Safe reaction kettle for nitration reaction

Abstract

The invention relates to the technical field of reaction kettles, in particular to a safe reaction kettle for nitration reaction, which comprises a kettle body, a premixing mechanism, a stirring mechanism, a temperature control mechanism, a waste gas treatment mechanism and a protection mechanism, the premixing mechanism comprises a raw material mixing tank and a filter which are connected with the kettle body; the stirring mechanism comprises a push type stirring blade and an anchor type stirring blade; the temperature control mechanism comprises a jacket arranged outside the kettle body and an inner coil pipe arranged on the inner side wall of the kettle body, heat conduction oil is introduced into the jacket, and cooling liquid is introduced into the inner coil pipe; the waste gas treatment mechanism comprises a condensing tower, an adsorption tower and an exhaust funnel which are communicated in sequence; the stirring mechanism adopts a combined structure of push type stirring blades and anchor type stirring blades, so that the raw material mixing uniformity is improved by more than 30%, the problem of non-uniform local mixing in traditional stirring is solved, and the raw material mixing efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of reaction vessel technology, and in particular to a safe reaction vessel for nitration reactions. Background Technology

[0002] Nitration is a key reaction in the field of organic chemistry, widely used in the production of pharmaceutical intermediates, dyes, explosives, and pesticides. Its core is the chemical reaction process of introducing a nitro group (-NO2) into the molecule of an organic compound. Because nitration typically uses highly corrosive media such as nitric acid or mixed acids (a mixture of nitric and sulfuric acid), and the reaction process is accompanied by intense exothermic reactions, extremely high requirements are placed on the mixing efficiency, temperature control precision, safety protection capabilities, and environmental treatment standards of the reaction equipment (i.e., the nitration reactor).

[0003] Currently, traditional nitration reactors on the market still face the following pressing technical problems in practical industrial applications: 1. Uneven mixing of raw materials leads to low reaction efficiency. Traditional nitration reactors often use single-blade agitators (such as straight impellers or turbine impellers). Due to the limitations of the reactor structure, "dead zones" easily form on the reactor walls and bottom, resulting in insufficient mixing of nitration raw materials (such as benzene compounds) and oxidants (such as nitric acid). Excessively high raw material concentrations in some areas can trigger violent localized reactions, while excessively low concentrations in others prolong the reaction induction period. The overall reaction time can reach 4-6 hours, and the purity of the reaction products fluctuates significantly (purity deviation can reach 5%-8%), making it difficult to meet the production requirements of high-precision chemical products.

[0004] 2. Poor temperature control accuracy and significant safety risks: Nitration is a strongly exothermic reaction, with each mole of nitro group releasing 120-180 kJ of heat. If this heat cannot be removed in time, it can easily lead to a sudden temperature rise inside the reactor (i.e., "runaway temperature"), causing nitric acid decomposition, carbonization of organic materials, and even explosions. Traditional reactors mostly rely on a single-layer jacket to circulate heat transfer oil or coolant for temperature control. The heat transfer efficiency between the jacket and the materials inside the reactor is low, and temperature sensors are only installed in a single area of ​​the reactor body, making it impossible to monitor temperature differences between different areas in real time. The temperature control accuracy can only be maintained within ±5℃, making it difficult to cope with sudden temperature fluctuations during the reaction process.

[0005] 3. Incomplete waste gas treatment leads to severe environmental pollution. During the nitration reaction, the volatility of nitric acid and partial decomposition of organic materials produce a mixed waste gas containing nitrogen oxides (NOx) and volatile organic compounds (VOCs). Traditional reactors typically treat the waste gas only with a simple water washing tower. Water washing can only remove a small amount of NOx, and the removal rate of VOCs is less than 30%. As a result, the direct emission of waste gas does not meet the requirements of the "Emission Standard of Pollutants for Petrochemical Industry" (GB 31571-2015) for NOx ≤ 200 mg / m³ and VOCs ≤ 60 mg / m³, causing not only air pollution but also posing a threat to the health of operators.

[0006] 4. The safety protection system is inadequate, and the ability to resist risks is weak. The safety protection of traditional nitration reactors mostly relies on a single pressure relief valve, without forming a multi-level protection mechanism. When the pressure inside the reactor rises sharply due to abnormal reaction (such as a sudden temperature rise causing material vaporization), if the pressure relief valve cannot open in time due to impurities or mechanical failure, the pressure inside the reactor will quickly exceed the rated pressure value, which can easily cause the reactor body to crack or even explode. In addition, the inner wall of the reactor is mostly made of ordinary stainless steel, which will be severely corroded by long-term contact with highly corrosive mixed acids, resulting in thinning of the reactor wall and a decrease in strength, further increasing the safety hazards of equipment operation.

[0007] 5. Lack of raw material pretreatment affects reaction stability. Industrial-grade nitration feedstocks often contain small amounts of solid impurities (such as catalyst particles and dust remaining from the raw material synthesis process). Traditional reactors do not have a raw material pretreatment stage. When impurities enter the reactor directly, they will adhere to the surface of the stirring blades or temperature control components, reducing mass transfer efficiency. On the other hand, they may react with nitric acid to generate other unstable impurities, which not only affect the purity of the final product but may also induce local reaction runaway.

[0008] In summary, given the problems of low mixing efficiency, poor temperature control accuracy, insufficient safety protection, and poor environmental performance of traditional nitration reactors, there is an urgent need to design a nitration reactor that integrates efficient mixing, precise temperature control, multi-level safety protection, and environmentally friendly waste gas treatment functions to meet the needs of the modern organic chemical industry for safe, efficient, and green production. Summary of the Invention

[0009] In view of this, the purpose of this invention is to provide a safe reaction vessel for nitration reactions to solve the problem of uneven mixing in traditional stirring.

[0010] To achieve the above objectives, the present invention provides a safe reaction vessel for nitration reactions, comprising: a vessel body, a premixing mechanism, a stirring mechanism, a temperature control mechanism, a waste gas treatment mechanism, and a protective mechanism. The vessel body has a feed inlet and an oxidant addition inlet at the top and a discharge outlet at the bottom. The premixing mechanism includes a raw material mixing tank and a filter connected to the vessel body. The stirring mechanism includes propeller-type stirring blades and anchor-type stirring blades. The temperature control mechanism includes a jacket disposed outside the vessel body and an inner coil disposed on the inner side wall of the vessel body. Heat transfer oil is circulated in the jacket, and coolant is circulated in the inner coil. A temperature sensor is disposed inside the vessel body and is electrically connected to an external temperature controller. The waste gas treatment mechanism includes a condenser tower, an adsorption tower, and an exhaust stack connected in sequence. The protective mechanism includes a pressure sensor and an emergency pressure relief valve. The emergency pressure relief valve is electrically connected to the pressure sensor, which is disposed inside the vessel body. The emergency pressure relief valve is disposed at a pressure relief port at the top of the vessel body.

[0011] Preferably, the stirring mechanism further includes a stirring motor and a stirring shaft disposed at the output end of the stirring motor. The propulsion stirring blade is disposed along the axial direction of the stirring shaft, and the anchor stirring blade is disposed at the bottom of the stirring shaft. The two sides of the anchor stirring blade are fitted with the inner wall of the vessel with a clearance of 3-8 mm.

[0012] Preferably, the propulsion stirring blade is provided with a plurality of guide holes evenly distributed on it, and the diameter of the guide holes is 5-15mm.

[0013] Preferably, the jacket is provided with a heat transfer oil inlet and a heat transfer oil outlet, the heat transfer oil inlet is connected to a first circulation pump, the inner coil is provided with a coolant inlet and a coolant outlet, the coolant inlet is connected to a second circulation pump, and the external temperature controller is electrically connected to the first circulation pump and the second circulation pump respectively.

[0014] Preferably, the raw material mixing tank is connected to the inlet of the vessel body through a feed pipe, and the feed pipe is also equipped with a feed valve. The filter is located between the raw material mixing tank and the inlet. An auxiliary stirring paddle is provided inside the raw material mixing tank, and the auxiliary stirring paddle is driven by an auxiliary motor.

[0015] Preferably, the protective mechanism further includes an explosion-proof port disposed on the top of the vessel body, wherein an explosion-proof membrane is fixedly installed inside the explosion-proof port, and the burst pressure value of the explosion-proof membrane is higher than the opening pressure value of the emergency pressure relief valve and lower than the rated pressure bearing value of the vessel body.

[0016] Preferably, the condensation tower is connected to the exhaust port at the top of the vessel via a pipe, the condensation tower is equipped with a condensation coil, and the adsorption tower is filled with activated carbon adsorbent.

[0017] Preferably, at least two temperature sensors are provided, located in the upper and lower half of the interior of the vessel body, respectively.

[0018] Preferably, the inner wall of the vessel is coated with a corrosion-resistant coating, which is a polytetrafluoroethylene coating or a ceramic coating, with a coating thickness of 0.1-0.3 mm. The outer wall of the jacket is also provided with a heat insulation layer, which is a rock wool insulation layer or a polyurethane insulation layer, with a thickness of 20-50 mm.

[0019] Preferably, an adjustment assembly is further provided between the upper propeller-type stirring blade and the periphery of the stirring shaft. The adjustment assembly includes an adjustment plate fixedly installed near the top of the stirring shaft and a fixing ring located below the adjustment plate. The inner sidewall of the fixing ring is fixedly installed on the stirring shaft. Movable shafts are rotatably installed on both sides of the periphery of the fixing ring. Fixed plates are fixedly connected to the disjoint ends of the two movable shafts. The disjoint ends of the two fixed plates are respectively fixedly connected to the two propeller-type stirring blades. Connecting seats are fixedly installed at both ends of the fixed plates near the stirring shaft. An adapter is fixedly installed above the connecting seat. A lead screw is fixedly installed on the top of the adapter. An anti-slip sleeve is fixedly connected to the top of the lead screw through the adjustment plate. The lead screw is threadedly connected to the adjustment plate.

[0020] The beneficial effects of this invention are: The mixing mechanism employs a combination of propeller-type and anchor-type stirring blades, improving the uniformity of raw material mixing by over 30%, solving the problem of uneven mixing in certain areas in traditional stirring, and enhancing raw material mixing efficiency. The premixing function of the premixing mechanism effectively shortens the reaction induction period, reducing the overall reaction time by 20%-25% compared to traditional reactors, making it suitable for large-scale industrial production. Heat transfer oil is introduced through the jacket to achieve initial temperature rise and basic temperature control during the reaction process. Coolant is then introduced through the internal coil to cope with the sudden temperature rise caused by exothermic reactions. A temperature sensor is linked to an external temperature controller; when the temperature exceeds a preset threshold, the heat transfer oil temperature and coolant flow rate are automatically adjusted, improving temperature control accuracy to ±1℃ and avoiding safety risks caused by temperature runaway. The exhaust gas treatment mechanism ensures that emissions meet environmental standards, solving the problem of direct discharge pollution from traditional nitration reactions and meeting environmental requirements. The protective mechanism effectively handles abnormal pressure, preventing the risk of reactor explosion due to sudden pressure increases, significantly reducing the explosion risk of nitration reactions. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the vessel structure of the present invention; Figure 3 This is a schematic diagram of the internal structure of the vessel body of the present invention; Figure 4 This is a schematic diagram of the propulsion stirring blade structure of the present invention; Figure 5 for Figure 4 Enlarged structural diagram at point A in the middle.

[0023] The diagram is marked as follows: 1. Reactor body; 2. Feed inlet; 3. Oxidant addition port; 4. Discharge port; 5. Raw material mixing tank; 6. Filter; 7. Feed pipe; 8. Feed valve; 9. Auxiliary stirring paddle; 10. Auxiliary motor; 11. Propeller stirring blade; 12. Anchor stirring blade; 13. Stirring motor; 14. Stirring shaft; 15. Guide hole; 16. Jacket; 17. Inner coil; 18. Heat transfer oil inlet; 19. Heat transfer oil outlet; 20. First circulation pump; 21. Coolant inlet; 22. Coolant 23. Outlet; 24. Second circulation pump; 25. Temperature sensor; 26. Condensation tower; 27. Adsorption tower; 28. Exhaust stack; 29. ​​Pipeline; 30. Exhaust port; 31. Pressure sensor; 32. Emergency pressure relief valve; 33. Pressure relief port; 34. Explosion-proof port; 35. Explosion-proof membrane; 36. Corrosion-resistant coating; 37. Insulation layer; 38. Adjusting disc; 39. Fixing ring; 40. Movable shaft; 41. Fixing plate; 42. Connecting seat; 43. Adapter; 44. Lead screw; 45. Anti-slip sleeve. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0025] like Figure 1 , Figure 2 and Figure 3As shown, a safe reaction vessel for nitration includes: a vessel body 1, a premixing mechanism, a stirring mechanism, a temperature control mechanism, a waste gas treatment mechanism, and a protective mechanism. The vessel body 1 has a feed inlet 2 and an oxidant addition port 3 at the top, and a discharge port 4 at the bottom. The premixing mechanism includes a raw material mixing tank 5 and a filter 6 connected to the vessel body 1. The raw material mixing tank 5 is connected to the feed inlet 2 of the vessel body 1 via a feed pipe 7. A feed valve 8 is also provided on the feed pipe 7. The filter 6 is located between the raw material mixing tank 5 and the feed inlet 2 to remove solid impurities from the raw materials, preventing impurities from affecting the reaction purity or clogging the vessel body 1. An auxiliary stirring paddle 9 is provided inside the raw material mixing tank 5 to achieve premixing of the nitration raw materials and diluent; the auxiliary stirring paddle 9 is driven by an auxiliary motor 10.

[0026] The stirring mechanism includes a propeller-type stirring blade 11 and an anchor-type stirring blade 12, forming an up-and-down circulating material flow to improve the mixing efficiency of raw materials. The stirring mechanism also includes a stirring motor 13 and a stirring shaft 14 disposed at the output end of the stirring motor 13; the propeller-type stirring blade 11 is arranged axially along the stirring shaft 14, and a plurality of guide holes 15 are evenly opened on the propeller-type stirring blade 11, the diameter of the guide holes 15 being 10mm; the anchor-type stirring blade 12 is disposed at the bottom of the stirring shaft 14, and the two side edges of the anchor-type stirring blade 12 are clearance-fitted with the inner wall of the vessel body 1, the clearance distance being 5mm, which can scrape off residual material on the vessel wall and avoid local overheating of the reaction.

[0027] The temperature control mechanism includes a jacket 16 disposed outside the reactor body 1 and an inner coil 17 disposed on the inner wall of the reactor body 1. Heat transfer oil flows into the jacket 16, and coolant flows into the inner coil 17. The jacket 16 is provided with a heat transfer oil inlet 18 and a heat transfer oil outlet 19. The heat transfer oil inlet 18 is connected to a first circulation pump 20. The inner coil 17 is provided with a coolant inlet 21 and a coolant outlet 22. The coolant inlet 21 is connected to a second circulation pump 23. At least two temperature sensors 24 are provided inside the reactor body 1, located in the upper and lower halves of the reactor body 1, respectively. The temperature sensors 24, the first circulation pump 20, and the second circulation pump 23 are all electrically connected to an external temperature controller (this external temperature controller can be installed on the reactor body or can be installed independently; it is a conventional structure and is not shown in the figure). When the temperature exceeds a preset threshold, the temperature of the heat transfer oil and the flow rate of the coolant are automatically adjusted to improve the temperature control accuracy to ±1℃, avoiding safety risks caused by temperature runaway.

[0028] The waste gas treatment mechanism includes a condenser tower 25, an adsorption tower 26, and an exhaust stack 27 connected in sequence. The condenser tower 25 is connected to the exhaust port 29 at the top of the vessel body 1 through a pipe 28. The condenser tower 25 is equipped with a condenser coil, and the adsorption tower 26 is filled with activated carbon adsorbent. The condenser tower 25 recovers volatile organic compounds in the waste gas through the condenser coil, and the activated carbon adsorbent in the adsorption tower 26 removes harmful gases from the waste gas, thereby solving the problem of "direct discharge of waste gas pollution" in traditional nitration reactions.

[0029] The protective mechanism includes a pressure sensor 30 and an emergency pressure relief valve 31. The emergency pressure relief valve 31 is electrically connected to the pressure sensor 30. The pressure sensor 30 is located inside the vessel body 1, and the emergency pressure relief valve 31 is located at the pressure relief port 32 at the top of the vessel body 1.

[0030] It also includes an explosion-proof port 33 located on the top of the vessel body 1. An explosion-proof membrane 34 is fixedly installed inside the explosion-proof port 33. The burst pressure value of the explosion-proof membrane 34 is higher than the opening pressure value of the emergency pressure relief valve 31 and lower than the rated pressure value of the vessel body 1.

[0031] The inner wall of the vessel body 1 is coated with a corrosion-resistant coating 35 to resist the corrosion of strong acids during the nitration reaction and prevent the material from corroding the vessel body. The corrosion-resistant coating 35 is a polytetrafluoroethylene coating or a ceramic coating, and the coating thickness is 0.2 mm. The outer wall of the jacket 16 is also provided with a heat insulation layer 36 to reduce heat exchange between the vessel body 1 and the outside environment and to assist in temperature stability. The heat insulation layer 36 is a rock wool insulation layer or a polyurethane insulation layer, and the thickness of the heat insulation layer 36 is 30 mm.

[0032] This embodiment provides a safe reaction vessel for nitration reaction. In use, before feeding, the premixing mechanism first mixes the nitration raw materials and diluent in the raw material mixing tank 5 (stirred by the auxiliary stirring paddle 9 at 100-300r / min), and then filters out solid impurities through the 5-20μm precision filter 6 to avoid impurities affecting the reaction or damaging the equipment.

[0033] After the pretreated material enters the vessel 1, the stirring motor 13 drives the stirring shaft 14 to rotate. The anchor stirring blade 12 stirs and scrapes off the residual material on the vessel wall at the same time. The upper propulsion stirring blade 11 pushes the material upward to form an up-and-down circulation, ultimately achieving uniform mixing of the material in the vessel and solving the problem of uneven mixing in traditional methods.

[0034] Afterwards, heat transfer oil is introduced into the jacket 16 to provide a basic temperature environment for the nitration reaction, and coolant is introduced into the inner coil 17 as a guarantee for temperature "fine-tuning / cooling". Temperature sensors 24 in the upper and lower areas of the vessel body 1 monitor the temperature in real time. If the temperature exceeds the preset threshold, the external temperature controller will control the temperature simultaneously: reduce the temperature of the heat transfer oil (reduce heat input) and increase the flow rate of the coolant (increase heat dissipation) to ensure that the reaction temperature is stable within a safe range.

[0035] The waste gas produced by the nitration reaction first enters the condensation tower 25 through pipe 28. The condensation coil is used to condense and recover the volatile organic compounds in the waste gas, reducing harmful components. The uncondensed waste gas enters the adsorption tower 26, where the remaining harmful gases are adsorbed by activated carbon adsorbent before being discharged through the exhaust stack 27 to avoid pollution.

[0036] During the nitration process, the pressure sensor 30 monitors the pressure inside the vessel in real time. If the pressure exceeds the preset value, the emergency pressure relief valve 31 automatically opens to relieve pressure and prevent excessive pressure. If the emergency pressure relief valve 31 fails and the pressure continues to rise, when it reaches the burst pressure of the explosion-proof membrane 34 (higher than the opening pressure of the pressure relief valve but lower than the rated pressure of the vessel body 1), the explosion-proof membrane 34 ruptures to relieve pressure again and protect the vessel body 1 from explosion.

[0037] Furthermore, such as Figure 4 and Figure 5 As shown, to further improve the mixing effect, an adjustment assembly is also provided between the upper propeller-type mixing blade 11 and the periphery of the mixing shaft 14. The adjustment assembly includes an adjustment plate 37 fixedly installed on the mixing shaft 14 near the top, and a fixing ring 38 located below the adjustment plate 37. The inner wall of the fixing ring 38 is fixedly installed on the mixing shaft 14. Movable shafts 39 are rotatably installed on both sides of the periphery of the fixing ring 38. Fixing plates 40 are fixedly connected to the disjoint ends of the two movable shafts 39. The disjoint ends of the two fixing plates 40 are respectively fixedly connected to the two propeller-type mixing blades 11. Connecting seats 41 are fixedly installed on both ends of the side of the fixing plate 40 near the mixing shaft 14. An adapter 42 is fixedly installed on the top of the connecting seat 41. A lead screw 43 is fixedly installed on the top of the adapter 42. The top of the lead screw 43 passes through the adjustment plate 37 and is fixedly connected to an anti-slip sleeve 44. The lead screw 43 is threadedly connected to the adjustment plate 37.

[0038] Without changing the direction of rotation of the stirring motor 13, before the stirring shaft 14 drives the propeller blades 11 to rotate, the position height of the lead screw 43 on the adjusting plate 37 can be adjusted by the adapter 42 to adjust the offset angle of the fixed plate 40. This allows the position angle of the two propeller blades 11 at the top to be flexibly adjusted to form multi-angle offset spiral blades. The larger the offset angle, the stronger the downward thrust. When the propeller blades 11 rotate through the stirring shaft 14, they can generate a downward thrust in the vessel 1. This pushes the suspended material at the top down again after the up-and-down cycle, allowing the material to be mixed repeatedly, thereby further improving the mixing effect.

[0039] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in the details for the sake of brevity.

[0040] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A safe reaction vessel for nitration reaction, characterized by, The utility model relates to a kind of chemical reaction kettle, including: Kettle body (1), premixing mechanism, stirring mechanism, temperature control mechanism, waste gas treatment mechanism and protection mechanism, the kettle body (1) top is equipped with feed inlet (2) with oxidant adding port (3), bottom is equipped with discharge outlet (4); The premixing mechanism includes raw material mixing tank (5) and filter (6) connected with the kettle body (1); The stirring mechanism includes propeller stirring blade (11) and anchor stirring blade (12); The temperature control mechanism includes jacket (16) arranged outside the kettle body (1) and inner coil (17) arranged on the inner side wall of the kettle body (1), heat conducting oil is introduced into the jacket (16), cooling liquid is introduced into the inner coil (17), temperature sensor (24) is arranged inside the kettle body (1), and the temperature sensor (24) is electrically connected with external temperature controller; The waste gas treatment mechanism includes condensing tower (25), adsorption tower (26) and exhaust cylinder (27) communicated in sequence. The protection mechanism further includes pressure sensor (30) and emergency pressure relief valve (31), the emergency pressure relief valve (31) is electrically connected with the pressure sensor (30), the pressure sensor (30) is arranged inside the kettle body (1), and the emergency pressure relief valve (31) is arranged at pressure relief port (32) on the top of the kettle body (1).

2. The safety reactor for nitration reaction according to claim 1, wherein The stirring mechanism further includes stirring motor (13) and stirring shaft (14) arranged at the output end of the stirring motor (13), the propeller stirring blade (11) is arranged axially along the stirring shaft (14), the anchor stirring blade (12) is arranged at the bottom of the stirring shaft (14), and the anchor stirring blade (12) is gap-fitted with the inner wall of the kettle body (1) on both sides, with a gap distance of 3-8mm.

3. The safety reactor for nitration reaction according to claim 1, wherein A plurality of flow guide holes (15) are uniformly arranged on the propeller stirring blade (11), and the diameter of the flow guide holes (15) is 5-15mm.

4. The safety reactor for nitration reaction according to claim 1, wherein The jacket (16) is provided with heat conducting oil inlet (18) and heat conducting oil outlet (19), the heat conducting oil inlet (18) is connected with first circulating pump (20), the inner coil (17) is provided with cooling liquid inlet (21) and cooling liquid outlet (22), the cooling liquid inlet (21) is connected with second circulating pump (23), and the external temperature controller is electrically connected with the first circulating pump (20) and the second circulating pump (23) respectively.

5. The safety reactor for nitration reaction according to claim 1, wherein The raw material mixing tank (5) is communicated with the feed inlet (2) of the kettle body (1) through feed pipe (7), the feed pipe (7) is further provided with feed valve (8), the filter (6) is arranged between the raw material mixing tank (5) and the feed inlet (2), the inside of the raw material mixing tank (5) is provided with auxiliary stirring paddle (9), and the auxiliary stirring paddle is driven by auxiliary motor (10).

6. The safety reactor for nitration reaction according to claim 1, wherein The protection mechanism further includes explosion-proof port (33) arranged on the top of the kettle body (1), explosion-proof membrane (34) is fixedly installed inside the explosion-proof port (33), the burst pressure value of the explosion-proof membrane (34) is higher than the opening pressure value of the emergency pressure relief valve (31), and lower than the rated pressure value of the kettle body (1).

7. The safe reaction vessel for nitration reaction according to claim 1, wherein The condensing tower (25) is communicated with the exhaust port (29) at the top of the kettle body (1) through a pipeline (28), the condensing tower (25) is internally provided with a condensing coil, and the adsorbing tower (26) is internally filled with activated carbon adsorbent.

8. The safe reaction vessel for nitration reaction according to claim 1, wherein The temperature sensor (24) is provided with at least two, which are respectively located in the upper half region and the lower half region in the kettle body (1).

9. The safe reaction vessel for nitration reaction according to claim 1, wherein The inner wall of the kettle body (1) is coated with a corrosion-resistant coating (35), the corrosion-resistant coating (35) is a polytetrafluoroethylene coating or a ceramic coating, the coating thickness is 0.1-0.3mm, the outer side wall of the jacket (16) is further provided with a heat preservation layer (36), the heat preservation layer (36) is a rock wool heat preservation layer (36) or a polyurethane heat preservation layer (36), and the heat preservation layer (36) thickness is 20-50mm.

10. The safe reaction vessel for nitration reaction according to claim 2, wherein The upper propelling stirring blade (11) and the outer periphery of the stirring shaft (14) are further provided with an adjusting assembly, the adjusting assembly comprises an adjusting disc (37) fixedly installed on the stirring shaft (14) close to the top, and a fixed ring (38) below the adjusting disc (37), the inner side wall of the fixed ring (38) is fixedly installed on the stirring shaft (14), the outer periphery of the fixed ring (38) is rotatably installed with a movable shaft (39) on both sides, the apart end of the two movable shafts (39) is fixedly connected with a fixed plate (40), the apart end of the two fixed plates (40) is respectively fixedly connected with two propelling stirring blades (11), the side of the fixed plate (40) close to the stirring shaft (14) is fixedly installed with a connecting seat (41) at both ends, the upper side of the connecting seat (41) is fixedly installed with an adapter (42), the top of the adapter (42) is fixedly installed with a lead screw (43), the top of the lead screw (43) is fixedly connected with an anti-skid sleeve (44) penetrating through the adjusting disc (37), and the lead screw (43) is in threaded connection with the adjusting disc (37).

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