Liquid ammonia closed sampling system
By introducing nitrogen purge and safety valve pressure relief functions into the liquid ammonia sampling system, the safety hazards of residual liquid ammonia gasification and expansion after sampling are solved, and a safe and reliable sampling operation is achieved.
Patent Information
- Application Number
- CN202421391226.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-18
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-06-18
AI Technical Summary
The existing liquid ammonia sampling system lacks automatic pressure relief and pipeline purge functions, which leads to gasification and expansion of residual liquid ammonia after sampling, posing safety hazards.
A liquid ammonia sealed sampling system is designed, including a nitrogen purge pipeline and a pressure relief pipeline with a safety valve. After sampling, the pipeline is purged through a nitrogen purge pipeline, and the pressure is automatically released under the starting pressure of the safety valve to eliminate safety hazards.
The safety of the sampling system is improved, the explosion risk caused by liquid ammonia residue and gasification expansion is avoided, and the safety and reliability of operations are ensured.
Smart Images
Figure CN223139035U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of liquid ammonia sampling, and particularly relates to a liquid ammonia closed sampling system. Background Art
[0002] Liquid ammonia, also known as anhydrous liquid ammonia, is a colorless and transparent liquid with a strong pungent odor. As an important chemical raw material, for the convenience of transportation and storage, gaseous ammonia is usually pressurized or cooled to obtain liquid ammonia. Ammonia is highly soluble in water and forms ammonium ions NH4 + and hydroxide ions OH - , forming an alkaline solution. Liquid ammonia is widely used in industry, is corrosive and volatile, so the incidence of chemical accidents is very high.
[0003] In order to test the impurity components in liquid ammonia, it is usually necessary to sample the liquid ammonia and then conduct tests to determine whether the liquid ammonia can be used. Since liquid ammonia is a volatile cryogenic liquid, conventional sampling cannot be carried out, and closed sampling is required.
[0004] However, the current conventional closed sampling system does not have an automatic pressure relief function and a pipeline purging function. The liquid ammonia remaining in the pipeline after sampling cannot be discharged. When the cryogenic liquid ammonia encounters heat, it will immediately vaporize, and the volume after vaporization can expand by 850 times, with a huge expansion amount. The liquid ammonia remaining in the sampling pipeline gradually vaporizes when slowly absorbing heat, the pipeline pressure rises, there are potential safety hazards, and when the pressure rises and cannot be discharged, an explosion accident will occur when the internal pressure of the pipe exceeds the bearing pressure of the pipeline. Content of the Utility Model
[0005] In order to solve the above technical problems, the utility model designs a liquid ammonia closed sampling system, adds a nitrogen purging pipeline. After the sampling is completed, nitrogen is used to displace and purge each pipeline of the sampling system to avoid liquid ammonia remaining in the sampling system. At the same time, a pressure relief pipeline with a safety valve is set. If the displacement is insufficient or the sampling valve leaks, when the liquid ammonia in the pipeline vaporizes and reaches the safety valve opening pressure, the safety valve opens to automatically relieve pressure and eliminate potential safety hazards.
[0006] In order to achieve the above technical purpose, the utility model is realized through the following technical solutions: A liquid ammonia closed sampling system includes a liquid ammonia delivery pipeline and a sampling cylinder;
[0007] The liquid outlet interface of the liquid ammonia delivery pipeline is connected to the liquid inlet interface of the sampling pipeline, and the liquid outlet interface of the sampling pipeline is connected to the liquid inlet pipe of the sampling cylinder through a quick connector;
[0008] The outlet end of a nitrogen purge pipeline is connected to the sampling pipeline near the liquid inlet interface. A first stop valve is provided at the inlet end of the nitrogen purge pipeline, and a second stop valve is provided on the sampling pipeline in front of the outlet end of the nitrogen purge pipeline. The sampling pipeline behind the outlet end of the nitrogen purge pipeline is also connected to the inlet end of a pressure relief pipeline equipped with a safety valve. A three-way valve is provided on the pipeline between the liquid outlet interface of the sampling pipeline and the inlet end of the pressure relief pipeline. The third interface of the three-way valve is connected to the inlet end of a purge and replacement connection pipeline. The outlet ends of the pressure relief pipeline and the purge and replacement connection pipeline are jointly connected to an exhaust gas recovery pipeline.
[0009] A connecting pipe is connected to the inlet end of the purge and replacement connection pipeline. The other end of the connecting pipe is connected to the liquid outlet pipe of a sampling cylinder through a quick connector. The quick connectors at the liquid outlet interface of the sampling pipeline and on the connecting pipe are male and female connectors that can be cooperatively connected.
[0010] Preferably, a third stop valve is further installed on the sampling pipeline between the three-way valve and the inlet end of the pressure relief pipeline. A fourth stop valve is installed on the purge and replacement connection pipeline behind the connecting pipe. A fifth stop valve and a sixth stop valve are respectively installed on the liquid inlet pipe and the liquid outlet pipe of the sampling cylinder.
[0011] Preferably, a first check valve is further installed behind the first stop valve on the nitrogen purge pipeline, and a second check valve is further installed behind the fourth stop valve on the purge and replacement connection pipeline.
[0012] Preferably, the set pressure of the safety valve is 2.5 MPa.
[0013] Preferably, a section of the pipeline after the three-way valve of the sampling pipeline is a metal hose, and the connecting pipe is also a metal hose, which is convenient for the disassembly and connection of the quick connectors.
[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:
[0015] First, a nitrogen purge pipeline is connected to the sampling pipeline, increasing the nitrogen purge function. After the sampling is completed, nitrogen is used to purge and replace each pipeline of the sampling system to avoid the residual liquid ammonia in the sampling system.
[0016] Second, a pressure relief pipeline equipped with a safety valve is connected to the sampling pipeline. If the nitrogen purge is insufficient or the valve of the sampling pipeline leaks, when the liquid ammonia in the pipeline vaporizes and reaches the set pressure of the safety valve, the safety valve opens and the pipeline automatically relieves pressure to eliminate potential safety hazards.
[0017] Thirdly, the liquid outlet interface of the sampling pipeline is connected to the liquid inlet pipe of the sampling cylinder through a quick connector. A connecting pipe is connected to the air inlet end of the purging and replacing connecting pipeline, and the other end of the connecting pipe is connected to the liquid outlet pipe of the sampling cylinder through a quick connector; moreover, the quick connectors at the liquid outlet interface of the sampling pipeline and on the connecting pipe are male and female heads that can be cooperatively connected. After the sampling is completed, the two quick connectors are unplugged, and the quick connector at the liquid outlet interface of the sampling pipeline is quickly connected to the quick connector on the connecting pipe to instantaneously block the two pipelines, avoiding the leakage of liquid ammonia, achieving smooth connection of the sampling pipeline, and facilitating the subsequent complete purging of the sampling system. Brief Description of the Drawings
[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below.
[0019] Figure 1 It is a schematic structural diagram of the sampling system in Embodiment 1;
[0020] Figure 2 It is a schematic connection structure diagram of the sampling system in the purging and replacing state in Embodiment 1.
[0021] In the drawings, the structural names represented by each reference numeral are as follows:
[0022] L1 - Liquid ammonia transmission pipeline, L2 - Sampling pipeline, L3 - Nitrogen purging pipeline, L4 - Purging and replacing connecting pipeline, L5 - Waste gas recovery pipeline, L6 - Pressure relief pipeline.
[0023] 1 - First stop valve, 2 - Second stop valve, 3 - Third stop valve, 4 - Fourth stop valve, 5 - Fifth stop valve, 6 - Sixth stop valve, 7 - Three-way valve, 8 - First check valve, 9 - Second check valve, 10 - Safety valve, 11 - Quick connector, 12 - Connecting pipe, 20 - Sampling cylinder. Detailed Embodiments
[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.
[0025] Embodiment 1
[0026] In order to solve the problem that the current conventional closed sampling system does not have an automatic pressure relief function and a pipeline purging function, resulting in potential safety hazards in the pipeline after sampling. Refer to Figure 1 as shown, a liquid ammonia closed sampling system is designed, including a liquid ammonia transmission pipeline L1 and a sampling cylinder 20;
[0027] The liquid outlet interface of the liquid ammonia delivery pipeline L1 is connected to the liquid inlet interface of the sampling pipeline L2, and the liquid outlet interface of the sampling pipeline L2 is connected to the liquid inlet pipe of the sampling cylinder 20 through a quick-insert connector 11;
[0028] The sampling line L2 is connected to the outlet end of the nitrogen purge line L3 near the liquid inlet interface, and nitrogen can be introduced into the sampling line L2 for purging. The inlet end of the nitrogen purge line L3 is provided with a first stop valve 1 to control the opening and closing of the nitrogen purge. The sampling line L2 in front of the outlet end of the nitrogen purge line L3 is provided with a second stop valve 2 to control the opening and closing of the sampling line L2. The sampling line L2 after the outlet end of the nitrogen purge line L3 is also connected to the inlet end of the pressure relief line L6 with a safety valve 10.
[0029] A three-way valve 7 is provided on the pipeline between the liquid outlet interface of the sampling pipeline L2 and the air inlet end of the pressure relief pipeline L6. The third interface of the three-way valve 7 is connected to the air inlet end of the purge replacement connecting pipeline L4. By adjusting the opening and closing of the three-way valve 7, the on-off of the sampling pipeline L2 and the purge replacement connecting pipeline L4 can be controlled, so as to facilitate the adjustment of the conversion of the purge state or the sampling state; the air outlet end of the pressure relief pipeline L6 and the air outlet end of the purge replacement connecting pipeline L4 are connected to the exhaust gas recovery pipeline L5, and the exhaust gas is output to the exhaust gas recovery pipeline L5 for treatment;
[0030] At the same time, when the sampling system is not fully replaced or the second stop valve 2 of the sampling pipeline L2 leaks, the tripping pressure of the safety valve 10 is 2.5MPa. When the liquid ammonia in the pipeline is gasified and reaches the tripping pressure of the safety valve 10 of the pressure relief pipeline L6, the safety valve 10 opens and the pipeline automatically releases pressure to eliminate safety hazards.
[0031] The air inlet end of the purge replacement connecting pipeline L4 is connected with a connecting pipe 12, and the other end of the connecting pipe 12 is connected to the liquid outlet pipe of the sampling cylinder 20 through a quick-connect connector 11;
[0032] The quick-insert connector 11 at the liquid outlet interface of the sampling pipeline L2 and the quick-insert connector 11 on the connecting pipe 12 are a male and female plug set that can be matched and connected.
[0033] In order to facilitate the disassembly and connection of the quick-connect connector 11, the section of the sampling pipeline L2 after the three-way valve 7 is made into a metal hose, and the connecting pipe 12 is also made into a metal hose.
[0034] When connected with the sampling cylinder 20, the liquid inlet pipe and the liquid outlet pipe on the sampling cylinder 20 are respectively connected to the male and female heads of the quick-insert connector 11 at the liquid outlet interface of the sampling line L2 and the quick-insert connector 11 at the air inlet of the connecting pipe 12. Quick connection is achieved while avoiding connection errors.
[0035] When performing a replacement purge on the sampling system, refer to Figure 2As shown, quickly connect the quick connector 11 at the liquid outlet interface of the sampling pipeline L2 with the quick connector 11 on the connecting pipe 12, that is, connect the end of the sampling pipeline L2 with the purge and replacement connection pipeline L4, and fully conduct nitrogen purging and replacement of all pipelines.
[0036] To further ensure the sealing of each pipeline, a third stop valve 3 is also installed on the sampling pipeline L2 between the three-way valve 7 and the inlet end of the pressure relief pipeline L6 to control the flow rate. A fourth stop valve 4 is installed on the purge and replacement connection pipeline L4 after the connecting pipe 12. A fifth stop valve 5 and a sixth stop valve 6 are respectively installed on the liquid inlet pipe and the liquid outlet pipe of the sampling cylinder 20.
[0037] To prevent liquid ammonia from flowing into the nitrogen purge pipeline L3, a first check valve 8 is installed after the first stop valve 1 on the nitrogen purge pipeline L3. At the same time, to prevent waste gas from flowing into the sampling pipeline L2, a second check valve 9 is installed after the fourth stop valve 4 on the purge and replacement connection pipeline L4.
[0038] The sampling operation process of the sampling system is as follows:
[0039] 1. Weigh a 1L sampling cylinder 20, and its weight is 3.5 kg;
[0040] 2. In the initial state of the sampling system, the quick connector 11 at the liquid outlet interface of the sampling pipeline L2 and the quick connector 11 on the connecting pipe 12 are in a connected state, that is, the end of the sampling pipeline L2 is connected to the purge and replacement connection pipeline L4. Before sampling, open the first stop valve 1, the third stop valve 3, and the fourth stop valve 4, adjust the three-way valve 7 to be in a state of being connected to the purge and replacement connection pipeline L4 (i.e., the replacement position), purge the sampling pipeline L2 with nitrogen. After 2 minutes, adjust the three-way valve 7 to be connected to the sampling pipeline L2 (i.e., the sampling position), continue to purge the metal hose for 1 minute, and then place the three-way valve 7 upward to the replacement position;
[0041] 3. Close the first stop valve 1, the third stop valve 3, and the fourth stop valve 4, and connect the male and female heads of the liquid inlet pipe and the liquid outlet pipe on the sampling cylinder 20 to the quick connector 11 at the liquid outlet interface of the sampling pipeline L2 and the quick connector 11 at the air inlet of the connecting pipe 12 respectively;
[0042] 4. Open the second stop valve 2, the third stop valve 3, and the fourth stop valve 4, and introduce liquid ammonia into the pipeline. After 2 minutes, ice forms outside the sampling pipeline L2, indicating that the sampling pipeline L2 has been fully purged;
[0043] 5. Place the three-way valve 7 downward to the sampling position, open the fifth stop valve 5 and the sixth stop valve 6 on the liquid inlet pipe and the liquid outlet pipe of the sampling cylinder 20, and introduce liquid ammonia into the sampling cylinder 20 for replacement sampling;
[0044] 6. After 1 minute, the sampling cylinder 20 and the metal hose were all frozen, and the sampling was completed. The fifth stop valve 5 and the sixth stop valve 6 were closed in sequence. The three-way valve 7 was placed upward in the replacement position, the second stop valve 2 was closed, the two quick connectors 11 were disassembled, and the sampling cylinder 20 was removed. The weight of the liquid ammonia cylinder was weighed as 4.2 kg, and the sampling amount was approximately 0.7 kg, meeting the sampling requirements.
[0045] 7. Open the first stop valve 1 and introduce nitrogen to replace the liquid ammonia in the sampling pipeline L2. All pipelines were replaced within 2 minutes.
[0046] 8. Close the first stop valve 1, connect the quick connector 11 at the liquid outlet interface of the sampling pipeline L2 with the quick connector 11 on the connecting pipe 12, then open the first stop valve 1, and place the three-way valve 7 downward in the sampling position to purge the metal hose for 1 minute. The pipeline was replaced clean.
[0047] 9. Place the three-way valve 7 upward in the replacement position, and close the first stop valve 1, the third stop valve 3, and the fourth stop valve 4.
[0048] The preferred embodiments of the present utility model disclosed above are only used to help illustrate the present utility model. The preferred embodiments do not describe all the details in detail, nor do they limit the present utility model to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification.
Claims
1. A liquid ammonia closed sampling system, comprising a liquid ammonia delivery pipeline (L1) and a sampling cylinder (20), characterized in that: The liquid outlet interface of the liquid ammonia delivery pipeline (L1) is connected to the liquid inlet interface of the sampling pipeline (L2), and the liquid outlet interface of the sampling pipeline (L2) is connected to the liquid inlet pipe of the sampling cylinder (20) through a quick connector (11); The nitrogen purge pipeline (L3) outlet end is connected to the sampling pipeline (L2) near the liquid inlet interface. A first stop valve (1) is provided at the inlet end of the nitrogen purge pipeline (L3), and a second stop valve (2) is provided on the sampling pipeline (L2) in front of the outlet end of the nitrogen purge pipeline (L3). The sampling pipeline (L2) behind the outlet end of the nitrogen purge pipeline (L3) is also connected to the inlet end of a pressure relief pipeline (L6) with a safety valve (10). A three-way valve (7) is provided on the pipeline between the liquid outlet interface of the sampling pipeline (L2) and the inlet end of the pressure relief pipeline (L6), and the third interface of the three-way valve (7) is connected to the inlet end of a purge and replacement connection pipeline (L4). The outlet end of the pressure relief pipeline (L6) and the outlet end of the purge and replacement connection pipeline (L4) are jointly connected to an exhaust gas recovery pipeline (L5); A connecting pipe (12) is connected to the inlet end of the purge and replacement connection pipeline (L4), and the other end of the connecting pipe (12) is connected to the liquid outlet pipe of the sampling cylinder (20) through a quick connector (11). The quick connectors (11) at the liquid outlet interface of the sampling pipeline (L2) and on the connecting pipe (12) are male and female heads that can be fitted and connected.
2. The liquid ammonia closed sampling system according to claim 1, wherein A third stop valve (3) is also installed on the sampling pipeline (L2) between the three-way valve (7) and the inlet end of the pressure relief pipeline (L6), a fourth stop valve (4) is installed on the purge and replacement connection pipeline (L4) behind the connecting pipe (12), and a fifth stop valve (5) and a sixth stop valve (6) are respectively installed on the liquid inlet pipe and the liquid outlet pipe of the sampling cylinder (20).
3. The liquid ammonia closed sampling system according to claim 2, wherein A first check valve (8) is also installed behind the first stop valve (1) on the nitrogen purge pipeline (L3), and a second check valve (9) is installed behind the fourth stop valve (4) on the purge and replacement connection pipeline (L4).
4. The liquid ammonia closed sampling system according to claim 1, wherein The set pressure of the safety valve (10) is 2.5 MPa.
5. The liquid ammonia closed sampling system according to claim 1, wherein The section of the pipeline after the three-way valve (7) of the sampling pipeline (L2) is a metal hose, and the connecting pipe (12) is also a metal hose.