A low-pollution sampling system, apparatus and method for toxic propellants

Abstract

A low-pollution sampling system, equipment, and method for toxic propellants includes: a sampling bottle; a neutralization tank module; a first tee connector; a backflush gas path connected at both ends to the first tee connector and a gas cylinder; the backflush gas path sequentially connected to the first tee connector, valve V1, valve K2, a first backflush branch, a second backflush branch, and a gas cylinder; a sampling liquid path connected at both ends to the first tee connector and valve K7; the sampling liquid path sequentially connected to the first tee connector, valve K1, vacuum ejector ZK1, valve K4, and a second tee connector; the other end of the first backflush branch connected to the vacuum ejector ZK1; a neutralization pipeline connected at both ends to valve K8 and the neutralization tank module; the neutralization pipeline sequentially connected to the third tee connector, valve K6, vacuum ejector ZK2, and valve K10; the other end of the second backflush branch connected to the vacuum ejector ZK2; and a connecting pipeline connected between the second tee connector and the third tee connector. This significantly reduces the harm to personnel and environmental pollution caused by propellants.

Description

Technical Field

[0001] This application relates to a low-pollution sampling system, equipment, and method for toxic propellants, belonging to the field of testing and storage of toxic and hazardous liquids. Background Technology

[0002] Before refueling, both monopropellant and bipropellant propellants undergo sampling and testing. In the past, during the sampling process, staff members typically wore protective suits and used the back pressure of the storage tank to squeeze the propellant into the sampling bottle in an atmospheric environment. The sampling connection pipeline could not be completely closed-loop into the sampling bottle, resulting in a small amount of vapor evaporating into the atmosphere even for propellants with relatively high boiling points, with nitrogen tetroxide evaporation being particularly severe. Secondly, in areas with high humidity, the sampled propellant may absorb a small amount of water, leading to errors in the propellant test results.

[0003] A search revealed patent document CN210513793U, which discloses a fully sealed sampling system for conventional liquid propellants, relating to the testing and storage of toxic and hazardous liquids. The system includes a storage tank, a sampling cylinder, and a waste collection tank. The storage tank and sampling cylinder are sealed together via a first liquid pipeline, and the sampling cylinder and waste collection tank are sealed together via a second liquid pipeline. The upper end of the waste collection tank is connected to a discharge pipe and a cleaning pipe. The cleaning pipe is connected to an inner tube located within the cavity of the waste collection tank, with the lower end of the inner tube located at the bottom of the cavity. However, this patent only achieves a closed system during the sampling process; it lacks pipeline purging and vacuuming mechanisms. In actual use, some propellant will still leak into the atmosphere around the operator, posing a potential risk to personnel and causing some environmental pollution.

[0004] Patent document CN110448999B discloses an integrated device for propellant exhaust gas treatment, and provides a system and method for using this integrated device for propellant exhaust gas treatment. The integrated device includes a gas-liquid contact section, a static washing section, and a hypergravity process enhancement section. When used for propellant exhaust gas treatment, the exhaust gas enters the device via a fan for three-stage treatment. The treated gas is discharged through a gas outlet, while the liquid circulates from the bottom of the device into a rotating packing rotor. The absorbent can be replenished by a replenishment tank. This patent primarily focuses on propellant treatment, also performing three absorption treatments on the exhaust gas. It requires electric drive, and all electrical components must comply with explosion-proof standards, making it suitable for fixed equipment but not for mobile sampling.

[0005] Patent document CN103920385B discloses an oxidation absorption method for converting high-concentration dinitrogen tetroxide waste gas into potassium fertilizer. The method involves oxidizing and absorbing dinitrogen tetroxide waste gas with a molar content of 20%–70% through a two-stage process of dilute nitric acid and hydrogen peroxide, converting it into nitric acid, and then converting it into potassium fertilizer using potassium hydroxide alkaline solution. This patent primarily focuses on propellant treatment, also employing a three-stage absorption treatment for the waste gas. Summary of the Invention

[0006] The technical problem solved by this application is to overcome the shortcomings of the prior art and provide a low-pollution sampling system, equipment and method for toxic propellants. The system samples inside a closed system and neutralizes and absorbs the volatile gases. The residual propellant inside the connected pipeline is carried to the neutralization tank for neutralization and absorption by vacuum ejection, which greatly reduces the harm of propellants to personnel and pollution to the environment.

[0007] The technical solution provided in this application is as follows:

[0008] In a first aspect, a low-pollution sampling system for toxic propellants is provided for sampling from a propellant storage tank connected to a valve K102, comprising:

[0009] The sampling bottle is connected to valves K7 and K8.

[0010] Neutralization tank module, containing a neutralization solution for neutralizing the propellant;

[0011] The first tee fitting has three connectors, one of which is used to connect to valve K102;

[0012] The backflush air path is connected at one end to a connector of the first three-way connector and at the other end to a gas cylinder; between the first three-way connector and the gas cylinder, valve V1, valve K2, the first backflush branch and the second backflush branch are connected in sequence on the backflush air path;

[0013] The sampling liquid path is connected at one end to a connector of the first three-way connector and at the other end to valve K7. Between the first three-way connector and valve K7, valve K1, vacuum ejector ZK1, valve K4 and the second three-way connector are connected in sequence on the sampling liquid path. The other end of the first backflush branch is connected to vacuum ejector ZK1, and valve K3 is installed on the first backflush branch.

[0014] The neutralization pipeline is connected to valve K8 at one end and to the neutralization tank module at the other end. Between valve K8 and the neutralization tank, the neutralization pipeline is connected in sequence to the third tee joint, valve K6, vacuum ejector ZK2 and valve K10. The other end of the second return blow branch is connected to vacuum ejector ZK2, and valve K9 is provided on the second return blow branch.

[0015] The connecting pipe is connected between the second tee joint and the third tee joint, and valve K5 is installed on the connecting pipe.

[0016] Furthermore, it also includes a platform scale, which is used to place the sampling bottle to weigh the mass of the propellant sample taken from the bottle.

[0017] Furthermore, valve V1 is located close to the first three-way connector, and valve K2 is located near the connection point between the first return air branch and the return air path.

[0018] Furthermore, the valve K1 is located immediately adjacent to the vacuum ejector ZK1.

[0019] Furthermore, a pressure reducer J1 is also connected to the return air path, and pressure gauges are connected to both sides of the pressure reducer J1 in the return air path; the pressure reducer J1 and the pressure gauges are both located between the connection point of the second return branch and the return air path and the gas cylinder.

[0020] Furthermore, a one-way valve D1 is also connected to the return air line. The one-way valve D1 is located between the connection point of the second return branch and the return air line and the pressure reducer J1.

[0021] Furthermore, the neutralization tank module is a single neutralization tank, or the neutralization tank module comprises multiple neutralization tanks connected in series.

[0022] In a second aspect, a low-pollution sampling device for toxic propellants is provided, comprising any of the aforementioned low-pollution sampling systems for toxic propellants, and further comprising a housing;

[0023] The backflush air path includes a second backflush pipeline and a first backflush pipeline, and the sampling liquid path includes a first backflush pipeline and a first sampling liquid path;

[0024] The second return air pipeline is connected at one end to a connector of the first tee connector, and at the other end to the return air connector.

[0025] The second sampling fluid path is connected at one end to one of the connectors of the first three-way connector, and at the other end to the sampling connector.

[0026] The first backflush pipeline is connected to a backflush connector at one end and a gas cylinder at the other end. Between the backflush connector and the gas cylinder, valve K2, the first backflush branch, and the second backflush branch are connected in sequence on the first backflush pipeline.

[0027] The first sampling liquid path has a sampling connector at one end and a valve K7 at the other end; between the sampling connector and the valve K7, the first sampling liquid path is connected in sequence to the valve K1, the vacuum ejector ZK1, the valve K4, and the second three-way connector.

[0028] The shell, platform scale, neutralization tank module, first backflush pipeline, first sampling liquid line, neutralization pipeline, first backflush branch and second backflush branch are all located inside the shell;

[0029] The backflush connector, sampling connector, valves V1, K2, K1, K4, K3, K6, K10, K5, and K9 are all connected to the housing.

[0030] Thirdly, a low-pollution sampling system for toxic propellants is provided, comprising:

[0031] S1. Confirm that the gas cylinder contains gas and that the neutralization solution is prepared in the neutralization tank; confirm that all valves are closed.

[0032] S2. Open the valves of the gas cylinder, open valves K2, K3, V1 and K1, purge for the set time, connect the connector of the first three-way connector to valve K102, and close valves K1, K2 and V1.

[0033] S3. Connect valve K7 to the second tee connector and valve K8 to the third tee connector to complete the connection of the sampling bottle;

[0034] S4. Open valves K4, K5, K6 and K10, and close valve K3 after purging for the set time;

[0035] S5. Open valve K1 and slowly open valve K102. The propellant inside the propellant storage tank flows into the neutralization tank module through the first three-way connector, sampling liquid line, connecting pipeline and neutralization pipeline in sequence under the back pressure inside the tank. Then close valve K102.

[0036] S6. Close valve K5, open valve K7, open valve K102, and then open valve K8. Under back pressure, the propellant in the propellant storage tank enters the sampling bottle through the first three-way connector and the sampling liquid line. At the same time, the gas in the sampling bottle enters the neutralization tank through valve K8 and the neutralization pipeline to achieve sampling. After sampling is completed, close valves K7, K8 and K102.

[0037] S7. Increase the pressure of helium in the backflush gas path, open valves K2, V1, and K5. After the helium is blown out of the gas cylinder, it is blown along the backflush gas path to the first three-way connector. Then, the propellant liquid in the sampling liquid path and neutralization pipeline is blown into the neutralization tank for neutralization. During this process, valve K2 is intermittently closed and opened, and the cycle is repeated several times. Then, valve K2 and valve V1 are closed.

[0038] S8. Open valve K9. Helium enters vacuum ejector ZK2 through the first backflush branch and is blown into neutralization tank through valve K10. The high-speed helium gas flow in vacuum ejector ZK2 ejects the propellant in the sampling liquid path and the part between the third tee joint of the neutralization pipeline and vacuum ejector ZK2.

[0039] After setting the time using S9 and S8, close valve K10, open valve K3 to pressurize, and then close valve K3 after pressurization.

[0040] After S10 and S9 are pressurized and left to stand for a set time, valve K10 is opened and vacuum ejector ZK2 performs vacuum ejection. After the set time, valve K3 is opened and vacuum ejectors ZK1 and ZK2 perform ejection simultaneously.

[0041] S11. Repeat S9 and S10 multiple times;

[0042] S12. Close valves K3 and K4. In vacuum ejector mode, first disconnect the connection between the second tee connector and valve K7, and install the valve plug of valve K7; then disconnect the connection between the third tee connector and valve K8, install the valve plug of valve K8, and remove the sampling bottle.

[0043] S13. Open valves K3 and K4. Vacuum ejectors ZK1 and ZK2 are in vacuum ejection mode. Disconnect the first tee connector from valve K102 and then install the plug of the first tee connector onto valve K102.

[0044] S14. Close the gas cylinder valve and close all valves.

[0045] In summary, this application includes at least the following beneficial technical effects:

[0046] Sampling is performed within a closed system; vacuum extraction is used for evacuation; multiple neutralization vessels are used for multiple absorption processes to improve absorption efficiency. The entire process is gas-driven, without the use of any electrical equipment, achieving vacuum and positive pressure replacement and purging.

[0047] The system has a simple overall structure, uses gas to drive the entire process, and achieves positive pressure purging and vacuum replacement; it eliminates the need for explosion-proof electrical components, reduces weight, and its application is no longer limited by power supply requirements (explosion-proof requirements and outdoor use); it significantly reduces the possibility of propellant evaporation into the atmosphere, greatly protecting operators; and the corresponding equipment is easy to manufacture.

[0048] This system can also be used to remove propellant and perform initial replacement purging from product tanks containing small amounts of propellant. Examples include removing residual propellant and performing initial replacement purging on recoverable satellites, and removing and performing initial replacement purging on propellant in aircraft emergency systems. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of a low-pollution sampling system for toxic propellants in an embodiment of this application;

[0050] Figure 2 This is a schematic diagram of the state of S2 in the embodiment;

[0051] Figure 3 This is a schematic diagram of the state of S3 in the embodiment;

[0052] Figure 4 This is a schematic diagram of the state of S4 in the embodiment;

[0053] Figure 5 This is a schematic diagram of the state of S5 in the embodiment;

[0054] Figure 6 This is a schematic diagram of the state of S6 in the embodiment;

[0055] Figure 7 This is a schematic diagram of the state of S7 in the embodiment;

[0056] Figure 8 This is a schematic diagram of the state of S8 in the embodiment;

[0057] Figure 9 This is a schematic diagram of the state of S9 in the embodiment;

[0058] Figure 10 This is a schematic diagram of the state of S10 in the embodiment;

[0059] Figure 11 This is a schematic diagram of the helium flow path during the removal of the sample bottle in S12 of the embodiment.

[0060] Figure 12 This is a schematic diagram of the state of the sample bottle after it is removed in step S12 of the embodiment.

[0061] Figure 13 This is a schematic diagram of the state of S13 in the embodiment;

[0062] Figure 14 This is a schematic diagram of the state of S14 in the embodiment.

[0063] Explanation of reference numerals in the attached diagram: 1. Propellant storage tank; 2. Sampling bottle; 21. Platform scale;

[0064] 31. Primary neutralization tank; 32. Secondary neutralization tank; 33. Tertiary neutralization tank;

[0065] 4. Backflush air path; 41. First tee connector; Valve V1; Valve K2; Check valve D1; Pressure gauge P1; Pressure regulator J1; Pressure gauge P2; 48. Gas cylinder;

[0066] 5. Sampling fluid path; Valve K1; Pressure gauge P3; Vacuum ejector ZK1; Valve K4; 55. Second tee connector; 56. Connecting pipeline; Valve K5;

[0067] 6. Neutralization piping; 61. Third tee connector; Valve K6; Vacuum ejector ZK2; Valve K10;

[0068] 7. First return blow branch; Valve K3;

[0069] 8. Second return air branch; valve K9. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments disclosed in this application will be described in further detail below with reference to the accompanying drawings.

[0071] This application discloses a low-pollution sampling system for toxic propellants, used for sampling from a propellant storage tank 1. The propellant storage tank 1 is connected to a valve K102, such as... Figure 1 As shown, the sampling system includes a sampling bottle 2, a platform scale 21, a neutralization tank, a backflush gas path 4, a sampling liquid path 5, a connecting pipe 56, a neutralization pipe 6, a first backflush branch 7, and a second backflush branch 8.

[0072] Sampling vial 2 is connected to valves K7 and K8. Sampling vial 2 is placed on platform scale 21, which is used to measure the mass of propellant sample taken from sampling vial 2.

[0073] One end of the backflush gas path 4 is connected to one connector of the first tee connector 41, and the other end is connected to a gas cylinder 48. Between the first tee connector 41 and the gas cylinder 48, the backflush gas path 4 is connected in sequence to valve V1, valve K2, first backflush branch 7, second backflush branch 8, one-way valve D1, pressure gauge P1, pressure reducer J1, and pressure gauge P2. Among them, valve V1 is close to the first tee connector 41, valve K2 is close to the connection position between the first backflush branch 7 and the backflush gas path 4, one-way valve D1 is used to prevent propellant vapor from flowing back into the gas cylinder 48, pressure reducer J1 is used to reduce the pressure of the high-pressure helium flowing out of the gas cylinder 48, pressure gauge P2 is used to detect the pressure of the high-pressure helium flowing out of the gas cylinder 48 in the backflush gas path 4, and pressure gauge P1 is used to detect the pressure of the helium in the backflush gas path 4 after being reduced by pressure reducer J1.

[0074] One end of the sampling fluid path 5 is connected to one connector of the first tee connector 41, and the other end is connected to valve K7. Between the first tee connector 41 and valve K7, valve K1, pressure gauge P3, vacuum ejector ZK1, valve K4, and second tee connector 55 are connected in sequence on the sampling fluid path 5. Valve K1 is adjacent to vacuum ejector ZK1. The other end of the first backflush branch 7 is connected to vacuum ejector ZK1, and valve K3 is installed on the first backflush branch 7.

[0075] The third connector of the first tee connector 41 is used to connect valve K102.

[0076] One end of the neutralization pipeline 6 is connected to valve K8, and the other end is connected to the neutralization tank. Between valve K8 and the neutralization tank, the neutralization pipeline 6 is sequentially connected to a third tee connector 61, valve K6, vacuum ejector ZK2, and valve K10. The connecting pipeline 56 is connected between the second tee connector 55 and the third tee connector 61, and valve K5 is installed on the connecting pipeline 56. The other end of the second backflushing branch 8 is connected to vacuum ejector ZK2, and valve K9 is installed on the second backflushing branch 8.

[0077] The neutralization tank consists of three tanks, namely, a primary neutralization tank 31, a secondary neutralization tank 32, and a tertiary neutralization tank 33 connected in series.

[0078] The neutralization tank contains a saturated neutralization solution for neutralizing the corresponding propellant. The top of the neutralization tank has a feeding port, and the inside of the neutralization tank has multiple stainless steel filters with a pore size of 2-4mm to increase the contact area. Using three neutralization tanks can absorb propellant in multiple and large quantities.

[0079] After sampling, the neutralization solution was handed over to a professional toxic substance disposal unit for treatment.

[0080] The piping from valve K102 to the sampling system is a small-sized, internally polished pipe with an inner diameter of 4-6mm.

[0081] Small-sized, internally polished spiral tubing is used between valves K4 and K7, and between valves K6 and K8, to increase connection flexibility while minimizing propellant adhesion to the inner surface of the tubing.

[0082] Compared to engine testing, propellant transfer, and propellant loading, the sampling process releases a relatively small amount of propellant. Under gas-driven and triple-absorption conditions, and assuming the final exhaust emissions meet standards, the amount of gas source and neutralization solution prepared in a single operation is sufficient for at least 15 sampling tasks.

[0083] Currently, the propellant for monopropellant satellites is mainly anhydrous hydrazine, while the propellant for bipropellant satellites is methylhydrazine and nitrogen tetroxide (containing 1% NO, appearing green).

[0084] A low-pollution sampling device for toxic propellants includes a housing, a first tee connector 41, a second backflush line, and a second sampling fluid line. Both the second backflush line and the second sampling fluid line are flexible hoses. One end of the second backflush line is connected to one connector of the first tee connector 41, and one end of the second sampling fluid line is connected to one connector of the first tee connector 41. The third connector of the first tee connector 41 is used to connect to a valve K102.

[0085] The shell contains a platform scale 21, a neutralization tank, a first backflush pipeline, a first sampling liquid pipeline, a neutralization pipeline, a first backflush branch 7, and a second backflush branch 8.

[0086] The platform scale 21 is used to place the sampling bottle 2 and weigh the mass of the propellant sampled from the sampling bottle 2.

[0087] One end of the first backflush pipeline is connected to a backflush connector, and the other end is connected to a gas cylinder 48. Between the backflush connector and the gas cylinder 48, the first backflush pipeline is connected in sequence to a valve K2, a first backflush branch 7, a second backflush branch 8, a check valve D1, a pressure gauge P1, a pressure reducer J1, and a pressure gauge P2.

[0088] One end of the first sampling fluid path is connected to a sampling connector, and the other end is connected to valve K7; between the sampling connector and valve K7, valve K1, pressure gauge P3, vacuum ejector ZK1, valve K4, and second tee connector 55 are connected in sequence on the first sampling fluid path.

[0089] The other end of the second backflush line is used to connect to the backflush connector, and the other end of the second sampling liquid line is used to connect to the sampling connector. After the second backflush line is connected to the backflush connector, the second backflush line and the first backflush line form the backflush air path 4. After the second sampling liquid line is connected to the sampling connector, the second sampling liquid line and the first sampling liquid line form the sampling liquid path 5.

[0090] One end of the neutralization pipeline 6 is connected to valve K8, and the other end is connected to the neutralization tank. Between valve K8 and the neutralization tank, the neutralization pipeline 6 is sequentially connected to a third tee connector 61, valve K6, vacuum ejector ZK2, and valve K10. The connecting pipeline 56 is connected between the second tee connector 55 and the third tee connector 61, and valve K5 is installed on the connecting pipeline 56. The other end of the second backflushing branch 8 is connected to vacuum ejector ZK2, and valve K9 is installed on the second backflushing branch 8.

[0091] The backflush connector, sampling connector, valve V1, valve K2, check valve D1, pressure gauge P1, pressure reducer J1, pressure gauge P2, valve V1, valve K1, pressure gauge P3, valve K4, valve K3, valve K9, valve K5, valve K6 and valve K10 are all integrated on the housing.

[0092] The housing is provided with a door that can be opened and closed, so as to place the sampling bottle 2 on the platform scale 21 and remove the sampling bottle 2 from the platform scale 21, and to facilitate the connection of the sampling bottle 2 with the first sampling liquid path and the neutralizing liquid path 6.

[0093] The above setup creates a sampling device that is easy to move and use, improving the convenience of sampling.

[0094] A low-pollution sampling method for toxic propellants includes the following steps:

[0095] 1) Make preparations. Confirm that gas cylinder 48 contains gas, and prepare the neutralization solution inside the neutralization tank to neutralize the residual propellant; initially, all valves should be closed;

[0096] 2) Piping Connections. Clean the connectors, backflush connector, and sampling connector of the first tee connector 41. First, connect the second backflush pipeline to the backflush connector and the second sampling liquid line to the sampling connector. Open the valve of gas cylinder 48, adjust the pressure regulator J1 to 0.2MPa, and open valves K2, K3, V1, and K1. The helium gas blown out of gas cylinder 48 passes through valve K2 on the backflush gas line 4 and is blown out from the first tee connector 41. The helium gas blown out of gas cylinder 48 passes through valve K3, vacuum ejector ZK1, valve K1, and then... The first three-way connector 41 is purged, purging the section between the vacuum ejector ZK1 and the first three-way connector 41 in the return air path 4, the first return branch 7, and the sampling liquid path 5. After three minutes, the pressure regulator J1 is adjusted to 0.03MPa~0.05MPa, and the connector of the first three-way connector 41 is connected to valve K102, while valves K1 and K2 are closed. This process uses positive pressure connection to prevent atmospheric impurities from entering the first three-way connector 41. The sampling liquid path 5 is preferably made of transparent PTFE tubing. Figure 2 As shown;

[0097] 3) Connect sampling bottle 2. Connect valve K7 to the second tee connector 55, and connect valve K8 to the third tee connector 61 to complete the connection of sampling bottle 2; Figure 3 As shown.

[0098] 4) Sampling system pipeline purging. Adjust pressure regulator J1 to 0.2MPa, open valves K4, K5, K6, and K10. Helium gas is purged from cylinder 48, passing sequentially through valve K3, vacuum ejector ZK1, valve K4, valve K5, valve K6, vacuum ejector ZK2, and valve K10, finally entering the neutralization tank. This purifies part of the backflush gas path 4, the first backflush branch 7, part of the sampling liquid path 5, the first backflush branch 7, and the neutralization pipeline 6. After three minutes, close valve K3. Figure 4 As shown.

[0099] 5) Pipeline filling. Open valve K1, then slowly open valve K102. Under back pressure, the propellant inside propellant tank 1 flows sequentially through the first tee connector 41, sampling liquid line 5, connecting pipe 56, and neutralization pipe 6 into the neutralization tank. This process continues for approximately one minute to ensure the propellant completely fills sampling liquid line 5 and neutralization pipe 6 and enters the neutralization tank. Then close valve K102. This process flushes sampling liquid line 5 and neutralization pipe 6, resulting in cleaner samples and more accurate test results later. Figure 5As shown.

[0100] 6) Sampling. Close valve K5, open valve K7, then slowly open valve K102, and then open valve K8. At this time, the propellant in propellant storage tank 1, under back pressure, enters sampling bottle 2 through the first three-way connector 41 and sampling liquid line 5. Simultaneously, the gas in sampling bottle 2 enters the neutralization tank through valve K8 and neutralization pipeline 6, thus achieving sampling. After sampling, close valves K7, K8, and K102. (The sampling weight is given by the mechanical platform scale 21. Generally, 2-3 kg is sampled. The back pressure of the satellite-grade methylhydrazine / anhydrous hydrazine storage tank is 0.05±0.01 MPa during storage, and that of nitrogen tetroxide is 0.17±0.01 MPa). Figure 6 As shown.

[0101] 7) Sampling line purging. Adjust the pressure regulator to 0.3 MPa, open valves K2 and V1, and open valve K5; after helium gas is purged from cylinder 48, it is blown along the return gas path 4 to the first tee connector 41, and then the propellant liquid in the sampling liquid path 5 and neutralization line 6 is purged into the neutralization tank for neutralization. After 2 minutes, close valve K2; after 1 minute, open valve K2 again, repeating this cycle 5 times, then close valves K2 and V1. Repeat the purging process multiple times to purge as much propellant and propellant vapor as possible from the pressure gauges, valves, connectors, and other blind cavities in the sampling line 5 into the neutralization tank. Figure 7 As shown.

[0102] 8) Vacuum ejector ZK2 vacuum ejection. Open valve K9, and helium gas enters vacuum ejector ZK2 through the second backflush branch 8, and is blown into the neutralization tank through valve K10. The high-speed helium gas flow in vacuum ejector ZK2 ejects the propellant in the section between the sampling liquid path 5 and the third tee joint 61 of the neutralization pipeline 6 and vacuum ejector ZK2. Using vacuum ejector ZK2 for vacuum ejection achieves vacuuming in the section between the sampling liquid path 5 and the third tee joint 61 of the neutralization pipeline 6 and vacuum ejector ZK2. Under the action of the gas flow, the propellant residue in the pipeline between valve K102 and vacuum ejector ZK2 is carried into the neutralization tank. The propellant inside the pipeline between valve K9 and vacuum ejector ZK2, and between vacuum ejector ZK2 and valve K10, is carried into the neutralization tank by the positive pressure gas flow. Figure 8 As shown.

[0103] 9) Pressurization. After 2 minutes, close valves K9 and K10, and open valve K3. Since valve K10 is closed, vacuum ejectors ZK1 and ZK2 do not have vacuum ejection function at this time. Vacuum ejectors ZK1 and ZK2 are internally connected, and only have a connecting function. Helium gas enters from the return gas path 4 through the first return branch 7 and enters the section between the third tee joint 61 of the sampling liquid path 5 and the neutralization pipeline 6 and the vacuum ejector ZK2 for pressurization. After pressurization, close valve K3.

[0104] This process mixes helium with the remaining small amount of propellant vapor in sampling fluid line 5 and neutralization line 6, increasing the total gas volume in these two lines and reducing the concentration of propellant vapor. This allows for more propellant vapor to be ejected and flow into the neutralization tank during the next vacuum ejection process of vacuum ejector ZK2; for example... Figure 9 As shown.

[0105] 10) Secondary vacuum ejection. After standing for 3 minutes, open valves K10 and K9. Vacuum ejector ZK2 performs vacuum ejection, evacuating the portion connecting the sampling liquid path 5 and the third tee joint 61 of the neutralization pipeline 6 to vacuum ejector ZK2. After 2 minutes, open valve K3, and vacuum ejectors ZK1 and ZK2 simultaneously perform ejection. This is the second stage of vacuum evacuation. Figure 10 As shown.

[0106] 11) Repeat steps 9) and 10) 3-5 times;

[0107] 12) Disassemble the sampling bottle. Close valves K3 and K4. With vacuum ejector ZK2 in vacuum ejection mode, disassemble sampling bottle 2. First, disconnect the connection between the second tee connector 55 and valve K7. Then, plug the connection point of valve K7 with a plug and simultaneously install the valve plug of valve K7. Next, disconnect the connection between the third tee connector 61 and valve K8. Then, plug the connection point of valve K8 with a plug and simultaneously install the valve plug of valve K8. Remove sampling bottle 2. Figure 11 and Figure 12 As shown.

[0108] During this process, because the vacuum ejector ZK2 is in vacuum ejection mode, when the second three-way connector 55 and the third three-way connector 61 are removed, atmospheric gas is ejected from the outlets where the second three-way connector 55 and the third three-way connector 61 are removed into the first return blow branch 7 and the neutralization pipe 6, thus preventing residual propellant vapor in the first return blow branch 7 and the neutralization pipe 6 from entering the atmosphere and directly avoiding damage to the human body.

[0109] 13) Disconnect the sampling pipeline. Open valves K3 and K4, and vacuum ejector ZK1 and vacuum ejector ZK2 in vacuum ejection mode. Disconnect the connection between the first tee connector 41 and valve K102, and then install the plug of the first tee connector 41 and the plug of valve K102.

[0110] During this process, because vacuum ejectors ZK1 and ZK2 are in vacuum ejection mode, after the first three-way connector 41 is removed, atmospheric gas is ejected from the point where the first three-way connector 41 was removed into the sampling liquid path 5, preventing residual propellant vapor in the sampling liquid path 5 from entering the atmosphere and directly avoiding damage to the human body. Figure 13 As shown.

[0111] 14) Close valve 48 on gas cylinder, depressurize the system, close all valves, and sampling is complete. Figure 14 As shown.

[0112] The contents not described in detail in this application specification are common knowledge to those skilled in the art.

[0113] The present application has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present application. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and implementation methods of the present application without departing from the spirit and scope of the present application, and all such modifications and improvements fall within the scope of the present application. The scope of protection of the present application is determined by the appended claims.

Claims

1. A low-pollution sampling system for toxic propellants, used for sampling from a propellant storage tank (1), the propellant storage tank (1) being connected to a valve K102, characterized in that, include: Sampling bottle (2) is connected to valves K7 and K8; Neutralization tank module, containing a neutralization solution for neutralizing the propellant; The first tee connector (41) has three connectors, one of which is used to connect to valve K102; The backflush air passage (4) is connected at one end to a connector of the first three-way connector (41) and at the other end to a gas cylinder (48); between the first three-way connector (41) and the gas cylinder (48), valve V1, valve K2, the first backflush branch (7) and the second backflush branch (8) are connected in sequence on the backflush air passage (4); The sampling fluid path (5) is connected at one end to a connector of the first three-way connector (41) and at the other end to a connector of the second three-way connector (55). The second three-way connector (55) is used to connect valve K7. Between the first three-way connector (41) and the second three-way connector (55), valve K1, vacuum ejector ZK1 and valve K4 are connected in sequence on the sampling fluid path (5). The other end of the first backflush branch (7) is connected to vacuum ejector ZK1. Valve K3 is provided on the first backflush branch (7). The neutralization pipeline (6) is connected at one end to a connector of the third tee connector (61) and at the other end to the neutralization tank module; the third tee connector (61) is used to connect valve K8. Between the third tee connector (61) and the neutralization tank, valve K6, vacuum ejector ZK2 and valve K10 are connected in sequence on the neutralization pipeline (6); the other end of the second backflush branch (8) is connected to vacuum ejector ZK2, and valve K9 is provided on the second backflush branch (8); A connecting pipe (56) is connected between the second tee joint (55) and the third tee joint (61), and a valve K5 is provided on the connecting pipe (56).

2. The low-pollution sampling system for toxic propellants according to claim 1, characterized in that: It also includes a platform scale (21) for placing the sampling bottle (2) to weigh the mass of the propellant sample in the sampling bottle (2).

3. The low-pollution sampling system for toxic propellants according to claim 1, characterized in that: The valve V1 is close to the first three-way connector (41), and the valve K2 is close to the connection position between the first return air branch (7) and the return air path (4).

4. A low-pollution sampling system for toxic propellants according to claim 1, characterized in that: The valve K1 is located next to the vacuum ejector ZK1.

5. A low-pollution sampling system for toxic propellants according to claim 1, characterized in that: A pressure reducer J1 is also connected to the backflush gas path (4), and pressure gauges are connected to both sides of the pressure reducer J1 in the backflush gas path (4); the pressure reducer J1 and the pressure gauges are located between the connection point of the second backflush branch (8) and the backflush gas path (4) and the gas cylinder (48).

6. A low-pollution sampling system for toxic propellants according to claim 1, characterized in that: A one-way valve D1 is also connected to the return air passage (4). The one-way valve D1 is located between the connection point of the second return branch (8) and the return air passage (4) and the pressure reducer J1.

7. A low-pollution sampling system for toxic propellants according to claim 1, characterized in that: The neutralization tank module is a single neutralization tank, or the neutralization tank module includes multiple neutralization tanks connected in series.

8. A low-pollution sampling device for toxic propellants, characterized in that, A low-pollution sampling system for toxic propellants according to any one of claims 1-7, further comprising a housing; The backflush gas path (4) includes a second backflush pipeline and a first backflush pipeline, and the sampling liquid path (5) includes a first backflush pipeline and a first sampling liquid path; The second return air pipeline is connected at one end to a connector of the first tee connector (41), and at the other end to a return air connector. The second sampling liquid path is connected at one end to a connector of the first three-way connector (41), and at the other end to a sampling connector. The first return pipeline is connected to a return connector at one end and a gas cylinder (48) at the other end; between the return connector and the gas cylinder (48), the first return pipeline is connected in sequence to a valve K2, a first return branch (7), and a second return branch (8); The first sampling liquid path is connected to a sampling connector at one end and to valve K7 at the other end; between the sampling connector and valve K7, valve K1, vacuum ejector ZK1, valve K4 and second three-way connector (55) are connected in sequence on the first sampling liquid path. The shell, platform scale (21), neutralization tank module, first backflush pipeline, first sampling liquid line, neutralization pipeline, first backflush branch (7) and second backflush branch (8) are all installed inside the shell; The backflush connector, sampling connector, valves V1, K2, K1, K4, K3, K6, K10, K5, and K9 are all connected to the housing.

9. A low-pollution sampling system for toxic propellants according to any one of claims 1-7, characterized in that, include: S1. Confirm that the gas cylinder (48) contains gas and prepare the neutralization solution in the neutralization tank; All valves are confirmed to be closed; S2. Open the valve of the gas cylinder (48), open valves K2, K3, V1 and K1, purge for a set time, connect the connector of the first three-way connector (41) to valve K102, and close valves K1, K2 and V1. S3. Connect valve K7 to the second tee connector (55) and valve K8 to the third tee connector (61) to complete the connection of the sampling bottle (2); S4. Open valves K4, K5, K6 and K10, and close valve K3 after purging for the set time; S5. Open valve K1 and slowly open valve K102. The propellant inside the propellant storage tank (1) flows into the neutralization tank module through the first three-way connector (41), sampling liquid line (5), connecting pipeline (56) and neutralization pipeline (6) in sequence under the back pressure inside the tank. Then close valve K102. S6. Close valve K5, open valve K7, open valve K102, and then open valve K8. Under back pressure, the propellant in the propellant storage tank (1) enters the sampling bottle (2) through the first three-way connector (41) and the sampling liquid path (5). At the same time, the gas in the sampling bottle (2) enters the neutralization tank through valve K8 and the neutralization pipeline (6) to achieve sampling. After sampling is completed, close valve K7, valve K8 and valve K102. S7. Increase the pressure of helium in the backflush gas path (4), open valves K2, V1 and K5, and after the helium is blown out from the gas cylinder (48), it is blown along the backflush gas path (4) to the first three-way connector (41), and then the propellant liquid in the sampling liquid path (5) and neutralization pipeline (6) is blown into the neutralization tank for neutralization. During this process, valve K2 is intermittently closed and opened, repeated multiple times; then valve K2 and valve V1 are closed. S8. Open valve K9. Helium enters vacuum ejector ZK2 through the first backflush branch (7) and is blown into neutralization tank through valve K10. The high-speed helium gas flow in vacuum ejector ZK2 ejects the propellant in the part between the sampling liquid path (5) and the third tee joint (61) of the neutralization pipeline (6) and vacuum ejector ZK2. After S9 and S8 have set the time, close valves K9 and K10, open valve K3 to pressurize, and close valve K3 after pressurization. After S10 and S9 are pressurized and left to stand for a set time, open valves K10 and K9, and vacuum ejector ZK2 performs vacuum ejection. After the set time, open valve K3, and vacuum ejectors ZK1 and ZK2 perform ejection simultaneously. S11. Repeat S9 and S10 multiple times; S12. Close valves K3 and K4. In vacuum ejector mode, first disconnect the connection between the second three-way connector (55) and valve K7, and install the valve plug of valve K7; then disconnect the connection between the third three-way connector (61) and valve K8, install the valve plug of valve K8, and remove the sampling bottle (2). S13. Open valves K3 and K4. Vacuum ejector ZK1 and vacuum ejector ZK2 are in vacuum ejection mode. Disconnect the first tee connector (41) and valve K102. Then install the plug of the first tee connector (41) and valve K102. S14. Close the gas cylinder (48) valve and close all valves.

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