Continuous and efficient reaction device for high viscosity and operation method of continuous and efficient reaction device

Abstract

The invention discloses a continuous and efficient reaction device for high viscosity and an operation method thereof, and relates to the technical field of reaction devices, the continuous and efficient reaction device comprises a dynamic reactor, a first pump, a second pump, corresponding connecting pipelines and a material inlet and outlet, an outlet of the first pump is connected to an inlet of the second pump through a pipeline, and an outlet of the second pump is connected to an inlet of the dynamic reactor; an outlet of the dynamic reactor is connected to a first feeding port of the first pump, the first feeding port is formed in the front end of an inlet of the first pump, a feeding port of the second pump serves as a second feeding port, and a discharging port is formed in a pipeline connected with the dynamic reactor. According to the invention, mass transfer and heat transfer can be enhanced through forced stirring, and the mixing capacity and heat exchange capacity of high-viscosity materials in the reactor can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of reaction devices, and in particular to a continuous and efficient reaction device for high viscosity and an operating method thereof. Background Art

[0002] As the chemical industry places increasingly stringent requirements on process safety design and control, the need for enhanced intrinsic safety in hazardous chemical processes, particularly those under key regulatory oversight, is growing. The "Guidelines for Safety Risk Assessment of Fine Chemical Reactions (Trial)" state that for processes with hazard levels 4 and 5, particularly those with high risk but requiring industrialization, efforts should prioritize process optimization or changes in process methods to reduce risk, such as through micro-reactions or continuous flow reactions.

[0003] In the fine chemical industry, we often encounter reaction types with high viscosity, fast reaction speed and large heat release. Our traditional continuous reaction devices, such as microchannel reaction devices and tubular reaction devices, are often helpless. We often encounter blockage of the reaction device, poor heat exchange and mass transfer effects, resulting in a significant decrease in yield, poor reactor efficiency, and even safety risks.

[0004] Channel reactors have many advantages, such as continuity, large specific surface area / volume ratio, significantly enhanced mass and heat transfer, rapid mixing, precise temperature control, low online liquid holdup, intrinsic safety, no amplification effect, shortened development cycle, and more conducive to automated control. They are often used to solve chemical reactions with strong exothermicity, unstable reactants or intermediates, and easy loss of control [cited micro-reaction related patents and articles "A safe and environmentally friendly nitration reaction microchannel reaction device": CN202221877610.1". Taghavi-Moghadam S, Kleemann A, Golbig G. Microreaction technology as a novel approach to drug design, process development and reliability [J], Organi [CProcess Research & Development, 2001, 5(6): 652-658]. However, due to the small channels, microchannel reactors are prone to clogging for solid-containing materials or materials with high viscosity. For materials with high viscosity, the system pressure is too high. In addition, due to the high viscosity and slow flow rate, the heat and mass transfer efficiency of microchannel reactors is greatly reduced. It is not suitable for gas-liquid phase reactions. The reaction device has low production capacity and high investment intensity, which greatly limits the application of microchannel reactors in the production of fine chemicals.

[0005] Tubular reactors offer advantages such as a large surface area to volume ratio, excellent heat and mass transfer, low liquid holdup, high production capacity, and relatively low investment, making them a promising complement to microchannel reactors in the fine chemical industry [cited in the patent for tubular reactors, "A Tubular Reactor for the Production of Ammonium Persulfate": CN115282898B]. However, tubular reactors cannot effectively handle reactions with high solids content, high viscosity, and high exothermicity, and their poor suitability for gas-liquid phase reactions limits their industrial application.

[0006] In recent years, the dynamic tubular reactor has been widely promoted in industry [citing the patent for dynamic tubular reactors from manufacturers such as Haomai or the article "A Method for Preparing 2,3-Dichlorobenzaldehyde" CN107337276B]. By adding a stirring method, it improves its applicability to solid-containing and high-viscosity materials. However, due to its general heat exchange capacity, even with the addition of internal heat exchange channels, it cannot effectively solve the problem of highly exothermic and high-viscosity reaction systems. It has a general effect on gas-liquid mixing and poor applicability to gas-liquid reactions.

[0007] A loop reactor that integrates a loop pipe, a heat exchanger, and a circulation pump can improve the heat exchange capacity of the reactor through forced circulation heat exchange. However, the mass transfer capacity of the reaction device is relatively weak. For rapid reactions and reactions with high viscosity, it is easy to cause local excessive temperatures, resulting in high impurities.

[0008] The solvent for the nitration reaction is often a solvent with a relatively high viscosity, such as sulfuric acid. The viscosity of the nitration raw material solution after dissolution is further increased. The viscosity of some nitration raw material liquids dissolved in sulfuric acid is as high as 200-2000cp. The nitration reaction is often fast and releases a lot of heat. If a microchannel or tubular reactor is directly used as a continuous nitration reaction device for direct reaction, it is not only prone to blockage and system overpressure, but also the material reacts instantly when it comes into contact with the nitrating agent. The large amount of heat released cannot be removed quickly and in time. The local reaction temperature is too high and the mixing effect is poor, resulting in a significant increase in impurities such as nitration isomers. Summary of the Invention

[0009] The object of the present invention is to provide a continuous and efficient reaction device for high viscosity and an operating method thereof, which can effectively solve reactions in gas-liquid phase, gas-liquid-solid phase, high viscosity, rapid reaction and strong heat release, and narrow reaction temperature range. It is also applicable to solid-free and low-viscosity reaction systems, and is particularly suitable for nitration reactions with high viscosity and strong heat release.

[0010] The purpose of the present invention can be achieved through the following technical solutions:

[0011] A continuous and efficient reaction device for high viscosity, comprising a dynamic reactor, a first pump, a second pump, corresponding connecting pipes and material inlets and outlets, wherein the outlet of the first pump is connected to the inlet of the second pump via a pipe, the outlet of the second pump is connected to the inlet of the dynamic reactor, the outlet of the dynamic reactor is connected to the first feed port of the first pump, the first feed port is arranged at the front end of the inlet of the first pump, the feed of the second pump serves as the second feed port, and a discharge port is provided on the pipe connected to the dynamic reactor.

[0012] As a further solution of the present invention: the first pump is a circulation pump, and the circulation pump is one of a centrifugal pump, an axial flow pump, a rotor pump, a gear pump, a screw pump, a shielded pump, and a diaphragm pump;

[0013] The second pump is a mixing pump, which is one of a homogenizing pump, a grinding pump, an emulsifying pump, a centrifugal pump, an axial flow pump, a gear pump, and a rotor pump.

[0014] As a further solution of the present invention: the dynamic reactor is a dynamic tubular reactor, and the heat exchanger is a shell-and-tube heat exchanger or a wound heat exchanger.

[0015] As a further solution of the present invention: the outlet of pump two is connected to the inlet of the heat exchanger, the outlet of the heat exchanger is connected to the inlet of pump three, the outlet of pump three is connected to the inlet of the dynamic reactor, and the feed of pump three serves as feed port three.

[0016] As a further solution of the present invention: the third pump is a mixing pump, and the mixing pump is one of a homogenizing pump, a grinding pump, an emulsifying pump, a centrifugal pump, an axial flow pump, a gear pump, and a rotor pump.

[0017] As a further solution of the present invention: the homogenizing pump, grinding pump and emulsifying pump adopt a multi-layer or single-layer geared disc structure of dynamic and static discs, the geared discs have straight teeth, helical teeth and triangular teeth, the geared discs have 1-5 layers, and the tooth spacing is 1-20 mm.

[0018] As a further solution of the present invention: it is applied to reactions in hazardous chemical processes such as nitration, oxidation, peroxidation, fluorination and chlorination.

[0019] As a further solution of the present invention, the invention can be applied to the reactions of hazardous chemical processes such as nitration, oxidation, peroxidation, fluorination and chlorination with high viscosity, fast reaction speed and strong exothermicity.

[0020] As a further solution of the present invention: it is applied to nitration reactions with high viscosity, fast reaction speed and strong exotherm.

[0021] As a further embodiment of the present invention: a method for operating a high-viscosity continuous and efficient reaction device comprises the following steps:

[0022] Step 1: Open the cooling water inlet and outlet valves of the dynamic reactor, open the top discharge valve, start pump 1 and pump 2; use a metering pump to pass the high-viscosity reaction liquid containing the raw materials into the reaction device through the feed port 1, and close the feed port 1 valve; the volume of the material in step 1 accounts for 30-80% of the reaction system;

[0023] Step 2: The reaction reagents are fed into the reaction device from the feed port 2 by a metering pump, and the valve of the feed port 2 is closed; the mixture is dispersed, sheared, and emulsified under the action of the pump 2; the material circulates under the action of the high-flow pump 1 until the material is uniform, and the heat generated by the reaction is taken away by a large amount of products, and heat exchange and cooling are carried out in the dynamic reactor;

[0024] Step 3: Open feed port 1 and feed port 2, add high-viscosity reaction liquid containing raw materials and reaction reagents into the reaction device, and discharge the reaction liquid from the discharge port after the reaction is completed; the mass ratio of materials in feed port 1, feed port 2 and the circulation pipeline between the two is 0.1:100-90:100.

[0025] In the above reaction process: the high-viscosity reaction liquid selectively contains raw materials, solvents, etc.; the reaction reagent is nitric acid; the raw material is 7-fluoro-2H-1,4-benzoxazine-3(4H)-one (II), and the solvent is one or a combination of sulfuric acid and nitric acid.

[0026] As a further embodiment of the present invention: a method for preparing 7-fluoro-6-nitro-2H-1,4-benzoxazin-3(4H)-one (I) using 7-fluoro-2H-1,4-benzoxazin-3(4H)-one (II) as a raw material in the presence of a nitrating agent using a continuous reaction apparatus, the reaction equation is as follows:

[0027]

[0028] Wherein, the nitrating agent is a combination of sulfuric acid and nitric acid;

[0029] The specific operations are:

[0030] Step 1: Open the cooling water inlet and outlet valves of the dynamic reactor and the top discharge valve; start pump 1 and pump 2; use a metering pump to pass a sulfuric acid solution of 7-fluoro-2H-1,4-benzoxazin-3(4H)-one (II) through feed port 1 into the reaction device, and close the feed port 1 valve; the volume of the material in step 1 accounts for 30-80% of the reaction system;

[0031] Step 2: nitric acid is introduced into the reaction device from feed port 2 using a metering pump, and the valve of feed port 2 is closed; the mixture is dispersed, sheared, and emulsified under the action of pump 2; the material circulates under the action of high-flow pump 1 until the material is uniform, and the heat generated by the reaction is taken away by a large amount of products and heat exchanged and cooled in heat exchanger 1;

[0032] Step 3: Open feed port 1 and feed port 2, add sulfuric acid solution and nitric acid of 7-fluoro-2H-1,4-benzoxazine-3(4H)-one to the reaction device, and discharge the reaction liquid from the discharge port after the reaction is completed; the mass ratio of the materials in the feed port 1, feed port 2 and the circulation pipeline between the two is 0.1:100-90:100.

[0033] Beneficial effects of the present invention:

[0034] The present invention can enhance mass transfer and heat transfer through forced stirring, thereby improving the mixing ability and heat exchange capacity of high-viscosity materials in the reactor.

[0035] A homogenizing pump is a device that can achieve the process of efficiently, quickly, and evenly transferring one or more phases (liquid, solid, gas) into another immiscible continuous phase (usually liquid). The high tangential speed and high-frequency mechanical effect generated by the high-speed rotation of the stator and rotor of the homogenizing pump bring about a strong mixing effect, so that the material is subjected to strong mechanical and hydraulic shear, centrifugal extrusion, liquid layer friction, impact tearing, and turbulence in the narrow gap between the stator and rotor, and is instantly and evenly dispersed and mixed, dispersing, shearing, and emulsifying the material in a very short time. The use of a homogenizing pump greatly enhances the mass transfer and mixing effect, especially for high-viscosity materials. For material systems where mass transfer and mixing cannot be effectively improved by flow, static mixers, and conventional stirring, this problem can be well solved in the device of the present invention, achieving rapid and effective mixing and reaction.

[0036] The present invention achieves efficient heat exchange through high-flow forced circulation and forced stirring in a dynamic tubular reactor. The material circulates under the action of a high-flow pump 1, and the heat generated by the reaction is removed by a large amount of product. Heat exchange and cooling are further carried out within the dynamic reactor. After cooling, some of the product is discharged from the reaction system, while some is circulated within the reaction unit. The mass ratio of the materials in the first feed port, the second feed port, and the circulation pipeline between the two is 0.1:100 to 20:100.

[0037] Traditionally, high-viscosity materials have been treated with a combination of a circulating pump or mixing pump and a heat exchanger, but due to their high viscosity, timely heat transfer cannot be guaranteed. The addition of a dynamic reactor in the present invention further ensures efficient heat and mass transfer, avoiding risks such as blockage and system overpressure. It also prevents the instantaneous reaction between the material and the nitrating agent, which results in a high exotherm and inability to quickly remove the heat, resulting in excessively high local reaction temperatures and poor mixing, leading to a significant increase in impurities such as nitrated isomers. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be further described below with reference to the accompanying drawings.

[0039] Figure 1 It is a structural diagram of embodiment 1 of the present invention;

[0040] Figure 2 is a structural diagram of embodiment 2 of the present invention;

[0041] Figure 3 It is a structural schematic diagram of comparative example 1 of the present invention;

[0042] Figure 4 It is a structural schematic diagram of comparative example 3 of the present invention;

[0043] Figure 5 It is a structural schematic diagram of comparative example 4 of the present invention. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0045] The present invention provides a continuous, efficient reaction device for high-viscosity liquids. The Reynolds number (Re) is a key parameter used in the field to determine the flow state of a fluid. Generally speaking, when the Reynolds number (Re) is greater than 4000, the fluid is in a turbulent state, which results in ideal mixing. As can be seen from the formula, a higher flow rate is required for a high-viscosity liquid to achieve the same Reynolds number (Re) as a low-viscosity liquid.

[0046]

[0047] in:

[0048] -ρ is the liquid density

[0049] -v is the flow rate

[0050] -D is the pipe diameter

[0051] -μ is the viscosity of the liquid.

[0052] Under turbulent flow conditions (Reynolds number Re > 4000), according to the Fanning equation, the pressure difference ΔP within a pipeline is proportional to the square of the flow velocity. Therefore, compared to low-viscosity liquids, when high-viscosity liquids reach turbulent flow within a pipeline, the pressure rises dramatically. This undoubtedly poses a significant challenge to the reliability and stability of equipment such as pumps. Equipment such as microreactors also struggle to withstand such high pressures.

[0053]

[0054] Therefore, this solution innovatively adopts a mixing pump forced mixing method to replace the traditional pipeline turbulent mixing, successfully overcoming the problem of excessive pressure during pipeline turbulent mixing.

[0055]

[0056] Impurity structural formula:

[0057]

[0058] The specific operations are:

[0059] Step 1: Open the cooling water inlet and outlet valves of the dynamic reactor 1, and open the valve of the top discharge port 11; start pump 1 2 and pump 2 3; use a metering pump to allow the sulfuric acid solution of 7-fluoro-2H-1,4-benzoxazin-3(4H)-one (II) to enter the reaction device through the feed port 1 21, and close the valve of the feed port 1 21; the volume of the material in step 1 accounts for 60-80% of the reaction system;

[0060] Step 2: Nitric acid is introduced into the reaction device from the feed port 2 31 using a metering pump, and the valve of the feed port 2 31 is closed; the mixture is dispersed, sheared, and emulsified under the action of the pump 2 3; the material circulates under the action of the high-flow pump 1 2 until the material is uniform, and the heat generated by the reaction is taken away by a large amount of products and heat exchanged and cooled in the heat exchanger 1;

[0061] Step 3: Open feed port 1 21 and feed port 2 31, add sulfuric acid solution and nitric acid of 7-fluoro-2H-1,4-benzoxazine-3(4H)-one to the reaction device, and after the reaction is completed, the reaction liquid is discharged from the discharge port 11; the mass ratio of the materials in the feed port 1 21, feed port 2 31 and the circulation pipeline between the two is 0.1:100-20:100.

[0062] Example 1

[0063] See also Figure 1As shown, dynamic reactor 1 is a dynamic tubular reactor with a reactor capacity of 30 L and an agitator speed of 300 r / min. Pump 1-2 is a centrifugal pump, and Pump 2-3 is a homogenizing pump. A 35% mass fraction raw sulfuric acid solution is introduced into the reactor via feed port 1-21 by a metering pump, and a 67% mass fraction nitric acid solution is introduced into the reactor via feed port 2-31 by a metering pump. The molar ratio of 35% raw sulfuric acid solution to 67% nitric acid is 1:1.05.

[0064] Specifically:

[0065] Open the cooling water inlet and outlet valves of the dynamic reactor 1 and the valve of the top discharge port 11. Start pump 2 (flow rate is 1m 3 / h), pump 23. The 35% raw sulfuric acid solution enters the reaction device through the feed port 121 with a metering pump. After the total amount reaches 25L, close the feed port 121 valve;

[0066] 67% raw nitric acid is fed into the reaction device from feed port 2 31 by a metering pump. When the total amount reaches 5 L, the valve of feed port 2 31 is closed;

[0067] After running for 5 minutes, the feed port 1 21 and the feed port 2 31 are opened at the same time, and 35% raw sulfuric acid solution and 67% nitric acid are added to the reaction device. The mass ratio of the materials in the feed port 1 21, the feed port 2 31 and the circulation pipeline between the two is 0.1:100-90:100. The mass ratio is preferably 0.1:100-50:100, and more preferably 0.1:100-20:100, indicating that less feed and larger circulation volume are the best; 35% raw sulfuric acid solution is fed at flow rates 1 and 2, respectively. Experiments with different sulfuric acids are performed, flow rate 1 is 45 L / h; flow rate 2 is 60 L / h, and the flow rate of 67% nitric acid is controlled at the same time to ensure that the 35% flow raw sulfuric acid solution: nitric acid ratio = 1:1.05 (molar ratio);

[0068] Adjust the cooling water valve switch to control the temperature of the reaction device. The reaction liquid flows out from the discharge port 21.

[0069] Samples were taken from the discharge port for HPLC analysis, as shown in the following table.

[0070]

[0071] Example 2

[0072] See also Figure 2 As shown, the dynamic reactor 1 is a dynamic tubular reactor with a reactor capacity of 30L and a stirring speed of 300r / min; the pump 2 is a centrifugal pump (with a flow rate of 1m 3 / h), pump 2 3, pump 3 5 are grinding pumps, and heat exchanger 4 is a shell and tube heat exchanger.

[0073] 35% raw sulfuric acid liquid is fed into the reaction apparatus via feed port 1 21 using a metering pump. 67% nitric acid is fed into the reaction apparatus via feed port 2 31 and feed port 3 51 using a metering pump. The flow rate ratio of pump 2 2 to pump 3 is 1:1. 35% raw sulfuric acid liquid: 67% nitric acid = 1:1.05 (molar ratio);

[0074] Specifically:

[0075] Open the cooling water inlet and outlet valves of the dynamic reactor 1 and the heat exchanger 4, and open the discharge valve. Start pump 2 (flow rate is 1m 3 / h), pump 2 3, pump 3 5. The raw sulfuric acid solution enters the reaction device through the feed port 1 21. When the total amount reaches 25L, close the feed port 1 21 valve;

[0076] Nitric acid enters the reactor via metering pumps 51 and 3, with a flow rate ratio of 1:1 between pumps 3 and 5. Once the total volume reaches 30 L, close the valves at feed ports 31 and 51.

[0077] After running for 5 minutes, open feed port 1 21, feed port 2 31, and feed port 3 51 simultaneously. Control the flow rate of 67% nitric acid to ensure that the ratio of 35% flow rate raw sulfuric acid solution: nitric acid = 1:1.05 (molar ratio);

[0078] The reaction solution flowed out from the discharge port. Samples were taken from the discharge port every half hour for HPLC analysis, as shown in the following table.

[0079]

[0080] Comparative Example 1

[0081] like Figure 3 As shown: A microchannel reaction device is built as shown, and the raw sulfuric acid solution and nitric acid enter the microchannel reactor through metering pumps P1 and P2.

[0082] The microchannel reactor was set to a temperature of 25°C. Metering pumps P1 and P2 were then used to simultaneously deliver dilute nitric acid and a 35% raw sulfuric acid solution (viscosity 380 cp at 25°C) into the microchannel reactor. The molar ratio of dilute nitric acid to sulfuric acid solution was controlled to be 1:1.05.

[0083] The dilute nitric acid and sulfuric acid solution enter the microchannels and begin mixing. After passing through four modules, the solution flows into a reaction liquid receiving flask. Once the outflowing reaction liquid exceeds 100ml, it is sampled and analyzed by HPLC. (The total volume of the channels in a single microchannel reactor is 8.2ml.)

[0084] Test results:

[0085]

[0086] As the reaction proceeded, the internal channels of the microchannel reaction device became clogged, and the pressure gradually increased. After 10 minutes, the reaction device became overpressured.

[0087] Comparative Example 2

[0088] like Figure 3 A microchannel reaction device was constructed as shown.

[0089] The temperature of the microchannel reactor was set at 30°C. Metering pumps P1 and P2 were then used to simultaneously deliver dilute nitric acid and a raw sulfuric acid solution (viscosity 300 cp, 30°C) into the microchannel reactor. The molar ratio of nitric acid to raw sulfuric acid solution was controlled to be 1:1.05.

[0090] The nitric acid and sulfuric acid solutions enter the microchannels and begin mixing. After passing through four modules, they flow into a reaction liquid receiving flask. Once the outflowing reaction liquid exceeds 100ml, samples are taken for HPLC analysis. (The total volume of the channels in a single microchannel reactor is 8.2ml.)

[0091] Test results:

[0092]

[0093]

[0094] As the reaction proceeded, the internal channels of the microchannel reaction device became clogged, and the pressure gradually increased. After 10 minutes, the reaction device became overpressured.

[0095] Comparative Example 3

[0096] like Figure 4 The dynamic tubular reaction device is shown in FIG. The raw sulfuric acid solution is transported by metering pump 1, and the nitric acid is transported by metering pump 2.

[0097] Start the cooling external circulation of the dynamic tubular reactor. Then, use metering pumps P1 and P2 to simultaneously deliver dilute nitric acid and a raw sulfuric acid solution (viscosity 380 cp, 25°C) into the microchannel reactor. Control the nitric acid:raw sulfuric acid solution ratio to be 1:1.07 (molar ratio).

[0098] Nitric acid and sulfuric acid solution enter a dynamic tubular reactor (1.5L internal volume). Mix and react, and the reaction liquid enters a collection flask. Control the opening of the external cooling water valve to maintain the reaction temperature at around 25°C; the speed of the dynamic tubular reactor is controlled at 300 rpm. The flow rate of the raw material solution is 54 ml / min, and the flow rate of nitric acid is 7.8 ml / min.

[0099] When the volume of the outflowing reaction liquid exceeds 4.5 L, sampling and HPLC analysis of the reaction liquid content are started.

[0100] Test results:

[0101] Serial number raw material / % product / % Isomers / % Dinitro impurities / % Temperature 1 / ℃ Temperature 2 / ℃ Sample 1: (30 minutes) 4.14 88.39 2.61 0.84 27.1 21.6 Sample 2: (60 minutes) 4.28 88.7 2.37 0.93 28.5 22.7 Control kettle ＜0.5％ 95％ ＜0.8％ ＜0.8％

[0102] Comparative Example 4

[0103] like Figure 5 The dynamic tubular reaction device is shown in FIG. The raw sulfuric acid solution is transported by metering pump 1, and the nitric acid is transported by metering pumps 2 and 3.

[0104] Start the cooling external circulation system in the dynamic tubular reactor. Then, use metering pumps P1 and P2 to simultaneously deliver the raw sulfuric acid solution (viscosity 380 cps; 25°C) and dilute nitric acid to the microchannel reactor. Once the reaction liquid begins to flow out of the dynamic tubular reactor, start metering pump P3. Control the molar ratio of nitric acid to raw sulfuric acid solution to 1:1.07; and maintain a 1:1 flow rate ratio between metering pumps 2 and 3.

[0105] The materials react in the dynamic tubular reactor, and the reaction liquid enters the collection device. The opening of the external cooling water valve is controlled to maintain the reaction temperature at around 25°C; the speed of the dynamic tubular reactor is controlled at 300 rpm. The raw material flow rate is 54 ml / min; the total nitric acid flow rate is 7.8 ml / min.

[0106] When the volume of the outflowing reaction liquid exceeds 4.5 L, sampling and HPLC analysis of the reaction liquid content are started.

[0107] Test results:

[0108] Serial number raw material / % product / % Isomers / % Dinitro impurities / % Temperature 1 / ℃ Temperature 2 / ℃ Sample 1: (30 minutes) 1.54 86.9 2.31 1.47 27.1 25.4 Sample 2: (60 minutes) 2.08 86.7 2.25 1.54 27.5 25.1 Control kettle ＜0.5％ 95％ ＜0.8％ ＜0.8％

[0109] The above is a detailed description of an embodiment of the present invention. However, the content described is only a preferred embodiment of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A continuous and efficient reaction device for high viscosity, characterized in that: The invention comprises a dynamic reactor (1), a pump 1 (2), a pump 2 (3) and corresponding connecting pipes and material inlets and outlets. The outlet of the pump 1 (2) is connected to the inlet of the pump 2 (3) through a pipe. The outlet of the pump 2 (3) is connected to the inlet of the dynamic reactor (1). The outlet of the dynamic reactor (1) is connected to the feed port 1 (21) of the pump 1 (2). The feed port 1 (21) is arranged at the front end of the inlet of the pump 1 (2). The feed of the pump 2 (3) serves as the feed port 2 (31). A discharge port (11) is arranged on the pipe connected to the dynamic reactor (1).

2. A continuous and efficient reaction device for high viscosity according to claim 1, characterized in that: The pump 1 (2) is a circulation pump, and the circulation pump is one of a centrifugal pump, an axial flow pump, a rotor pump, a gear pump, a screw pump, a shielded pump, and a diaphragm pump; The second pump (3) is a mixing pump, which is one of a homogenizing pump, a grinding pump, an emulsifying pump, a centrifugal pump, an axial flow pump, a gear pump, and a rotor pump.

3. A continuous and efficient reaction device for high viscosity according to claim 1, characterized in that: The outlet of the second pump (3) is connected to the inlet of the heat exchanger (4), the outlet of the heat exchanger (4) is connected to the inlet of the third pump (5), the outlet of the third pump (5) is connected to the inlet of the dynamic reactor (1), and the feed of the third pump (5) serves as the feed port three (51).

4. A continuous and efficient reaction device for high viscosity according to claim 3, characterized in that: The dynamic reactor (1) is a dynamic tubular reactor; the heat exchanger (4) is a shell-and-tube heat exchanger or a winding heat exchanger.

5. A continuous and efficient reaction device for high viscosity according to claim 3, characterized in that: The pump three (5) is a mixing pump, and the mixing pump is one of a homogenizing pump, a grinding pump, an emulsifying pump, a centrifugal pump, an axial flow pump, a gear pump, and a rotor pump.

6. A continuous and efficient reaction device for high viscosity according to claim 2 or 5, characterized in that: The homogenizing pump, grinding pump and emulsifying pump adopt a multi-layer or single-layer geared disc structure of moving disc and static disc. The geared disc has straight teeth, oblique teeth and triangular teeth, 1-5 layers of geared disc and a tooth spacing of 1-20 mm.

7. A continuous and efficient reaction device for high viscosity according to claim 1, characterized in that: Applicable to reactions in hazardous chemical processes such as nitration, oxidation, peroxidation, fluorination and chlorination.

8. A continuous and efficient reaction device for high viscosity according to claim 7, characterized in that: It is used in hazardous chemical processes such as nitration, oxidation, peroxidation, fluorination and chlorination with high viscosity, fast reaction speed and strong exothermicity.

9. A continuous and efficient reaction device for high viscosity according to claim 7, characterized in that: Applicable to nitration reactions with high viscosity, fast reaction speed and strong exotherm.

10. A method for operating a high-viscosity continuous and efficient reaction device, characterized in that: The continuous and efficient reaction device for high viscosity according to any one of claims 1 to 9 comprises the following steps: Step 1: Open the cooling water inlet and outlet valves of the dynamic reactor (1), open the valve of the top discharge port (11), start pump 1 (2) and pump 2 (3); use a metering pump to pass the high-viscosity reaction liquid containing the raw materials into the reaction device through the feed port 1 (21), and close the feed port 1 (21) valve; the volume of the material in step 1 accounts for 30-80% of the reaction system; Step 2: The reaction reagent is fed into the reaction device from the second feed port (31) by a metering pump, and the valve of the second feed port (31) is closed; the mixed material is dispersed, sheared, and emulsified under the action of the second pump (3); the material is circulated under the action of the high-flow pump (2) until the material is uniform, and the heat generated by the reaction is taken away by a large amount of products, and heat exchange and cooling are carried out in the dynamic reactor (1); Step 3: Open feed port 1 (21) and feed port 2 (31), add high-viscosity reaction liquid containing raw materials and reaction reagents into the reaction device, and after the reaction is completed, the reaction liquid is discharged from the discharge port (11); the mass ratio of the materials in the feed port 1 (21), feed port 2 (31) and the circulation pipeline between the two is 0.1:100-90:100.

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