Anti-explosion ammonia decomposition reactor system
By introducing an explosion-proof shell and a nitrogen replacement system into the ammonia decomposition reactor, combined with an online analyzer and a tail gas treatment device, the problem of combustible gas leakage and detection in the ammonia decomposition reactor was solved, achieving a safe and efficient explosion-proof effect.
Patent Information
- Application Number
- CN202422953682.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-02
- Publication Date
- 2025-11-18
- Estimated Expiration
- 2034-12-02
AI Technical Summary
Existing ammonia decomposition reactors pose an explosion risk in terms of combustible gas leakage and detection, and cannot safely and promptly collect and handle the gas, resulting in a high risk of potential explosion accidents.
An explosion-proof ammonia decomposition reactor system was designed, comprising an explosion-proof shell, a nitrogen source, a nitrogen flow regulating valve, a heat exchanger, an electric heating furnace, an online analyzer, and a tail gas treatment device. By replacing and detecting combustible gases with nitrogen, the system achieves automatic detection and disposal, thereby reducing the risk of explosion.
It enables automatic detection and handling of the ammonia decomposition reactor, rapid replacement of combustible gases, reduces the risk of explosion, and ensures the safe operation of the equipment.
Smart Images
Figure CN223555986U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to ammonia decomposition technical field relates to a kind of ammonia decomposition reactor, specifically relates to a kind of ammonia decomposition reactor system with good explosion-proof effect and combustible gas self-detection and disposal. BACKGROUND
[0002] Ammonia decomposition reactor is a kind of chemical reaction device that ammonia is decomposed into nitrogen and hydrogen, and is widely used in chemical fertilizer, petroleum chemical industry, natural gas treatment and other fields.However, ammonia decomposition reactor involves combustible gas, such as hydrogen, ammonia and other in use process, and these combustible gas may cause explosion accident if it meets fire source under certain environment.
[0003] The existing ammonia decomposition reactor and system have some problems in combustible gas explosion-proof in practical application.Firstly, ammonia decomposition reaction involves ammonia, which is easy to corrode pipeline, causing combustible gas leakage, and there is explosion risk, so how to reduce the explosion risk of gas leakage is the key to improve ammonia decomposition safety production.Secondly, there are difficulties in detecting the content of combustible gas on site, and it is not safe and timely to collect and analyze the content of combustible gas on site.Therefore, how to ensure the safe operation of ammonia decomposition reactor and prevent explosion accident is a problem to be solved. SUMMARY
[0004] The utility model aims at providing a kind of ammonia decomposition reactor system with good explosion-proof effect, to the combustible gas leakage of existing ammonia decomposition reactor, cannot safely and timely carry out on-site combustible gas collection and disposal and other problems, can exclude potential explosion risk, prevent explosion accident and ensure the safe operation of device.
[0005] The technical scheme adopted by the utility model to solve its technical problems is:
[0006] An explosion-proof ammonia decomposition reactor system, comprising an ammonia decomposition reactor, characterized in that the ammonia decomposition reactor system further comprises an explosion-proof part and a combustible gas detection and processing part;The explosion-proof part comprises a closed explosion-proof shell, a nitrogen source, a nitrogen flow regulating valve, a heat exchanger and an electric heating furnace, and the gas detection and processing part comprises an online analyzer and a tail gas treatment device;
[0007] The ammonia decomposition reactor is placed in the explosion-proof shell of the explosion-proof part, and the internal space contains combustible gas generated by the ammonia decomposition reactor;Nitrogen inlet and gas vent are provided on the explosion-proof shell, the nitrogen source is connected to the nitrogen inlet after passing through the nitrogen flow regulating valve, the heat exchanger and the electric heating furnace in sequence, nitrogen is filled into the explosion-proof shell from the nitrogen inlet, and nitrogen is discharged from the explosion-proof shell from the gas vent;
[0008] The explosion-proof shell discharges nitrogen gas containing combustible gas to the gas detection processing part; the gas vent is connected to the heat exchanger, and the nitrogen gas containing combustible gas is sent to the tail gas treatment device and the online analyzer of the gas detection processing part after heat exchange, respectively;
[0009] The nitrogen flow regulating valve and the online analyzer are connected to the DCS control system, and the online analyzer is connected to the nitrogen flow regulating valve in cascade control.
[0010] The explosion-proof ammonia decomposition reactor system continuously fills nitrogen into the explosion-proof shell of the explosion-proof part during the reaction process of the ammonia decomposition reactor and discharges it to the gas detection processing part for detection and treatment. The gas detection processing part includes a tail gas treatment device and an online analyzer. The online analyzer automatically samples and analyzes the combustible gas (ammonia and hydrogen) content online, monitors whether the ammonia decomposition device leaks, and outputs the detection results of the online analyzer to the DCS control system to adjust the control module of the nitrogen flow regulating valve and adjust the nitrogen flow through the control module to supplement nitrogen to the interior of the explosion-proof shell and achieve the purpose of rapid replacement. The nitrogen gas containing combustible gas discharged from the explosion-proof shell enters the tail gas treatment device.
[0011] Further, the DCS control system includes a first threshold value. When the hydrogen or ammonia content detected by the online analyzer exceeds the first threshold value, the nitrogen flow regulating valve opening degree is increased. When the hydrogen or ammonia content is lower than the first threshold value, the nitrogen flow regulating valve opening degree is decreased. Preferably, the first threshold value is 0.5% of the volume percentage of hydrogen or ammonia.
[0012] Further, the ammonia decomposition reactor is various forms of reactors known in the prior art, including fixed bed reactors, fluidized bed reactors, and catalytic membrane reactors, such as commonly used fixed bed reactors with tubes.
[0013] Further, the tail gas treatment device is various forms of tail gas treatment devices known in the prior art, including regenerative oxidation furnaces (RTO), regenerative catalytic combustion (RCO) tail gas treatment devices, and ultra-low emission combustion (CEB) tail gas treatment devices. Preferably, the tail gas treatment device is an ultra-low emission combustion (CEB) tail gas treatment device.
[0014] Further, the online analyzer includes an online hydrogen analyzer and an online ammonia analyzer.
[0015] Further, a cooler is arranged in front of the online analyzer.
[0016] Further, the ammonia inlet of the ammonia decomposition reactor is provided with an ammonia valve, the nitrogen source is connected to the ammonia inlet downstream of the ammonia valve through the nitrogen valve; the decomposition gas outlet of the ammonia decomposition reactor is provided with a decomposition gas valve, which is connected to the flare upstream of the discharge valve. Preferably, the nitrogen valve, ammonia valve, decomposition gas valve and discharge valve are automatic shut-off valves connected to the DCS control system.
[0017] Further, the DCS control system comprises a second threshold value, when the hydrogen or ammonia content detected by the online analyzer exceeds the second threshold value, the DCS control system is linked to control the ammonia valve to be closed, the nitrogen valve to be opened, the ammonia decomposition reaction to be closed, the ammonia decomposition reactor to be purged, the decomposition gas valve to be closed and the discharge valve to be opened, so that the purged decomposition gas is sent into the flare to prevent entering the downstream of the reactor.
[0018] Preferably, the second threshold value is 3% of the volume percentage of hydrogen or ammonia.
[0019] Beneficial effects: the explosion-proof ammonia decomposition reactor system can automatically detect and dispose combustible gas, effectively reduce the possibility of explosion caused by leakage of the ammonia decomposition reactor, has good explosion-proof effect, and can safely, efficiently and conveniently monitor the ammonia decomposition device, and reduce the explosion risk caused by leakage. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 It is a structural schematic view of the explosion-proof ammonia decomposition reactor system of the utility model;
[0021] Among them, 1: explosion-proof shell; 2: heat exchanger; 3: tail gas treatment device; 4: online analyzer; 5: cooler; 6: nitrogen flow regulating valve; 7: nitrogen valve; 8: ammonia valve; 9: decomposition gas valve; 10: discharge valve; 11: electric heating furnace; 12: ammonia decomposition reactor. DETAILED DESCRIPTION
[0022] The technical scheme of the utility model will be described clearly and completely in combination with the drawings, obviously, the described embodiment is only one specific embodiment of the utility model, not all the implementation manners. Based on the description of the utility model and the embodiment, all other implementation manners obtained by the person skilled in the art without making creative labor belong to the protection scope of the utility model.
[0023] As Figure 1As shown, the utility model discloses a kind of explosion-proof ammonia decomposition reactor systems, including ammonia decomposition reactor 12, and explosion-proof part and combustible gas detection processing part.The explosion-proof part includes closed explosion-proof shell 1, nitrogen source, nitrogen flow regulating valve 6, heat exchanger 2 and electric heating furnace 11, and the gas detection processing part includes cooler 5, on-line analyzer 4 and tail gas treatment device 3.
[0024] The ammonia decomposition reactor 12 is a tube-type fixed bed ammonia decomposition reactor, located inside the explosion-proof shell 1.The ammonia decomposition reactor 12 includes a catalyst fixed bed, ammonia gas enters the reactor through the ammonia gas inlet, and the gas reacts through the catalyst bed, and the decomposition gas flows out through the decomposition gas outlet.The ammonia gas inlet is provided with an ammonia valve 8, and the decomposition gas outlet is provided with a decomposition gas valve 9.The explosion-proof shell 1 completely contains the ammonia decomposition reactor 12 and is firmly welded with steel plates, and the welds are polished flat.The reactor inlet and outlet, nitrogen inlet and gas vent are arranged on different sides of the explosion-proof shell 1, and the ammonia gas inlet and decomposition gas outlet of the ammonia decomposition reactor 12 pass through the reactor inlet and outlet to enter and exit the explosion-proof shell 1, and each connection port is firmly welded with polished welds.Once the ammonia decomposition reactor leaks, combustible gases such as hydrogen and ammonia will enter the explosion-proof shell 1, preventing further leakage.In the explosion-proof part, the explosion-proof shell 1 includes a nitrogen inlet and a gas vent, the nitrogen inlet is connected to the nitrogen source, and the nitrogen is sequentially filled into the explosion-proof shell 1 through the nitrogen flow regulating valve 6, the heat exchanger 2 and the electric heating furnace 11, the combustible gas leaked from the ammonia decomposition reactor 12 is carried by the nitrogen in the explosion-proof shell 1 and discharged from the gas vent, the nitrogen is heated by the heat exchanger 2 with the gas discharged from the explosion-proof shell 1, and the electric heating furnace 11 is heated to ensure that the nitrogen entering will not cause the material in the ammonia decomposition reactor 12 to be suddenly cooled and the reaction temperature to drop.
[0025] The nitrogen containing combustible gas discharged from the explosion-proof shell 1 is sent to the gas detection processing part.The nitrogen containing combustible gas enters the heat exchanger 2 from the gas vent, is heated with the nitrogen after passing through the heat exchanger 2, and is sent to the tail gas treatment device 3 for treatment, and the tail gas treatment device 3 is an ultra-low emission combustion (CEB) tail gas treatment device.To analyze and detect the content of combustible gas in the gas, the sampling port after the heat exchanger 2 is connected to the on-line analyzer 4 through the cooler 5.
[0026] The on-line analyzer 4 includes an on-line hydrogen analyzer and an on-line ammonia analyzer, such as a PDM400 on-line hydrogen analyzer and a SGA-500B-NH3 on-line ammonia analyzer.The on-line analyzer 4 is connected to the DCS control system, and the nitrogen flow regulating valve 6 of the explosion-proof part is also connected to the DCS control system, and the on-line analyzer 4 and the nitrogen flow regulating valve 6 are connected in series for control.
[0027] In the case of a serious leak in the ammonia decomposition reactor 12, in order to interrupt the reaction in time, a nitrogen valve 7 and a discharge valve 10 are arranged in the ammonia decomposition reactor 12, the nitrogen source is connected to the ammonia gas inlet of the ammonia decomposition reactor 12 downstream of the ammonia gas valve 8 through the nitrogen valve 7, and the decomposition gas outlet is connected to the flare upstream of the decomposition gas valve 9 through the discharge valve 10. The nitrogen valve 7, the ammonia gas valve 8, the decomposition gas valve 9 and the discharge valve 10 are all automatic shut-off valves, and the actuators thereof are connected to the DCS control system.
[0028] The DCS control system comprises a first threshold value and a second threshold value, which are 0.5% and 3% of the volume percentage of hydrogen or ammonia respectively. When the hydrogen or ammonia content detected by the online analyzer 4 exceeds the first threshold value, the opening degree of the nitrogen flow regulating valve 6 is increased under linkage control, and when the hydrogen or ammonia content is lower than the first threshold value, the opening degree of the nitrogen flow regulating valve 6 is decreased. When the hydrogen or ammonia content detected by the online analyzer exceeds the second threshold value, the DCS control system linkage controls to close the ammonia shut-off valve 8, open the nitrogen shut-off valve 7, close the ammonia decomposition reaction, and purge the ammonia decomposition reactor 12, while closing the decomposition gas shut-off valve 9 and opening the discharge shut-off valve 10, so that the purged decomposition gas is sent to the flare to prevent entering the downstream of the reactor.
[0029] According to the explosion-proof ammonia decomposition reactor system of the utility model, the ammonia decomposition reactor 12 is completely contained in the explosion-proof shell 1, the space between the ammonia decomposition reactor 12 and the explosion-proof shell 1 is replaced by N2 after adjusting the flow by the nitrogen flow regulating valve 6 and heating by the electric heating furnace 11, and the inside air of the explosion-proof shell 1 is continuously filled with nitrogen, the ammonia decomposition reactor 12 may produce combustible gases such as hydrogen and ammonia during use, and these combustible gases may cause an explosion accident if they meet a fire source under a specific environment. By continuously replacing the gas between the ammonia decomposition reactor 12 and the explosion-proof shell 1 with N2, the nitrogen gas for diluting the combustible gas (ammonia and hydrogen) in the explosion-proof shell 1 enters the tail gas treatment device 3 through the gas vent, which can effectively reduce the explosion risk of the ammonia decomposition device and achieve good explosion-proof effect.
[0030] Obviously, the above embodiments are only examples for clearly illustrating, and are not limited to the embodiments of the utility model. For ordinary skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to exhaust all the embodiments. The changes or variations derived therefrom are still within the protection scope of the utility model.
Claims
1. An explosion-proof ammonia decomposition reactor system, comprising an ammonia decomposition reactor (12), characterized in that, The ammonia decomposition reactor system also includes an explosion-proof section and a combustible gas detection and processing section; the explosion-proof section includes a closed explosion-proof shell (1), a nitrogen source, a nitrogen flow regulating valve (6), a heat exchanger (2) and an electric heating furnace (11); the gas detection and processing section includes an online analyzer (4) and a tail gas treatment device (3). The ammonia decomposition reactor (12) is placed inside the explosion-proof housing (1) of the explosion-proof section, and its internal space contains the combustible gas generated by the ammonia decomposition reactor (12); the explosion-proof housing (1) is provided with a nitrogen inlet and a gas vent. The nitrogen source is connected to the heat exchanger (2) and the electric heating furnace (11) in sequence through the nitrogen flow regulating valve (6), and then connected to the nitrogen inlet. Nitrogen is filled into the explosion-proof housing (1) through the nitrogen inlet and discharged from the explosion-proof housing (1) through the gas vent. The nitrogen gas containing combustible gas discharged from the explosion-proof housing (1) is sent to the gas detection and processing unit; the gas vent is connected to the heat exchanger (2), and the nitrogen gas containing combustible gas is sent to the tail gas treatment device (3) and the online analyzer (4) after heat exchange. The nitrogen flow regulating valve (6) and the online analyzer (4) are connected to the DCS control system, and the online analyzer (4) and the nitrogen flow regulating valve (6) are connected in cascade control.
2. The explosion-proof ammonia decomposition reactor system according to claim 1, characterized in that, The DCS control system includes a first threshold. When the hydrogen or ammonia content detected by the online analyzer (4) exceeds the first threshold, the opening of the nitrogen flow regulating valve (6) is increased in linkage control. When the hydrogen or ammonia content is lower than the first threshold, the opening of the nitrogen flow regulating valve (6) is decreased in linkage control.
3. The explosion-proof ammonia decomposition reactor system according to claim 2, characterized in that, The first threshold is a hydrogen or ammonia volume percentage of 0.5%.
4. The explosion-proof ammonia decomposition reactor system according to claim 1, characterized in that, The ammonia decomposition reactor (12) is a tubular fixed-bed reactor.
5. The explosion-proof ammonia decomposition reactor system according to claim 1, characterized in that, The exhaust gas treatment device (3) is an ultra-low emission combustion exhaust gas treatment device, a regenerative oxidizer, or a regenerative catalytic combustion exhaust gas treatment device.
6. The explosion-proof ammonia decomposition reactor system according to claim 1, characterized in that, The online analyzer (4) is an online hydrogen analyzer and an online ammonia analyzer, and a cooler (5) is installed in front of the online analyzer (4).
7. The explosion-proof ammonia decomposition reactor system according to claim 1, characterized in that, The ammonia inlet of the ammonia decomposition reactor (12) is provided with an ammonia valve (8), and the nitrogen source is connected to the ammonia inlet downstream of the ammonia valve (8) via a nitrogen valve (7); the decomposition gas outlet of the ammonia decomposition reactor (12) is provided with a decomposition gas valve (9), and the decomposition gas valve (9) is connected to the flare upstream via a discharge valve (10).
8. The explosion-proof ammonia decomposition reactor system according to claim 7, characterized in that, The nitrogen valve (7), ammonia valve (8), decomposition gas valve (9) and discharge valve (10) are automatic shut-off valves connected to the DCS control system.
9. The explosion-proof ammonia decomposition reactor system according to claim 8, characterized in that, The DCS control system includes a second threshold. When the hydrogen or ammonia content detected by the online analyzer (4) exceeds the second threshold, the DCS control system will control the ammonia valve (8) to close, the nitrogen valve (7) to open, the decomposition gas valve (9) to close, and the discharge valve (10) to open.
10. The explosion-proof ammonia decomposition reactor system according to claim 9, characterized in that, The second threshold is a hydrogen or ammonia volume percentage of 3%.