Continuous separation system based on a continuous separator for nitration reactions

Abstract

The application belongs to the field of special equipment for chemical industry, and particularly relates to a continuous separation system based on a continuous separator for nitration reaction. A material storage tank is connected to a material inlet N1 of the continuous separator for nitration reaction through a material pipeline, and a material conveying pump and a material metering meter L1 are arranged on the material pipeline in sequence. A nitric acid storage tank is connected to a nitric acid inlet N2 of the continuous separator for nitration reaction through a nitric acid pipeline, and a nitric acid conveying pump and a nitric acid metering meter L2 are arranged on the nitric acid pipeline in sequence. The material and the nitric acid are pumped into a primary mixing cavity formed between an outer wall of an isolation cylinder and an inner wall of a shell through the material pipeline and the nitric acid pipeline respectively, and then are sucked into a dispersion cavity formed by a small rotary drum cavity through a guide cylinder, and then enter a separation cavity formed by a rotary drum inner cavity through a communication hole at a bottom surface of the rotary drum. The nitration product after separation and clarification is centrifugally thrown out from a discharge port at a top of the rotary drum, and is discharged from a nitration product outlet N3 at an upper part of the shell to a nitration product storage tank. The application ensures the continuity, efficiency and safety of the nitration reaction, and can realize the operation purposes of systematization, high efficiency, continuous and closed operation and intrinsic safety.

Description

Technical Field

[0001] This application belongs to the field of chemical special equipment, specifically relating to a continuous separation system based on a nitration reaction continuous separator. Background Technology

[0002] Nitration is generally the process of introducing a nitro group into an organic compound molecule. It is a strongly exothermic reaction, prone to runaway reactions. Current nitration methods mainly include: dilute nitric acid nitration, concentrated nitric acid nitration, nitric acid nitration in concentrated sulfuric acid, nitric acid nitration in organic solvents, and heterogeneous mixed acid nitration. For example, aromatic hydrocarbon nitration is an important route for preparing amino compounds, and subsequently phenols, fluorides, and other compounds. The synthesis of high-performance energetic materials in the defense industry also relies heavily on nitration reactions. Nitration reactions are characterized by high exothermic activity, rapid exothermic rates, a tendency to runaway reactions, and the presence of flammable and explosive nitration products, all of which pose fire and explosion hazards.

[0003] Nitrification is a heterogeneous process, requiring nitration reactors equipped with strong and efficient agitation to ensure sufficient contact between the acid and organic phases. This places high demands on agitation performance. Simultaneously, the flammable and explosive nature of nitration necessitates inherently safe and highly reliable equipment. Currently, nitration reactions primarily utilize batch reactors, such as enamel-lined, steel, cast iron, or stainless steel reactors. Considering the intensity of the nitration reaction, small, single-batch feeding is often employed, accompanied by intermittent operation and limited agitation. This results in limited mixing intensity, insufficient production capacity, low efficiency, and high labor intensity. Later, microchannel reactors emerged to achieve nitration. In simple terms, this involves shifting from the traditional batch reactor's "small, single-batch addition" to a "continuous, small-batch supply" by breaking down the entire reactor into smaller, interconnected components. The flow-limiting characteristics of the microchannels ensure a small but continuous supply of materials. Clearly, while the microchannel method described above solves the problem of continuous reaction, the drawback of insufficient production capacity due to small-scale addition remains, hindering its engineering application. Furthermore, nitration reactions often involve the generation of impurities, which gradually accumulate within the microchannels and cannot be removed, causing blockages. This is another fundamental reason why the microchannel method is difficult to implement in engineering. Therefore, there is an urgent need to develop a novel nitration reaction system that ensures the normal operation of the nitration reaction while maintaining its continuity, efficiency, and safety. Summary of the Invention

[0004] The application aims to overcome the above-mentioned deficiencies of the prior art, and provide a continuous separation system based on a nitration reaction continuous separator, which utilizes the centrifugal force field of the nitration reaction continuous separator to match the isolated channels, and cooperates with various storage tanks and pipelines to ensure the continuity, efficiency and safety of the nitration reaction, and can realize the operation purposes of systematization, high efficiency, continuous sealing and intrinsic safety.

[0005] To achieve the above-mentioned purposes, the application adopts the following technical solutions:

[0006] A continuous separation system based on a nitration reaction continuous separator, characterized in that: the system comprises a nitration reaction continuous separator, a material storage tank is connected to a material inlet N1 of the nitration reaction continuous separator through a material pipeline, and a material conveying pump and a material metering meter L1 are arranged in sequence on the material pipeline; a nitric acid storage tank is connected to a nitric acid inlet N2 of the nitration reaction continuous separator through a nitric acid pipeline, and a nitric acid conveying pump and a nitric acid metering meter L2 are arranged in sequence on the nitric acid pipeline.

[0007] The nitration reaction continuous separator comprises a shell, a rotating drum located in the shell, and an isolation cylinder located in the shell and accommodated at the lower part of the rotating drum, the top cylinder opening height of the isolation cylinder is higher than the material inlet N1 and the nitric acid inlet N2; a guide cylinder is coaxially extended upward from the bottom cylinder opening of the isolation cylinder, a small rotating cylinder is coaxially extended downward from the bottom of the rotating drum, the bottom cylinder opening of the small rotating cylinder is wrapped on the outer wall of the guide cylinder and forms a rotary fit therebetween, and the area between the inner wall of the isolation cylinder and the outer wall of the small rotating cylinder constitutes a reaction isolation area.

[0008] The material and the nitric acid are pumped into the primary mixing cavity formed between the outer wall of the isolation cylinder and the inner wall of the shell to complete the primary nitration reaction, then enter the guide cylinder to complete the secondary nitration reaction, then are sucked into the dispersion cavity formed in the cylinder cavity of the small rotating cylinder to realize the tertiary nitration reaction, and then enter the separation cavity formed in the inner cavity of the rotating drum through the communication hole at the bottom surface of the rotating drum, the nitration product after being separated and clarified is centrifugally thrown out from the discharge port at the top of the rotating drum, and is discharged to the nitration product storage tank through the nitration product outlet N3 at the upper part of the shell, thereby completing the reaction process.

[0009] Preferably, an overflow port N3 is arranged at the outer wall of the shell, the overflow port N3 communicates with the primary mixing cavity, the inlet height of the overflow port N3 is lower than the top cylinder opening height of the isolation cylinder and higher than the height of the material inlet N1 and the nitric acid inlet N2, and the overflow port N3 is connected to the material storage tank through an overflow pipeline.

[0010] Preferably, an emptying port N7 is arranged at the bottom of the shell, which communicates with the primary mixing cavity and has an inlet at the lowest part of the primary mixing cavity, and the emptying port N7 is connected to the material storage tank through an emptying pipeline.

[0011] Preferably, the inner wall of the rotating drum is provided with co-directional inclined fin-shaped lifting paddles, which are inclined in the opposite direction of the rotating direction of the rotating drum, for gradually lifting the mixed liquid in the rotating drum to the discharge port at the top of the rotating drum under the action of centrifugal force.

[0012] Preferably, the rotating drum is coaxially extended downward with an extension shaft, and the part of the extension shaft extending into the barrel cavity of the guide barrel is provided with self-suction paddles, so that a suction cavity is formed between the barrel cavity of the guide barrel and the self-suction paddles.

[0013] Preferably, the inner wall of the small rotating drum is radially provided with a dispersion plate for driving the mixture to the synchronous rotating speed of the rotating drum.

[0014] Preferably, the rotating drum sequentially includes a gland, a rotor body, a bottom cover and a small rotating drum from top to bottom along the vertical direction; the communication hole is arranged through the bottom cover and is arranged close to the barrel wall of the small rotating drum; the discharge port is coaxially arranged through the gland, and the diameter of the discharge port is smaller than the barrel diameter of the rotor body.

[0015] Preferably, the inner wall of the shell at the top of the rotating drum is coaxially provided with an annular transition groove with the notch facing upward, and the upper surface of the gland is fixed with a clamping plate extending to the outer groove wall, the clamping plate clamps on the outer groove wall and can generate a rotating motion relative to the outer groove wall during the rotation of the rotating drum; the nitration product separated and clarified by the rotating drum is thrown out through the discharge port of the rotating drum, enters the annular transition groove through the clamping plate, and is discharged through the nitration product outlet N4 of the annular transition groove cavity and arranged on the outer wall of the shell.

[0016] Preferably, the barrel wall of the rotating drum is axially provided with a connecting hole, and a plurality of connecting holes arranged in sequence around the circumference of the rotating drum are communicated with each other through the transition rings located at the two end faces of the rotating drum, so as to combine to form a refrigerant channel, the power shaft at the top of the rotating drum is coaxially arranged with a first refrigerant pipe, and the first refrigerant pipe is coaxially inserted with a second refrigerant pipe, and the two refrigerant pipes are respectively connected with the refrigerant inlet N5 and the refrigerant outlet N6 through rotary joints;

[0017] The refrigerant enters one of the refrigerant pipes through the refrigerant inlet N5, then enters the transition ring through the inlet pipe radially extending from the end face of the rotating drum, and finally flows through the refrigerant channel and then flows to the other refrigerant pipe through the outlet pipe radially extending from the end face of the rotating drum, and is finally discharged through the refrigerant outlet N6, completing the direct cooling cycle; at this time, the refrigerant channel, the refrigerant pipe, the inlet pipe and the outlet pipe jointly constitute a direct cooling assembly.

[0018] The refrigerant inlet N5 and the refrigerant outlet N6 are respectively communicated with the inlet and outlet of the refrigerant storage tank.

[0019] Preferably, the shell is provided with a cooling jacket, and the inner wall of the shell is provided with a water-cooled wall, and the cooling jacket and the water-cooled wall jointly constitute an auxiliary cooling assembly; the input end and the output end of the auxiliary cooling assembly constitute the inlet and the outlet of the refrigerant storage tank, respectively.

[0020] The beneficial effects of the present application are:

[0021] 1) Through the above scheme, on the one hand, the present application is aimed at the violent nature of the nitration reaction, and therefore a separate cylinder is specially added; when the rotating drum rotates and disperses the stirring, the mixed liquid around the rotating drum will produce a violent reaction, at this time, relying on the existence of the separate cylinder, the uncontrollability of the high-speed rotation of the rotating drum to the reaction can be avoided, so that the freshly entered nitric acid and the material can have a relatively stable transition period and initial mixing period before entering the violent reaction area; the present application decomposes the nitration reaction stage, so as to realize the multi-stage gradual reaction of nitration reaction and the intrinsic safety purpose from the equipment operation mechanism. On the other hand, the present application utilizes the clarification and separation operation of the rotating drum, so that the solid phase in the mixed liquid is left on the drum surface, and subsequent periodic cleaning is not required, without considering the blockage problem of the traditional solid phase flow channel. Finally, in combination with various storage tanks and pipelines, the continuous closed operation characteristics of the nitration reaction can be ensured, and the efficiency and safety of the process are ensured, and the operation purposes of systematization, high efficiency, continuous closed operation and intrinsic safety are finally realized.

[0022] In other words, the present application leaves out the space between the separate cylinder and the rotating drum to provide sufficient safety space for the violent reaction of the material, and uses the separate cylinder to directly divide a liquid-free reaction isolation area in the cavity of the shell, so as to ensure the effective isolation effect between the separation cavity of the high-speed turbulent environment and the primary mixing cavity of the initial liquid; at the same time, the problem of solid phase collection and blockage inevitably encountered in conventional continuous nitration reaction is also solved; in combination with external auxiliary pipelines, the engineering application purpose is maximized.

[0023] 2) The setting of the overflow port is another highlight of the present application; on the one hand, there is a gap between the separate cylinder and the shell, and on the other hand, there is also a gap between the separate cylinder and the rotating drum, so it is possible that the material and nitric acid overflow from the gap between the separate cylinder and the shell and flow into the reaction isolation area of the separate cylinder from the top port of the separate cylinder, which is obviously prohibited. Therefore, by arranging the overflow port, the present application can prevent the initial mixed liquid formed by the material and nitric acid from rising into the reaction isolation area under the condition of too large feeding or violent reaction, so as to avoid safety hazards, realize the effective diversion of the high liquid level of the initial mixed liquid, and improve the intrinsic safety and working reliability of the present application.

[0024] 3) The rotating drum can gradually lift the mixed liquid at the bottom to the top under the action of centrifugal force; and more preferably, the present application also arranges a same-direction inclined lifting paddle inside the rotating drum to further improve the lifting effect of the mixed liquid, so as to improve the displacement and throwing effect of the clarified phase to the top discharge port of the rotating drum under the premise of high-speed centrifugation and liquid phase separation effect; more noteworthy is that the uniformly distributed lifting paddle can also avoid the out-of-sync "shaking" of the material in the rotating drum, which is effective.

[0025] 4) The high-speed rotation of the drum and the small drum also generates a certain suction force on the communication hole and even the material guide cylinder, thereby realizing the upward movement of the liquid phase; preferably, the present application also extends self-suction paddles at the drum, so as to use the self-suction pump structure formed by the combination of the self-suction paddles and the material guide cylinder to speed up the self-suction effect, ensure that the primary mixed liquid in the primary mixing chamber can be quickly pumped into the small drum, and finally sucked into the separation chamber where the drum is located through the communication hole, and the separation purpose is completed. Of course, the dispersion plate is also arranged in the small drum to ensure that the liquid phase entering the small drum can quickly complete the synchronous rotation with the drum, thereby laying a foundation for the subsequent separation work.

[0026] 5) For the drum, it is composed of a gland, a rotor body, a bottom cover, a small drum and even a self-suction paddle. It should be noted that the diameter of the discharge port is preferably smaller than the cylinder diameter of the rotor body; in this way, the discharge port forms a structure similar to an overflow weir, thereby facilitating the clarification and separation effect of the mixed liquid in the drum. The separated and clarified nitration product is discharged through the annular transition groove into the nitration product outlet N4, and the entire linear process can be completed.

[0027] 6) As the third highlight of the present application, the present application provides a series of cooling components, including a direct cooling component and an auxiliary cooling component. The direct cooling component is used for the direct cooling purpose of the liquid in the high-speed heated reaction in the drum, and the auxiliary cooling component ensures the overall cooling effect inside the shell. Through the regulation of the above cooling temperature, the process temperature requirement of the reaction can be easily realized, thereby completing the cooling and heat exchange of the intense heat release of the nitration reaction, and finally ensuring the stability, reliability and continuity of the process. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a working state diagram of the nitration reaction continuous separator of the present application;

[0029] Figure 2 is a partial enlarged view of I part of Figure 1

[0030] Figure 3 is a partial enlarged view of II part of Figure 1

[0031] Figure 4 is a structure sectional view of the shell;

[0032] Figure 5 is a structure sectional view of the drum;

[0033] Figure 6 is a layout state diagram of the lifting paddle;

[0034] Figure 7 is a piping installation diagram of the present application.

[0035] ​​The actual correspondence between the various designations and component names in the present application is as follows:

[0036] a - primary mixing chamber; b - suction chamber; c - dispersion chamber; d - separation chamber; e - reaction isolation zone

[0037] 10 - housing; 11 - annular transition groove; 12 - cooling jacket; 13 - water-cooled wall

[0038] 20 - rotating drum; 20a - communication hole; 20b - discharge port; 20c - lifting paddle; 20d - self-suction paddle; 21 - small drum; 21a - dispersion plate; 22 - gland; 23 - rotor body; 24 - bottom cover; 25 - lap

[0039] 30 - isolation cylinder; 31 - material guiding cylinder

[0040] 40 - frame; 41 - power motor; 42 - connecting rib

[0041] 51 - connecting hole; 52 - transition ring; 53 - first refrigerant pipe; 54 - second refrigerant pipe; 55 - rotary joint; 56 - inlet pipe; 57 - outlet pipe

[0042] 60 - material storage tank; 61 - material delivery pump; 70 - nitric acid storage tank; 71 - nitric acid delivery pump; 80 - nitrated product storage tank; 90 - refrigerant storage tank 80 DETAILED DESCRIPTION

[0043] For the sake of understanding, the present application will be described herein below in conjunction with Figures 1-7 The specific structure and working manner of the present application will be described further as follows:

[0044] In actual operation, the present application forms a system as shown in Figure 6The system structure is shown. In the entire nitration reaction continuous separation system, the material storage tank 60 contains material, and the material status can be monitored by liquid level sensors, etc. The material transfer pump 61 pumps the material out of the material storage tank 60, and the material enters through the material inlet N1 via the material flow meter L1 on the pipeline; the nitric acid storage tank 70 contains nitric acid of a certain concentration, and the loading status can be monitored by liquid level sensors, etc. The nitric acid transfer pump 71 pumps the nitric acid out of the nitric acid storage tank 70, and the nitric acid enters through the nitric acid inlet N2 via the nitric acid flow meter L2 on the pipeline. The two meet in the primary mixing chamber a, and under their respective feed pressures, they undergo preliminary mixing and mass transfer reactions; then, under the pumping action of the self-priming impeller 20d, the preliminary mixture undergoes secondary and tertiary nitration reactions in the suction chamber b and dispersion chamber c, respectively, generating heat, and then enters the separation chamber d through the connecting hole 20a, where it is gradually separated and cooled. Under the action of the lifting impeller 20c, the material is lifted and flows from the bottom of the rotor body 23 to the top, completing cooling and clarification. Trace impurities, due to their higher density, are thrown towards the inner wall of rotor 23 under centrifugal force and are manually cleaned periodically. The cooled and clarified nitration products are centrifuged out of outlet 20b, enter the annular transition tank 11, and are discharged from nitration product outlet N4, entering nitration product storage tank 80 or subsequent nitration product processes, thus completing a continuous production process. Overflow outlet N3 and vent outlet N7 are both connected to the inlet of material storage tank 60; the discharge from overflow outlet N3 and vent outlet N7 is a mixture, small in quantity, and not a contaminant, and after returning to material storage tank 60, it will re-enter the continuous nitration reaction separator to continue the reaction. The refrigerant storage tank 90 is connected to the corresponding refrigerant components.

[0045] Accordingly, the aforementioned continuous separator for nitration reaction mainly consists of a rotating drum 20, a shell 10, a frame 40, and transmission components, as detailed below. Figure 1 The drum 20 and the housing 10 are arranged coaxially. The drum 20 is fixed to the large plate on the top of the frame 40 by a bearing seat. The motor of the transmission component drives the drum 20 to rotate at high speed through a pulley pair, and its speed can be precisely adjusted by the electrical control system to adapt to the material working conditions.

[0046] like Figure 4 As shown, the shell 10 is the place where materials (organic phase), nitric acid, etc. enter the equipment and where the liquid accumulated after the mixing and mass transfer reaction is discharged. It is equipped with a material inlet N1, a nitric acid inlet N2, an overflow port N3, a nitration product outlet N4, a refrigerant inlet N5, and a refrigerant outlet N6; it also has several refrigerant ports for cooling the auxiliary cooling components. In addition, a vent N7 is arranged at the bottom of the shell 10, and the vent N7 is located at the lowest point of the shell 10 and is generally equipped with a valve.

[0047] The barrel of the shell 10 is welded by a straight cylinder segment and a head segment, the head is located at the bottom of the straight cylinder segment, the upper part of the straight cylinder segment is coaxially welded with a circular flange to form an inner cavity; the material inlet N1 and the nitric acid inlet N2 are arranged at the outer wall of the shell 10 close to the bottom of the inner cavity. There is a suitable space between the inner diameter of the barrel and the rotating drum 20, which provides enough space for the violent reaction of the material. In order to avoid the uncontrollability of the high-speed rotation of the rotating drum 20 on the reaction, a separation cylinder 30 is arranged between the barrel and the rotating drum 20, the upper edge of the separation cylinder 30, i.e. the top barrel opening, is higher than the material inlet N1 and the nitric acid inlet N2, so as to effectively isolate the high-speed rotation of the rotating drum 20 from the mixing of the material, and to ensure that the initial liquid in the primary mixing cavity a does not directly participate in the high-speed stirring and violent reaction process in the separation cavity d of the rotating drum 20. At the same time, in order to prevent the material from rising into the reaction isolation area between the rotating drum 20 and the separation cylinder 30 due to too large material feeding or violent reaction and other unexpected situations, causing safety hazards, as shown in Figures 1-2 and Figure 4 The application also provides an overflow port N3 arranged at the upper edge of the separation cylinder 30 to effectively guide the material with high liquid level out. In this way, the outer surface of the separation cylinder 30, the lower part of the straight cylinder segment of the barrel and the inner surface of the head are enclosed to form the primary mixing cavity a, and the material and nitric acid are contacted and start the primary nitration reaction here. A material guiding cylinder 31 is arranged at the center position of the separation cylinder 30, the material guiding cylinder 31 cooperates with the self-suction paddle 20d, the inner diameter of the material guiding cylinder 31 and the outer diameter of the self-suction paddle 20d leave a suitable gap, and through the comprehensive consideration of the shape, position, angle, size and other technical parameters of the blades on the self-suction paddle 20d, as well as the rotation speed and direction, the pumping effect is achieved. The mixture of the primary nitration reaction is pumped under the pumping action to have a larger contact surface and a shorter contact time for the secondary nitration reaction, and then enters the dispersion cavity c composed of the small rotating cylinder 21 at the bottom of the rotating drum 20, and the material has a tertiary nitration reaction under high-speed rotation.

[0048] Through the above material transfer, the nitration reaction is divided into three stages, which relieves the violent reaction process, and relieves the heat release and material boiling, and enhances the safety.

[0049] As shown in Figures 3-4As shown, the upper part of the shell 10 is provided with a liquid accumulation cylinder, and the cylinder body is combined with the upper part of the straight cylinder section to form an annular transition groove 11. After centrifugal clarification of the nitration product after nitration by the rotary drum 20, the centrifugal ejection is discharged from the top discharge port 20b of the rotary drum 20, enters the annular transition groove 11 through the lap plate 25, and is discharged from the nitration product outlet N4. In order to quickly discharge the heat released during the nitration reaction process, the outer part of the shell 10 is also provided with a cooling jacket 12, and the jacket cavity of the cooling jacket 12 is in full contact with the straight cylinder section and the head section of the cylinder body, thereby maximizing the heat exchange area. Further, if the cooling area needs to be increased, a single or double layer of coil pipes can be additionally arranged inside the shell 10 to form a water cooling wall 13. The cooling jacket 12 and the water cooling wall 13 are both auxiliary cooling parts, and together form an auxiliary cooling assembly.

[0050] As shown in Figures 5-6 The rotary drum 20 is mainly composed of a cover 22, a rotor body 23, a bottom cover 24 and a small rotary drum 21 coaxially arranged. The rotor body 23 is provided with connection holes 51 arranged along the axial direction on the cylinder wall, and the connection holes 51 are uniformly distributed in sequence around the circumference of the rotor body 23. Considering the connection relationship of the connection holes 51, each connection hole 51 is provided with a certain depth of a waist-shaped upper connection groove at the upper part and a certain depth of a waist-shaped lower connection groove at the lower part. The transition ring 52 formed by the upper connection groove and the lower connection groove directly connects the two ends of the connection hole 51, forming a refrigerant passage similar to a squirrel cage. The power shaft is coaxial with the rotary drum 20 and is driven by the power motor 41 while being fixed on the rotary drum 20 by the connecting rib 42, realizing the power transmission process. The power shaft is provided with a hollow hole, which is a first refrigerant pipe 53 and is in communication with the refrigerant outlet N6 of the rotary joint 55. A second refrigerant pipe 54 is concentrically arranged inside the first refrigerant pipe 53, and the upper part of the second refrigerant pipe 54 is also concentrically connected with the rotary joint 55 and is in communication with the refrigerant inlet N5 of the rotary joint 55. The lower part of the second refrigerant pipe 54 is sealed by a sealing ring and inputs the refrigerant into the transition ring 52 through the inlet pipe 56. Then, the refrigerant flows from the upper transition ring 52 to the connection hole 51, thereby delivering the refrigerant to the circumferential surface of the rotor body 23 and directly contacting the material to fully remove the reaction heat of the material in the rotary drum 20. The refrigerant is finally collected in the lower transition ring 52 and then delivered to the first refrigerant pipe 53 through the outlet pipe 57, and is discharged from the refrigerant outlet N6, completing the direct cooling heat exchange process.

[0051] As shown in Figure 5As shown, the bottom end of the bottom cover 24 is concentrically provided with an extension shaft, which rotates synchronously with the rotating drum 20. A certain number of self-suction paddles 20d are provided at a suitable position of the extension shaft, and the self-suction paddles 20d have a certain angle and outer dimensions. The outer diameter of the self-suction paddles 20d is kept a certain gap δ from the inner diameter of the guide cylinder 31. By controlling the number, angle, shape, gap δ, and rotating speed of the self-suction paddles 20d, different upward suction forces and suction amounts can be generated to form a suction cavity b. The mixture after the first three stages of nitration reaction is stirred and mixed under the action of the self-suction paddles 20d through the suction cavity b, and the final nitration reaction is completed. Subsequently, the mixture enters the dispersion cavity c and is rapidly flung to the cylinder wall of the small rotating drum 21 under the action of centrifugal force. A certain number of dispersion plates 21a are provided in the small rotating drum 21, which can quickly drive the mixture to reach the synchronous rotating speed of the rotating drum 20. A series of communication holes 20a are uniformly provided on the bottom cover 24 near the inner diameter of the rotor body 23 to realize the communication between the separation cavity d and the dispersion cavity c. The mixture after the reaction is completed enters the separation cavity d through the communication hole 20a, and the mixture moves from the bottom to the top of the rotor body 23 under the action of the lifting paddle 20c, and fully contacts the cooling area of the aforementioned connecting hole 51 to complete the direct cooling heat exchange process. Finally, the nitration product after separation and clarification is flung out of the rotor body 23 from the discharge port 20b at the top of the rotating drum 20, falls into the annular transition groove 11, and is then discharged from the nitration product outlet N4. The lifting paddles 20c are uniformly and obliquely arranged in the rotor body 23 at a certain angle; the oblique angle of the lifting paddles 20c should generate a lifting force upward under the action of rotation. The uniformly arranged lifting paddles 20c can also quickly drive the mixture to synchronize, avoiding the "shaking" of the mixture in the rotor body 23 and causing useless work due to asynchronization.

[0052] Correspondingly, the refrigerant entering is divided into three parts: the first part cools the entire outer part of the cylinder through the cooling jacket 12; the second part cools the space between the cylinder and the rotor body 23 by the water-cooled wall 13; the above two kinds of cooling can be called auxiliary cooling. The third part of the refrigerant enters the series of connecting holes 51 provided on the cylinder wall of the rotor body 23 from the refrigerant inlet N5, and the refrigerant is directly arranged on the cylinder wall of the rotor body 23 and directly contacts the material in the rotor body 23 for heat exchange, which can be called direct cooling. According to the process requirements, the connecting holes 51 can be provided with single or double rows, which are various and have a wide range of adaptation; the refrigerant after heat exchange is discharged from the refrigerant outlet N6. In this way, the cooling and heat exchange of the intense heat release of the nitration reaction is completed, which ensures the stability, reliability, and continuity of the process. From the equipment operation mechanism, by decomposing the nitration reaction stage and using multiple cooling methods, the intrinsic safety of the nitration reaction is realized. Through the regulation of the cooling temperature of the three parts, the process temperature requirement of the reaction is also easily realized.

[0053] It is worth noting that the connecting holes 51 of the present application are arranged axially along the drum 20, not only to achieve a simple cooling effect, but also to take into account the centrifugal force generated by the high-speed rotation of the drum, which can cause bubbles in the usual flow channel, thereby affecting the cooling effect. The axially arranged connecting holes can effectively avoid the bubble phenomenon caused by the radial centrifugal force, thereby improving the cooling effect.

[0054] Of course, for those skilled in the art, the present application is not limited to the details of the above exemplary embodiments, but also includes the same or similar manner that can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description.

[0055] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that those skilled in the art can understand.

[0056] The technical parts not described in detail in the present application are well-known technologies.

Claims

1. Continuous separation system based on a continuous separator of nitrification reaction, characterized in that: The nitration reaction continuous separator comprises a casing (10), a rotating drum (20) located in the casing (10), and a separation cylinder (30) located in the casing (10) and arranged in the lower part of the rotating drum (20); the top cylinder opening of the separation cylinder (30) is higher than the material inlet N1 and the nitric acid inlet N2; the bottom cylinder opening of the separation cylinder (30) extends upward coaxially to form a material guide cylinder (31); the bottom of the rotating drum (20) extends downward coaxially to form a small rotating cylinder (21); the bottom cylinder opening of the small rotating cylinder (21) is coaxially wrapped on the outer wall of the material guide cylinder (31) to form a rotary fit therebetween, and the area between the inner wall of the separation cylinder (30) and the outer wall of the small rotating cylinder (21) forms a reaction isolation area (e); The material and the nitric acid are pumped into the primary mixing cavity (a) formed between the outer wall of the separation cylinder (30) and the inner wall of the casing (10) to complete the primary nitration reaction, then enter the material guide cylinder (31) to complete the secondary nitration reaction, then enter the dispersion cavity (c) formed in the cylinder cavity of the small rotating cylinder (21) to complete the tertiary nitration reaction, and then enter the separation cavity (d) formed in the inner cavity of the rotating drum (20) through the communication hole (20a) at the bottom surface of the rotating drum (20); the clarified nitration product separated by the rotating drum (20) is centrifugally thrown out through the discharge port (20b) at the top of the rotating drum (20) and discharged to the nitration product storage tank (80) through the nitration product outlet N3 at the upper part of the casing (10) to complete the reaction process; An overflow port N3 is arranged on the outer wall of the casing (10) and communicates with the primary mixing cavity (a); the inlet height of the overflow port N3 is lower than the top cylinder opening height of the separation cylinder (30) and higher than the heights of the material inlet N1 and the nitric acid inlet N2; the overflow port N3 is connected to the material storage tank (60) through an overflow pipeline; The cylinder wall of the rotating drum (20) is provided with a connecting hole (51) in the axial direction; a plurality of connecting holes (51) arranged in sequence in the circumferential direction of the rotating drum (20) are connected to each other through the transition ring (52) located at the two end surfaces of the rotating drum (20) to form a refrigerant channel; the power shaft at the top of the rotating drum (20) is coaxially penetrated by the first refrigerant pipe (53); the second refrigerant pipe (54) is coaxially inserted into the first refrigerant pipe (53); the two refrigerant pipes are connected to the refrigerant inlet N5 and the refrigerant outlet N6 through the rotary joint (55). ​ The refrigerant enters one of the refrigerant pipes through the refrigerant inlet N5, then enters the transition ring (52) through the radially extending inlet pipe (56) at the end face of the rotating drum (20), and finally is discharged through the refrigerant outlet N6 after flowing through the refrigerant channel, to complete the direct cooling cycle; at this time, the refrigerant channel, the refrigerant pipe, the inlet pipe (56) and the outlet pipe (57) together constitute a direct cooling assembly. The refrigerant inlet N5 and the refrigerant outlet N6 are respectively connected to the inlet and outlet of the refrigerant storage tank (90).

2. The continuous separation system based on a continuous separator of nitration reaction according to claim 1, characterized in that: The bottom of the shell (10) is provided with a discharge port N7 which is connected to the primary mixing chamber (a) and has an inlet located at the lowest part of the primary mixing chamber (a), and the discharge port N7 is connected to the material storage tank (60) through a discharge pipe.

3. Continuous separation system based on a continuous separator of nitration reaction according to any one of claims 1-2, characterized in that: The inner wall of the rotating drum (20) is provided with co-directional inclined fin-shaped lifting paddles (20c), and the inclined direction of the lifting paddles (20c) is opposite to the rotating direction of the rotating drum (20), so as to gradually lift the mixed liquid in the rotating drum (20) to the discharge port (20b) at the top of the rotating drum (20) under the action of centrifugal force.

4. The continuous separation system based on a continuous separator of nitration reaction according to claim 3, characterized in that: The rotating drum (20) coaxially extends downward to form an extension shaft, and the part of the extension shaft extending into the barrel cavity of the guide barrel (31) is provided with a self-suction paddle (20d), so that a suction cavity (b) is formed between the barrel cavity of the guide barrel (31) and the self-suction paddle (20d).

5. The continuous separation system based on a continuous separator of nitration reaction according to any one of claims 1-2, characterized in that: The inner wall of the small rotating drum (21) is radially provided with a dispersion plate (21a) for driving the mixed material to reach the synchronous rotating speed of the rotating drum (20).

6. The continuous separation system based on a continuous separator of nitration reaction according to any one of claims 1-2, characterized in that: The rotating drum (20) sequentially includes a gland (22), a rotor body (23), a bottom cover (24) and a small rotating drum (21) from top to bottom along the vertical direction; the communication hole (20a) is arranged through the bottom cover (24), and the arrangement position is close to the barrel wall of the small rotating drum (21); the discharge port (20b) is coaxially arranged on the gland (22), and the diameter of the discharge port (20b) is smaller than the barrel diameter of the rotor body (23).

7. The continuous separation system based on a continuous separator of nitration reaction according to claim 6, characterized in that: The inner wall of the shell (10) at the top of the rotating drum (20) is coaxially provided with an annular transition groove (11) with a notch facing upward, and the upper surface of the gland (22) is fixedly provided with an extension plate (25) extending outward from the groove wall; the extension plate (25) is arranged on the outer groove wall and can rotate relative to the outer groove wall when the rotating drum (20) rotates; the separated and clarified nitration product of the rotating drum (20) is thrown out through the discharge port (20b) of the rotating drum (20), enters the annular transition groove (11) through the extension plate (25), is collected, and is discharged through the nitration product outlet N4 which is connected to the groove cavity of the annular transition groove (11) and is arranged on the outer wall of the shell (10).

8. The continuous separation system based on a continuous separator of nitration reaction according to claim 1, characterized in that: The shell (10) is provided with a cooling jacket (12), and the inner wall of the shell (10) is provided with a water-cooled wall (13), and the cooling jacket (12) and the water-cooled wall (13) together constitute an auxiliary cooling assembly; the input end and the output end of the auxiliary cooling assembly are respectively the inlet and the outlet of the refrigerant storage tank (90).

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