated into the gas pressure control inlet valve. The precision pressure regulating valve has an adjustment accuracy of ±0.05MPa. The gas filter assembly has a built-in 5μm stainless steel filter screen and is used to remove particulate impurities from the external gas source. The external gas source is inert gas or compressed air, and the pressure adjustment range of the external gas source is 0.5-2MPa.

7. The constant pressure piston liquefied gas sampler according to claim 1, characterized in that, The first gas pressure gauge has an accuracy class of 0.5 and a range of 0-2.5 MPa. The first gas pressure gauge supports Bluetooth connection to mobile terminals.

8. The constant pressure piston liquefied gas sampler according to claim 1, characterized in that, The second gas pressure gauge uses a wireless transmission type digital display pressure sensor. The second gas pressure gauge has an accuracy of 0.25 grade and a range of 0-2.5MPa. The second gas pressure gauge is equipped with an overload protection function, which automatically triggers an audible and visual alarm when the pressure exceeds 1.2MPa.

9. The constant pressure piston liquefied gas sampler according to claim 1, characterized in that, The reducing connector has a tapered transition structure, the threads at both ends of the reducing connector are 1 / 4 NPT, and the material of the reducing connector is 316L stainless steel.

10. The constant pressure piston liquefied gas sampler according to claim 1, characterized in that, The sampler is made of 316L stainless steel, and its applicable temperature range is -20℃ to 80℃. The sampler has a pressure resistance rating of 6.0MPa.

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